1995 GSX Smoking and cant figure out why...

[Milosis]

Hey guys, Ive got an annoying problem and Im thinking about attaching C4 to it.

Ive built a 1995 eclipse GSX and installed a fully built 6 bolt AMS 2.3 stroker motor along with a fully built head. All the fuel upgrades and cooling upgrades installed. I went and bought a forced performance 3575 turbocharger and installed it.

Now for the first 50 or so miles it ran great, as great as an untuned car can run that is.. And then it started smoking crazy like. I figured somehow a new headgasket just blew and replaced that.. Seeing how that ment taking the head off, i went ahead and had my head guy tear it down and rebuild it to see if anything was off, valve seals, guides etc.. And it all came back with a clean bill of health.. So I put everything back together and started it back up, and still have the same problem.. So I called auto motor sports(AMS) in illinois and asked why and how this could happen..(Pretty broad question I know. At this time Id already performed a compression test as well as a leakdown test.. 150 accross the board! New motor checked out good..) I asked them about blowby and they told me that the motor is going to have blowby, being a 2.3 high output stroker and all.. Goodie, that explains the dipstick popping out.. But it still didnt explain why it smokes like Ive been hired to kill every mosquito in florida...

I looked into any and all means of relieving the harmful gases that were building up in the crankcase and ended up replacing the PCV valve. I have the breather plumbed into the FP intake. Now it wont smoke at startup or idle unless I Rev the motor... Then it wont stop. I pull the turbocharger back off and examine it.. The south side of the exhaust housing has oil coming out of it and its literally draining into the down pipe... Beautiful, Ive got a new turbo that leaks oil. Thats when I went to Forced Performances F.A.Q. read this...

The crankcase vents are the second largest cause of oil loss from a good condition turbocharger. The seals in the turbocharger were designed with expectation that the pressure inside the compressor and turbine housing will always be greater than the pressure in the bearing housing. If this is ever not the case then oil will come out pass the seals. A restricted crankcase vent will cause this to happen. If the amount of ring blowby exceeds the ability of the crank vents to release the pressure positive pressure will build within the crankcase. This pressure within the crankcase can exceed the pressure inside the compressor and turbine housings under some operating conditions resulting in oil being driven pass the seals by the improperly biased pressure gradient across the seal rings. In severe cases it may be necessary to introduce vacuum pumps to deal with crankcase pressure, but these would be very severe high boost applications where even low percentages of blowby produce a high volume of crankcase vent flow.

And now for the questions... How do I check for restricted crankcase vents?.. And whats this talk of introducing vacuum pumps to deal with crankcase pressure? And Will a greddy oil catchcan relieve this pressure build up?

 

[asexton6969]

OK, to start off this is a somewhat controversial subject. I have a 7 bolt that is a stock rebuild nothing major done to it. (16g, 3" exhaust, SSAC FMIC, 255 Fuel Pump) I use to blow the dipstick out all the time. Tons of blowby into my intercooler through the hose from the Valve Cover to the intake pipe. I have tried so many different kinds of ways to release the pressure including take OLDMAN's advice to put a filter in line to catch the fluid. After about 2 or 3 years at this time I have the valve cover hose going straight to a mt dew bottle. The intake capped off. I used to fill the filter with all kinds of "film" and after that I had a bottle in there as well that I could fill up in a day. Im not sure if by modifying my car something has changed but the mt dew bottle I have in there right now. I don't get any blowby buildup within. Continue searching as there are many different solutions and it seems that each car is different. I will try to post a picture so you can see how I had to route the breather for my valve cover.

By the way, where is your oil feed line routed from? Are you coming off of the head, or are you going from the oil pump?

 

[kenamond]

The only way out of the crankcase under boost (assuming valve guide seals are good and your dipstick tube stays put) is the VC breather. If you do like asexton6969 suggests with your VC breather, you can see if it helps at all, but under boost, the intake pipe is lower than atmospheric pressure, so stock VC breather routing should be helping a bit to pull blowby out of the crankcase.

Verify that your VC breather isn't blocked. If that checks out, you might try a larger VC breather line (put a small length of stock size line over the nipples and a larger hose that fits over the stock line and run it between the two nipples). That should help the VC breather flow. If that doesn't work, you'd have to consider the vaccuum pump solution, but I know nothing about that.

I'm under the impression that the nipple in the VC is either press-fit or glued in. If you could get that out, you might be able to add a larger breather nipple. I'd search around to see if you can find out what the inside end of the VC breather looks like at the nipple (it's hidden behind a baffle). The PCV valve has a snorkel protruding into the VC cavity to keep it from drawing in any oil that is running down the walls of the VC, and the VC breather may have something similar. If so, you'd probably want to retain that feature for the larger breather to keep oil out of the breather line.

That's all I can think of.

 

[Calan]

I'm under the impression that the nipple in the VC is either press-fit or glued in. If you could get that out, you might be able to add a larger breather nipple.

Yep... I just pulled one from my old cracked VC to use on a "new" one. Long story short, I ended up destroying the old nipple trying to get it out (I tried finesse, bullying it, heat, etc etc.)

It finally came out, but was in no shape to reuse. YMMV

 

[kenamond]

Yep... I just pulled one from my old cracked VC to use on a "new" one. Long story short, I ended up destroying the old nipple trying to get it out (I tried finesse, bullying it, heat, etc etc.)

It finally came out, but was in no shape to reuse. YMMV

Did you get a sense of whether it was glued, threaded, pressed? I don't like the fact that my 1g VC has the 90* bend in the VC nipple which sends the line in the wrong direction, but the VC cost way too much for me to try removing the breather. Any suggestions on how to get it out if you don't care about the nipple?

 

[asexton6969]

I just wanted to add in that, by no way do I think my setup is "correct." I just have tried everything that has been suggested (even from Wisemen) and my current setup is the only thing that works. However I do think something has "settled" or changed because my other setups would fill up with this thick liquid and now I don't get anything. I have tried to retrace modifications and/or maintenance and I can't determine anything conclusive. My suggestion would be to try a few different setups and just see what works for you.

 

[architechnik]

Does your VC have a metal plate thing that blocks direct flow out?
Mine ('94 GSX) has an indirect route to the breather outlet and when I first purchased it, it was filled with gunk. Mostly old, burnt oil that had been flung up inside the plate and stayed there, but it restricted that actual flow from the line.

Also, if it seems that there is continuously greater pressure on the one end of the turbo, perhaps there is a leak on the exhaust end?

Oh, and check your oil return line. If that is clogged, then it will pump oil in and the only place for it to go is out of the seals, into your exhaust.

 

[Milosis]

Sorry it took a little while to get back on.. Internet being finicky.. I dont think Theres any restriction in the flow from the VC... I made sure there wasnt anything hindering the flow of oil through the turbo, from the oil line going to the turbo and into the return oil line. I just cant seem to hammer this problem down. The turbos fed from the oil cooler. Ive heard that some turbos require an oil restrictor because they can be over fed with oil but when I called forced performance about it they said my turbo doesnt need it.. My only solution is getting the rebuild kit for the turbo and rebuilding it.

If I add an oil catch can will that help reduce blowby pressure? Ive been told that additional venting might be needed for my kind of setup(like drilling holes into the valve cover and installing additional pcv valves.... Thanks for the imput so far fellas