Help diagnosis overheating problems...Cylinder Head?

[Mark B]

Hey guys,
My beater car is having issues....

We are talking about a 1993 Cavalier 2.2L Auto w/ 151K miles. I think that my cylinder head is cracked/warped. But please let me know what you think. Here are the symptoms/history:


I purchased this car a month ago, knowing that it needed a head gasket. I replaced the head gasket last week. But I tried to get out cheap and I didnt have the head checked/machined/replaced. (Oops) The car ran good for a day or so, but now... well, it doesnt.
1) It feels like it running on 3 cylinders (Very rough. Possibly becasue so much coolant is geting into the combustion chamber that the fuel cant ignite right)
2) Its got a mysterious Coolant leak. No visible leaks anywhere.
3) Sweet smell in the exhaust (Kinda smells like burring oil too)
4) Overheating. Sometimes it will go 5 minutes before overheating & sometimes it will take 15 minutes. Its kinda random. The temp gauge sometime will drop very fast from hot to cold. Usually once I take to load off the engine.
5) Takes along time for it to overheat if you are just letting it idol. But as soon as you put a load on the engine...the temp goes up in a hurry.

What do you think?... Probably the head? I want to fix it this weekend... So please let me know ASAP. Also, if it is the head, should I get the stock one machined or pick up a used one? New ones go for about $400. I dont want to spend that much. (I only paid $300 for the whole car!)

[Jeff_in_Atl]

Warped or cracked head.

Have it magnafluxed first. This usually but not always will show if it is cracked. If it is not, have it machined flat. Put valve seals on it in case I get behind you.

[Joe 1320]

Could be warped head, cracked head, partially blown headgasket, cracked radiator end tank, the list goes on. A cooling system pressure check, leakdown and compression check will narrow stuff down.

[fastTa]

Aluminum or Iron Head?

You really need to have the cylinder head deck squared to ensure proper gasket seat.

Only $40 for 1 head at NAPA auto parts.

I'm assuming this is an overhead cam motor? If it is be very careful to get the timing belt and all pullies back to their proper alignment. Overhead cam in-line fours usually are balanced via a timing belt driven internal conterweight balancer.

It is very important that you get it's pulley re-aligned properly or you will know it! Shouldn't be a problem though, there is usually a timing mark on all pulleys.

[Mark B]

Its a normal Over Head Valve engine. So I dont have to worry about timing and stuff like that. I havent checked myself, but I have been told that it is an aluminum head. What part are you talking about for $40? That cant be the cylinder head. The cheapest I found was $300 on E-Bay. Also, when I am putting the rockers back on, the book tells me to tork them all down to a specific torque. Should I just go by the book, or is there another way that I should do it?

[Dave M]

he meant napa only charges $40 to deck the cylinder head.

[fastTa]

Originally posted by Mark B
Its a normal Over Head Valve engine. So I dont have to worry about timing and stuff like that. I havent checked myself, but I have been told that it is an aluminum head. What part are you talking about for $40? That cant be the cylinder head. The cheapest I found was $300 on E-Bay. Also, when I am putting the rockers back on, the book tells me to tork them all down to a specific torque. Should I just go by the book, or is there another way that I should do it?

The book is probably fairly close as far as the torque specs on the rocker arm tension.

An old school technique that still works well on hydraulic valve trains is to twist the push rod back and forth with your fingertips and then slowly torque down the tension nut until you feel significant friction between the push rod and the rocker arm. Then tighten the nut 1/2 more of a turn. Done!

Torque specs are fine and dandy when the motor is fairly new, and there is no gunk and debris on the threads.... but the more the gunk and debris, the less accurate and effective the torque specs will be.

[Jeff_in_Atl]

Originally posted by fastTA
The book is probably fairly close as far as the torque specs on the rocker arm tension.

An old school technique that still works well on hydraulic valve trains is to twist the push rod back and forth with your fingertips and then slowly torque down the tension nut until you feel significant friction between the push rod and the rocker arm. Then tighten the nut 1/2 more of a turn. Done!

Torque specs are fine and dandy when the motor is fairly new, and there is no gunk and debris on the threads.... but the more the gunk and debris, the less accurate and effective the torque specs will be.

Yes and if he shaves the heads it acts as if the push rods just got longer so the rockers shouldn't go down as far.

[fastTa]

And like Jeff said earlier, it would be well worth the time to freshen up the valve seals while you have the head off.

When you have a head decked, it effectively ups the compression which will in turn only make your oil burning worse.

[Mark B]

I pulled the head off tonight. Looks like its cracked at the #2 piston. The #2 is definitly the problem though. Combustion chambers #1, 3 & 4 are black and carboned.... #2 is smooth clean aluminum. Looks like the coolant blew off the carbon from that cylinder. Anyway, I will take a picture tomorrow and post a close up of the area that I think is the culprit. Then you all can see what the problem was. I hope it doesnt cost too much to get it fixed.

[Mark B]

I took the head to the shop and it turns out that its beyond fixing. Its cracked between the spark plug and the exhaust valve. The shop said that they cant fix that kinda crack. So I either have to get a new one for $400 or pick up a used one and hope that it works.

[fastTa]

Start making calls to all the local salvage yards. I'm sure you could pick up a decent used head for a fraction of the new cost.

Or maybe even the infamous Ebay.