coolent in #3 and #7 cylinder on a 5.7 Gmc

This topic contains 4 replies and was last updated by ben 10 years 2 months ago
August 16th, 2011 12:33am
my 88' gmc has had an overheating propblem, ive narrowed it down to the heads. i replaced the head gaskets, but im still getting coolant in the #3 cylinder and now the #7 cylinder.

any ideas as to what may be causing this, i think it could be a cracked head, warped head or possibly a crack in the Block.:unsure:
August 16th, 2011 6:09am
When you had the heads off, did you use a straight edge on the head, and check for the head to be true, from end to end? As well as on the block?
August 17th, 2011 7:30pm
in my own stupidity i did not, i had to get the truck moved because it was soon to be preventing my dads business from working. so when i pull the heads again i will have to check that. i am also going to replace the head bolts, and exaust manifold bolts.

but a warped head would make sense, the engine has gotten pretty hot a couple times.
August 20th, 2011 6:30am
Yup, I would agree with Brazeau. warped head. while your at it might as well check the other side as well. Top end kits come in sets.
August 22nd, 2011 8:44am
yes both sides have to come off, an exhaust bolt on the #2 cylinder snapped off so i have to drill out and re tap the hole. i'll pull the heads, check for cracks & straightness. if they aint straight ill take em' down to a machine shop, have em shave off a few millimeters then see if they can drill and tap the exhaust manifold bolt hole and tap it

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