Okay i just got a fresh rebuild with a streetport and its got like 1700 miles on the build. Ive had a couple of leaks and have gone around fixing them( leaking water pump, turbo cooling line on water pump housing, oil leak on turbo dump). MY Cat converter has been smoking for a couple of days now, i kinda figured it was because i just installed it, but i guess theres oil going into the exhaust....
thers no smoke coming out of the exhaust tips but theres is a light smoke that comes from the cat and flange that connects the cat to the Y-pipe.
Ive seen that i had small splash amounts of oil on the passanger side firewall and was wondering where the leak was coming from, i inspected the turbo on the topside and jacked the car up and inspected from down under. No visible leaks on the turbo.

So defeated i kept driving the car, until yesterday i decided to remove the UIM to see if it was an oil injector that has a leak or seepage... no luck no seepage.
i lifted the car again and this time i noticed that the LIM IS SEEPING OIL!!! its leaking a good amount of oil which gets all over my transmission bell housing and on the firewall.


i just got the engine rebuilt and Ive done its first oil change after the first 500 and about to change it at the 2000 mark,

any ideas guys?

 

check all oil metering lines and crush washers.

 

thats the first thing i checked when i removed the UIM...i even got new lines when i installed the engine in thinking if it was the oil injectors they would be the ones on the LIM but everything seemed in order.....

 

pictures as promised:

I made the mistake of wiping the wall down but this ill do maybe someone has had this issue before


and

 

I will post pictures of the actual leak on the LIM Tomorrow, the leak however seems to only be seeping on the side closer to the firewall...

 

i checked the whole LIM and it seems like its just the rear bolt, it seems to be leaking just the side closer to the firewall, the other side it fine, i just dont understand why its leaking soo much.... i just got it rebuilt and haven't even pushed the car at all.... unless its the oil injector on the LIM but even then it a leaky injector wouldnt make my cat smoke up would it?

 

I've had the oil supply hard line fracture imperceptibly before, it was spraying oil on the turbo and smoked pretty bad. Sounds like yours isn't leaking that much, but maybe you have seepage from one of the oil lines on the turbo. Just throwing this out there, it's all I can think of atm.

 

since your car is an s4 delete the omp and premix see if that fixes it http://banzai-racing.com/store/FC_oi...imination.html

 

okay thanks guys ill start my hunt with the turbo lines

 

Yea, there aren't any oil lines going through the LIM.... other than the OMP lines running "underneath" the manifold to the housings. Definitely start with the turbo oil supply and OMP lines.

 

+1, I have this issue going on right now.

 

i really doubt the LIM itself is leaking the oil, there is probably a stream of oil coming from somewhere at higher RPMs that is spraying across and onto the firewall and LIM i would have to think it is probably the turbo oil feed line, i have had them have some hairline cracks that only have a tendency to leak while higher in the RPM range as oil pressure rises. next likely one would be the OMP leaking oil and drafting the oil back under the car and splashing it on the cat and firewall while at freeway speeds. the OMPs are notorious for leaking oil.

 

kool, my engine is going to be finally broken in in 150 miles!!! i will inspect the line this wednesday and report back...thanks.

 

The turbine piston ring oil seal on my turbo was crap when I bought my S5 hybrid (same internals as an S4, with minor difference). It looked like it came from the LIM, but that didn't make any sense. My OMP is blocked off, and it was smoking REALLY bad from the exhaust. I know you said it's not smoking out the back of the exhaust, but if it's coming from out around the cat, crack open the exhaust around there and see if there's any oil dripping out.

 

ill take a look but the thing is it doesnt smoke heavily its like a light smoke, but i will inspect as well

 

okay guys, i took the heat shields off the turbo jacked the car up and the turbo is fine no leaks on the oil feed, the line is dry the leak is coming from up the LIM right on top of EGR. im thinking it was the rear oil injector on the top, but the funny thing is that i Took of the UIM and nothing wet was visible.... im stumped!

 

did you check the OMP?

 

the pump itself is fine no leaks im thinking that its the injectors or a hardline thats leaking....what would be right above the egr?

 

There are four hard lines for the OMP, and from what I hear they don't age well. Mine is removed, I premix.

 

it turned out to be the rear main seal.

thanks to Bens advice i too the little check plate off of the underside of the transmission to chek if there was oil seepage and there was oil everywhere and it was getting through the cracks of the bellhousing. Since theres a big gap on the paddagerside where the oil was spraying all over my firewall, it made the illusion thw it could have been my turbo or my omp... the tresmission is covered in oil on the underside and so it the starter....i will have to remove the transmission and flywheel to get to the seal to replace.,... thanks for the advice guys,
i will repost later with an update or if anything else comes up...

 

Who on earth rebuilt that motor?

 

after 8.5 hours of work i got it done, i managed to remove the rear stationary gear without the engine turning, it was really hard to line the transmission up again that alone took me 3 hours.... the leak was coming from both the rear main seal and the o ring. i hope everything turns out good i added silicon engine sealant to help the rear main slide in and i also put a little on the o ring grove before installing the ring...i will start it and drive it on Tuesday or Wednesday...thanks guys

 

Adding silicone to a gasket causes a double gasketing effect, it may not leak now but it might start later.