The other day after a few hard pull in my rb25det s13 i noticed my car bog and just wasn't idling the same. I smelled smoke so i pulled over and checked under my hood. there was oil leaking out of my valve covers and the tube from my valve cover had popped out. It was still running and i noticed some smoke/vapors coming from the hole. The way its plummed is the intake side valve cover vent connected to the exhaust side valve cover vent with a T that goes to my intake tube in between MAF and turbo.



I put it back in and drove it home, i was only about 3 miles away. when i get home i take off the coil cover and the inner valve cover had leaked a lot of oil into the spark plug galleys, one got so bad one spark plug was like 90% submerged in oil. I figure this is why it bogged and not running the same, plug probably not firing or not as strong because all of the oil.

Thinking about what happened lead me to believe the pcv valve had let boost into the valve covers, causing them to leak oil and pop the fitting off. Take off the pcv and blow into it and indeed it lets quite a bit of air through, and thats just with my mouth so imagine 20-22psi of boost that i was doing allowed a lot of high pressure air through.

At this time i noticed oil leaking through a coupler for my ic piping. Took it off and theres quite a bit of oil in my intake tube to the turbo and my intercooler pipes. Id guess the pressure forced oil to the vent tube to my intake, went through the turbo and into the pipes.

So i have it all cleaned up now from all the oil and im going to pick up a new pcv and grommet today and put it back together and see what happens.

So finally the big question... what damage could have been done? Anyone know the part number for the pcv and grommet? After what happened im definitely putting in a catch can and im debating deleting the pcv all together and plugging the hole in the valve cover and capping the vacuum feed to it on the intake manifold. Hoping nothing major but i have the worst luck with my rb so im preparing myself mentally for the worst... let me know your opinions. Thanks in advance and thanks for reading.

sounds like you have it setup properly, id advise against deleting the system as youll end up with even more problems. Both VCs need to have vaccuum and the check valve goes on the intake side so you dont expose boost to the oil system. The only difference is i have a catchcan between the exhaust VC and the vacuum side of the turbo, my valve has never failed, so Ive never had an issue. Make sure the arrow is pointed to the intake manifold.

I picked up a new pcv and grommet and nice cusco baffled catch can over the weekend and hopefully have time to install today. Tested my old pcv and blowing through it was indeed allowing air pass pretty easily. Got all my pipes cleaned and fmic all cleaned and everything else.


Planning to install catch can like this and decided to keep my pcv

So i got everything cleaned up and put back together and it still ran rough. Decided to compression test and 1-4 is 155-165 and 5 is 90 and 6 is at around 70 ;(

taking a break cuz im super bummed and irritated knowing its likely something major. Point me in the right direction? what can i do to confirm what needs to be done? Can bad valve stem seals cause that bad of a compression drop?

you can blow out oil seals pressurizing the crank case like that but a better question is how much boost is being run into the motor and how was it tuned?

for compression to be that low something had to have happened relating to boost and the current tune...thats my guess.

If I were you, I would do a leakdown test and go from there.. Sometimes youll find its actually cheaper/faster/easier to get another engine shipped to you. Then you can rebuild the broken one over time for a monster motor. Once you pull the engine apart, you might as well do the crank collar and all the other upgrades while you have the chance, thats where it starts adding up. I wouldnt pull a motor apart and not spend a couple hundred more to put forged in instead of oem..

Carl H wrote:you can blow out oil seals pressurizing the crank case like that but a better question is how much boost is being run into the motor and how was it tuned?

for compression to be that low something had to have happened relating to boost and the current tune...thats my guess.

It was on an 18psi tune. A friend of mine is a pretty well known tuner up here but mostly for honda/subaru. I was told by hypergear rep The hypergear turbo i have should be able to make good power on my setup up to 24-26psi. Was attempting to retune to 24.

Richend the whole map and made a few pulls at 20 and 22psi before encountered the problem. Didnt get a chance to lean out or play with timing