Cracked Cylinder Head

[shamaal]

After another driver overheated my Navajo I noticed a few drops of oil in my coolant and heavy oil leak from the valve covers. Fearing the worst I pulled the heads. I'd post photos of the removal but am too embarassed that I had to cut off four of the manifold bolts because I rounded off the heads. Not only was the driver side gasket was bad, but the head was cracked - see photo. The question is - Does anyone sell cylinder heads using new castings? The Mazda place wants 1500+. O'Reilly doesn't carry and Autozone wants $400+ for a remanufactured head. Does anyone have any experience with remaunfactured heads? I understand they take a cracked head, weld the crack and remachine.

 

[alexefron]

you should be able to have the head welded. Call up some machine shops and get quotes.

 

[shamaal]

Thanks, I thought about that having them repaired, I pulled the other head last night and it too was cracked. I figure that the amount of time and money to weld, remachine and magnaflux the heads when coupled with my nagging suspicion everytime I saw a puff of smoke, it may be better to replace with new ones. I found a machinist yesterday who used new castings ($259 each) and did the valve job for $300 a head complete. He wasn't to keen on repairing each head.

 

[alexefron]

no, i know what you mean. im exactly the same way with repairs on my trucks. Might be worth trying to find some used heads that aren't cracked, and just having those cleaned up.

 

[Maniak]

When I replaced the heads on our '92 I tried 3 sets of used heads. Each set was cracked...

I went to Bills Cylinder Head Exchange in Phoenix and they got me a set of 93TM heads (which work on a '91-92 also). I believe the cost was $550 for the set of heads minus the money they gave me for my old heads. I believe I got about $200 for the pair old heads (one head was repairable, the other was junk)..

The nice thing was that I brought the heads to them, then disasembled them right there, then fluxed them to see the cracks, and then I left with my new 93tm heads (new to me).

I'd look around for cylinder head rebuilders in your area to see if you can find one that works about the same way..

~Mark

 

[charles88tc]

So what is the fix for this? I am a NEW-B here, but have owned my 93 sport since January of 2000. I have had to put 5 or 6 Heads on it. I think both have been replaced twice. Is there an aftermarket head available or would a bigger radiaitor, and electric fan combo help. Luckily for me my dad used to work in a machine shop where we got everything at cost. 135$ a piece for the heads wasnt bad. Too bad for me he doesnt work there any more. Is there anything you can do to keep it cool? I have located a complete motor for a GOOD price to throw in until I can figure out what all I am going to throw at a complete rebuild.

 

[Maniak]

Why are you going through so many heads? I'm on my 2nd set of heads at 329k miles.. (first set cracked at 236 due to a blown water pump and then overheating)..

We are in Southern Az and drive in 105F+ temps with an auto tranny cooler and a/c and don't overheat. I did change the fan clutch when I did the heads and the HD clutch seems to help keep the motor cooler, but it does seem to hurt the mileage some (the fan stays running more than you might expect).

Also, I got 93TM heads instead of the 90TM heads which are "supposed" to be better.. I can't tell you for sure, but I haven't blown the 93TM heads.

~Mark

 

[ma96782]

I'm finding this thread interesting.........and for folks that don't know..........review this:

http://www.therangerstation.com/tech_library/40rebuild.htm

Aloha, Mark

 

[charles88tc]

I am not sure as to why I have went through so many heads. My dad speculates that after the first set that the block may have some high and low spots (warped). But Since I am planning on doing the whole motor this time, I am going to have the radiator removed for cleaning . Possibly going to get a new one if budget allows. Also I am going to have my block fully prepped bore, hone, cleaned, and decked. After I am in the process of repairing my electrical system, I plan to add a dual electric fan setup. I love the truck and never plan to get rid of it. It was my first vehicle, and my uncle god bless his soul left me money in his will, to acquire it.

 

[je5]

After another driver overheated my Navajo I noticed a few drops of oil in my coolant and heavy oil leak from the valve covers. Fearing the worst I pulled the heads. I'd post photos of the removal but am too embarassed that I had to cut off four of the manifold bolts because I rounded off the heads. Not only was the driver side gasket was bad, but the head was cracked - see photo. The question is - Does anyone sell cylinder heads using new castings? The Mazda place wants 1500+. O'Reilly doesn't carry and Autozone wants $400+ for a remanufactured head. Does anyone have any experience with remaunfactured heads? I understand they take a cracked head, weld the crack and remachine.

I have one factory head cracked in the same spot between the valves and the other magnafluxed to be good. They are all on the way to cracking. I like my new replacement aftermarket heads so much that I bought a second pair and stored them. I have since traded for a 1997 so no longer need them. If interested I can list them.