Compression Results

[malucifer]

Well I finally got my Laser running (1990 RS Turbo) after a year of sitting WTF I hooked up my 3" Turbo Back exhaust and started it up. While idling the car would slightly start smoking (white, almost no smell to it, although it wasnt sweet smelling) after warming it up and giving it some rev's smoke was pooring out like crazy. I decided to pull out the compression gauge and get to work. First I noted that 2-4 spark plugs looked like they were burning great, spark plug 1 however had oil on it, this is where I believe the smoke is being caused from as the corresponding runner on the manifold had oil caked in it as well. Secondly the results from the compression test were as follows.

Test #1
Hot Test - Cracked Valve Cover
1)124
2)90
3)128
4)126

*NOTE* WOT and non WOT test were the same results?!? Can that be explained to me?

I didn't know if the cracked valve cover would affect the results so I changed the valve cover with a new one and redid the test.
Test #2
Probably not that hot considering I took a little break in between and changed the valve cover as well.
1)126
2)100
3)132
4)128

Now here is the thing, the car has no noticable performance issues it actually idles perfect and runs strong as hell. Anyone have any suggestions as to why my results are like this?

I haven't done the WET test yet but im assuming the leaking (Valve seal?) on 1 is why it hit near the same psi as the others.

Any help would be greatly appreciated. James...

 

[pj91gsx]

Sounds like you have a blown head gasket. Did the smoke go away? The service limit is 120 compression. What did you do to this car? Did you change the oil before storage?

 

[pj91gsx]

Sounds like you have a blown head gasket. Did the smoke go away? The service limit is 120 compression. What did you do to this car? Did you change the oil before storage?

*NOTE* WOT and non WOT test were the same results?!? Can that be explained to me?

Throttle has nothing to do with compression tests.

 

[malucifer]

Yeah I didnt expect throttle had anything to do with it(Even though my manual and almost all online guides say to do it) After the long sit (turned out to be a dead ecu) I replaced the oil filter and oil with Lucas motor oil, filled the coolant, cleaned my air filter, filled the tank and put injector cleaner in it. It wasnt smoking before the dead ecu problem. And the smoke I'm really thinking its from the 1st cylinder oil problem there is a "slight" hint of an oil smell in the smoke. The smoke as mentioned before is very hard to see while idle but as soon as I give it a bit of rpm's it'll start smoking profusely. And after 25 minutes the smoke still refused to dissipate. Thanks for your response. Any clues as to where I should go from here? I live in an area where they dont even know how to remove a turbo without looking it up first....so any garage specific methods are almost out of the question.

Also I pulled my oil pan plug slightly enough for some oil to come out it didn't look milky at all. I love dsm's and their sense of "humor."

 

[boosted86]

your next best bet is to do a leak down test so you can see where your loosing compression from.

 

[1992awdlaser]

Do a leak down test. Being wot will make the numbers on the gauge go up quicker.

 

[malucifer]

Do a leak down test. Being wot will make the numbers on the gauge go up quicker.

Ahh now I know what its for thanks. Ill do what I can and post back. Ill have to make a leakdown tester myself I guess because the garages here are all say a what?

 

[1992awdlaser]

Can you disconnect the gauge from the hose on the compression tester you have?

 

[malucifer]

Yes I can disconnect the gauge from my tester. I just ran the WET test across the board
1)190
2)150
3)202
4)200

So does this mean rings? And why is 2 still acting strange? Albeit a large jump in pressure still way lower than the rest. Thanks again for the replies.

EDIT:This wasnt a full warm test either Im afraid to run the car for that long right now.

 

[1992awdlaser]

Do this with the gauge disconnected from the tester(should have an air fitting on the hose:

1.Take the valve cover off
2.Rotate engine until cam lobes of cylinder #1 are pointing up.
3.Put air into the cylinder.
4.Listen to the intake manifold and the exhaust. If you hear air in either your valves are leaking.
5.Repeat on the other cylinders.


The wet test isn't accurate with the psitons we have. Our pistons have a dish on top and the oil will sit in it which will make the compression numbers always go up.

 

[malucifer]

Alright Ill give that a shot and would putting air in the cylinder with just a tire pump(12v lighter) provide enough air to do the test? I dont have an air compressor unfortunately. Thanks again for the continued help 92.

 

[1992awdlaser]

It should be enough. Just wait until it builds some pressure. Glad to help.

 

[malucifer]

Btw this is the tester I have is this.

NAPAONLINE®

It seems that the top doesn't unthread without breaking the sealant they used to hold it together...(Bangs head) any other easy way to put air in the cylinder?

Sorry and again thanks for the help.

 

[malucifer]

Well I was told of a nice sealant quick fixer (Block Seal from K&W) I decided to give it a shot and well it seems to have worked for the smoking issue, it smokes less and I believe it is only smoking now because the runner is still coated. Also I redid a compression test today and Cylinder 1 is now down to 100 which makes me think there is no longer oil sitting on top of the piston to raise the compression(was 126) so that is a good thing. Bad news is still low compression on 1 and 2 and 3-4 are just above service limit. Im thinking it was just the seals that were causing the leak on 1 since it seems to have desisted. Any ideas how I can get air into the cylinders to check for a leak being as my gauge doesnt come off and I have no shops that have a clue about a leak down test. Thanks James..

 

[1992awdlaser]

AutoZone.com | Shopping | Accessories | Product Detail - Actron Compression Tester Kit

That is how I was talking about it coming apart. It has a quick disconnect air fitting. The only problem would be figuring out a way to get your pump to hook up to it.

Autozone and Advance have a fitting that screws in place of the spark plug that an air hose hooks up to. But, you would have to figure out a way to hook it up since the spark plug wells are recessed into the head on these cars.

 

[malucifer]

Ahh I see too bad I cant return this 48.00 pos. Ill have 2 broken air compressors in the garage perhaps I can steal a gauge and make a leak down tester any good guides you know off hand for a custom leak down tester? Thanks again 92.

 

[1992awdlaser]

I just searched google for you. Everyone I see requires a hose like the one from the compression tester I was talking about and some other stuff. So, it would just be cheaper to buy that kind of compression tester and test it how I described.

 

[malucifer]

Alright thanks alot man, I guess I'll have to just grab one. After I get it and do the test I may have more questions.

 

[1992awdlaser]

No problem. Ask away.

 

[malucifer]

Well I believe I solved my compression issue... check the following pics out and let me know what you think (Doh)

http://i95.photobucket.com/albums/l144/malucifer/100_1644.jpg

http://i95.photobucket.com/albums/l144/malucifer/100_1646.jpg

http://i95.photobucket.com/albums/l144/malucifer/100_1650.jpg

So can anyone tell my how this could happen, its in between the #3 and #2 cylinder (Exactly between from what I seen)

And where is the best place to get Cylinder Heads for our 4g63's? And would it be worth it to get a 3-5 angle valve job at the same time for it? Sorry for the troubles but this sucks

 

[1992awdlaser]

That hole is supposed to be there. Any 6 bolt head you get will have that, 7 bolts might also.

 

[malucifer]

Oh my, I thought it was supposed to be there at first the damn thing has burs all around it like something mechanical shot through it. Strange well if its supposed to be there then all is not lost. Thanks again 92.


Quick Edit sidenote:

I purchased a universal valve spring compressor and well it doesnt fit very well in there, any ideas on the best way to compress the springs while the head is still on? (Damn you 16v in a small head) Thanks again.

 

[1992awdlaser]

Oh my, I thought it was supposed to be there at first the damn thing has burs all around it like something mechanical shot through it. Strange well if its supposed to be there then all is not lost. Thanks again 92.

That's what I thought the first time I took the valve cover off my car too.

 

[dsmrookie87]

hey whats up guys, I just did a compression test on my dsm here are the numbers...

169....149...129.....139...

should i be worried?? rebuilt maybe?? swap??

the car runs good and strong, no smoking whatsoever.

need some help?? thanks