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Brockoli

So my car went through 3 liters of oil in 700 miles!!! there might be a problem.

Everywhere I park I leave oil drops, not much usually the size of four dollar coins

.

However there is oil all over my driver side motor mount (which is great because I just got a new one made of unobtainium), and clutch cable mounting bracket.

I think there is something wrong with my evaporative emission control (EEC) system.

Here comes the questions....

Heres part of the problem (thats way too much oil in the air box)...

What is this supposed to be here and why is it plugged off? Can it stay like this or is something seriuosly missing! I talked to Chrenan about this but I cant remember what we came up with.

Why does my other engines intake manifold have it blocked off?

If my car didnt come with an EEC control valve as seen in the haynes manual, then how does it work without it? Especially item 13 in the haynes diagram (page 102, or see pic below).

What is this (PVC valve?)...

Also, I got rid of my EGR valve. I made an aluminum plate that bolts onto where the EGR valve used to be. Is this causing a vacuum problem that is causing all that oil in the air box. I blocked the vacuum port that the EGR valve should be attached to in the vacuum amplifier(?)(the thing that is on the passenger side fender that is attached to the vacuum resivor)

I talked to my Uncle who is a heavy duty mechanic and he said that the charcol canister will pull fume from the gas tank to the intake manifold and burn them. And that the oil that is coming out of the crankcase into the air box is because the vacuum system is not right. Air should be drawn into the crank case from the air box.

Hopefully that is enough detail, I dont think I missed anything.

I bought an aftermarket oil catch can (just like Chrenan's) I dont want to install it yet because I think there is more wrong than normal oil blow by.

Please help, I cant drive my car!!!
_________________
'80 924 M471,Wideband O2, Full coilover susp,23/19 sways,Bilstiens,KLA Strut Brace,Roll Bar,Test Pipe,BBS RS, Willwood BBK

25% of a '87 944 Chumpcar http://straightpipe.ca/forums/showthread.php?t=2454

'79 924 Sebring Edition(Sitting)

Lizard · Posted: Tue Oct 07, 2008 1:25 pm Post subject:

Do a leakdown test on the engine.

From the looks of your air filter you are pushing ALOT of oil out of your crankcase. The only thing that is causing this is 1 of 2 things, EXTREMELY worn rings, or overfilled oil.

Start with a leakdown test and let us know how much the rings are actually sealing.
_________________
3 928s,

Brockoli · Posted: Tue Oct 07, 2008 3:42 pm Post subject:

Is a leakdown test the same as a compression test?

If so I have doen 2 of these tests, 1 when I unsized the engine(it hadnt been run it at least 8yrs) and one after driving it for a bit (~25-100 miles and lots of idling time).

first test:
(cylinder/psi)
4/80
3/90
2/120
1/110

second test:
4/125
3/130
2/140
1/120

These numbers make sense because since the engine had not been turned over let alone run in a long time things would be dry and stiff. And after letting the engine wear in a bit the numbers are much better.

If my rings were really bad wouldnt I have a blue smoke coming from my exhaust, especially when starting up a cold engine, and when accelerating hard. I definetly have a pretty clean exhaust, if any thing it smells a little rich on fuel (I try not to smell my exhaust a lot, put it makes me feel sooo good

)

Also if my rings were bad I was burning oil I wouldnt know where it was going. I have a lot of oil on my oil pan/motor mount/tie rod/underneath the car/on the entire exhaust/ its everywhere.

I defintely do not over fill my engine with oil. I once had a friend over fill his POS sunbird and it took out the engine.
_________________
'80 924 M471,Wideband O2, Full coilover susp,23/19 sways,Bilstiens,KLA Strut Brace,Roll Bar,Test Pipe,BBS RS, Willwood BBK

25% of a '87 944 Chumpcar http://straightpipe.ca/forums/showthread.php?t=2454

'79 924 Sebring Edition(Sitting)

leadfoot · Posted: Tue Oct 07, 2008 4:32 pm Post subject:

EEC were standard on 1980 above yours is a 79?
the capped port on the manifold is for the air pump I think, later models did not use it or the vaccum amplifier.

Start by cleaning all the parts, and checking for blocked hoses.

A quick and very cool looking thing to do is to replace all the hoses with clear plastic ones. This shows you the way that fumes move around the engine bay.
They warm up and go soft but are ok under a little heat. Best to do this only for testing purposes.

Stu.
_________________
1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

Lizard · Posted: Wed Oct 08, 2008 4:12 am Post subject:

The oil in your airbox can ONLY come from this

that is the crankcase vent.
If the rings were really worn it is likely to have alot of blue smoke but not 100% improbable to consider it out of the question as the oil scaper rings could be doing a good job of getting the oil off the walls so it isnt burnt, but the compression rings could still be partially siezed.

And a leakdown test requires an air compressor and is far more informative then a compression test.
_________________
3 928s,

Brockoli · Posted: Wed Oct 08, 2008 10:00 am Post subject:

leadfoot - I think you mean EEC control valves were standard on 1980 and on. My car definetly has an EEC system. If your car has a charcol canister it has an EEC system, which I think is every north american car. Good idea with the clear hoses. I will definetly check for blockages.

Lizard - How can the compression rings be partially siezed? I have put 5XXX miles on the car since I got it running. Does that crankcase vent have a valve in it? Is it like a PCV valve? How do you preform a leakdown test, my dad told me awhile ago but i dont remember.

The fumes in gas tank and crank case go to the charcol canister and then get mixed with fresh air and are burnt in the engine to reduce hydrocarbons. (there is more detail in the haynes manual) My big question is how do fumes that are trapped in the charcol canister make it to the air box? There isnt a line going directly from the charcol canister to the air box. Only a line that goes from the charcol canister to the crankcase vent, where there is that T and then to the air box. How does the fumes go left at that T to the air box instead of going into the crankcase? Im really confused....
_________________
'80 924 M471,Wideband O2, Full coilover susp,23/19 sways,Bilstiens,KLA Strut Brace,Roll Bar,Test Pipe,BBS RS, Willwood BBK

25% of a '87 944 Chumpcar http://straightpipe.ca/forums/showthread.php?t=2454

'79 924 Sebring Edition(Sitting)

!tom · Posted: Wed Oct 08, 2008 10:24 am Post subject:

Brockoli · Posted: Wed Oct 08, 2008 10:29 am Post subject:

that makes a lot of sense, I forgot about the running engine causing vacuum in the air box

_________________
'80 924 M471,Wideband O2, Full coilover susp,23/19 sways,Bilstiens,KLA Strut Brace,Roll Bar,Test Pipe,BBS RS, Willwood BBK

25% of a '87 944 Chumpcar http://straightpipe.ca/forums/showthread.php?t=2454

'79 924 Sebring Edition(Sitting)

Lizard · Posted: Wed Oct 08, 2008 1:19 pm Post subject:

that has no vent in it, it has a hose which goes straight from it to the airbox. And this is what is carrying the oil to the airbox, regardless of vacuum. If you have that much oil something is causing it.
_________________
3 928s,

leadfoot · Posted: Wed Oct 08, 2008 1:53 pm Post subject:

Yes EEC control valve... the one with the vaccum port that sit in front of the firewall near the battery/ charcoal cannister.

The charcoal cannister also has a vent line to draw in fresh air. If this is blocked I'm assuming it will suck air straight through into the airbox as it is essentially running in a closed loop and not mixing as it should.

Stu
_________________
1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

Brockoli · Posted: Thu Oct 09, 2008 4:49 am Post subject:

i think there must be a blockage somewhere in the lines that go to the charcol canister. I plan on replacing them all with new ones. I was thinking of using the colored plastic/silicone ones. But i dont know if these will collapse under vacuum. I saw someone on the board with blue ones.
_________________
'80 924 M471,Wideband O2, Full coilover susp,23/19 sways,Bilstiens,KLA Strut Brace,Roll Bar,Test Pipe,BBS RS, Willwood BBK

25% of a '87 944 Chumpcar http://straightpipe.ca/forums/showthread.php?t=2454

'79 924 Sebring Edition(Sitting)

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

Slam · Posted: Thu Oct 09, 2008 5:21 am Post subject:

What you're pointing to in your second pic is the intake valve for the air pump system, so blocking it off (leaving it blocked in your case) is a good idea. California cars have this.

You know one thing for sure - your crankcase breather isn't clogged! I'd say you've got lots of blowby. EEC won't scavenge the crankcase.
_________________
'84 944 - kid blew motor
'83 944 - resting comfortably. For 12 years
'87 944 - sideswiped by trucker
'80 924 - gone
'78 924 - gone
'77 924 - rusting comfortably

Brockoli · Posted: Thu Oct 09, 2008 5:37 am Post subject:

ideoal - thats definetly the engine i was looking at. I sometimes look at sooo many engine bays i cant remember whos is whos. Thanks for the info, hopefully one of mine is blocked and replacing the lines fixing it. If not at least they look cool

slam - i think the EEC does scavenge the crank case, I thought fumes from crankcase and gas tank are burt. Crankcase fumes mix with gas tank fumes at that T thingy on the block and pulled into the airbox. Or am i wrong???
_________________
'80 924 M471,Wideband O2, Full coilover susp,23/19 sways,Bilstiens,KLA Strut Brace,Roll Bar,Test Pipe,BBS RS, Willwood BBK

25% of a '87 944 Chumpcar http://straightpipe.ca/forums/showthread.php?t=2454

'79 924 Sebring Edition(Sitting)

Brockoli · Posted: Mon Oct 20, 2008 8:25 am Post subject:

so i finally had time to do a compression test,

May '07 ( just got the engine running, it was sitting for who's knows how long):
80 90 120 110

July '07 (couple hundred miles on the engine);
125 130 140 120

Oct '08 (dry comp test/wet comp test);
95/120 105/115 130/130 100/100

So, I havent done a leak down test yet, but its pretty clear my enigne is a little tired. I dont have the time (yet...) to rebuild it so I am just going to drive it the way it is until I have the time/$$$ to rebuild it.

Until I rebuild it I need to fix the oil blow bye problem. I bought an oil catch can from chrenan and want to install it to relieve the pressue built up in the crankcase. The instructions that came with it say the input on the can should be attached to the valve cover and the can should output to the intake manifold. I believe this is too have the vacuum from the intake manifold pull the fumes from the crankcase and burn them into the engine. However, How can I access fumes from the valve cove. Or do I have to?

My uncle said to tap/drill a hole in the valve cover and install a fitting to vent the fumes, But i dont really want to drill the valve cover and there is a lot of oil splashing in there from the cam that I dont want oil pouring into the catch can. There isnt a flat spot on the valve cover either. I was thinking to vent the top of the crankcase into the can instead of into the intake box.

this is what I plan, to run the crankcase vent that is at the top of the crankcase into the catch can, and then the catch can into the intake by splicing into the vacuum line that goes from the intake to the brake booster. Will this work and help relieve the pressure? Will this cause oil to go into the brake booster? I dont think it will hurt the brake booster because the vacuum is sucking into the intake and not pushing anything into the brake booster.

ANy help/comments would be very helpful!
_________________
'80 924 M471,Wideband O2, Full coilover susp,23/19 sways,Bilstiens,KLA Strut Brace,Roll Bar,Test Pipe,BBS RS, Willwood BBK

25% of a '87 944 Chumpcar http://straightpipe.ca/forums/showthread.php?t=2454

'79 924 Sebring Edition(Sitting)