Head Gasket?

[mikey]

First off, I,m just trying to get the old beast into next summer, as cheaply as possible. It's dented up with a salvage title, and any major repair which I'm uncomfortable doing myself will probably be the end. Sad but true!

Coming home late at night a week ago the engine started missing at 80mph, but I got the car home. I replaced the plugs, wires and distributor cap, and the car is driveable, but lacks power while accelerating, jerking a bit, around 2000 rpm, ok by 3000. It idles roughly, but I don't think it's a vacuum leak. At first I wondered about the distributor, but since I cleaned off the engine block to trace some oil leaks, I've noticed a small amount of oil coming from the seam between the block and the head, near the rear, on the distributor side. Seems to be spreading forward. The #3 plug was really fouled, #4 not so bad. There is no coolant leak that I know of.

The engine has been eating oil for over a year, about a quart every tank of gas or so, above and beyond my external leaks. Seems to be blowing out through the exhaust pipe. Does this sound like a head gasket problem? If so, I'm scared, but willing to tackle it. I've done the timing belt, strut inserts, replaced the rear differential, and more, and Petros' repair guide gives me some confidence. Looks like all the parts and supplies would set me back less than $100, and I could do it over a weekend.

Any other ideas?

[Petros]

Not likely the head gasket, but it may have to come off anyway. Either bad valve stem seals or even damaged exhaust valve. do a compression check, if the pressures are all fairly even you are good, it just needs now stem seals. If you have one really low or no compression, you need to replace the damage valve, which means the head has to come off. That is not that bad of a job, once the head is off you should replace all of the exhuat valves and all of the valve stem seals. You might consider having a machine shop regrind the valve seats and the intake valves if you have to take the head off.

If your compression is fairly even and all decent you may just have bad valve stem steals. You can try putting some "Restore" into it, I have had good luck with that. I had a car that would foul number two plug so bad I had to remove it and clean it every tank of gas and add another quart of oil. I put the Restore in it and drove it from Austin TX to Seattle and only burned one quart of oil and no more spark plug fouling. But this is only a temp fix, you can replace the valve stem seals without pulling the engine: rent a valve spring compressor (the type that looks like a little gear puller, Autozone has them for free rental), and with the piston at TDC for each cylinder you work on (to prevent you dropping the valves after you remove the reatainer), you remove each retainer and keepers set, replace the stem seal, and than install the spring, retainer and keepers. work your way down the valves until all are done. It should not cost much at all, and you avoid removing the head. This only works if your valves are sealing okay, that you determine from the compression test (Autozone also rents the compression tester for free as well, or you can buy a cheap one from Harbor Freight).

There are a few other rare condition that can cause only one cylinder to have low compression, but you will know that after you get the head off, if that is what you find. I have seen damaged piston crowns that allow oil into the combustion chamber, and once where a wrist pin came lose somehow and gouged out a deep groove in the side of the cylinder wall. But do not worry about that, those are really rare. Get the compression test done and report back.

Good luck.

[mikey]

Looks grim.....

Cylinders 1,2,3,4........135,135,135,0

With oil squirted into spark plug holes........142,155,152,0

analysis, doctors?

[rer233]

valve or poss. head gasket (not likely.) either way- off with his head! good luck.

[keith]

Pull the #4 plug and pump in compressed air and see if it comes out from around the engine or out the exhaust pipe.

[mikey]

I see what you're getting at, Keith, but I don't have compressed air available in my driveway. I suppose that I would need the engine rotated to a point where the #4 valves should be closed. Maybe I can Rube Goldberg my vacuum cleaner to it!

No rush at this point. I'm buying an '82 Corolla really cheap tomorrow which probably needs a new power steering pump, but otherwise is in good shape. It's not as homely looking as my Tercel, though....too normal looking.

[Petros]

either way, the head has to come off. Likely a bad exhaust valve, though a few other things can cause that. Make sure you use my procedure to replace the head gasket over in the repair guilds section. Good luck.