Engine/Transmission (1998.5 - 2002) Head Cracks

[Lockwood]

Hi guys, I've been lurking here for a long time and have learned quite alot about my truck. I have a 98. 5 with 305K on it. Oil in the coolant. (not much more like bad cream in coffee globs). So I pulled the head and took it in for a valve job check and the machinist said that there are about six cracks in between the some of the valves. So I have located some heads at a salvage yard and the guy at the yard said that hair line cracks between the valves are quite common but don't seem to go anywhere. So the question is, to you guys that have done head work, what's the deal on head cracks. Common not common. OK not OK. I don't quite know where to go with this.

Thanks, Lynn

 

[HBarlow]

I'm not a mechanic so someone with superior knowledge and experience may provide an answer better than mine but I think cylinder head cracks are relatively rare. I ran an '01 with 275hp MH injectors that routinely ran 1300* on long grades 325,000 miles without ever seeing a problem. Your engine has probably been highly modified and run hard.

A good machine shop/engine builder can magnaflux your cylinder head to determine if the cracks are minor around the exhaust valves or significant and into the water jacket.

My first thought would be your problem is somewhere else but I may be completely incorrect.

 

[Lockwood]

Thanks for the reply Harvey. My truck is mostly stock except for an EZ and 4in. exhaust. However, it has been hot several times. Real hot. So I haven't seen the cracks yet. It will be the end of next week before I can get to the

shop to check it out. I'm just trying to get some information and advise to make the right decision. A head from Cummins is a little ouchy.

Lynn

 

[Bob4x4]

Cracks in the head are common,just not all the way to the water jackets. Cummins tosses out more core heads than it builds thus the high cost of recon heads.

 

[Lockwood]

Thanks Bob, so hairline cracks that go nowhere should not be a problem in the combustion chamber right?? If thats the case with mine maybe its usable. I'll be able to see it next Thursday. Thanks again.

Lynn