Head Gasket replacement problem ....

[peterg000]

Hope someone can help ....

I have a fourwinns 16 ft with an omc cobra I/O config. The engine is GM 3.0L 4 cylinder. Was having some blow by (oil coming out of valve cover valve) and decided to replace head gasket. started by unbolting combination exhaust and just pulling away from head. Then took valve cover off and took out lifter rods and rockers (kept them all number to go back in where they came from). then unbolted head .... numbered bolts .... pulled head .... cleaned surface on block and head. Bought Flexpro head gasket(expensive) ... mounted it .... mounted head ..... put bolts in and started tightening to specs (middle working out). Torqued according to specs. lined up gasket for manifold and pushed manifold into place .... put in bolts and tightened manifold in place. also forgot that I had to take thermostat housing off .... reintalled that as well. I then adjusted lifters per spec. Everything looked good ..... went to turn engine over and nothing. Checked compression in cylinder 1 ... it was 0 .... it was around 110 before head replacement project. Was tired at that point and just hung it up for the night. I keep re-thinking all the steps and cant think of anything that I didnt do. After pulling the head, do you have to prime in some way to get compression back? Did I miss something? any help would be most welcome!!

Thanks in advance .....

Glenn

 

[cooter2506]

Re: Head Gasket replacement problem ....

Shouldnt have to prime it. What was the compression readings on all cylinders before and after the head gasket change?

 

[Bondo]

Re: Head Gasket replacement problem ....

I then adjusted lifters per spec.

Ayuh,.... Welcome Aboard,....

My Guess,... That where you missed something....

There ain't no Prime to loose...

Blow by is more of a Ring thing...

 

[peterg000]

Re: Head Gasket replacement problem ....

Cooter ..... I was getting oil coming out the air valve on my valve cover. Everything I read lead me to think this was blow-by that could have been caused by head gasket issues (other issues as well). When I took head gasket off, i saw a little portion broke off around the cylinder seal of the head gasket, but couldnt really tell you if this was causing blow by. Any suggestions as to what I could look at to try and figure out what I missed on the install?

Bondo ..... anything I can check to try and track down?

Glenn

Update: sorry cooter almost forgot tel let you know compression .... I only did cylinder 1 and it was around 110

 

[Don S]

Re: Head Gasket replacement problem ....

You have the valves adjusted wrong. Probably didn't have it on #1TDC on the compression stroke when you started. Most likely 1 turn off.
Go back get the motor to #1 TDC on the compression stroke and readjust the valves.
I have to assume you have a manual and understand what I just said, RIGHT ????

 

[peterg000]

Re: Head Gasket replacement problem ....

Don .... I will check again, but almost certain it was TDC when started valve adjustment. Would that cause absolutely no compression reading? and yes, I have book, but took some instructions from online as well .... maybe I took wrong instructions. I found TDC and adjusted 2 valves for cyl 1 ... cranked 1/2 turn and then cyl 3 .... cranked 1/2 turn(back to TDC) and then cyl 4 ... cranked another 1/2 turn and then did cyl 2. And my adjustment was to take out play and then tighten 3/4-1 full turn. Does this sound ok?

Glen

 

[gettin'even]

Re: Head Gasket replacement problem ....

You have the valves adjusted wrong. Probably didn't have it on #1TDC on the compression stroke when you started. Most likely 1 turn off.
Go back get the motor to #1 TDC on the compression stroke and readjust the valves.
I have to assume you have a manual and understand what I just said, RIGHT ????

Note the above "highlighted" section. Valves cannot be adjusted correctly unless #1 is at TDC AND on the compression stroke............


PS. Welcome aboard Peter.

 

[peterg000]

Re: Head Gasket replacement problem ....

Thanks gettin .... believe me, would love that to be it, but 99.9% sure I was at TDC for cyl 1 when I started. Reason why I feel comfortable with being at TDC was that rotor was pointing to terminal for cyl 1 and timing mark was lined up. With all that said, I will definitely go through the process of re-adjusting just to make sure. But lets just say, I did that ... is there anything else that I could look for to tell me where I might have messed up?

Glenn

 

[Bt Doctur]

Re: Head Gasket replacement problem ....

Try adjusting them 1 cyl. at a time. turn motor unitll the intake opens and then closes for that cyl. this is the beginning of the compression stroke, adjust intake and exaust for that cyl. adjust rockers to "0" lash + 3/4 more. Do the same for #2,#3,#4.

 

[peterg000]

Re: Head Gasket replacement problem ....

BT ..... the way I found TDC for cyl 1 was the rotor was at position for cyl 1 terminal and the timing line was TDC ..... is there another way to make sure Im a compression stroke for cyl 1? Is there a way to eyeball the valves?

Glenn

 

[Bt Doctur]

Re: Head Gasket replacement problem ....

Just watch the rocker arms move. When the 2nd rocker arm stops moving , your coming up on compression(intake valve just closed)
Front to back EI IE EI IE
1 2 3 4

 

[Don S]

Re: Head Gasket replacement problem ....

Put it back on #1 that you show on your distributor with the timing marks lined up on the front. With the valve cover off. Turn the crankshaft by hand both directions. Then see if either one of the valves on number 1 cylinder move. If they do, you are 180? out. ( One full turn of the crankshaft out of time)

 

[peterg000]

Re: Head Gasket replacement problem ....

Thanks Don ..... will give it a shot tomorrow morning.

So I guess the consensus is .... absolutely no compression is because the valves are not adjusted properly. Sounds like there is not much else to check out .... will let everyone know tomorrow if successful. In the meantime if anyone can think of anything else I could check, would luv to here it.

Thanks all ....

Glenn

 

[Don S]

Re: Head Gasket replacement problem ....

What service manual were you following?

 

[JustJason]

Re: Head Gasket replacement problem ....

So I guess the consensus is .... absolutely no compression is because the valves are not adjusted properly

Yes, your intake or your exhaust valve, or both, are not closing.

 

[Don S]

Re: Head Gasket replacement problem ....

One other thought.
Even if you did follow a manual that stated to turn the adjusing nut down till you go zero lash, then turn an additional turn or 3/4 turn or whatever, but, you got down to zero lash, waited for a few seconds and readjusted to zero lash, then tried it again and again.
Well, you screwed up. You turn them down to zero lash ONE TIME only. then adjust the aditional amount. DO NOT readjust zero lash.

 

[peterg000]

Re: Head Gasket replacement problem ....

Don .... using 2 manuals .... service manual for OMC Cobra models I found online ... and a SELOC manual.

Glenn

 

[peterg000]

Re: Head Gasket replacement problem ....

don .... on the adjustment .... I tightened bolt while feeling play ... kept tightening until no play ... then did 3/4-1 full turn. If I re-adjust, Im just going to back off anf tyhen start the process ... is this ok?

Glenn

 

[45Auto]

Re: Head Gasket replacement problem ....

Was having some blow by (oil coming out of valve cover valve) and decided to replace head gasket.

Might have been a good idea to do a little basic troubleshooting (compression check using oil in cylinders, leak down test, etc) before wasting the time and money on the head gasket. It's going to do absolutely nothing about your blow by problem.

 

[ENSIGN]

Re: Head Gasket replacement problem ....

Sounds like you got a piston/piston ring issue,when you get the valves adjusted right(read don's post) Do a cylinder leak down test and you will know where the excess crankcase pressure is coming from.