Please help me figure this out

B

BARRACUDA1968

Well-Known Member
Joined
May 4, 2011
I know there's a thousand PCV threads but I have the same problem on 2 different engines so there's something I'm missing.

I have a fresh motor, both motors had breathers in both valve covers, old motor had good cylinders and rings and of course so does new motor. Both motors using the same PCV valve and it functions properly.

I use a catch can on both motors. PCV to catch can then to vacuum port. Hooked up correctly.

I keep smelling oil and it's not from leaks on either engine.

This morning I started the car in the driveway, visited with the neighbor for a few minutes and had a little smoke out the tail pipes while it warmed up. Drove to work and no smell. I'm convinced I'm sucking oil through the PCV in the motor somehow?

Drove the car last night about 40 miles, did some 15 psi pulls and the car runs great. Didn't really smell any oil last night but my catch can had oil in it this morning. Maybe 2 to 3 ounces. I'm bummed after only 40 miles. Both motors did this so I have to look at something other than engine related.

Here is the PCV I'm using. The black one on the right. PO installed it and I have no idea where he got it either.



Bottom view, the other PCV's came with the car in a box. AC Delco CV 893 and AC Delco CV 893 C I've tried them and the car will barely idle.



Top view



Why does this black PCV work and what I'm assuming is a factory AC Delco PCV won't work? Is this black PCV creating a lot more vacuum because of the smaller ID causing more suction in the valley pan area which is grabbing oil out of the motor?

If that's the case I would also wonder if that extra vacuum would hinder the catch can holding the oil that's being sucked out and allowing some to get in the intake?

Hopefully someone has been down this road and knows what I should do next. I'm tired of this problem.

Thanks Brett
 
Do these motors have the correct valley pan??
The 893's should work. I use a puralator PV893 in my GN's and they work perfectly. Why yours don't work? Maybe the tun is far enough off at idle to make it seem the PCV is the faulty issue.
Since your still running a MAF, I'd suggest a very close look for any vacuum leaks and the tune in your translator and/or chip for the idle area.
 
The old motor had the metal valley pan and the new motor has a rubber/paper type valley pan I got from Husek. Only difference between the 2 is the new one is a little thicker.

I set the translator per the instructions and went over all vacuum lines and CAI again last night. Won't hurt to go over it again.

If I go from the black PCV to the AC Delco the car acts like I have a huge vacuum leak. Have you ever seen this black PCV before? This thing really zings the air when hooked up. Better than my shop vac!;)
 
That seems like a lot of oil for a short trip. Rings not seated yet and too much crankcase pressure at cruise?
 
Tried the A/C Delco again after checking for vacuum leaks. No leaks I can detect. Thought maybe a small leak but figured out it is just how the car wants to idle. I just happened to time the carb cleaner at the same time as the sporadic idle.

Car started and idled better than the old engine would but idle is sporadic. WB goes 13.8 to high 16's once in a while then would settle somewhere in the 14.7 range, back and forth. Temp was 160. Keep in mind I have not touched chip setting other than increase timing 1 notch to turn off timing delay. Not sure I can do much with chip settings anyway.

I will try the A/C Delco PCV. I'll empty catch can and go for a drive to see what happens. Never got that far on the old motor. I think the smaller PCV ID was to prevent oil from entering in to the system but in turn would increase velocity because of the smaller ID.
 
we4Mateo said:
That seems like a lot of oil for a short trip. Rings not seated yet and too much crankcase pressure at cruise?
Click to expand...

Well I have 400 miles on the motor and I did the 10 psi pulls like Husek said and kept doing it on a regular basis. Moved up to 15 psi last night. I used a regular oil, no synthetic, primed the motor before start up rotating it 90 degree's after each prime etc. I really followed the book so I'd have a healthy motor.

I agree about the oil in the catch can. I really shouldn't have any. I can't imagine that the rings are not seated? But I guess if there not by now they probably won't.

The only thing both motors have in common dealing with this issue is that black PCV. If that's not it I'm out of ideas.
 
Try restricting the size id of the line to the catch can.
 
mikestertwo said:
I moved my PCV valve up to the right valve cover. Problem solved.
Click to expand...

Are you running stock valve covers? I'm running aftermarket with no splash shield. Not sure if they make a grommet for PCV like they do for breathers to block oil? But that's another good idea. I did that on my 474 Pontiac and have no issues with that motor but it's a whole different animal.
 
The black plastic PCV looks like the one Eric recommends from Auto Zone. Being plastic mine broke in half when I tried to remove it. I think it was already broken from the heat. It was full of oil. Went back to the metal GM valve.
 
I've been running the AutoZone (black plastic) PCV valve for years with out issue. I also have an AMW catch can installed on the PCV system & use the normal 3/8" PCV hose. You must install a check valve in this line or you will pressurize your catch can under boost conditions, which could be causing the symptoms that you are seeing. US Plastics has a 3/8" hose barbed Kynar (PVDF - high temperature thermoplastic) that is a low crack pressure check valve that is inexpensive & works well.
The check valve is placed in the out line of our catch can somewhere before it returns to the plenum. Believe the part number is 1162 at AutoZone & is made by Luberfiner. I know a lot of other members are using this PCV valve with no problems. When I did my research on this PCV valve several years ago I found Eric Marshall & Bob Bailey both were using it , so I gave it a try & found it worked great! Just be sure to check them by blowing in the to be sure they seal in one direction & function proplery in the store before leaving as I have found many are defective.

http://www.accmachtech.com/PCVCatchCanInstallationInstructions.pdf
 
Looks like we are having the exact same issue Barra. I too am wondering if the smoke from my tailpipes has something to do with pcv or oil leak.
 
I have been using the ATR and RJC style pvc's for many years without problems. Soon as i pop in ac delco pvc, I get problems. Might have something to do with our different cams and vacuum IDK. I know they dont totally seal under boost and your going to be running higher psi too.
 
It is a miss conception that oil gets pulled through the pcv under boost. It happens under vacuum. The most vacuum happens at idle and deceleration. Thats when vacuum is the highest. Thats when oil gets pulled in. New motors have more vacuum resulting in more oil being consumed. The rings are sealed just fine. Like mentioned restricting volume through the pcv would help.

Rick
 
TT/Ameasap said:
I have been using the ATR and RJC style pvc's for many years without problems. Soon as i pop in ac delco pvc, I get problems. Might have something to do with our different cams and vacuum IDK. I know they dont totally seal under boost and your going to be running higher psi too.
Click to expand...

The RJC pcv is actually spring loaded resulting in less volume. Those guy's at RJC know their stuff.

Rick
 
Thanks for all the information! I had a metal check valve on the system just like described but it went south so I eliminated it. I emptied the catch can last night and drove the car 30 miles round trip to play golf. Did 2 15 psi pulls. One concern I have about seating the rings is I'm probably washing the cylinder walls down doing these pulls. I go 10.0 instantly when boost comes on. Alky on 6. I have no idea if it's 10.0-9.5-9.0 afr? Gauge only goes 10.0. Don't I need some heat in the cylinder to properly seat the rings? I had 0.2 knock at 63 mph and SM was way in the 800's. 63 mph would have been about when boost started to build. Could just be a fluke but if I need to get some heat in the cylinders don't I need to lean this thing out a bit? I bring this up only because unseated rings could be part of my problem or not?

Smelt oil vapor all the way to work this morning just cruising, pulled 3 cc's of oil out of the catch can from a 30 miles drive (mostly highway speeds) and 2 15psi pulls. I do have the AC Delco PCV in the car now. Car don't idle near as well as it did with the black PCV.

What I can't figure out is how in the world does oil make its way in to the PCV system that easy with the valley pan?
 
m3x1c0 said:
Looks like we are having the exact same issue Barra. I too am wondering if the smoke from my tailpipes has something to do with pcv or oil leak.
Click to expand...

Typically and oil leak will give you the smell if it's landing on something hot like exhaust but wouldn't have anything to do with smoke out the tail pipe. Now if you're sucking oil in to the intake then you'll have smoke out the tailpipe if it's sufficient enough. I would work real hard on getting the oil leaks under control and also get your PCV system working right before you do any else. I feel your pain believe me! One thing I can't deal with is smelling oil, then oil leaks a close second. Drives me nuts :eek:
 
And alky will always limit the heat you generate but I would do some tuning and try to get those 15psi pulls a bit leaner. Your rings are probably seated fine by now. I think you are generating a lot of vacuum and pulling oil through the pcv system. Better use a more restrictive pcv as well as a check valve between your can and tb.
 
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