Jump to content
SAU Community

Recommended Posts

Hey all,

Driving home this morning, car seemed to be running well. Started to come on boost a little bit and the engine had a little shudder and didn't feel right, started producing a fair bit of white/grey smoke so I slowed down to pull over and the rev's dropped right down and the engine died.

Got towed home and have been over it. Intake pipes are clean, turbo appears to be in good nick, timing is all lined up, can crank over with hand. Hasn't lost water or oil and has plenty of fuel.

After I'd gone over it I had the coil packs unplugged and turned it over and it seemed to be turning over alright but then the whole engine locked up with a reasonable good thump. Wen't over it again, plugs out, manually turning over all was well. Put plugs back in and turned over with the key and same result with the locking up.

I'm a little stumped now and I have the feeling like it's going to be something highly undesirable that is up.

Anyone care to have a go with diagnosing this?

Cheers,

- Lance

Link to comment
https://www.sau.com.au/forums/topic/429723-rb25det-neo-stopped/
Share on other sites

Stupid question man, but have you checked your battery Voltage? I had a similar issue a few months back and it turned out that my battery dropped a cell while I was driving. Doesn't really explain the smoke, but could explain the lack of crank. New Yellow Top fitted now, all is good.

Just food for thought..

It's hard to tell why it stops. It cranks over for a second or two but sort of thumps to a stop. Enough of a thump to physically shake the engine a bit. It's not a great feeling or sound so I'm a little reluctant to keep doing it. I might take out the plugs and disconnect the fuel pump and see if I can crank it over without issue.

Yeah, I've checked the battery. It's a matter of a few months old but it's usually one of the first things I check just incase. Cheers anyway.

- Lance

Lance, sorry mate, but by the sounds of the engine locking while cranking, it's hydraulic locking (you can't compress a liquid).I don't recommend cranking the engine anymore with the spark plugs in, or you will smash a piston &/or rings. I reckon it's head gasket time mate. Try some of these things:

Remove the spark plugs.

Keep them in order.

Look for either a WET or CLEAN spark plug.

Do a compression test.

Buy a cheap inspection camera (boreoscope) to jam down the holes & look around.

Decent figures should be around the 150psi mark.

Hey mate. I had hydro locking in mind, which is why I stopped the cranking lol.

From memory, number 5 cylinder plug was wet when I pulled them out today. I did check down the spark plug hole with a torch but couldn't see a lot so a boreoscope is the way to go.

I was going to do a compression test tomorrow as I've had an overheating issue a while ago, though it's not been using any water even with a couple of long trips under it's belt since. However it's something I will check anyways.

I'll have a bit more time tomorrow to look into it properly with the right tools and things you've suggested.

Thanks a lot for your help,

- Lance

Over heating issues aren't good.

Shit happens.

Recently my wife's Cube didn't start one Monday morning (wasn't used all weekend). When I heard the way the engine was cranking I knew it had dropped a cylinder. Blown between 1&2. both cylinders were a perfect 82psi.

It drove perfectly as I was the last to drive it & it had never had ANY issues with overheating.

Spose now is the time to be thinking of upgrades!!!!!!!!!!

Might have a stuck injector, causing the overfuel and locking?

Timing mark meets up with TDC? Hasn't skipped teeth on the timing belt?

Haven't checked for stuck injector (don't know how just yet) but I will figure out how and put that on the list of checks.

Timing all lines up if I'm correct in assuming that the first mark on the left on the harmonic balancer is T.D.C?

Over heating issues aren't good.

Shit happens.

Recently my wife's Cube didn't start one Monday morning (wasn't used all weekend). When I heard the way the engine was cranking I knew it had dropped a cylinder. Blown between 1&2. both cylinders were a perfect 82psi.

It drove perfectly as I was the last to drive it & it had never had ANY issues with overheating.

Spose now is the time to be thinking of upgrades!!!!!!!!!!

My electric fan stopped when the Mrs was taking the Stag out for a drive so yeah, shit happens lol. I though I'd been lucky enough to get away with no damage but it may transpire that I wasn't quite so lucky. Ah well, it's all part of the game with cars.

Haven't checked for stuck injector (don't know how just yet) but I will figure out how and put that on the list of checks.

Timing all lines up if I'm correct in assuming that the first mark on the left on the harmonic balancer is T.D.C?

Yes that's right. Timing is here:

http://www.skylinesaustralia.com/forums/topic/73824-adj-camshaft-pulley-new-cam-belt/

Suggest you pull the plugs out and try turning it over by hand and you should be able to see if any cylinder is hydraulicked

Ah brilliant! I was looking for a timing guide but hadn't sourced one, cheers Bob!

I'm unsure of what to check for in regards with hydro lock. I'll do some research unless you have some advice?

- Lance

  • Like 1

Well a cylinder can only be filled with oil (not likely) petrol - possible but you should smell it as soon as you pull the plugs out - or water - blown head gasket and/or cracked head. If you take the plugs out and turn the engine over (with a remote switch on the starter or pref by hand) you may see some of the offending liquid come out the plughole. Are you losing water from the radiator? Does there appear to be water in the oil (or oil in the radiator)?

My other idea is faulty CAS or damaged CAS drive on the end of the camshaft.

Good luck!

Ah brilliant! I was looking for a timing guide but hadn't sourced one, cheers Bob!

I'm unsure of what to check for in regards with hydro lock. I'll do some research unless you have some advice?

- Lance

There was a reasonably strong smell of fuel and I didn't see and oil upon my quick inspection with a torch down the spark plug hole but I'll check again while turning it over tonight.

Water level is staying constant and no water in oil or oil in water that I can make out. However I'll Tee Kay test anyways.

I did have a quick look at the CAS when I took it out and physically it seemed fine but I do have a spare that I could also try.

Cheers,

- Lance

Righto, hydro lock is the winner :/ I turned it over by hand when I got home this afternoon and number 4 cylinder erupted with fuel. Fingers crossed that rings and rods are still okay with a couple of false starts under it's belt. I'll compression test it once I've got the over fuelling sorted.

I'm going to assume that the injector is leaking as I didn't notice an excess of fuel yesterday when I was turning it over but over 24 hours there was a clear build up of fuel. Can anyone confirm what these injectors are? I was told they were out of a 350Z.

post-106462-0-25239100-1375691621_thumb.jpg

Cheers,

- Lance

Edited by Captain Wow

I got hold of the chap I purchased the car off and asked him what injectors they are. Apparently they're VQ35 decaped injectors that are flow rated to 550cc. Not so keen on decaped so I'll keen an eye out for some legit replacements.

I sent the injectors off to the cleaners yesterday and picked them up this morning. Number 4 (the offending cylinder) injector was stuck open and was blatantly pouring fuel out so they've put it through the ultrasonic cleaner and it's come up good. He also told me he's put bigger filter baskets in them so that should be great.

I'll get the compression tester onto the engine tonight and check the health of the engine (fingers crossed) Then hopefully put her all back together and get it up and running.


Cheer for all the help guys, and I hope not to have to carry on this topic haha.

- Lance

Edited by Captain Wow
  • 2 weeks later...

Oh yeah!

Winnah!

Nope doesn't look like a 350z injector. Are you sure they aren't stock? 350z would be smaller than rb25det

Spot on Alex!

Stuck injectors are not that common - especially for white/grey smoke!

All running good now Lance?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Even more fun, leave all the ADAS stuff plugged in, but in different locations, hopefully avoid any codes!   And honestly, all these new cars with their weird electronics. Pull all the electronics out Duncan, and just shove an aftermarket ECU and if needed a trans controller in, along with a PDM. Make it run basic but race car styled!
    • To follow up a question from earlier too since I had the front bar off again (fking!) This is what is between the bumper and the drivers side wheel And this is the navigator side, only one thing but its a biggy! So basically....no putting coolers in the wheel arches without a lot of moving other stuff. Assuming I move to properly race prepping this car I'll take that job on and see how the computers respond to removing a whole bunch of ADAS modules
    • So I prepped the car for another track day on Wednesday (will be interesting to see coolant temps post flushing out and the larger reservoir, with a forecast of 3-14 being 20o cooler than last time I took it out). Couple of things to mention; since I am just driving the car and not taking a support vehicle, I took the rear seats out and just loaded the back up Team Trackday style. Look at all that space! To cover off removing the rear seat....it is weird (note the hybrid is probably different because it wouldn't have folding rear seats) Basically, you remove the lower seat base, very similar to a r series but it is a clip that pulls forward to release the base rather than it being bolted down. Easy Then, you need to remove the side section of the rear seat on each side. There is a 14mm head nut at the bottom of the side piece, the it slides upwards off a hook at the top to release; you also need to unhook the seatbelt from the loop at the top. Then the centre piece is weird. You need to release/fold the seats forward with the tab in the boot on each side From there, there are 2,x12mm headed bolts holding the rear of each seat to the folding bracket, under the trim between the rear seat and the boot (4x christmas tree clips there, they suck). The seat is out but you can see where the bolts attach to the bracket
    • As discussed in the previous post, the bushes in the 110 needed replacing. I took this opportunity to replace the castor bushes, the front lower control arm, lower the car and get the alignment dialled in with new tyres. I took it down to Alignment Motorsports on the GC to get this work done and also get more out of the Shockworks as I felt like I wasn't getting the full use out of them.  To cut a very long story short, it ended up being the case the passenger side castor arm wouldn't accept the brand new bush as the sleeve had worn badly enough to the point you could push the new bush in by hand and completely through. Trying a pair of TRD bushes didn't fix the issue either (I had originally gone with Hardrace bushes). We needed to urgently source another castor arm, and thankfully this was sourced and the guys at the shop worked on my car until 7pm on a Saturday to get everything done. The car rides a lot nicer now with the suspension dialled in properly. Lowered the car a little as well to suit the lower profile front tyres, and just bring the car down generally. Eternally thankful for the guys down at the shop to get the car sorted, we both pulled big favours from our contacts to get it done on the Saturday.  Also plugged in the new Stedi foglights into the S15, and even from a quick test in the garage I'm keen to see how they look out on the road. I had some concerns about the length of the LED body and whether it'd fit in the foglight housing but it's fine.  I've got a small window coming up next month where I'll likely get a little paint work done on the 110 to remove the rear wing, add a boot wing and roof wing, get the side skirt fixed up and colour match the little panel on the tail lights so that I can install some badges that I've kept in storage. I'm also tempted to put in a new pair of headlights on the 110.  Until then, here's some more pictures from Easter this year. 
    • I would put a fuel pressure gauge between the filter and the fuel rail, see if it's maintaining good fuel pressure at idle going up to the point when it stalls. Do you see any strange behavior in commanded fuel leading up to the point when it stalls? You might have to start going through the service manual and doing a long list of sensor tests if it's not the fuel system for whatever reason.
×
×
  • Create New...