Rear main seal

[steveo1502]

So recently swapped my turbos for a rebuilt set, since then I noticed a smell of burning oil when hard on the gas, thought maybe one of the oil lines on the turbo was leaking but everything around turbo looks clean, but oil everywhere underneath, looks like it coming from between the engine and transmission, is it possible too much boost blew the rear main seal? I don't run it any higher than before, maybe 14-15 psi. Any other suggestions on what it might b, or ways to check. I really don't want pull the tranny but I guess I could do the clutch same time

[knate]

That rubber seal could be 20+ years old. If your worried about too much pressure in your crank case might want to look into a catch can setup.

[steveo1502]

I just installed a catch can actually, it's not vented though, kinda just recirculated, it came with a plug for venting.is it better to vent? I guess if your looking to lower the pressure.So it would be possible for too much boost to blow the seal, if it is than I'm pretty sure that would be my prob . Guess dropping just the tranny would suck in one of these? I changed a clutch in my rb20 couple years ago, those top bolts really sucked, would it be easier to pull the whole engine and tranny as one? Do it out of the car.

[knate]

where did you recirculate it to? If too the intake then that should be fine. larger diameter piping to catch can would relive any pressure in crank case better. I think its probably just wore out. If it blew because you turned up the boost you have bigger problems ie piston rings. as for changing your rear main I don't know if it would be easier to drop the tranny or pull the motor as I've never done it. Have you done a wet/dry compression test?

[knate]

*Intake before turbo*

[bobbo]

Thoroughly check your cam cover gaskets. I had what I thought was a blown rear main seal but it was a leaking cam cover gasket.

[steveo1502]

It's recirculated back to the intake, 15 mm lines, hope it not the rings but seems like a good place to start by checking the compression, or the valve cover gaskets, at first I thought that was where it's was coming from but now I'm all turned around

[steveo1502]

The instructions for the catch can was all japaneese and I didn't really know what I was doing, I think I got it right but looking online I found a bunch of different ways to do it, on pass side so above turbos hose comes from right valve cover to the intake,( right before turbo). Pretty much just hooked to each side, so it has a vaccume on one side and valve cover on other, is this right?

[steveo1502]

Sorry for all the stupid questions but if I were to vent the catch can, I would just plug the intake side and just engine pressure would blow the oil out? I was wondering if the can was hooked up right cause I havent seen any oil in it, just thought it was a good sign

[knate]

sounds like you did it right best way i can explain it is your intake should draw the air out of your valve covers through your catch can. And if you vent instead of hooking your catch to your intake you block the hole on your intake and just put a small filter on the side of your can where the intake hose was hooked to

[steveo1502]

Yeah, I have it right just wanted to make sure, I think I will vent it and see how it is, and do a compression check also, thanks for your help

[caliber676]

If you want to cut the diagnosis time down just pick up some leak detection dye and put it in your oil. Drive it around for a few days and see wheres its coming from with a black light. Given that your still able to drive the car. It would be better than trying a bunch of things and guessing at where or what is causing it.

[speedfreak]

Take a picture of the catch can setup and them we can see connected right.
I've seen people do it wrong and pressurize the crankcase.

[steveo1502]

So, I unhooked the can, just for now, gonna grab a filter and vent it , also tested the compression, it's around 140 on all cylinders, be read that 170 is normal, so does this mean its toast? Or just getting bad? Or is it better to preform a leak down test? I wouldn't mind doing a rebuild, but would like to get this summer out of it, have some time to gather some parts or look into a swap.

[Silbee]

Did you compression test it at operating temperature?