2.5L - Need advice

[87Chief]

I just got my comanche back a few weeks ago. The previous owner said it was over heating going all the way to red line and such but he said he would stop and let it cool down. Well he went to auto zone and got a thermostat and tried to replace it, and couldn't. So he left the thermo out and drove it home like that...

 

I haven't looked into to the truck much it has started up and ran for about a minute (to move in and out of the garage) and seemed fine.

 

I guess my question is should I just take it out and rebuild the motor? I would run a compression test and such before I took it out, I just need some advice whether to spend the money on the 2.5 or let it sit aND save up for a 4.0 swap?

 

Any 2.5s out there with some advice? Jeep is a 1987 2.5l 5 speed 4x4

 

Thanks

[benjy_26]

I have a 2.5 MJ and I like it. It keeps up with traffic just fine, gets good mileage even on 31's, and hauls and tows pretty well for what it is.

[Eagle]

Any 2.5s out there with some advice? Jeep is a 1987 2.5l 5 speed 4x4

How many miles on the engine?

 

I have an '88 2.5L that runs okay, but at 209,000 miles it's pretty tired.

[87MJTIM]

I'm not familiar with the 2.5.  Does it have an open or closed cooling system?

 

If it over heats while operating, it sounds like a cooling sys problem.

 

Closed system:

 

Is the cap busted?  Get the Volvo cap.

 

Is the reservoir bottle cracked?  Need to replace it, with the Volvo cap.

[87Chief]

It has about 200k miles on it, and it does have the open cooling system from what I can tell. I used to drive it every other day before I sold it, with no problems. I guess that's what I get for selling it  :hmm:

I've never heard of the volvo cap? Have a part number? If I was going to rebuild it I would replace the radiator also, it's pretty old and crusty. The bottle seems to have no cracks in it. If I remember I'll go home today and take some pictures and see what yall think.

[benjy_26]

The 2.5 has the open cooling system. No Volvo cap needed. I have well over 220,000 on mine and it's still running strong. Maybe the PO gave mine good maintenance.

[yxmj]

Just my opinion but rebuilding seems to be an extream to fix an overheating problem....flush the system change your T-stat and maybe your water pump first...that would be under $100 if you do it yourself....then you can drive it while you make a decision on a 4.0   :dunno:  

[87Chief]

Just my opinion but rebuilding seems to be an extream to fix an overheating problem....flush the system change your T-stat and maybe your water pump first...that would be under $100 if you do it yourself....then you can drive it while you make a decision on a 4.0   :dunno:  

 

Thanks, I will look into it later today. I'm sure it's going to need all of it anyway.

[MJanky]

I agree with yxmj. The 2.5 is all iron, not like a lot of other engines with alloy heads and whatnot where once they overheat they warp and crack. Fix the overheating issue and you will probably find rebuilding isn't necessary. Even a high mileage 2.5 that has withstood abuse can give decent service. I hate to sound cliche but compared to other engines I've dealt with the AMC 2.5 is built like a tank.

[87Chief]

Here are some pictures. I found a manifold bolt is broken off inside the head..

[benjy_26]

Pretty standard stuff. You'll need to get your manifolds off, extract the bolt, install a new gasket, and re-assemble. Not too bad, really.

[87Chief]

I'm guessing it would be easier to remove the power steering bracket and extract the bolt once the manifolds are off, or remove the head and get new valve seals and such?

[benjy_26]

If your compression is testing within specs, I'd just extract the bolt.

[SVPete]

By the photo, that radiator looks pretty clogged. It looks like a starting point for the overheating problem.

 

 

In addition to the taped hose that looks like it has been leaking also.

[13 Legion]

Address the overheating problem. Check all facets of your cooling system. Is coolant just low,old?Act as if the PO did zero maintenance on this system. Replace thermostat. Check your water pump for leaks. Check radiator for leaks. Replace hoses as well as flush and refill with fresh coolant. Than at least you have a fresh starting point. Do this prior to just doing an expensive( time and money) rebuild right off the bat. I have an 87 2.5 and currently just did all of these things. It's not expensive and you can do all the work yourself. Your only big expense in this may be buying a radiator or water pump if needed.

[87Chief]

Thanks for the advice guys! Hopefully I can dig into it this weekend!