White smoke problem - is it terminal? - THREAD CLOSED

[aloshan]

Hey guys

So im really worried, I think my fresh rebuild might be over after just 1400km..

Anyway I get white smoke , im definitely not burning coolant , the smoke smells like diesel , im quite sure im burning oil. no i havnt blown my headgasket.

- the white smoke only occurs when the car has warmed up , never on start up

- the white smoke will happen mostly and ALOT on idle , but not that much when there is load on the engine, will puff out white smoke when I slow down and put it into first gear

- the white smoke only starting happening AFTER my first oil change after the rebuild, it started immediately after I changed the ooil. Oil 10w-30 was used to run in and I filled 10w-40 Castrol Magnatec. Ive since done another oil change just incase I overfilled ,im now using fully synthetic 5w-40

- did a compression test today , wet and dry (as Im scared it might be my piston rings)



Dry 140 140 140 150 140 150

Wet 170 160 150 180 150 160

So... theres a 30psi variance between wet and dry in cylinders 1 & 4....

After my rebuild which included forged pistons and 288/288 cams I had to stick with my stock ecu as my autobox was/is playing up and im unable to tune any standalone because of this. This lead to me running very rich - ive heard that running very rich can wash the bores not allwoing the piston rings to bed in properly.

The way I see it there are 3 possibilities

a) overfilled oil , taking a while to burn of as a little oil = alot of white smoke. already traveled over 200km since possible overfill so dont know if this is possible that oil is still burning

b) turbo seal is gone , i have a stock 25 year old ct26 that might have just let go , but only after my oil change...to much of a coincendance.

c) dropped a piston ring - leading to white smoke ....this seems to be the most plausible ..

Here are some pics that was taken while I was doing the comp test and replacing my valve cover gasket(as it seemed to be leaking onto my exhaust manifold) -
















Notice anything out of the ordinary? Ideas , suggestions?

any help is much appreciated

[lexsmaz]

Does not sound ideal, you are getting a fair increase in your wet test, but how much oil are you using for the test, should only use around a couple of good squirts from a oil can per pot ..

I would stay off the synthetic oil for the moment too & after you have changed the oil i would give it quite a few good hard loaded up runs

I have seen white smoke from a Auto trans modulator valve failure, it will suck up the Auto fliuid along the vacuum line, not sure if your box has one though ? ..

Do all the spark plugs look the same, or are some looking oily, is there any oil in the turbo intercooler pipes may even pay to drop the dump pipe too & have a look there ..

Good luck ..

[aloshan]

Does not sound ideal, you are getting a fair increase in your wet test, but how much oil are you using for the test, should only use around a couple of good squirts from a oil can per pot ..

I would stay off the synthetic oil for the moment too & after you have changed the oil i would give it quite a few good hard loaded up runs

I have seen white smoke from a Auto trans modulator valve failure, it will suck up the Auto fliuid along the vacuum line, not sure if your box has one though ? ..

Do all the spark plugs look the same, or are some looking oily, is there any oil in the turbo intercooler pipes may even pay to drop the dump pipe too & have a look there ..

Good luck ..

thanks for the advice man. This may be my problem as the oil i put in for each cylinder for the wet test wasnt exactly the same amount...

Yes im thinking of changing back to 20w-50 for now as the synthetic may be to thin and making my current problem worse

Plus 5 and especially 6 was messed with oil(plus furthers away fromt he cam gears) , i assumed this was due to my valve cover gaskets leaking which i replaced. Is there another reason that there would be oil on my 5th,6th plugs that relates to white smoke out the exhuast during idle?

[aloshan]

oh and there seemed to be a small amount of oil in the intercooler pipes

[lexsmaz]

Synthetic is thin but its the friction modifiers in it that is the worry, if the rings have not bed in properly yet it can glaze the bores up & cause smoking / oil consumption issues ..

Any cylinder can start to use oil its not dependant on its location to the cam gears, the oil in 5 & 6 was it around the out side of the spark plug or just on the electrode & end of the thread / porcelain area, was the spark plug socket wet, if it was wet its only from the leaking cam cover, would pay to check it again but let it idle for quite a while when its smoking & remove the plugs again & recheck them ...

If your Auto trans has a modulator valve the vacuum line take off is usually around the rear of the plenum chamber which will feed the rear cylinders ..

[blakeg]

yeh i would be using good old mineral oil for the first few services to let the rings bed , hope thats all it is.

[George]

Correct me if I'm wrong but I thought oil produces black smoke (maybe a bit blue), while white exhaust color usually indicates coolant in cylinder(s)

[JDM hachi]

Not too sure what your exact problem may be but I'll put this out there....., "burning" oil is blueish, white smoke in my experience can be either -coolant (which you have ruled out) or -oil "vapourising" in the hot exhaust of the turbo (not combusted in cylinder), so if it is only doing it when warm, look at a stuffed turbo seal (I don't know how the ct26 are sealed, take off the exhaust dump and check for wetness/oil deposits). If the problem has started with new, thinner oil, this may cause your problem. How is the oil drain from the turbo? if its blocked partially/kinked, will pool oil in turbo which can leak past turbo seal. If you have nasty blow by with the new motor this may also result in the oil drain from turbo not performing correctly, thus lowering the amount of oil returned to sump, again this will also result in oil leaking past the turbo seal.

You really need to correctly do the compression tests, make sure battery is fully charged, and fuel pump fuse(?) removed, always hold throttle open when cranking, and do all this with a warm motor.

matty.

[aloshan]

Synthetic is thin but its the friction modifiers in it that is the worry, if the rings have not bed in properly yet it can glaze the bores up & cause smoking / oil consumption issues ..

Any cylinder can start to use oil its not dependant on its location to the cam gears, the oil in 5 & 6 was it around the out side of the spark plug or just on the electrode & end of the thread / porcelain area, was the spark plug socket wet, if it was wet its only from the leaking cam cover, would pay to check it again but let it idle for quite a while when its smoking & remove the plugs again & recheck them ...

If your Auto trans has a modulator valve the vacuum line take off is usually around the rear of the plenum chamber which will feed the rear cylinders ..

Oil seemed to be on end of spark plug and around. not sure if my auto trans has a modulator valve. I have the a340e.

Correct me if I'm wrong but I thought oil produces black smoke (maybe a bit blue), while white exhaust color usually indicates coolant in cylinder(s)

You are right but I have confirmed its not coolant and definetly burning oil , as suggested below it might be vapourised oil from the turbo seals

Not too sure what your exact problem may be but I'll put this out there....., "burning" oil is blueish, white smoke in my experience can be either -coolant (which you have ruled out) or -oil "vapourising" in the hot exhaust of the turbo (not combusted in cylinder), so if it is only doing it when warm, look at a stuffed turbo seal (I don't know how the ct26 are sealed, take off the exhaust dump and check for wetness/oil deposits). If the problem has started with new, thinner oil, this may cause your problem. How is the oil drain from the turbo? if its blocked partially/kinked, will pool oil in turbo which can leak past turbo seal. If you have nasty blow by with the new motor this may also result in the oil drain from turbo not performing correctly, thus lowering the amount of oil returned to sump, again this will also result in oil leaking past the turbo seal.

You really need to correctly do the compression tests, make sure battery is fully charged, and fuel pump fuse(?) removed, always hold throttle open when cranking, and do all this with a warm motor.

matty.

excellent advice! Im hoping and thinking that it might be this as well.

So to clarify , it is possible that by changing to a thinner oil , could result in the oil leaking past the fucked turbo seal because its thinner? Ive been thinking its the turbo seal all along yet i thought it was to much of a coincidence for the turbo seal to go EXACTLY the same time as I did my oil change but if there is a reason the turbo seal failed at the same time then this might be it!

I do have nasty blow by ,smoke from the cam cover breathers and also smoke from the hole where I fill engine oil if I take the oil cap off....this is why I thought i Had dropped a ring ....because of my high crankcase pressure.

Im hoping this is what it is and yes I will do another compression test , making sure I do all that you have said above. Also hoping to get a leak down test done this week.

[allencr]

...a stock 25 year old ct26...

How much does it wiggle?

[SHEPPO3930]

Does it have a catch can fitted? if so, is it full of oil?

If it's piston rings, under boost the combustion pressure will blow past the rings, pressurising the bottom end, and eventually blowing out thru the cam cover breathers and into the catch can = no smoke from the exhaust. If you DONT have a catch can, the cam cover breaters will vent back into the intake pipe, and the oily air will get burnt = smoke from the exhaust. You should pull off the cam cover breather hoses and check for oil.

Also, if the rings haven't bedded in properly, under decelleration and idling, the negative pressure will suck the oil up past the rings and the engine will burn it - causing smoke.

my gut feeling is the rings have not bedded in properly and you have an oil consumption issue as a result.

[EldarO]

Correct me if I'm wrong but I thought oil produces black smoke (maybe a bit blue), while white exhaust color usually indicates coolant in cylinder(s)

White/light blue is oil

Black is fuel.

Although ive had a whole host of cockups with motors that have produced various results, but thats my general interpretation.

[aloshan]

How much does it wiggle?

havnt had a chance to disconnect first. turbos are a b*tich to get of from a 7m.will only have time later this week

Does it have a catch can fitted? if so, is it full of oil?

If it's piston rings, under boost the combustion pressure will blow past the rings, pressurising the bottom end, and eventually blowing out thru the cam cover breathers and into the catch can = no smoke from the exhaust. If you DONT have a catch can, the cam cover breaters will vent back into the intake pipe, and the oily air will get burnt = smoke from the exhaust. You should pull off the cam cover breather hoses and check for oil.

Also, if the rings haven't bedded in properly, under decelleration and idling, the negative pressure will suck the oil up past the rings and the engine will burn it - causing smoke.

my gut feeling is the rings have not bedded in properly and you have an oil consumption issue as a result.

i dont have a catch can. If i remove the breather hose to the crankcase , smoke billows out. There seems to be a large amount of crankcase pressure

Will be checking my turbo this weeknd

My plans as it stands are

- do another proper compression test this weekend , make sure pedal is at WOT , make sure im putting the same amount of oil in each cylinder for wet test. Test each cylinder 3 times to get an average psi reading

-do an oil change and drop my 5w-40 fully synthetic and change to 20w-50 full mineral. Thinking the thicker viscosity might help to bed in parts that havnt already bed in...in saying that ive done 1500km already so if it hasnt already bed in ,doubt it ever will. still , couldnt hurt. i know my synthetic isnt doing me any favours if lack of bedding in is the problem

-anything else I should get done while im doing my compression and oil test

- remove turbo and check turbo oil seal , downpipe etc for oil and oil residue

- remove ISCV and clean all hoses connected to it

- TRY and get a leakdown test done somewhere.

-It was burning oil is bluish,white smoke + burning oil smell indicates oil "vapourising" in the hot exhaust of the turbo (not combusted in cylinder), so since its only doing it when warm I should look for a stuffed turbo seal. Is this correct thinking?? ( honestly im hoping its this , dont know how plausible this is though)

-What else besides piston rings smoke only when warm and on idle but never on startup and on load?

[boxh34d]

Should be able to get the turbo off in an easy hour, but you don't need to.
Just take the turbo intake hose off and grab the shaft nut to check for shaft play - takes 2 mins. Check for side movement and end float (wiggle side to side and push in and out). Little bit of side to side is ok, in and out = bad. Have a look at the comp fins while your there. If any looked chipped, or there is scoring on the inducer of the turbo, its rebuild time.
Take the dump off the back of the turbo to check for oil post turbo - 10 mins to 2 hours depending on your dump pipe setup. Black soot is normal, but any moisture or oil is bad. Just make sure you do it after the car has actually been running for a bit, not straight after a dry / wet comp test.

And + 1 to everything that everyone else in the 100 threads has said.

[Suavemechanic]

-What else besides piston rings smoke only when warm and on idle but never on startup and on load?[/QUOTE]

Valve stem seals
and what lexmaz says , have seen autos make good smoke
not sure changing viscosity will make much difference seals either work or not work
but it will help with the bedding in of the rings if you use cheap mineral oil
good luck