I have a 2003 jaguar s type. It has the 4.2 engine. It isn't supercharged. The radiator failed and caused head gasket to blow. I got car used that way. I am getting head gaskets done and other things. My question is do the head bolts have to be replaced on the 4.2 motor? They are $12-13 each and for 20 bolts they cost more than the gasket set. Anyone done this or have any answers please? Or advice new to site. Thanks for everything. Can also email me direct to dhuff73@icloud.com. Or call 540-294-6144. I'm trying get this car fixed ASAP. I also have a 86 xj6 ill be fixing up later. Love jags

 

Rule of thumb for me (I've built/rebuilt several motors), is to always use new head bolts. Why?

I'm torquing it to a specific spec. Due to a massive amount of heat, these bolts are specifically designed by the factory to stretch/warp as the engine gets hotter and cooler. This means that the old bolts are stretched, warped, and generally not the same as they were once new. This is fine when they're stretching/warping along w/ the motor and original torqued position. This is definitely not fine when you're trying to reseat them.

Get new bolts. Esp when when you're getting your head gasket done (pretty big job), you MIGHT AS WELL change out the bolts while you're there. Do the job right the first time =)

 

I have no idea where you are (what country??) but as far as I know all the V8s can use the FEL-PRO Part # ES72262 available from auto parts stores in the U.S. and Rock Auto for the Lincoln LS 3.9 liter V8.

These bolts are 'torque-to-yield' so they are a one time use bolt. Jaguar authorized the AJ6 and AJ16 bolts to be 'used-twice' but that is another debate????

The FEL-PRO Part # ES72262 are M10 X 175mm with the 13mm hex head. The newer Jaguar bolts are the RIBE poly-drive but I don't think it matters once the head is bolted down, they hold like the others??

I have installed many 4.0 cylinder heads with the FEL-PRO Part # ES72262 and they work fine.

Maybe someone knows why the 4.2 can't use the FEL-PRO Part # ES72262 and hopefully will post here and explain??

bob gauff

 

Welcome to the forum Dhuff, cross posting is against forum rules so I've deleted your other two identical posts.
Don't forget your intro in the new members section.