[EscudoNZ]

Hi all I have a 2006 GV, running the J20a engine and automatic transmission. I bought it as a non runner after the previous owner overheated it after a leaking radiator let him down. I replaced the entire engine one from a wrecker and ever since I have owned it had this weird problem with the engine emitting a large cloud of white smoke after a long cruise at highway speeds. I can use it daily around town for months and it will never smoke, but if I sit at highway speeds for an hour and then stop and rev the engine it's like a fogging machine for approx 15 seconds before clearing and not reappearing until another long run at motorway speeds is done. I swapped the pcv valve from another car but it still did the same thing. I've tried engine braking done large hills and accelerating at the bottom but no smoke is visible. The smoke when present is very white but definitely smells like smoke rather than steam and hangs in the air for a while. Any ideas appreciated! Thanks

 

[aquanaut20]

The only issue I can suggest is the top drains from the valve section may be partially plugged filling the valve cover with oil.. and weeping past the valve seals..

 

[EscudoNZ]

Is it possible that the trans modulator valve is allowing trans fluid to be sucked into the combustion chamber?

 

[2013GV]

Is it possible that the trans modulator valve is allowing trans fluid to be sucked into the combustion chamber?

does yours have a modulator? its a possibility but it would do it on the over run downhill when you pressed the pedal at the bottom. Cover drains are unlikely but possible, the J20's don't seem to suffer like the V6'sdo in that regard.

using any water? I gather you replaced the long block and used all the manifolds off the old motor, was the inlet manifold flat?

 

[aquanaut20]

The J20 has an electrically shifted trans, no modulator... no connection to the vacuum...

 

[2013GV]

The J20 has an electrically shifted trans, no modulator... no connection to the vacuum...

thought so, i'm suspecting it may be coolant, smells like oil and heat soak with that little increase in pressure and a leaking inlet gasket or throttle body gasket.

Another option to prove the PCV is to block the hose to the manifold and let the PCV puke into a catch bottle for a day to see if theres any difference, will at least rule out that item.

 

[EscudoNZ]

Thanks guys... The modulator was just something I had read about, but didn't realise my model does not use one. I've checked the transmission fluid and its way over full (prob unrelated if there is no connection). Yep I used the inlet manifold off the original engine, it wasn't ideal as it had suffered some deformation from the over heat but the sealing surfaces still seemed to match. If the inlet manifold wasn't sealing perfectly it still wouldn't result in smoke? I like the catch bottle idea, blocking the manifold side of the pcv valve path won't cause any idle issues etc? Thanks

 

[2013GV]

not for a couple of days, that will at least prove that part, It could be EGR related as well. Evap purges into the manifold too.

what end of the country are you?

 

[antila]

Hi.

Have same issue with same motor. Lot of white smoke only after driving highway, and making stop on traffic light etc. Idles fine and if I start moving, sounds like motor works without few cylinders for a sec., and white smoke comes out from exhaust. After that, everything is back to normal, until next longer trip on highway.
Just passed PTI, and emission test results were "like a new car".
No coolant loss, no oil level changes, no gasoline smell in oil, no DTC codes..
I have:
1) changed A/F sensor (seemed like little acceleration improvement)
2) changed MAF sensor
3) changed spark plugs
4) controlled, cleaned and re-learned throttle valve
5) controlled PCV
6) controlled resistance of ignition coils
6) Compared sensors readings, with car technical manual tables. (All that I can see with cheaper diagnostic scanners,) Everything were in range.

My last ideas are, that this is caused by faulty injector or ECU trims fuel wrong? Is it possible?
Because motor also has little hesitation in 1700-2000 rpm range.

 

[Steeneren]

Hey Guys.

Did you ever find a solution to this problem?
I have the exact same problem with my GV 2007 2,0 4x4 automatic.

I've also taking into consideration if this could be pre ignition related since I've been hearing a rattling noise from the engine when coming to a stop and starting to move again.

S

 

[aquanaut20]

Rather than pre ignition, consider checking for chain slap or sticky lifter. Of course this would depend on you confirming which engine you are running..

What is the mileage and service DATA. ?
How long have you had this vehicle ?

 

[Steeneren]

Hey Aquanaut20
Thanks for replying
My engine is a 2.0 Petrol JB420,
240.000km and I've only had this car for 3 weeks.
So I have nothing about service data.
Actually my timing chain is slapping against the engine (if that's what you're referring to)
I actually have a mechanic appointment tomorrow to check for oil pressure and before mentioned white smoke.
Do you think that these 2 issues can be related?

 

[aquanaut20]

The smoke could be rings or valve seals and is not related to the chain slap... do not ignore the chain, because if it snaps/slips, the valve train will be damaged..,

Perform a cylinder compression test ( wet and dry) if not to spec, a cylinder leak down to see where it is leaking..

 

[Steeneren]

But if the valve seals are broken, shouldn't the be smoke all the time and not just as mentioned above in the thread?

The mechanic will perform an oil pressure test tomorrow to see if that could be the problem with the chain slap since the chain tensioner needs correct oil pressure to perform correctly.
I will also ask him to do a compression test.

 

[2013GV]

If its slapping bad enough to hear it, it needs looking at, and fast.

 

[antila]

Hey Guys.

Did you ever find a solution to this problem?

Unfortunately still no solution for the problem.
In my case, there is one thing, that I have noticed. I made extra exhaust gas test.
In idle (meas.2 in picture) my HC value goes slowly up.
In revs it cleares out, and starts to rise again after some time in idle.

 

[2013GV]

You have either parasitic air (vacuum leak at idle) which the ecm is trying to correct by adding fuel, or excess fuel from another source ( whether that's oil or petrol you will need to determine)

Graph both O2 sensors (up and down stream), and ltft and stft at idle and 2500 rpms for at least 30 seconds and report back.

 

[Steeneren]

My mechanic suggested a faulty fuel injector nozzle.
All though i would believe that that the engine light would turn on if there was a fault.

 

[aquanaut20]

If the mechanic is guessing about a FI, perform a fuel/injector bleed down test..

 

[2013GV]

My mechanic suggested a faulty fuel injector nozzle.
All though i would believe that that the engine light would turn on if there was a fault.

Not necessarily, it sounds like a guess. Fuel trims and O2 sensors will tell you what's happening and where to start diagnosis.

As Philip suggests, injector / fuel rail bleed down test is probably not a bad idea.