Any Direct Injected 300gt / 250gt V35's?

[Blade NZ]

I pulled off the engine cover and used the vacuum hose on the left of the plenum (master cylinder side not intake side) I thought this hose would be the most direct for getting the cleaner into the turbulent air.

Thanks for that, but it will have to wait a week now. My Bose 6-disc has died. The F3 error, which according to Chris is a stuffed laser. It goes back to the dealer tomorrow to be fixed and with the long weekend I probably won't get it back before mid next week. Oh well at least it happened now and not a few months down the track, the dealer will have to fix it at their cost as I've had it less than 2 weeks. When it's back I'll give it the clean out. Cheers!

[Spong]

Hi Spong,

As a bit of an update I have completed 26,000 trouble free Kilometers in my VQ30DD Stagea. As you have just received the car, I would recommend pulling down the intake, removing the big plenum and giving it a good water blast on the driveway, the rest of the gunk can be cleaned off with brake and parts cleaner. I say this because there will be a lot of buildup at this stage if it has not been addressed offshore (unlikely). When you put the intake back together, try to put together a blank off plate for the EGR valve (metal pipe coming from intake just past throttle), it's rather simple, just two holes, I used an old exhaust gasket that I had lying around, this should slow down or prevent the buildup from occuring in the future, it'll throw a check engine light but I ignore this or reset the ECU and it stays off for a month or so.

I have made a habit of pulling the lid off of the plenum once every two service intervals just for a checkup, but so far the gunk has not returned.

Regarding the Subaru upper engine cleaner, there are instructions on the can, follow them and you'll be fine. I'm not sure how well this worked as I did not open the plenum after application.

So this issue isn't really the bugbear that the mechanics get worked up about, the intake is a doddle to remove and the rest is common sense.

Thanks for that really useful info. Can you can generally re-use the gasket between the top and bottom sections of the plenum? I'm guessing you'd need to remove the top section, then the lower section for a good clean? Can you then see the valve stems, and heaps more carbon, or does the drama end there? I'm thinking I may tackle this at 100,000km along with new plugs, and just use the Subaru magic juice until then, assuming things keep running smoothly for now. My car (just arrived in the country) has done 84,000km in 4 years, so could have been a lot of long trips. I've read a few overseas forums, and they suggest minimising the problem by using very good synthetic oil, high octane petrol and regular thrashing! It seems Di engines everywhere are suffering this black scourge.

[Ant]

Thanks for that really useful info. Can you can generally re-use the gasket between the top and bottom sections of the plenum? I'm guessing you'd need to remove the top section, then the lower section for a good clean? Can you then see the valve stems, and heaps more carbon, or does the drama end there? I'm thinking I may tackle this at 100,000km along with new plugs, and just use the Subaru magic juice until then, assuming things keep running smoothly for now. My car (just arrived in the country) has done 84,000km in 4 years, so could have been a lot of long trips. I've read a few overseas forums, and they suggest minimising the problem by using very good synthetic oil, high octane petrol and regular thrashing! It seems Di engines everywhere are suffering this black scourge.

I saw your post in the M35 info thread on talking to Warwick @ City Nissan Takapuna about this... He must have a short memory - when I had my V35 serviced there just before Xmas last year I talked to him about the carbon build-up issue in direct injected engines. That was after reading the original post in this thread...

I'm having an issue in my 250GT where at high revs (>4500) it lets out a bit of smoke - not sure if it is due to the engine running rich at high RPM (technique often used in high-compression engines to prevent detonation) or perhaps due to the buildup of crud getting flushed out when thrashed. Doesn't seem to be any real underlying prob (touch wood), the car has always done this since I got it about 3 years ago, behaves quite normally otherwise and it doesn't use any oil. The oil does seem to get quite dirty in a short period of time after an oil change though.

City Nissan Takapuna haven't been able to shed any light on the smoke issue - they did take readings using the Consult datalogging gizmo and sent these off to Nissan Japan for analysis - but I never heard anything further on this. Must chase them up about that...

[chad bob]

Thanks for that really useful info. Can you can generally re-use the gasket between the top and bottom sections of the plenum? I'm guessing you'd need to remove the top section, then the lower section for a good clean? Can you then see the valve stems, and heaps more carbon, or does the drama end there? I'm thinking I may tackle this at 100,000km along with new plugs, and just use the Subaru magic juice until then, assuming things keep running smoothly for now. My car (just arrived in the country) has done 84,000km in 4 years, so could have been a lot of long trips. I've read a few overseas forums, and they suggest minimising the problem by using very good synthetic oil, high octane petrol and regular thrashing! It seems Di engines everywhere are suffering this black scourge.

Yes I re-used the gaskets and it seals just fine, they don't break up like paper gaskets, they're not under high vacuum / pressure like other motor gaskets.

I use FUCHS GTO fully synth 10W-40, it is some very good quality German oil and a good thrash once a week seems to do the motor well. The worst thing you can do is 'mother' a Di motor for months on end aparrently. My motor wasn't responding well when I got it, but since my initial clean out it has remained free revving and very responsive.

[Blade NZ]

Yes I re-used the gaskets and it seals just fine, they don't break up like paper gaskets, they're not under high vacuum / pressure like other motor gaskets.

I use FUCHS GTO fully synth 10W-40, it is some very good quality German oil and a good thrash once a week seems to do the motor well. The worst thing you can do is 'mother' a Di motor for months on end aparrently. My motor wasn't responding well when I got it, but since my initial clean out it has remained free revving and very responsive.

That's all good to hear, thanks for that. I can't wait to get mine back, clean it all out and go for a fang in the country. I thought it had gone to a stereo repair shop but it's actually gone back to the compliance centre...to fix the radio! Oh well so long as it's fixed soon!

[chad bob]

That's all good to hear, thanks for that. I can't wait to get mine back, clean it all out and go for a fang in the country. I thought it had gone to a stereo repair shop but it's actually gone back to the compliance centre...to fix the radio! Oh well so long as it's fixed soon!

That should be fun. The 300RX is probably the most underrated M35 model variant in my opinion, it carries 100Kg less pork than the 4WD models with only 10Kw lower peak power, so she'll get up and go when required.

My only gripe is the price you pay for 191Kw from an NA 3000cc motor, it's always going to be peaky, the 300RX does absolutely nothing until it swaps cams at 4000RPM, then it really starts pulling. I quite enjoy sitting just under 4000RPM on twisty roads, theres quite a nice kick when the cam timing changes, just watch the back end, i'll come round on you if the power band comes in at the wrong time.

I've removed the inspection hatch on the airbox to give me some indication when the cam phasing changes, the noise is amazing! It is still silent below 4000RPM though.

[ajc300gt]

Hi,

I've just bought my V35 300GT and been reading this thread with interest. Performance seems about spot on, but I do think idle is maybe a tad lumpy and fuel consumption could be better, (plus I seem to be having hot start issues where it stalls unless I quickly prod the acclerator), so I suspect similar problems with intake full of gunk.

Thinking about using the Subaru / Seafoam stuff that everyone uses first just and then pulling down intake if no improvement. Just wondering do you guys not worry about all the gunk being burnt and sent through engine / exhaust / catalytic converter?? Just thought it might block it up or something and cause other issues down the track?? Might be irrelevant, don't know, just thought I'd ask...

I'll let you all know how it all goes.

Cheers

Edited June 15, 2010 by ajc300gt

[Blade NZ]

That should be fun. The 300RX is probably the most underrated M35 model variant in my opinion, it carries 100Kg less pork than the 4WD models with only 10Kw lower peak power, so she'll get up and go when required.

My only gripe is the price you pay for 191Kw from an NA 3000cc motor, it's always going to be peaky, the 300RX does absolutely nothing until it swaps cams at 4000RPM, then it really starts pulling. I quite enjoy sitting just under 4000RPM on twisty roads, theres quite a nice kick when the cam timing changes, just watch the back end, i'll come round on you if the power band comes in at the wrong time.

I've removed the inspection hatch on the airbox to give me some indication when the cam phasing changes, the noise is amazing! It is still silent below 4000RPM though.

I'm loving this 300RX and I don't really mind the peaky power...it does fair rip up top don't it! Kind of works like my bikes anyway, they like the upper rev range as well. I like the mild manner down low too as it suits just cruising around town and I've usually got my kids in tow so it's really smooth. Give it some and it feels stronger than the '06 3.6 SV6 Commy I had. It is such a comfy, cruisy wagon but has a powerful, good handling alter ego. Very nice.

Might try the inspection hatch just to hear the pickup, but how do you get on in the rain? Have you checked it now that it's pissisting so much.

[Blade NZ]

Hi,

I've just bought my V35 300GT and been reading this thread with interest. Performance seems about spot on, but I do think idle is maybe a tad lumpy and fuel consumption could be better, (plus I seem to be having hot start issues where it stalls unless I quickly prod the acclerator), so I suspect similar problems with intake full of gunk.

Thinking about using the Subaru / Seafoam stuff that everyone uses first just and then pulling down intake if no improvement. Just wondering do you guys not worry about all the gunk being burnt and sent through engine / exhaust / catalytic converter?? Just thought it might block it up or something and cause other issues down the track?? Might be irrelevant, don't know, just thought I'd ask...

I'll let you all know how it all goes.

Cheers

Nice buy! If I didn't have to cart 2 kids around I would have looked closely at a V.

As for the gunk I'll be giving the car a service after treating for the reasons you mentioned. Apparently it can smoke something cronic for a few minutes till it's all gone. I think it will all pass thru without effecting anything as many have used the stuff already and I've not read off an issue. I'm more worried a neighbour will call the fire brigade...or worse, the greenies.

[chad bob]

Hi,

I've just bought my V35 300GT and been reading this thread with interest. Performance seems about spot on, but I do think idle is maybe a tad lumpy and fuel consumption could be better, (plus I seem to be having hot start issues where it stalls unless I quickly prod the acclerator), so I suspect similar problems with intake full of gunk.

Thinking about using the Subaru / Seafoam stuff that everyone uses first just and then pulling down intake if no improvement. Just wondering do you guys not worry about all the gunk being burnt and sent through engine / exhaust / catalytic converter?? Just thought it might block it up or something and cause other issues down the track?? Might be irrelevant, don't know, just thought I'd ask...

I'll let you all know how it all goes.

Cheers

Hi,

I think you are right to be worried about the motor injesting too much of the gunk, it's rather solid at times.

I would suggest that you have the intake stripped and manually cleaned the first time round because it WILL be full of crud, I used the SUBARU upper engine cleaner 3 months after my initial manual clean just to keep the intake squeaky clean (there was little or no smoke so it must have been clean still). I don't think the Upper engine cleaner will be able to break down the heavy long term deposits though, my motor had only 80,000Km on the clock and the gunk was 5mm thick in places! A little too much to be forcing through the motor I would think!

I have invested in a hand held steam cleaner that I will be using next time round.

Concerning fuel economy, I get around 8L/100Km on open road driving only and 9-11L/100Km doing mixed and city driving respectively.

PS: concerning removing the inspection hatch, the V35 coupe's come from the factory with a 'power duct' which is effectively an opening that replaces the inspection hatch and vents straight under the bonnet, so you have nothing to worry about concerning rain, mines been off for 6 months and the filter is still clean and dry. It does give an excellent indicator when the VVT changes cam settings.

Edited June 18, 2010 by chad bob

[Blade NZ]

Hi,

I think you are right to be worried about the motor injesting too much of the gunk, it's rather solid at times.

I would suggest that you have the intake stripped and manually cleaned the first time round because it WILL be full of crud, I used the SUBARU upper engine cleaner 3 months after my initial manual clean just to keep the intake squeaky clean (there was little or no smoke so it must have been clean still). I don't think the Upper engine cleaner will be able to break down the heavy long term deposits though, my motor had only 80,000Km on the clock and the gunk was 5mm thick in places! A little too much to be forcing through the motor I would think!

I have invested in a hand held steam cleaner that I will be using next time round.

Concerning fuel economy, I get around 8L/100Km on open road driving only and 9-11L/100Km doing mixed and city driving respectively.

PS: concerning removing the inspection hatch, the V35 coupe's come from the factory with a 'power duct' which is effectively an opening that replaces the inspection hatch and vents straight under the bonnet, so you have nothing to worry about concerning rain, mines been off for 6 months and the filter is still clean and dry. It does give an excellent indicator when the VVT changes cam settings.

You make a good point about the amount of crud potentially there. I think I'll pull it apart first. Did you remove the bottom half or clean it in place?

Early days for me but economy is sitting around 7.6 to 7.8 km per litre as per the computer display. This is only around town and no motorway yet. A tune and clean out should see improvement.

I'll also give the inspection hatch removal a go as well.

Cheers!

[Spong]

You make a good point about the amount of crud potentially there. I think I'll pull it apart first. Did you remove the bottom half or clean it in place?

Early days for me but economy is sitting around 7.6 to 7.8 km per litre as per the computer display. This is only around town and no motorway yet. A tune and clean out should see improvement.

I'll also give the inspection hatch removal a go as well.

Cheers!

Yeah I bought some of that Subaru cleaner, but think I'll do a manual clean of the plenum first when I get a spare weekend. I was wondering if there's a step by step guide anywhere on the net? Do I remove the lower half of the plenum chamber also, and what lies beneath that? I'm guessing the inlet ports, and will they be clean? I guess there'll be the temptation to scrape away there, and fill the combustion chamber with evil black crap?

From two tankfuls so far, our RX250 FOUR has varied between worst case 18.8mpg (lots of very short trips) and 29mpg (mixture of short and longer trips around town). I'm sure it will do a lot better on a long trip.

BTW, when I use the computer to monitor fuel consumption, my Japanese lady friend chatters away almost endlessly. I've figured out how to quieten her down, but I may leave her active, and end up fluent in Japanese. Not sure what she's on about. I suspect she telling me to do a U turn to reach Osaka as the previous owner left a route in there. Unfortunately the English translation hasn't happened yet for my series 2.

Edited June 18, 2010 by Spong

[Blade NZ]

Yeah I bought some of that Subaru cleaner, but think I'll do a manual clean of the plenum first when I get a spare weekend. I was wondering if there's a step by step guide anywhere on the net? Do I remove the lower half of the plenum chamber also, and what lies beneath that? I'm guessing the inlet ports, and will they be clean? I guess there'll be the temptation to scrape away there, and fill the combustion chamber with evil black crap?

From two tankfuls so far, our RX250 FOUR has varied between worst case 18.8mpg (lots of very short trips) and 29mpg (mixture of short and longer trips around town). I'm sure it will do a lot better on a long trip.

BTW, when I use the computer to monitor fuel consumption, my Japanese lady friend chatters away almost endlessly. I've figured out how to quieten her down, but I may leave her active, and end up fluent in Japanese. Not sure what she's on about. I suspect she telling me to do a U turn to reach Osaka as the previous owner left a route in there. Unfortunately the English translation hasn't happened yet for my series 2.

Ha ha that would be hard case listening to endless Japanese chatter. I do not have the disc so all is quiet, probably a blessing but I would like to get hold of one to see it in action. As for the translation, I am aware thru this site that the translation for an S2 has not been done but it might be informative to give the following a call. I have his business card and he claims to convert all V35 & M35 computers. He makes no distinction between the series. He is Shaun Hoines and is in New Lynn. His number is 021 182 4522. He quoted me NZ$280 for a full conversion.

I would also like to find out more about the lower plenum removal before diving in and finding out I need to order a lower gasket or something. I might ask Nissan to do it at service time if I can't find any further info.

[Spong]

Ha ha that would be hard case listening to endless Japanese chatter. I do not have the disc so all is quiet, probably a blessing but I would like to get hold of one to see it in action. As for the translation, I am aware thru this site that the translation for an S2 has not been done but it might be informative to give the following a call. I have his business card and he claims to convert all V35 & M35 computers. He makes no distinction between the series. He is Shaun Hoines and is in New Lynn. His number is 021 182 4522. He quoted me NZ$280 for a full conversion.

I would also like to find out more about the lower plenum removal before diving in and finding out I need to order a lower gasket or something. I might ask Nissan to do it at service time if I can't find any further info.

The V35/M35 Jap to English conversion you mention is covered in 2x long threads here in the V35 forum. It was done by a Russian crowd - www.xanavi.ru and it was co-ordinated by a SAU member "andy65b". He's arranged people throughout Australia and a couple of installers in NZ (Christchurch) and Shaun in Auckland (as you mention). The website is www.xanavi.com.au

I've been in contact with Shaun, and the S2 conversion isn't ready yet, but your S1 has been done and Shaun should be able to convert yours. I'm 99% certain you'll need the original navigation DVD though, as the computer dosen't do anything much without it. Contact me as I maybe able to help there.

[Blade NZ]

The V35/M35 Jap to English conversion you mention is covered in 2x long threads here in the V35 forum. It was done by a Russian crowd - www.xanavi.ru and it was co-ordinated by a SAU member "andy65b". He's arranged people throughout Australia and a couple of installers in NZ (Christchurch) and Shaun in Auckland (as you mention). The website is www.xanavi.com.au

I've been in contact with Shaun, and the S2 conversion isn't ready yet, but your S1 has been done and Shaun should be able to convert yours. I'm 99% certain you'll need the original navigation DVD though, as the computer dosen't do anything much without it. Contact me as I maybe able to help there.

Yeah I got Shauns details from the threads here and youtube. Just wasn't sure if he knew anything more. Mine will be done in due course, it's down the priority list but on there none the less.

Interesting that I might need a disc for the conversion and thanks for the offer to assist. I'll let you know when I'm ready.

Cheers.

[FlyingEL]

Hey guys,

I was just wondering if anyone round here has a 300GT or 250GT V35. Reason I'm asking is that they're Dierct Injection and like most direct injection cars on the market (including my stagea) they may be in the process of or already on the way to fish town.

So I have been hearing a few complaints recently concerning 'Gasoline Direct Injection' engines, particularly concerning vehicles from Toyota, Mitsubishi and Nissan. GDI has become rather popular in late model cars recently, notably the Mitsy 'GDI' and Nissan 'NEO Di' which seem to be the most prolific of the GDI vehicles, european examples are the VW 'FSI' system and also Opels new GDI system which is now widely used on late model vehicles without advertisemsnt. Now the complaints are mostly concerning poor fuel economy and multiple sensor failure with expensive repairs.

This is strange because amongst a notable increase in power over similarly designed SFI (sequential injection) and Multi point injection motors, GDI motors usually have a rather impressive factory fuel consumption rating which makes them rather attractive to buyers. These buyers are often disappointed when they get to the pump with their new car only to find that it's been sucking fuel like a v8.

It is rather hard to find information on why these NEW cars are costing so much to maintain and using more gas than expected, the funny thing is that performance also drops rapidly as the fuel consumption rises.

Instead of providing an explanation, car companies remain tight lipped and owners get fed up with mechanic bills.

So given the listed issues:

-Poor fuel economy.

-Decreased performance.

-Injector and sensor failure.

What is going on?

What seems to be a constant in all examples is that problems start occurring once the vehicle millage passes 60,000Km. I discovered this while trying to research information on the VQ30DD motor in my Nissan, all the info I could find was in Japanese, but I did find the above information relating to GDI vehicles in general and also from personal accounts of friends with GDI vehicles. So I thought that since my car was GDI and was also passed that 60,000Km milestone, then it must be showing signs of whatever ailment has been plaguing other GDI motors.

I thought that since the difference between GDI and MPFI motors was on the induction side, I would start there. It didn't take long to find the culprit, in fact as soon as I opened the intake manifold it was all too obvious.... SOOT everywhere! it was like black snow coating everything from the port side of the throttle butterfly to the valves, it was 1mm thick in places and not unlike the oil residue found inside the crank case of an old 2stroke lawn mower. This was a shock and totally not on for a car that was other wise in 'as new' condition, it took a can of degreaser and a water blaster to get the manifold back to 'as cast' condition, I then set about looking for the cause.

The cause too was rather obvious, modern engines are being fitted with any manner of emission reducing gadgets, the most popular being the classic rocker cover vent breather and the horrible EGR or 'exhaust gas recirculation' system, both of these are designed to 're-burn' oil vapour and un-burnt fuel that would otherwise be vented into the atmosphere. When used in conjunction, the EGR and rocker cover vent supply both dense and water rich fuel soot and oil vapor back into the intake where they mix to create that lovely sooty crud, most of which goes back into the engine harmlessly as it's supposed to do, but much of it winds up stuck to the walls of the intake.

Now in a normal SFI MPFI (sequential, multi point fuel injection) fuel is injected into the intake piping right behind the valves, 'Sequential' systems are designed to only inject when the valves are open, but there is still deflection and fuel vapor ends up joining the EGR and Rocker cover emissions back up in the intake, this is good because the fuel mixes with the vapors, dissolving deposits and making them less likely to settle.

Of course since GDI engine injectors are inside the combustion chamber, on the other side of the valves, this means that there is nothing to stop the buildup of deposits, hence the GDI intake becomes more and more choked until the motor starts running rich and eventually large chunks of 'crud' become dislodged and end up passing the valves and become the proverbial 'spanner in the works' and this stuff does buildup into rather hard little lumps in places which wreak havoc on O2 sensors and injector nozzels.

There you have it, the cause of our problems, since the car companies dont care about cars out side of their warranties, car owners are left scratching their heads and local mechanics keep this to themselves because business is booming!

The only solution is, as soon as you notice your new ride becoming more thirsty, find a friend who knows motors relatively well or talk to your mechanic and ask them to check your intake once every 20,000Km or so as a standard servicing procedure. My car was not noticeably less powerful but it was using a little more juice than expected, hence my adventure into crud city.

If you don't want to pay extra for an intake clean on every second service, there is a way of making your GDI vehicle crud free for life!

Have a catch can installed on your rocker cover breather, this is a tank or 'can' installed in the line linking the rocker cover to the intake, vapors passing through the tank settle and this is where the oil deposits remain, leaving only clean dry air to enter your intake. In many cases this will only reduce the buildup slightly as there is still the deposits from the EGR valve, to fix this, I found an old exhaust manifold gasket and trimmed it down to fit the EGR pipe flange so replacing the original gasket seal, this creates a 'blanking plate' that effectively prevents the EGR from functioning but allows you to leave the EGR plugged in so that the ECU doesn't pick up any errors. These procedures will keep your intake crud free for life and will only slightly affect your vehicle emissions, the extra emissions produced by removing your EGR valve will be offset by the fact that your car will now run cleanly and efficiently without sucking down loads of fuel and smoking as the engine over fuels due to reduced breathing.

A friends Mitsubishi 2000cc RVR was using 16L/100Km on average, the intake looked like a smoker's lungs when I got it off, the original 45mm intake was nowhere near that in diameter due crud, go figure.

Just for your info. Mit GDI only take in 100 octane fuel. That's why a lot of country around the world didn't get the car Mit Made with GDI engine, as most countries do not have 100 octane fuel for sale. As far as I know, GDI cars are only available in Japan (of course) and Singapore in the South East Asia region. So Buying a import would be a mistake. Bare in mind, GDI technology is totally different from VW's FSI or Afla's JTS. Here is the read up: http://en.wikipedia.org/wiki/Gasoline_direct_injection

[o2bfit]

Hi,

I recently bought a 300GT with 113k on the clock. It was suffering from the occasional hot start stall and erratic idle.

I decided to use the subaru upper engine cleaner and sprayed it into the brake booster hose. Bugger all smoke came out of the exhaust so I assumed that it wasn't too dirty.After a week of driving, it hadn't resolved my issue with the hot start stall.

More googling, and decided to clean the throttle body .

When I took the throttle body off I was stunned to the amount of carbon crud on the back side of the throttle body. With some throttle body cleaner, I removed as much as the crap as I could. Now it runs much better and haven't experienced the hot stall issue. I'll clean the plenum at some stage as well.

Its a simple enough job to do and I would recommend get this done first and use the subaru upper cleaner as a regular service.

Cheers

[Blade NZ]

Hi,

I recently bought a 300GT with 113k on the clock. It was suffering from the occasional hot start stall and erratic idle.

I decided to use the subaru upper engine cleaner and sprayed it into the brake booster hose. Bugger all smoke came out of the exhaust so I assumed that it wasn't too dirty.After a week of driving, it hadn't resolved my issue with the hot start stall.

More googling, and decided to clean the throttle body .

When I took the throttle body off I was stunned to the amount of carbon crud on the back side of the throttle body. With some throttle body cleaner, I removed as much as the crap as I could. Now it runs much better and haven't experienced the hot stall issue. I'll clean the plenum at some stage as well.

Its a simple enough job to do and I would recommend get this done first and use the subaru upper cleaner as a regular service.

Cheers

Damn that's some difference, thanks heaps for the pics .

Priority no.1 for us new owners I'd say.

[Spong]

Hi,

I recently bought a 300GT with 113k on the clock. It was suffering from the occasional hot start stall and erratic idle.

I decided to use the subaru upper engine cleaner and sprayed it into the brake booster hose. Bugger all smoke came out of the exhaust so I assumed that it wasn't too dirty.After a week of driving, it hadn't resolved my issue with the hot start stall.

More googling, and decided to clean the throttle body .

When I took the throttle body off I was stunned to the amount of carbon crud on the back side of the throttle body. With some throttle body cleaner, I removed as much as the crap as I could. Now it runs much better and haven't experienced the hot stall issue. I'll clean the plenum at some stage as well.

Its a simple enough job to do and I would recommend get this done first and use the subaru upper cleaner as a regular service.

Cheers

That's pretty much what my VQ25DD looked like a couple of weeks ago (at 85,000K) although things are running fine at the moment. I came to the same conclusion. A full disassembly and clean is in order with maybe followup treatment every 10,000K or so with the Subaru cleaner. What's this "throttle body cleaner" you used?

[o2bfit]

That's pretty much what my VQ25DD looked like a couple of weeks ago (at 85,000K) although things are running fine at the moment. I came to the same conclusion. A full disassembly and clean is in order with maybe followup treatment every 10,000K or so with the Subaru cleaner. What's this "throttle body cleaner" you used?

I used Nulon Throttle body and Carby cleaner. Got it from Supercheap Auto for about $18. It was pretty much the only throttle body cleaner I found but it does a good job.

CRC do a throttle body cleaner but I couldn't find anyone who stocked it.