hello, first of all excuse me for the enunciation, but I am French and I use Google translate.

my 2004 350z internal forged, low compression piston with a used APS twin turbo kit started to make a huge thick oil smoke from the exhaust after 2~3000 km, without loss of power, but pops at the deceleration.

I dismantled the turbos and they were full of oil on the exhaust and intake side, but my engine intake is very dry.

so I put brand new turbos but first start exactly the same problem.

Oil drips from the joints to the y-pipe, I lose 500mL of oil in 10km, a huge amount of smoke at idle and acceleration, a little less when decelerating.

despite this it runs very well and starts without problem... I redid my oil return on both turbos, nothing has changed...
my compression tests are all good...




I really need help...

 

If you put new turbos in it, it's likely residual oil still burning off from the old ones that were leaking. I would try taking the exhaust off the car and cleaning it out the best you can and see if it still smokes. I would assume this was all from leaky turbos and nothing else.

 

that's what I thought at first, but with the new turbos when traveling less than 10km my oil level goes from the middle of the gauge to the bottom of the gauge...

 

Be sure you're checking your oil after the car has sat and cooled off. Checking it right after turning it off would likely read lower as a portion of the oil is still in the engine and not the pan.

 

Oil could be coming from the engine. Do a compression/leak down

 

all compressions are good, an additional leak test is necessary?

 

Clean your exhaust out of all the old oil. If compression is fine, it was likely the old turbos.

 

Have you installed an appropriate crankcase breather system for the TT setup? Excessive blow-by could be causing more oil burning or loss than normal. Also leaky valve guide seals could cause oil burning, a cylinder leak down test would help determine this. If crankcase pressure is high enough, your dipstick might even be popping out and shooting oil everywhere, so double check that.

Make sure all oil feed and return lines to the turbos are solid (no leaks). Going to need a lot of brake clean to get that residual oil cleaned up. Of course, make sure the oil leak isn't coming from your valve covers, and trickling down to burn on your turbos and exhaust. As others have stated, it might take some additional driving to burn off the residual oil left from the old turbos.
Cheers!
-Icer

 

I don't have any additional breather system, how does it work? I pierced the PCV valve and installed an oil catch tank to be sure, for the theory that it is oil that remained in the exhaust it does not seem possible to me as I lost 500 mL of oil level on my level in less than 10km, this means that I still have a huge loss of oil flowing directly into my exhaust. I don't have any leaks on my turbo oil inlet and return either. What I don't understand is why if my turbo oil circuit was bad I only had problems after several thousand km? and why if I lose half a liter of oil in less than 10km through the segments or the valve stem seals does the car start and drive very well?

 

Hi, can I ask how you solved the problem with the APS twin turbo kit? Thanks for the advice. I also have a problem with oil smoking from the exhaust, but I don't have a high oil consumption like you.

 

I removed my engine, dismantled the complete turbo kit then reassembled without the turbo and I ran the engine to check if the oil and the smoke was coming from there, no smoke or oil... I then ran the engine by reassembling only the turbo without the piping, then with a little piping without the exchanger, then with the exchanger and in the end I never had any smoke again having the engine with the complete reassembly kit, so I don't know how to what was this smoke and loss of oil due to..... a great mystery for me even today