3SGTE / CT26 Oil Leak through Exhaust - ideas? (pics)

[sw20r]

my motor recently had this issue..

blowing white smoke out the turbo once it was warmed up like no tomorrow.
its at the shop now having the main and engine bearings done as there was some metal pieces found upon dumping the oil.

the issue was the motor was built loosely thus piston to bore clerance wasnt spot on

[big_zop]

From your thread i was under the impression that it had done 300k (well i know the chassis had - wasnt sure that the engine had been replaced previously).

While i dont know too much bout different gen 3S motors, would it be better in the long run to rebuild the engine stronger (if thats your goal - what i tried to ask first but didnt quite word it right)? from what i remember, the Gen 3 is a MUCH better base and has more differences than cams, ect that would be changed later, negating the swap.

And while an engine rebuild may be out of your league (both skill and cost wise), i guess changing an engine isnt so thats another important factor.

If you cant find anything on the dry/wet compression test ill post up the magazine article later tonight (probably after top gear )

[RobST162]

I have a gen 2 in there now with circa 120k on it.. my chassis, yes 300k

if I could get some diagnosis I'd be better informed about the move to a Gen 3 or work with this one I guess...

I'm going to have to read more on these wet/dry test

after top gear

[Keith ST204]

I am not familiar with these turbos but it sounds to me as though the oil might be leaking from the exhaust side of the turbo and then being burnt in the turbo/exhaust pipe by the hot exhaust gases. I don't see how the valve stem seals could leak that much oil even if they were not there.

[af300e]

I am not familiar with these turbos but it sounds to me as though the oil might be leaking from the exhaust side of the turbo and then being burnt in the turbo/exhaust pipe by the hot exhaust gases. I don't see how the valve stem seals could leak that much oil even if they were not there.

Doesn't do it under load, most prevalent at states of high vacuum eg cruising and idle. Points to stem seals. If you've ever seen an early magna idling at lights you'll know just how much oil can get past stem seals, Then, once the ports clear on take off, no more smoke.

Roughly how much oil does it use?

[Keith ST204]

I still do not think that you could get that much oil down the valve stems with the way the valve lifter covers the top of the valve and direct the oil away from the stem. Also having less than 0.003" clearance I can't see it letting enough oil past to blow clouds of smoke when hot but not blow smoke on start up when valve stem seals normally give you smoke.

[lexsmaz]

I would be checking & "reading " the spark plugs, if its burning as much oil as you say, the spark plugs would be very oily / dirty ( as in the centre electrode area & surrounding area ) if the plugs are obviously clean & dry & free from large build up of deposits i would be definately looking at the seal on the exhaust side of the turbo ... Especially if you said the intercooler is clean its not sucking it through the system ...
Did the problen just happen all of a sudden or did it slowly get worse ...

if you wanted to also get your hands dirty, you could pull the exhaust manifold & dump pipe off & try & see were the oil starts from ? as in manifold clean ? but turbo dump oily ?
not very accurate because the temps will often burn off residue, but you could drive around the block & come back home let it smoke badly shut it down & check once cooled down ??

[big_zop]

Well, we are in the middle of moving and looks like its been packed. I have found this which should still help.

To do an accurate compression test, remove all the spark plugs from the engine. Then disconnect the coil wire from the distributor and connect a jumper wire from the coil wire to the negative (-) terminal of the battery. Prop the throttle plate so it is wide open. Connect a remote starter button from the positive (+) terminal of the battery to the small connector of the starter. Put the ignition key in your back pocket.

Now install the compression tester in cylinder number one and crank the engine about six or seven turns. Write down the compression reading and go on down the line. Good compression would be about 150 - 180 pounds. More important that the actual compression is that the readings should all be within 10% of each other.

Now that you have the dry readings, squirt two or three good squirts of motor oil into number one and do the test over. Note the reading next to the dry reading and go on down the line. Once you are done, compare the wet/dry readings. If the wet readings show a marked increase, say 20 to 25%, then you have ring problems and it's time for an engine overhaul. If there is a small increase, say 5 -10%, then the problem is in the valve seals and they will need to be replaced.

Other things that i remember is that if there is a particularly low reading, then something is letting the compression out. Cant remember how to tell when doing the dry/wet test but at least if you take your head off it might be obvious.
- between two cylinders, then may be headgasket. but obviously other symptoms and can perform a tee kay test (not sure spelling)
- only one, could be a cracked piston or valve or HG for that cyl only

There may have been something ive missed but if you havent found out more by the time i get the magazine, ill put it up.

[RobST162]

thanks guys

yeah looks like a bad magna and a little worse lol

1. Inside the dump / exhaust is not oily.. some nice carbon but that's it.
2. My dry comp test last week was 185psi on all 4

Zop, I'll run the wet/dry test and see what we pull out. It seems there's no oil leaking out of the turbo into the intake or exhaust though sadly as there's no evidence of it - the dry carbon powder is pretty undisturbed.