My lovely 89 didn't have a thermostat in it when I bought it. Which I didn't know. I put one in it and it runs fine at idle or low speeds. On the highway about 15 minutes of 60mph it starts getting hot. The water is pushing out of the radiator and over filling the coolant tank. Also when you Rev the engine it sounds like bubbles in the heater core. But no bubbles in radiator. Anyone have any ideas?

 

The bubble noise coming from the heater core usually means that you have air in the system. Park it on a hill where the top of the radiator is elevated and run it with the cap off for a while to burp the air out and top it off as needed.

 

Okay so it has been 4hrs u got a how to tip. Did you try it? If you did did it work?

 

impatient are we?

 

I've tried everything. Do you think it would have a blown head gasket? It started last night reving up and down when I press the brake.could the two problems be connected?

 

Its not skipping or anything but has a little flutter while at idle

 

IMO, I wouldn't start ripping the engine apart until I was certain it was a head gasket issue.

Does it have any other signs of a blown head gasket? Like water in oil, oil in water, overheating, fouled plugs (maybe), smoke out of the tail pipe. Get your hands on a compression tester and check it out.

Did you try to burp the air out of the system?

 

I did try burping it. Also I looked in the radiator while the testator was open and couldn't see the water moving. When I Rev it like that the water level goes down and then comes out when it idles back down.

 

I Just got pissed and dropped it off at the repair shop. Think the radiator is stopped up?

 

.......IMPATIENT ARENT WE.......
sorry, shouldnt have said that......I know you're frustrated. I would wonder about an issue with the water pump???? or water flow in the engine itself. I had a 99 dogde (and my brother had an 87 ford truck) that had a similar issue. my dodge, well I never figured it out before I sold it and my brother found his to be a leaking heater core.

 

i'd maybe think the lower radiator hose is failing but...

 

Well I just wonder why the previous owner removed the tstat? Hell it runs like a top other than this dang heating problem. And I do know that yotas Don't like to get hot. Found that out with my old 85 22r.

 

How did it run without the thermostat? If it did not overheat without a tstat and does overheat with one then the problem is with the thermos stat. Is the radiator cap OK?
Could you have installed the thermostat backwards?.

 

[quote=adsmith112379;51844891 And I do know that yotas Don't like to get hot. Found that out with my old 85 22r.[/quote]

Correct get the cooling system problem solved.

 

It ran fine without the tstat. Just wouldn't get the heater warm. I checked the tstat and its opening and closing fine. How do you check a radiator cap?

 

when you say the t-stat is opening but you dont have any water flow, how do you know its open?

what kind of stat did you put in? when you say it gets too hot are you maybe having an over-shoot problem that is so common with these trucks?

 

i check radiator caps by buying a new one, less than 10 bucks i think. 13lbs. cap runs great

 

Since your truck did not over heat before you put in the thermostat I think that you may have put the new one in backwards or put one in that opens above 190F. Flip it around and see if there is flow. Flow can be hard to detect. If you can't see any flow try a little spit and watch it either float there or flow away. If your water pump leaks out of the weep hole on the bottom, or has play when you wiggle the fan blade it is bad. If the radiator cap is leaking replace it. Your local auto parts store can test it for you.

 

Does the temp gauge needle go near the top then settle back down to the middle of the gauge? If so then you have an overshoot condition.

 

So let me get this straight. Your initial problem was the truck would run great without a thermostat. But put one in and it would overheat with the engine under load? It sounds like you have some blockage. Whether it be in the radiator, heater core, coolant passage, hose. That or the water pump isn't pumping enough water. When you put your thermostat in, did the heater work?

Like previously stated, check the inspection hole at the bottom of the water pump. If it leaks or the fan has up and down play then the pump is bad.

If there is a bad hose, no big deal. Trace each hose until you come across one that is plump or cracked.

If there is a blockage in the radiator, no big deal. You can either replace the radiator or have it boiled to get all the stuff out.

If it's a heater core, you can test it by bypassing it manually at the line on the firewall. Or turn the knob on your heater controls to cold. That should shut the valve on the firewall so the water flows past the heater core.

If you have the rear heat option, check the lines running under the body and into the center console.

These are all things that would be easy to check and will be nice to know how the system works later on if you run into it again.