Differing compression readings, Help

[jonnys303]

So I blew a head gasket a couple weeks ago and decided to pull the motor and do front, rear seals, clutch and timing belt. Well I'm 98.9% sure timing was set correctly but when everything went back together It would not start. I Verified spark as well as fuel both are present, so then tried to check compression on #1,2,3, and 4 cyl. the first go around I only got like 30 psi on #1 and 2 then around 40 psi on 3 and 4. 2nd time around I'm getting like 80 psi on all 4 cyl. I'm dead in the water, and fresh out of Ideas. Can someone Help Me. PLEASE!
Thanks Jon

 

[icekilla126]

do any work to the pistons?

 

[jonnys303]

No, didn't do anything with the pistons checked the cylinders for damage they looked fine but now I'm worried that I could have jacked up rings. there was no debris in the cylinders everything looked ok. Any Idea?

 

[LongJonSilver]

Did you remove the pistons? make sure your new head gasket is torqued down correctly? Did you bend any valves?

 

[clockworktoy]

Did you get the head resurfaced before slapping it back on? And did you try adding some oil during the compression test to see if your compression shot up?

 

[jonnys303]

I scraped & cleaned head surface made sure I followed tightening sequence and tourque specs. Pistons were never removed and as far as oil All I did was refill. The flywheel cranks, and from time to time you can feel a sputter from the exhaust its just not exploding like it should. Do I need to add oil other then to the obvious "oil Pan"?
Thanks

 

[jonnys303]

Oh, and as far as the valves go I checked the head when I removed it and stroked the valves, everything seemed fine to me.

 

[icekilla126]

are the compression reading consistent in any of the cylinders??? What i mean by consistant is you test cylinder #1 and get what ever you got and tested it agian and got somthing different. If you have no consistency any of the cylinders i would suspect that your timing isnt right. Hope this helps

 

[jonnys303]

I don't know that I would call the readings consistant because the 1st go around comp. was about the same in cyl. 1 & 2 were about 30 psi and 3 & 4 were about 40, 45 psi. Then I checked them again and I got roughly in the area of 75-90 psi through 4 cyl.

 

[icekilla126]

Ok try and pour a lil oil into the cylinder and do a comp test and see if it goes up. If it goes up the rings need replacing if not i would redo the timing again.

 

[jonnys303]

I'll try that, thanks! Icekilla126 ## help is appriciated.

 

[1stGenTSi]

Pour a capful of oil down each spark plug hole. If rings are worn then compression should go up quite a bit.

 

[LongJonSilver]

Did you have the head resurfaced? Did you reuse the bolts/studs because most likely if u resued the head studs again they are most likely stretched and not sealing properly.

 

[jonnys303]

OK, so i stuck a screw driver in #1 cyl. watched the timing marks on my cam's, I'm at TDC. I poured a cap full of oil in #1 cyl. and checked compression again, 70 psi again. So I guess my rings are fine because there was no difference in compression. Is it possible that the crank could be 180 degrees off? It doesn't seem like it would matter, I'm at TDC with all marks lined up. I don't know what else to try. Suggestions are very much appreciated

 

[BoredDSM]

You would have to perform a leak down test to find out exactly what it is. Did you reuse the head studs? That could be your main problem now allowing to seal correctly. That would also be the easier fix if you did reuse them cause all you would need is just a new set of head studs. Only other possibility is if your head is warped beyond repair.

 

[jonnys303]

Man, I hope it's not a warped head, But yes I did use new head bolts when I did the head. A friend at work insists that the timing is still off he thinks the crank is basically 180 degrees off or one full revolution off. Could that cause problems in relation to the crank positioning sensor?
Thanks Jon