Why I need a catch can.

[Meklo_4G63t]

Alright fella yesterday we had did a radiator changeout on my 91GST that i had for like a month and first turbo car from leaving nissans. Well we pulled the intake hose side of the turbo out yesterday and I notice a little oil. then I went to feel the blades and the shaft to see if the turbo was going bad and I found nothing. Well got the radiator in and changed the air filter and the car was pulling alot better but we did a bigger investigation and swaped the b.o.v. with a buddy of mine that bleeds to the atmosphere and ran it to were the turbo would spool up around 12psi. after 30 mins we got a film of oil coming aroud the bov. To me I was thinking a seal in the turbo is about to go bad but on cars like these like when u have a leaky valve seal do they do that. some advise from anybody on there opinion with this problem i would thank you because to see were the money would go

 

[SBstar]

Before you freak out there may be a very simple explanation. There is a breather/ventilation hose coming off your valve cover that should go to your intake pipe...is it there? If so the explanation is that your receiving oil from the valve cover/head into your intake pipe, into the turbo, and into your IC, where you've probably collected a fairly good amount of oil. Now that oil is being forced through your IC piping. Make sense? Good, now take your IC off, pour out the oil, and clean it with alcohol (just pour alcohol in, rinse it around, pour out, repeat).

If this isn't it, although I'm almost positive it is, then you can start looking for other issues.

 

[Meklo_4G63t]

Yeah its there with another hose but i forgot were that one runs to. But i will try that today.

 

[SBstar]

You can install a catch can, or even just a simple inline filter to help with that.

 

[DKneble]

Catch can is the best way to go. There are two nipples (avoid laughing) coming off the valve cover. One is a breather and the other is the pcv system valve. The pcv runs back into the intake manifold and I forget where the other runs in at (been a long time). Nice features for a stock car with emissions and drivability in mind but not a preformance driven automobile . They feed hot oil vapor back into the intake tract which increases the intake temp. and hence tendency to knock. In addition they coat your piping and intercooler with oil inside.

Best thing to do is run a line from each to a catch can. Make sure the catch can has an outlet (breather) and don't forget to block the port on the intake manifold or you'll have one very nice size boost/vac leak.

Megan Racing actually has a very nice polished catch can for this application.
Catch Can

Dave

If you can try to avoid just tossing a filter on because it tends to spray the whole engine bay with oil

 

[SBstar]

Do a search on this...Personally I ran a catch can and according to my logs and everything it ran just fine. However, there are some who will argue (and have a point) that there are issues with running it this way.
1. Unmetered air, much like venting your bov, the MAS/MAF thinks that air is coming back into the intake, which can cause issues.
2. The pcv has vacuum at idle which pulls that crankcase pressure out, running a catch can only system does not provide any vacuum and supposedly will not pull enough pressure out of your crankcase.

I'd post some threads for you but I've got to get to bed. Perhaps I'll search for them in the morning.

 

[MrBoxx]

I prefer the in-line filter solution to prevent blow-by from getting into the intake tract. The filter will let you see how much oil gunk you accumulate over time, which can alert you to potential problems. They're cheap (3.99 or so) and can be found at ANY auto parts store. Ask for a Fram G2 (or equivalent) style filter. Takes two minutes to install.

Try checking the turbo for shaft play again. Wiggle the compressor wheel up, down, side to side, and most importantly, in and out. Any in and out play means the turbo is failing. Any noticeable side to side or up and down motion means that the turbo MAY be failing. On a sleeve-bearing turbo, a small amount of play is necessary, but you should barely be able to feel it.

Recirculate the BOV.

 

[Defiant]

Install a catch can for your DSM (2G)
http://www.dsmtuners.com/forums/pro...-cleaning-ic-merged-11-7-clean-smic-fmic.html

 

[DKneble]

Sharing what I have been told here since I have not personally run the inline filter route but the opinion among the guys here at the shop and I seems to be that the inline filter would be the cheapest and quickest solution. Also, probably the most practical for a daily driven close to stock vehicle.

However, for highly modded, high boost applications the catch can is preferred since getting rid of hot air in the intake takes priority. This is also where the unmetered air issue isn't really an issue since the tune would account for that and a pseudo pcv valve would take care of getting rid of the excess crank pressure.

Dave

 

[Meklo_4G63t]

Okay im back with better results.....I took the intercooler of and got at least a 1/4 inch or so oil outta there. I think its been since the previous owner. And cleaned it with isopoloral(excuse my spelling) achool and let it sits a day and got the rest of the gunk and waited a couple hours to put it back in. Also I droped my oil pan to be on the safe side and cleaned it and restored the engine with some 10-30w castrol. She runs dam good now for a stock car.

To the guy how wanted me to check the turbo..I did no shaft play and the blades are fine on the TD05. I thought that it might be the bearing failing but I dont know. I still want to do the catch can because this engine is about to get overhauled.

 

[SBstar]

I think the best possible reason I've found to get rid of the pcv is because even brand new they leak...you can use a cheap plastic alternative type valve that supposedly doesn't leak but I have yet to try that since the dsm is now parts. If you have the ability to tune the car properly it does make it nice to run the breather into a catch can as it keeps that oil and hot air out of the intake tract.

 

[99GsxMD]

Well, i have been reading up on most of these posts and see that alot of them say blow seals on the turbo, etc.

I am getting a catchcan filter to put on but i need to find somewhere i can get one, anyone got a link to one?

Also what other ways do you all think that i could get gettin oil in my BoV and Intake? Any ideas? If so what are they and how can i fix them?

 

[snowborder714]

If you have oil in your intake pipe, it could be getting there from blow by from the valve cover vent line. As for the bov, I have no idea.

And yes, it's possible to rebuild a turbo. But, if you're still on the stock one (which it looks like you are) and you have a bad turbo, it might be a good time to upgrade to something a bit bigger.

I recommend using a Husky air filter as an inline catch can.
Home Made Oil Catch Can Photo Gallery by AZ Solo at pbase.com

 

[99GsxMD]

If you have oil in your intake pipe, it could be getting there from blow by from the valve cover vent line. As for the bov, I have no idea.

And yes, it's possible to rebuild a turbo. But, if you're still on the stock one (which it looks like you are) and you have a bad turbo, it might be a good time to upgrade to something a bit bigger.

I recommend using a Husky air filter as an inline catch can.
Home Made Oil Catch Can Photo Gallery by AZ Solo at pbase.com

What i meant is rebuild engine , i know you can replace and rebuild turbo. I prefer to upgrade my turbo if i am going to do anything, not rebuild a crap t25

 

[diablos991]

When my t25 slowly went, oil was leaking past the seals through the piping and ultimately some would make its way out the BOV and in the combustion chamber.

Shortly after I upgraded due to the seals severely failing.

 

[kenamond]

A small amount of oil will get blown out the VC breather and into the intake pipe. That oil gets propagated throughout the intake including the BOV. If you have a lot of oil in the intake, it may be a few things. If the turbo compressor seal is leaking, that will put a lot of oil in the intake, but you'd probably see blue smoke out the exhaust while boosting as the motor burns that oil. If the crankcase is being over-pressurized, then you could be blowing more oil out the VC breather. That would be due to either ring sealing issues (worn rings, broken ring land, burned piston), or bad PCV valve.

You can filter the VC breather air with the suggested Husky filter. If you boost leak test, you can see if the PCV valve is leaking (causing you to boost your crankcase). Once you have a filter on the VC breather, you can clean out the intake pipe, compressor (as much as you can reach), and LICP. Run it for a bit and then inspect the LICP/compressor outlet again for new oil. If you see more oil, I'd suspect the compressor seal.

 

[Mobile_DSM]

Yeah your turbo may be taking a shit, but if you still have the vacuum/emission line from the valve cover to the snorkel, you'll get oil in the i/c that way too. I wouldn't suggest putting a filter on the valve cover itself though. It will get saturated in oil and drip down making a mess in your engine bay.

 

[kenamond]

Yeah your turbo may be taking a shit, but if you still have the vacuum/emission line from the valve cover to the snorkel, you'll get oil in the i/c that way too. I wouldn't suggest putting a filter on the valve cover itself though. It will get saturated in oil and drip down making a mess in your engine bay.

If you put a filter on your VC breather line, it should still connect the VC breather to the intake pipe or you'll suck unmetered air into the system under vaccuum. The Husky filter is clear, so you can see if it's saturated or not. You could also get an *in-line* catch can with a filter, too, but that costs a lot more than a $5 filter. And the VC breather line isn't an emissions line; it ventilates fumes from the crankcase under idle, and it relieves crank case pressure under load.

 

[Meklo_4G63t]

Hey I got the whole assembly that looks like a catch can but i hope it will match up. I had the got the the hardware section for k-mart (not laugh) and it was dirt cheap since they got a 60% off sale. Because of that I will have to let you know tomorrow because the old lady said in there shoping till dark on my ass.

 

[Meklo_4G63t]

those of us that aren't so emissions freindly, just run lines to nothing that sit down in the engine bay. In NC its a visual inspection for any car prior to 1996, most of the time they don't know what they go to, or really care (its a cheap alternative) just my 2 cents

i forgot about that and they dont inspect up here and I know they dont do it back home in SC they got rid of that years ago. I think they still have the smog law though

 

[Defiant]

http://www.dsmtuners.com/forums/151359618-post8.html