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I've acquired a replacement engine for a 2004 Disco with a couple of slipped cylinder sleeves.
The donor engine, the one Im tearing down now to check out before I pull the bad engine has a couple of issues.
1) Cannot get a head bolt out. All the others are loose/out and Im left with one bolt, one of the deep ones inside the rocker cover at the front of the engine is now partially rounded off due to my attempts. I've tried a 2ft breaker bar with another 2ft ext pipe, then a 12 point socket and sadly its not budging. Any suggestions? I dont have anything to weld with and I dont know how anyone could weld a nut or sacrificial socket to the head of the bolt cause its down in there. Suggestions?
2) Check out the cylinders and heads when I pulled the one side off - wow - what is all this stuff? Burnt coolant? all four cylinders are full of chunky, sooty flakes. Is this block toast?
I had a similarly stuck head bolt once. First off, you should loosen head bolts in the same way as you tighten them. If you have removed all the other bolts, you've got extra tension on the one that remains.
I eventually got mine out by strategically grinding away chunks of it and cutting slots that I could get a chisel on.
The black stuff in the combustion chambers and on the piston tops is just carbon build up. Not unusual, but more than I recall from when I had the heads off from my truck. Certainly not a death sentence, and pretty easy to clean up.
I had a similarly stuck head bolt once. First off, you should loosen head bolts in the same way as you tighten them. If you have removed all the other bolts, you've got extra tension on the one that remains.
I eventually got mine out by strategically grinding away chunks of it and cutting slots that I could get a chisel on.
Thanks for the tip and yes, I did loosen them in a clockwise pattern. This last bolt wouldn't budge! Tomorrow im going to try some heat and a couple bangs with a center punch. Though Im not optimistic since there's a ton of torque on it still and the bolt head is rounded..... :-(
Have you cleaned all around the bolt, there is sometimes a lot of gunk in there that keeps a socket from fitting tightly all the way on. Use a six point impact socket, put some valve grinding compount on the inside of the socket. Use a hammer type impact wrench. Worst case you can drill/machine the head off but those bolts are hardened steel so it will not be easy, might be better to have a machine shop do it. Once you get it off, I would recommend hot pressure testing the block and check for leaks.
Have you cleaned all around the bolt, there is sometimes a lot of gunk in there that keeps a socket from fitting tightly all the way on. Use a six point impact socket, put some valve grinding compount on the inside of the socket. Use a hammer type impact wrench. Worst case you can drill/machine the head off but those bolts are hardened steel so it will not be easy, might be better to have a machine shop do it. Once you get it off, I would recommend hot pressure testing the block and check for leaks.
Yea - I cleaned up as much as I could around the head of the bolt. I used a 2ft breaker bar first, then tried a 1/2 impact socket, hammer type drill. Im going to heat it and center punch it tomorrow.
Yea - I cleaned up as much as I could around the head of the bolt. I used a 2ft breaker bar first, then tried a 1/2 impact socket, hammer type drill. Im going to heat it and center punch it tomorrow.
Hammer drill is different than hammer type impact wrench, not clear to me which one you used but this is what I was talking about
You'll want to stick with a 6 point socket versus a 12 for better contact and less chance of jumping. I cracked two 12 point sockets on a particularly tough headbolt, each time thinking I'd finally cracked it loose only to find another cracked socket. Eventually I got it loose with an impact 6 point and a foot foot bar. It's worth mentioning that it was one of the outside bolts about the exhaust manifold so there was decent clearance.
11-10-2022, 03:32 PM
Stuck head bolt and opinion on this!
