Vq25Det Oil Catch Can Setup?

[luthepa1]

Hey Guys,

Maybe a bit of a silly question but I want to install a oil catch can but not 100% sure on the how. Is it as simple as just putting inline? And I am thinking I want a oil catch can for the PCV hose drivers side and also on the intake passenger side. Do I need to use 2 catch cans or can I rig up one catch can for use on both side? And I want to keep it legal.

I want to do this as a bit of troubleshooting procedure more than anything. My car runs absolutely fine except I still see some smoke for a few seconds when reapplying throttle after a 10sec backoff decelleration @ 80kms or more. Or if the engine is warmed up and idling in park I rev it high, then the revs drop back down to idle and some smoke clears, but recently I tried this rev test on a hot 33*C days after 45mins of driving with aircon on and nothing! No smoke. So the issue seems intermittent. This issue only started after an accident where the wife snagged the exhaust and ripped it clean off which was only 1 month after a turbo upgrade/replacement as the original stock turbo blew up.

https://www.dropbox.com/s/1lvc2hgifqkuajy/Stag%20Smoke%20Blow%20Short.mp4

Paul.

[scotty nm35]

It almost sounds oil pressure related, when the oil is hot it's thinner and has less pressure. Can you try a thinner oil perhaps? What are you running now?

Were the banjo bolts drilled out? Perhaps too much for your turbo seals?

Dropping a catch can in will show you if there is blow by etc, but it won't fix the underlying issue. Have you checked the PCV operation?

[luthepa1]

It almost sounds oil pressure related, when the oil is hot it's thinner and has less pressure. Can you try a thinner oil perhaps? What are you running now?

Were the banjo bolts drilled out? Perhaps too much for your turbo seals?

Dropping a catch can in will show you if there is blow by etc, but it won't fix the underlying issue. Have you checked the PCV operation?

Hey Scott. I thought one might have been missed but Craig said that all 3 were drilled out now.

Currently running 10w60 castrol edge performance. Was running motul chrono v300 10w40 for a year. The 10w60 has reduced the amount of visible smoke frequency. I say it only happens when driving @80km or more but really its when the engine reaches max vacuum then i apply gas again. I have a cheapy boost gauge with max vacuum reading down to -15psi. At idle its around -9 to -10psi (-7 to -8 in drive and stationary). But i noticed when I do that "zippy" driving in back streets using only 1st and 2nd gear the car reaches -15psi easy when its all phsyc'd up. This is when smoke become visual looking in rearview mirror.

Like you say I know the catch can wont fix the issue but at least maybe I can get a indication of how much blowby gas there might be. I just need to start doing things to troubleshoot.

PCV seemed to work fine but I replaced with brand new genuine nissan PCV about 6 months ago. Made no difference.

[KiwiRS4T]

Where is the smoke coming from? If its coming out the tail pipe then its the opposite of blowby - oil getting past the rings and there's not much you can do about it short of new rings! You could check by doing a leak-down test to se if its your valve seals.

[scotty nm35]

I still think it might be the turbo seals, I have a Soarer I work on with a similar issue, nothing I do can stop the turbo seals leaking, but it isn't all the time, and mainly on decel.

Any chance you can drop the front pipe and check the dump for oil buildup? Shame the turbo is so hard to get to...

Drop two catch cans in if you can, it will at least tell you if there is an issue with the PCV or breather and rule them out.

[luthepa1]

I now have the ability to jack the car up on stands and work from home now. I'll try to have a look at the dump pipe for oil build up. Is it enough to look at it when cold? Or should I go for a hard drive then check (so super hot)?

After this might look into leak-down test. And still interested in getting catch cans.

[scotty nm35]

Catch cans aren't hard to fit, there are a few photo's of my setup in here somewhere.

You can't drop the front pipe when it's hot, just check it for wet oil when cold.

A compression/leak down test is a good idea. I just bought a tester myself for $40.

[luthepa1]

Ok I got some pics of the dump pipe now. See the link below. Let me know what you think?

https://www.dropbox.com/sh/na59gf9f8ccalpb/6JNvNV2xWW

[scotty nm35]

It all looks pretty clean, other than the intercooler piping. Could be coming from the rocker breather or the turbo seals.

Running a catch can will rule out the rocker breather, try it for a few days just venting under the car and see if the oil stops. Best if you clean the intercooler and piping so you can see if it is still filling with oil. If it is, it may point to a turbo drain problem, which isn't too hard to check anyway.

[m35stagea]

I am having exactly the same problems.

Hard vaccum on decel = puff daddy.

Turbo

Rings

Or pcv

But like you I just had my turbo swapped because last one was blown.

[m35stagea]

You checked dump yeah?

Could be from turbo and sucking into egr?