No compression after head gasket job?

[Pearl1990]

I did a head gasket job and only torqued it down to the point where the torque instructions says to let the car warm up and then torque it again. It's been a couple months since I did that and in the mean time I rebuilt the IP and did a few other things. Now I'm trying to get it running so I can warm it up and then torque the head again, but can't seem to get it going. It fired up for a bit but now it won't start. The engine ran fine before, but I'm going to test the compression today.

Was it a bad idea to let the head sit only partially torqued for that long? I'm getting fuel to the injectors and there doesn't seem to be any air in the lines. I'm stumped on why it started up the other night and now won't start at all.

[Dakotakid]

IF you assembled the head to block correctly-following-torque procedure (sequence of bolts, placement of gasket, etc.), letting the engine sit should not matter....proved you did not do it well and anti-freeze has run into a cylinder or two. We've seen it all here!

More than likely, you do not have the fuel pump totally primed (pressure in the lines has to be built up to actually FIRE the injector...not just pess a little out).

OR, you could have the inj. pump 180 degrees out.

Or, your pump is not put together properly. We weren't there.

[Pearl1990]

IF you assembled the head to block correctly-following-torque procedure (sequence of bolts, placement of gasket, etc.), letting the engine sit should not matter....proved you did not do it well and anti-freeze has run into a cylinder or two. We've seen it all here!

More than likely, you do not have the fuel pump totally primed (pressure in the lines has to be built up to actually FIRE the injector...not just pess a little out).

OR, you could have the inj. pump 180 degrees out.

Or, your pump is not put together properly. We weren't there.

Lo and behold, there was coolant in the 2 middle cylinders. What would have caused this? I feel like I did a pretty good job of torquing to spec. The block surface seemed clean enough, and the head surface had just been machined. Only thing I can think of is the threads in the block for the head studs weren't clean enough so they binded a bit and the torque was off? I didn't have a chaser or tap at the time. I just cleaned it out the best I could with compressed air and penetrating oil.

So I know I have to replace all of the head bolts now, but what about the head gasket? Can that be reused or should it be replaced?

[Dakotakid]

Just gotta do THIS: American ladies GOLD in Olympic Hockey!

New gasket. You really need to make use of a straightedge. Need to take comparisons in multiple planes....both head and block.

Personally, all I ever do is use old head bolts to clean threads and lots of carb cleaner and a blow-ooot of air. It works fine for me. Others will recommend more elaborate.

You can't bang the head down onto the gasket as you assemble. You can't wiggle the head around on the gasket either.

There could be the off chance the head is internally cracked.

[Pearl1990]

Just gotta do THIS: American ladies GOLD in Olympic Hockey!

New gasket. You really need to make use of a straightedge. Need to take comparisons in multiple planes....both head and block.

Personally, all I ever do is use old head bolts to clean threads and lots of carb cleaner and a blow-ooot of air. It works fine for me. Others will recommend more elaborate.

You can't bang the head down onto the gasket as you assemble. You can't wiggle the head around on the gasket either.

There could be the off chance the head is internally cracked.

Haha Congrats... *slow clap* Thanks for giving us a reason to take the game serious again! We were starting to just expect a gold every time

I may have wiggled the head a bit but never pushed down on it. I think I'll cut the head off of a few old studs and use them to guide the head on properly. I had the head looked over when I got it machined and he didn't notice anything. I'll maybe take a better look at it today. Thanks for the help.

[libbydiesel]

Did you have the cam installed in the head?  Did you have any of the pistons at TDC?  If yes to both, then there is a good chance you mashed an open valve into the top of a piston and weren't torquing the head down onto the gasket.  Instead you were torquing the open valve into a piston and bending the valve in the process. 

[Pearl1990]

Did you have the cam installed in the head?  Did you have any of the pistons at TDC?  If yes to both, then there is a good chance you mashed an open valve into the top of a piston and weren't torquing the head down onto the gasket.  Instead you were torquing the open valve into a piston and bending the valve in the process.

That did cross my mind at one point since I couldn't remember if I had the cam in or not, but I am pretty vigilant when it comes to timing. I have the head off now and there's no marks in the piston or any apparent damage to the valves.

[libbydiesel]

'Pretty vigilant" but "can't remember" doesn't sound good.  If you were vigilant about placing the crank at TDC for #1 (and #4) but were not vigilant about loosening the cam caps then the odds are very high that you smooshed a valve on #1 or #4.  Because the valves are oriented vertically, damaged ones often won't look damaged until the head falls off a few thousand miles later causing complete catastrophic engine failure.  The best procedure is to vigilantly make sure the crank is *not* at TDC (turn it 1/4 turn so the pistons are all mid-stroke) or make sure all the cam caps are loose or cam is removed for installation of the head on the block.