Rb25 Blowing Smoke

[battery]

hey guys i have just put an rb25 into 32 it runs great lights the wheels up way easier than my 20 and the torque down low is great!!!

just one problem, it blows white smoke on idle, decelaration and if im going up a hill under heavy load but it will stop once boost hits.

if i rev the car to 2000rpm from idle and hold it there i get zero smoke until i let off.

if i really hammer it hard and then stop i get crazy amounts of smoke, if i drive normal i still get some though it would pass as condensation smoke but its definately not

i have checked compression 125,126,125,126,129,129.

i pulled off the dump no oil and not much shaft play, cooler piping return is spotless but there is a slight film on the other side which i think is normal.

i blocked the PCV and intake and setup a vent to atmo catch can, no change.

spark plugs all look fine, no ecu errors.

no oil in water or the other way around.

smoke smells like normal exhaust smoke i guess, definately not acidic like it was when i did a head gasket

i have only driven it maybe 100k's so hard to say if its using oil..

the engine was refurbished(rings, bearings etc) about 3-4 years ago it then did about 15000ks after which it was pulled out of car and sat around for a year, the head was pulled off and checked new valve stem seals were installed and the engine was put back together it sat around for another year then i bought it and installed into my 32

any ideas on what i should try next??

[TiTAN]

pull the spark plugs and check which ones show signs of oil. If its only one cyl that is showing signs of oil it could be that one of the valve stem seals is leaking

[SECURITY]

i personally have never seen a blocked PVC setup work properly. im sure its been done before but not by anyone ive ever met.

put your PVC back to stock, check the valve is working properly and the hose has no splits in it - then see if its still doing it.

worn valve stem seals cause smoke on deceleration - so do valve seats AFAIK.

keep us posted.

[battery]

i personally have never seen a blocked PVC setup work properly. im sure its been done before but not by anyone ive ever met.

put your PVC back to stock, check the valve is working properly and the hose has no splits in it - then see if its still doing it.

worn valve stem seals cause smoke on deceleration - so do valve seats AFAIK.

keep us posted.

the plugs had no oil on the tips but a very very small amount on the threads.

it was smoking before the PVC valve was blocked, but it was defiantly working as there was a little oil on the plenum nipple.

the head was total reconditioned (new seal and valves etc) then sat on a stand for a year or two and hasn't been started till now.

it also only starts smoking once the car has warmed up, i think if it was valve stem seals it would do the opposite.

at the moment im thinking of just cleaning out all the piping, putting the thing back together and do a few more k's

Edited October 17, 2009 by battery

[Brood]

I also had this type of problem. However, in my situation, the turbos where the culprits. My car drove well and no other problems existed. So it took awhile to figure it out. I only found out by getting a new turbo turbos. The old ones looked fine when removed and the only evidence of any problem was the discolouring on the exhaust blades, dump pipes were fine and no oil was on them either probably due to high exhaust temp burning the oil and hence the smoke. If your turbo is new, I don't have any other suggestions to the coz.

[battery]

I also had this type of problem. However, in my situation, the turbos where the culprits. My car drove well and no other problems existed. So it took awhile to figure it out. I only found out by getting a new turbo turbos. The old ones looked fine when removed and the only evidence of any problem was the discolouring on the exhaust blades, dump pipes were fine and no oil was on them either probably due to high exhaust temp burning the oil and hence the smoke. If your turbo is new, I don't have any other suggestions to the coz.

turbo is now new it is possible the seals may have become brittle and leaky after sitting around for a few years idle.

what sort of discoloration did you have?

it makes sense that its the turbo but if there's no evidence of oil i cant be sure, i do have a good rb20 turbo here but its a lot of f**king around to swap it over.

the only other thing im not sure of is if its a crankcase pressure problem, how do i go about ruling this out?

[grippy]

My RB20 blows smoke when I rev it above 6000rpm and at no other time. I have no evidence of engine problem so I am suspecting my turbo is slow leaking oil. There is no evidence in the turbo of any leaks, I am still unsure of where it is coming from. The turbo is a hks item with about 5000kms on it and every time I have seen a turbo leak oil it has been in a big way and with huge plumes of smoke.

The engine only has light blue smoke at high rpm.

It may be my breather blowing oil back into my intake??

Will advise when I sort it.

Rgds,

Grippy