Headgasket Blown

Ok, i know for sure my headgasket just blew.(Coolant in the oil) So what would be cheaper/ easier, replacing the engine or rebuilding(its a 2.5 with 243,000 on the odo)?

replacing the headgasket would be easiest. unless you bent a rod or something.


-scott

But considering my high milage will i be taking a risk at later problems like bad rings and berings if i just replace the headgasket? I dont want to have a serious prob later down the road.

I don't think so - I've done a couple (mostly because I was doing lifters at the time...)

If you do any work on the head itself (like cleaning up the valvetrain,) a re-ring is also indicated, or you're likely to pop the rings. If you do a re-ring, cleaning up the valves is indicated. Wear on piston rings and valves should be kept about the same.

However, just changing the head gasket is not something that is likely to cause you trouble later. I did my 89 Limited about 80K ago (lifters "went solid,") and my 88 about 50K ago (liftes "went flat") - no trouble with either since.

5-90

Well in that case then ill just take off the head and look and see how bad things look. What should i look for in the rings to tell how bad they are? is it too late to do a compression check(im assuming so)?

Ayuh - too late for compression check (which tells you there is a leak) and a leakdown test (which tells you where it is.)

Good news - as long as you don't see any scoring or striations in the cylinder walls, your rings should be just fine. You can check that without even pulling the pistons.

Going off of your mileage as given, I'm inclined to think it's RENIX vintage (1990 and earlier.) I've got a batch of RENIX 4.0 engines - and everytime I've pulled the head off of one (two sets of lifters and a FAILED oil pump!) I've barely noted any "top cylinder ridge" - the soonest I'd pulled a head gasket off was at 180Kmiles, and even on the engine with the failed oil pump I just needed a re-ring in the block (and new lifters, and a new crankshaft, and a new oil pump, and ...)

Apparently, AMC used a high-nickel alloy (rather like the "grey iron" used in machine tool chassis) which is tougher than the hinges of Hell - because that engine with the failed oil pump had been through some serious abuse while I'd driven it!

Pull the head, take a set of bore gages, and measure the bores. I'd be mildly surprised if you measured one at any point larger than 3.878" (nominal original is 3.875")

5-90

ok, ill look for that. but actually its a 93, it used to be a forest ranger vehicle(i think that explains it the milage)

Oh. A lot of idling, possibly dusty conditions - use a bright spotlight when you check your cylinder walls (I like my SureFire G2Z for that - but any reasonably bright and well-focussed hand lamp will work.)

5-90