Warped Head?

"" wrote: > 1992 Geo Metro 3 cylinder. Car wants to start, but won't. > Overheated about > a week before this problem started. > > Compression tests show the middle cylinder is about 50 lbs > higher than the > outer cylinders. > Warped head? Head Gasket? > > Thanks, > > > -- > RJ in WV > > Saw on a bumper sticker..... > > Help the animals defoliate the world. > Join PETA today!

Is the oil milky looking?? White heavy smoke out of the exhaust??? Could have a blowed head gasket or just a burnt valve.

It would not be the first time that a head warped and a head gasket blew from it on a overheated engine. It happens a lot if you overheat it enough.

Thanks Sno and Shakes.

He won't tell the whole story, but I get the gist that he lost the fan belt in the freeway about eight miles from home. He doesn't know what the alternator light means. :o( The oil looks okay.

I just noticed the middle cylinder pressure is unusually high. The readings for the outer cylinders are 120, but the middle one shows 175. At least it sounds high to me.

I'd like to think the timing belt has jumped a notch, but this is an interference motor. It's probably fried, but I'll end up looking at the belt to satisfy my own curiosity.

Thanks again,

8 miles without a fan belt, it got pretty hot. I would pull the head and check it for warpage (as it likely is) and get it trued as needed ans install a new gasket and go from there. I would change oil too.

Hmm. He's got another Geo sitting in the weeds he ran out of oil and locked up, I wonder if the head is okay. He's one of those turn the key and it goes types.

If we're lucky, we may be able to just swap heads.

Thanks for your help! If we go that route, I'll let you know how it works out.

To see if you have a warped head you must remove it and use a strait edge (ruler or flat stock) and a set of feeler guages to determine what, if any warpage has occured. A blown head gasket would show itself pretty quickly, whitish smoke would be coming out of the tail pipe or your oil would turn milky. The most likely scenario I would come up with would be a bent valve from overheating.

Do or have a leak down test performed on the cylinders. This is a better way of checking the integrity of the rings and valves.

...Ron

--

68' Camaro RS 88' Firebird Formula 00' Mustang GT Vert

I guess you have not worked on many engines that have been cooked. THe head warping from high heat cause by exhaust when coolant it lost is one of the first thing to happen and headgasket generally do no just blow hot or not unless head warps or bolts loosen.

Not unless you consider working in a engine and cylinder head rebuilding shop experience. I'd be pretty comfortable stating that I've rebuilt more cylinder heads than most mechanics have worked on engines. Of course that means nothing to anyone but myself. What I'm getting at is that there were more heads with burned valves than with warped heads that came into my shop.

Either way I'd do a leakdown test before I started taking the engine apart. The OP didn't say anything about milky oil or white steam/smoke coming out of the exhaust before it stopped operating. A

50 psi drop compared to other cylinders doesn't exactly scream head gasket problem to me. Like I said before, I'd be looking at the sealing components of the engine. Either way the OP is eventually going to have to take the engine apart to see what's going on.

...Ron

--

68' Camaro RS 88' Firebird Formula 00' Mustang GT Vert