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

[chad bob]

It's not a pretty sight in there is it! Rather shocking to be honest. Concerning the cleaning of the final runners before the valves, I got in there with a wet and dry vacuum while I was scraping, removing the plugs is a good idea whilst doing this too.

Does anyone know if any workshops in Auckland can do this kind of thing without it costing an arm and a leg? And who could do it without breaking or ruining anything? Would like to get mine done but I think this is a bit beyond my basic DIY skills...

I would print off the photos in this thread and take the car into a good firm like city nissan Takapuna. I would also tell them that unskilled home mechanics can complete the job in 4-5 hours with coffee / beer breaks, so if you get a labor bill with 10 hours on it then you can tell them where to stick it. This should minimize your chances of getting shafted.

Edited July 11, 2010 by chad bob

[X-Modcarz]

Ok, guys here goes.

Got in there with a lot of brakeclean, rags wrapped around screw driver and a good compressor. Took a very long time to get most of it out, I did my best. Then cleaned the plenums, the lowest end block and throttle body. I did the cylinder head chambers first so when I cleaned the other parts, it could dry out good. I used a hack lot of compressed air to get the shit out plus any vapours.

Fitted all together, biting my lips all along. The exhaust flange bolts are officially the most *%$#*@ed of the lot and you need Jap. finger to reach and align them. I did not block the flange as my GF will have the fits if and when an engine light starts flicking.

Ok, time to start. Left the air filter out and sprayed a tiny bit of engine start in it. Did the throttle position learning as well before starting just to ensure all is done right the first time. Took me 2.5hrs to get all off and about 4 hours to get it all together. 40 mins of the 4 hours was spent on one exhaust bolt - *%&$# piece of %^#&*

She started in the first pop and hummed away. I was very pleased and let out a sigh of relief. Have driven it for 50kms now and all is running smooth. Made a heck lot of difference in pickup and go and catches up quite quickly on the top end.

All in all, I am happy. Thanks to info in this thread by you helpful lot. Cheers guys.

(PS - sorry no pics as the family camera was not in working order)

[Blade NZ]

Well done X-Mod! Hopefully this is a job that really only needs doing once, then just a follow up with the Subaru upper engine cleaner every 10k or so will be enough to keep it clean. This is not a job I want to be doing regularly!

[chad bob]

Well done X-Mod! Hopefully this is a job that really only needs doing once, then just a follow up with the Subaru upper engine cleaner every 10k or so will be enough to keep it clean. This is not a job I want to be doing regularly!

After my exploration I beleive that once all intake components have been cleaned and the EGR has been blocked and the secondary cam cover breather is re-routed, then the buildup will not return. I too would not be looking forward to stripping again which is why I decided to do everything I could while I was in there..

Edited July 15, 2010 by chad bob

[Spong]

I wonder if one of the accessory catch can systems available on Ebay for the G35/300Z/350Z like the one below would be one way to deal with the breather problem Chad_Bob?

http://cgi.ebay.com/ebaymotors/ws/eBayISAP...e=STRK:MEWAX:IT

Edited July 15, 2010 by Spong

[Blade NZ]

I wonder if one of the accessory catch can systems available on Ebay for the G35/300Z/350Z like the one below would be one way to deal with the breather problem Chad_Bob?

http://cgi.ebay.com/ebaymotors/ws/eBayISAP...e=STRK:MEWAX:IT

Hey that's a nice bit of kit. Site glass as well...very flash! Looks like the answer to me.

Damn you Dave, something else I want to get now .

[chad bob]

I wonder if one of the accessory catch can systems available on Ebay for the G35/300Z/350Z like the one below would be one way to deal with the breather problem Chad_Bob?

http://cgi.ebay.com/ebaymotors/ws/eBayISAP...e=STRK:MEWAX:IT

Most deffinitely, they work well, I have one of those on my trackdayer, you don't need a specific Nissan unit though, the generic ones work just as well from BNT/Supercheap/repco. I didn't grab one for the stag as I didn't want a foreign object sitting under the bonnet, like some shiny thing that'll raise questions (and eyebrows).

I pulled off the brether hose that enters the intake piping just afdter the AFM and just before the throttle and it looks dry, this means that the oil vapour is condensing in the pipe and running back into the cam cover (this is what we want to see), so I connected the second bank's breather into this pipe and it seems to be working wonders.

Edited July 15, 2010 by chad bob

[ajc300gt]

Hey guys, going to tackle this all at once in a few weeks, hopefully sort out a lot of niggles with car. Can those of you that installed catch can please let me know what size fitting you used, the choices I have are 9mm and 15mm.

Cheers

[chad bob]

9mm would probably fit better, if you use rubber hose it can stretch / contract with the pipe clamp to fit snug.

[250RS Dan]

Hi, hopefully some of the earlier contributors are still monitoring this thread as i'm interested to hear about any updates re the intake cleaning and results.

I read the thread with great interest as i bought a 2004 M35 250RS 12 months ago. I've been quite happy with it but noticed the occasional light surging when under a trialing throttle or going up a steep hill. I changed the spark plugs around Xmas 09 and was horrified at the state of the old plugs. They may well be the original plugs...the car's done 134000 now. Anyway, i expected to see a marked improvement in performance and economy given the state of the old plugs but i can't honestly say it drives any better. The fuel economy hasn't improved at all which really surprised me. I did notice at the time the build up of soot on the inside of the butterfly valve. This thread goes a long way to explaining why it's there.

So last week i bought some Subaru upper cylinder cleaner and followed the procedure expecting to see massive clouds of smoke billowing from the exhaust...i even warned the neighbours! To my surprise and mild disappointment there was no noticable increase in exhaust smoke from the normal exhaust smoke. Next step is to pull the intake apart and give it a good clean as described previously.

Thanks for all the input and information above, has been an interesting thread. 

[chad bob]

Yes we are still here

My 300RX has remained smooth and responsive for the past 10,000Km since stripping and cleaning the intake. It is using less gasoline than it did prior to the clean and is a joy to drive, I checked my plugs a few weeks ago and they are operating nicely with no unusual deposits.

Before you attempt the strip down, have a good look at the pictures that I posted previously, the only way to do it right is to remove the entire intake stack becuase there will be some SERIOUS gunk to remove after 130,000Km, but the results are worth the effort.

Post back here if you have any questions.

Edited September 7, 2010 by chad bob

[MikeMcL]

Hi guys

This post has been an interesting read!! Which Nissan engines had direct injection rather than MPFI? I am wondering if I should fit the oil catch-can option to my Series II V35 with the 3.5L engine?

Even if not DI it probably makes sense to keep the excess oil out of the intake system?

Mike

[chad bob]

A few people have complained of oil building up in the VQ35 intake as well, so it couldn't hurt.

Any Nissan engine who's engine code ends in 'DD' is a direct injected motor.

For our cars:

250GT / 250RS / 250RX = VQ25DD (Di)

300GT / 300RX = VQ30DD (Di)

350GT / 350RX = VQ35DE (MPFi)

[JayM35]

Sorry to drag up an old threat, but i'm going to tackle this next weekend.

Have already done the throttle body, as it was idling at 200rpm in drive, now 900rpm.

Any do's and donts I should be worried about? Under the intake stack, the ports that go into the black, are they ok to spray with carb/brake cleaner and then just engine start after?

It's at 180,000km, VQ25DD, doing spark plug's at same time.

[chad bob]

I would be careful not to let the stuff run down into the intake. A small bent scraper and a vacuum cleaner should make sure that it does not fall down. In my case some of it did run down with the carb cleaner and the car ran a bit rough for a few minutes, but it promptly came right and has been fine ever since.

Just make sure that you dont scratch up / ding the mating surfaces of the intake components, theres nothing particularly tricky about this job and you can't really hurt the engine in the process, except perhaps if you scrape a cup load of the crud into the intake, which is unlikely.

Edited November 1, 2010 by chad bob

[JayM35]

Wicked, i'll be giving it a go on saturday, as well as replacing the ribbed part of the intake with a pipe.

[chad bob]

Cool, just realized that yours and my Stag could be twins, same colour etc

[JayM35]

Sweet! Mine won't be so stagea looking soon.

Coilovers going in soon, not sure in the engine department but will be manual and turbo, either a VK45 or RB26.

Body-wise it will be all custom, i'm making my own kit for it, based off SuperGT/JGTC R35's.

[250RS Dan]

I attempted this engine cleaning procedure back in January but didn't get far. I dropped my 10mm socket onto the back of the motor as i was attempting to undo the EGR bolts. When i couldn't find it i lost my enthusiasm and put the throttle body back on. I had taken that off and given it a good clean but had hoped to clean out all the intake tract. Disappointed in my lack of mechanical skills and the fact that i lost my 10mm socket...i think it's still stuck somewhere behind the engine block on top of the transmission.

I may give this another go at some point as i'd purchased the cleaning gear to do the job. Will get myself a good set of ring spanners...i think they may help a bit.

Any advice in addition to what is already in the thread would be appreciated.

[chad bob]

Just be careful, avoid getting cleaning detergent down into the engine through the ports. Make sure you clean all intake parts once removed, don't get under the bonnet with a hose I mean

Also be careful with the polished mating surfaces of the intake parts, treat them like CD's, put down rags before placing them on concrete and dont cink the rigid gaskets, they need to be nice and straight.

The hardest part of this job is getting round under the throttle to undo the EGR valve transfer pipe, it's a bastard every time, I used a $35 air powered 1/2" ratchet from supercheap. This way I didn't need room to swing the handle, just put on the socket and pull the trigger. This also comes in handy when doing oil changes, that under engine cover has too many damn screws! Your arm will fall off after undoing all those little buggers!

Finally do not over tighten the bolts when you re-fit everything, the intake does not need to be cranked down, all it needs is sufficient torque to provide a good seal.

Once you remove the top of the intake plenum you will realize that you did the right thing by deciding to clean the intake. It'll be a dogs breakfast in there if your cars done anything close to 100,000Km's !

Edited May 6, 2011 by chad bob