The Stovebolt Site Forums The Shop Area Engine Shop Blown head gasket? What now?

Not a bolt related question.

I was drivin my old f*rd yesterday haulin dirt and she started shaking and banging. I nursed her home for about 5 miles or so.

I took one of the plugs out and it was covered in oil. No compresion either. Took the valve cover off and theres standing water. Check the oil and it looks milky.

What do I do know? Im assuming I blew the head gasket and thats why theres water in the oil. Also would a blown gasket account for absolutely no compression or did I punch a hole in the piston?

Its a 76' with a 390.

Any helps appreciated. Thanks, Jeff

From your description it does sound like a blown head gasket. As long as the head is not warped or cracked it should be a fairly easy fix (even on a F*rd) when you have some time to spare. Take the intake manifold, heads and anything else in the way off and install a new good quality head gasket. Once finished be sure to flush the cooling system and change the oil.

If it was just the head gasket, the pistons should still be in good shape. The reason there is no compression is because when 1 cylinder is on the compression stroke, the air that should be compressed leaks into another cylinder close by. This other cylinder will be on the intake or exhaust stroke, so the air from the first cylinder will leak out and not be compressed.

Good Luck
Adam

It might be worth while to have the head mounting surface checked and milled if necessary. Also, while yer at it, for $20 or so get the head mangnafluxed for cracks before you bolt it back on-

Head's gotta come off regardless, so I guess you'll know for sure then.

If you had water in the valve area, that is probably not due to a blown head gasket. However, 390 intake manifolds, and their water passages are partially under the valve cover so a blown intake gasket could cause a miss and water in the valve area as well as in the oil.

I would do a dry and wet compression check, the low compression and water may not be related. A leakdown test may tell you more than just compression. Also, if you have access to a cooling system tester you could pressurize the cooling system and look/listen for leaks.

I'll bet even money the engine's trashed, sorry. After you find out for sure, I would look for a good 460 to put in it,
Scott

Of course its trashed its a ford

Yeah the rod tore itself in half and threw itself through the top of the cylinder wall. (I noticed she knocked a little on the drive home! )

But she made there! Not a bad truck for 2 cords of firewood and been drivin it like a tractor for the past 6 years. Pullin stumps, logs, rocks and whatnot. I think ill look for another chev now...

Thanks again everyone. Jeff