my '97 12 valve with 226k has been using coolent with no visible leaks, the crankcase vent tube is puking out this cream color stuff when its parked overnight that i think is coolent finding its way into the crankcase and its just coming out with the blowby, this truck is moderatly bombed but has been experiencing only about 13 mpg on 3.55 when it should be getting 17 mpg, help guys, any suggestions would be greatly appreciated

 

Sounds like HG to me. There's not a lot of places that oil and coolant can mix, the oil cooler (behind the filter mount) is the only one I can think of besides head gasket. A leaky oil cooler will not diminish mpg though. I'd think the HG was most likely the issue.

 

I think ill pull the head tomorrow and take it to a machine shop to get reworked, when i put it all back together, im going to put head studs in. Does anyone have experience with A1 studs from pure diesel power? They say they are better than arp's, i would love to hear everyones opinion before i spend the money, the nice thing about the A1's is the rockers dont have to be milled.

 

you can take a Dremel to the inside 'rib' of the valve cover, if you are worried about that

 

can someone describe to me exactly what you have to do to the valve covers in order for them to work with A1 head studs, or maybe there is a link you could show me, thanks

 

I have the A1's and like them. I know a guy that has put more than his fair share of head studs in and he has had less problems with A1 than arp. You just need to grind the webbing flat on the inside of the valve cover for them to work. You can dremel, grind, or use a drill press to do it. takes 5 mins a piece. Its also a good Idea to get a bottom tap to make sure the threads go all the way down into the engine.

 

i ordered a new bottom tap with the head studs, should go back together fairly easily, do you guys think im going to have trouble putting the exhaust manifold back on being that its a factory manifold with over 226k on it and it has most likely shrunk some, any input would help on the subject, thanks

 

I doubt it's shrunk, most vehicles I've dealt with with cast iron manifolds warp and expand.

I've never removed the manifold from my truck, so I can't speak for our specific application, but I don't think the EGTs are hot enough to make it warp too bad (not in comparison, say, to a turbocharged gasser, where I have most of my experience). If so, I've found that you can usually get it close enough by enlarging the bolt holes in the manifold.