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View Full Version : Rough idle=head gaskets?



fixmysc
07-17-2007, 11:58 AM
Hi Folks;
I've been trying to get my '95 with a rebuilt '94 to idle properly for some time now with lots of help from the forum. Just to update, I took the entire S/C assembly, except the top cover, apart to make sure there was nothing stuck in there. Everything appears normal (and cleaner now!). Next I removed all the injectors and had them rebuilt. Flow rates were low (33, now at 87).
Before reassembly, with new gaskets, I did a compression check.
Cylinders, 1,2,3: 150, 150, 148, respectively. However, cylinders 4, 5, 6, all gave a max of 120-125, but wouldn't hold pressure.
I am just posting to see if this is a definite sign of head gasket failure.
Nothing unusual about any of the fluids (oil, and antifreeze), no unusual smoke, just the terrible idle syndrome.
Also, as I'm about to take the heads off, (after rad drain of course) is there anyway to get antifreeze out of the block?, this is one fluid I always seem to have leaking everywhere when I pull motor components off.
Thanks for your help, a little discouraged but still having fun!

fturner
07-17-2007, 12:30 PM
I still think its a valve issue, especially since the one side is low and not holding compression. Its very very rare a head gasket would go on all three cylinders on 1 bank.

fixmysc
07-17-2007, 02:49 PM
Just to let you know; It turns out that the compression check on my engine was fine, the gauge itself was sticking. Ran a little airline oil through it and it worked fine (ie, holding pressure). Anyway all my cylinders are between 145 and 150 cold.
Next, I'll reinstall the rebuilt injectors, new teflon I/C gaskets, and see what that does for the idle.

P.S. do I need those valve cover bolts with the long bolt that goes above nut used to tighten them? I'm thinking it would be easier to use regular bolts that I can reach with a socket.

fturner
07-17-2007, 02:58 PM
Just to let you know; It turns out that the compression check on my engine was fine, the gauge itself was sticking. Ran a little airline oil through it and it worked fine (ie, holding pressure). Anyway all my cylinders are between 145 and 150 cold.
Next, I'll reinstall the rebuilt injectors, new teflon I/C gaskets, and see what that does for the idle.

P.S. do I need those valve cover bolts with the long bolt that goes above nut used to tighten them? I'm thinking it would be easier to use regular bolts that I can reach with a socket.

The extensions on those bolts are so you can clip on the plastic holders for your spark plug wires.

cbt
07-18-2007, 11:23 AM
when i did my hg's ,the extensions for the valve covers bolts ,i cut them off or you could just replace them ,as they were used to hold the wire loom do-hickies
i've re-routed the wires so there is no need ,seems there is a need to re-route a lot of things on these cars ,as to make easier access
the water heater backets ,is another one along with the exhaust bolts

cheers