HI, I have an old and rusty, usually trusty 95 jeep cherokee. I started having over heating issues with water boiling in the over flow. I changed the thermostat, added water, burped it. Still the problem persisted. ONLY it was boiling over in the overflow and OUT of the over flow. Would have to drive with the heat on to keep it cool. SO, replaced the water pump, checked hoses for damage. Hoses good, water pump in. Still boiling into over flow. Replaced head gasket and tappet(SP?) gasket, and STILL BOILING! Today I over heated, boiling in overflow, and steam was coming out of the side of the engine where the gaskets had been replaced. Looked at my oil, that's good color, no water in it. Let the engine cool, added water as the resevoir emptied back into the engine.

What else could it be? I am at a loss... This is my work car for doing my route, and aside from this cooling issue, the engine is still running great. Would prefer to keep it that way.

 

Head gasket. Hate to say it, probably have to do it again. Not sealing right. Use felpro headgasket and new head bolts. Take time and make sure surface is clean. Would be good to have head checked for warping.

 

What about the radiator? It could be damaged which would constantly allow air in meaning that it would be impossible for you to actually fully burp the system of air.

 

I used the felpro head kit. The head was also checked prior to putting it back together... Radiator is 2 years old.

 

If its boiling out the overflow, replace the radiator.

IF its bubbling out the overflow before the radiator is warm, its the head gasket.

 

Head gasket is probably blown again now if you have over heated it that many times but u can test that . Did you ever change the radiator cap? If it does not hold pressure the coolant will boil at a much lower temperature. I would start by doing a pressure test on the cooling system u can normally rent the tool to do it . If the system holds pressure try a radiator cap. Btw dont just throw a new radiator in it because it is boiling dont just throw money at it find the problem first

 

head gasket, try n get your radiator cooked if you have a shop near you or just get a new one.. before you replace it this time, if its blowing out the side of the engine its the gasket, also check for any micro cracks in the head, just to verify

 

I agree if your seeing steam out the side you blew it again but you still need to find the problem either something went wrong when u changed it or something in the cooling system was not up to par. Still bet the cap is bad. A radiator that is 2 years old should not need to be replaced but the aftermarket ones always have cheap caps. Still would be good to check it out see how it is flowing

 

If you have an old radiator this could be the cause of your overheating. J"st buy a new one. Its not worth the guess.

ALso you can blow compressed air in each cylinder. This should blow back through the overflow if your head is leaking.

A rubber tipped blow gun works great. Or a leak down tester.

 

Ok... I did look at the rad cap. I can see no cracks in the rubbers on it. BUT, it is a cheap part, so buying a new one is not a problem. The radiator is getting hot before it boils in the over flow. Then it sucks it back down the bottom of the res as it cools. Yes, I realise I am going to have to redo the head gasket. It actually never steamed out the side of the engine prior to the head gasket change. The head gasket was done last week Tuesday. So, I will check for micro crack in the head.

Now, I didn't over heat it wear the light came on, but I am thinking that stupid thing isn't working right. I woudn't have even known that I was getting hot had I not hopped on the highway to cut over to the next road, then I heard that rattle... Shut it down right then, so maybe just didn't have a chance to get the light to turn on. I have one of the stupid lights. I wish it were the gage, but... I am not that talented to figure that one out.

Anyway, what else should I be looking for aside from the rad cap, could I possibly have a blockage in the engine itself not letting it circulate?

 

Actually, I have a red neck engineered sparkplug end that I used to figure out that it was the head gasket to begin with. One of the guys from work made it for me. Works like a dream.

 

Didnt see where your radiator was only two years old. It should be fine.

 

OH, and BTW, when I just do normal driving with it, it doesn't have any issues.... Just when I am doing my route work. Maybe I aught to just sell it to the kids down the way that want to turn it into a two track mud truck...

 

I take it you had the head resurfaced?

this is a must.

 

yes, the head was inspected and rolled by a machine shop.