'94 850 Wagon, blown head....

Mac_in_MA · Post by **Mac_in_MA** » 16 Jul 2007, 09:48

Hey all,

I've got a '94 850 (non-turbo, wagon, 150K miles) that has a blown head gasket. (Compression test results - 120 psi, 0, 0, 0, 80, turns over, but no start, fires only on cylinder 1, sparks on all cylinders) Same cause as a number of example I've seen here - overheating. In my case, the boots around the spark plugs (on the plug cables) melted. Is this normal, when it overheats? The various independents that I talked to, including a volvo specialist, said it "might" indicate lower engine damage (i.e. very big bucks), if it got that hot. Because of this I've not been persuing the repair (We bought a '98 V70 instead) but if the old one is fixable, I'm loath to junk it. I thought I might try to take the head off, and let the local expert take a look at the pistons to make sure only the head gasket needs fixing, and then.... take it down to one of them to let them put it back together.... (with neatly labelled parts that I'd taken off...)

The idea here would be to not invest any repair money until I'm fairly certain it just needs a new head gasket....

Is this dumb? The repair guys were saying for them to do the whole job, they'd have to get it apart to see if the lower engine has problems, and by then we've spent half the repair bill..

Everything in Haynes regarding the removing the head seems reasonably straight-forward except for the bit about taking out the cams, etc. Is it not possible to remove the head as a unit?

Any suggestions? Is the lower engine fairly bullet-proof (i.e. likely to be okay?) Have I laid an armor-piercing shell into it, by letting it overheat this much?

Thanks,

Mac

Trilarry · Post by **Trilarry** » 16 Jul 2007, 12:14

The Head removal is straight forward. About 4 hours, just mark the 2 cams I for intake ,E for exhaust. Once the head is off you can use a straight edge to see if the Block is warped or damaged.

You can do this head job if you take your time and somewhat mechanically inclined. Of course I would take the head to a machine shop to be looked at. You will save tons if you are able to do the removal yourself. The Block is a little tougher than the head, I'm not sure if it's cast iron or aluminum hopefully it's okay but you won't know until you remove the head. The head cannot be removed as a unit, only by removing top cover along with both cams and then unbolting the head bolts and taking off the manifolds etc. Follow your Haynes and continue asking questions on this forum.
Tri

bobsnow100 · Post by **bobsnow100** » 17 Jul 2007, 06:34

I would consider another engine. You should be able to get one for around $500 or so.

CarVolvo · Post by **CarVolvo** » 17 Jul 2007, 07:51

if your considering a used motor i might have one available for you .. but its about 1 hours drive into CT for you. It will go cheap as i dont plan to take it out on the car i purchased and parting out.

It will be available the first week in august..message me if your interested.

wyatt · Post by **wyatt** » 18 Jul 2007, 07:20

I would see what the oil looks like first,then you can get some sort of picture if you did engine damage.The block is alloy.You would not know it if there is a bearing problem or a burnt piston without taking the engine apart.Chances are pretty good if you melted the spark plug wires you did some real damage.But Ive seen engines that were cooked and after replacing the head gasket the engine ran great,its a crap shoot.The used motor sounds good,its alot cheaper than doing a rebuild with new pistons and machine shop work.A few thousand compared to a few hundred.If you do the head gasket yourself than all you pay for is gasket oil a filter and a few misc things,maybe its worth the try.Wyatt