blew a headgasket... but both heads were cracked....

[parson2008]

headgasket blew on my 93 ranger stx 4.0... got around to pulling the top end off 2nite and both of my heads were cracked. what year heads can i use? and also what year heads are the best? and any other suggestions? much appreciated thanks

 

[nine-teen91stxranger]

well... i can gaurentteeee a 93' will work =)

 

[bilzy7]

Ya.....

 

[holyford86]

91-94 will work

 

[stx4.0]

Yeah 91-94 are the same.They have part number 91TM for 91 and 92 and part number 93TM for 93 and 94 but they are the same casting so there no "better" ones.Alot of people use the aftermarket alabama heads which are supposed to be thicker and not as easily cracked.They are the ones I bought but I dont have many miles on them yet.You can get them on ebay from J&C Enterprices for $365.They were $335 and I noticed a couple days ago that they had a huge price increase but if you contact them and say you will buy/pay outside of ebay they will usually drop the price quite a bit.They also sell rebuilt heads for $239 which is usally alot cheaper than most machine shops will do them anymore but they will need your old cracked heads.Hopefully your heads were not cracked due to overheating.Ive been around many 4.0s that suffered cracked heads from that and changing them will do nothing.The blocks warp and you have to pull it to fix it to keep from having overheating problems.

 

[parson2008]

as i inspected it more the headgasket never went out... 3 cylinders were cracked between the valves and where it actually leaked into the middle cylinder on the passenger side the head had a nice crack in it. i checked the block for straightness and it was good. not warpage thank god. i never let the truck run hot because i did not want to wreck anything else. in the middle of winter my engine was idleing high around 1300 sounded like a vaccum leak but all lines were fine, i believe the lowere intake gasket went out on me again and it was sucking in more air causing it to run richer. im on a tight budget so trying to get around to buy heads but $ is the issue im not gonna put new heads on without headers too of course

 

[Big Jim M]

Nope!

as i inspected it more the headgasket never went out... 3 cylinders were cracked between the valves and where it actually leaked into the middle cylinder on the passenger side the head had a nice crack in it. i checked the block for straightness and it was good. not warpage thank god. i never let the truck run hot because i did not want to wreck anything else. in the middle of winter my engine was idleing high around 1300 sounded like a vaccum leak but all lines were fine, i believe the lowere intake gasket went out on me again and it was sucking in more air causing it to run richer. im on a tight budget so trying to get around to buy heads but $ is the issue im not gonna put new heads on without headers too of course

You do have the right idea but you used the wrong word... You indicated the air leak caused richer mixture... NOPE! It caused a LEAN mixture which is hundreds of degrees HOTTER! This HOTTER, LEAN mixture caused the cracks..

Air leaks, including exhaust manifold leaks, can cause severe damage to the engine. Your case is an extreme example but is the common result of air leaks that go undetected or repaired for only a short while.
Big Jim

 

[meff99]

I just found out my 99 4.0L possible has cracked heads. Plugs on 3 and 4 were cracked and I was low on coolant. Its never got hot but did run lean for awhile.
Going to tear into it pretty soon. Maybe it's just the gaskets

 

[polar765]

where are you located I just pulled a 93 4.0 ,heads are good just had lifter rattle ,I am in central Washinghton