1988 B2200 Heating Problem

[maclu]

Hello.

I have a 1988 B2200 that heats up too much in the summer heat. The needle almost gets to the H when climbing hills on hot days. Yet in the cold of winter, I have to fully block the rad with cardboard just to get the temp needle up to the half way mark, and the heater puts out very little heat. I've changed the RAD, thermostat and guage sending unit. I've been told by one mechanic that the head is cracked, but another mechanic says it definitely isn't. There are no signs of the head being cracked (ie. oil is clean, rad fluid isn't bubbling, motor runs great, etc). Any ideas on what else may be the problem?

Thanks

[BigEd1]

Sounds like one of two things could be goin on....Either the new thermostat is bad or installed backwards or theres an air pocket that needs to be burped.

[BigEd1]

Oh and by the way........I have a 90 2200 that calls for a 195 degree thermostat. The gauge never gets above the first mark after the thermostat opens. Til then it only gets a little above that line.
Too many times with it runnin as hot as it is and you will be replacing the head.
Sounds to me like the thermostat is hangin open lettin it run hot in the summer and cold in the winter.
Hope this helps.

[maclu]

Hi BigEd1. I've tried 3 different thermostats (either 185 or 195), and they were all installed correctly. I've tried burping the air out, but I'm not 100% sure if all the air is out. Could a blocked heater core cause this problem? I don't think so, but I thought I should mention it in case someone else has seen a blocked heater core affect engine temp.

Thanks

Originally Posted by BigEd1

Oh and by the way........I have a 90 2200 that calls for a 195 degree thermostat. The gauge never gets above the first mark after the thermostat opens. Til then it only gets a little above that line.
Too many times with it runnin as hot as it is and you will be replacing the head.
Sounds to me like the thermostat is hangin open lettin it run hot in the summer and cold in the winter.
Hope this helps.

[BigEd1]

Did you make sure the thermostat had opened before you deemed the radiator and block to be full?
And is there a control valve in the heater hose? If there is be sure it is opened as this could hold air too.
Other than these things, the next thing to look at is the water pump itself, though I really dont think thats the trouble. Let me know how it turns out, in case it happens to me too.

[maclu]

Originally Posted by BigEd1

Did you make sure the thermostat had opened before you deemed the radiator and block to be full?
And is there a control valve in the heater hose? If there is be sure it is opened as this could hold air too.
Other than these things, the next thing to look at is the water pump itself, though I really dont think thats the trouble. Let me know how it turns out, in case it happens to me too.

Hi BigEd1.

Yes, I made sure the thermsotat had opened before topping up the fluid in the rad. I can't find a control valve at all unfortunately. The water pump was checked, and as you suspected, it's fine. I'm at a loss as to what the problem is. Maybe it is a tiny crack in the head like the one mechanic told me, but would that cause these problems?

Thanks

[BigEd1]

I really dont think a cracked head would cause it to run hot TIL it runs low on fluids. As long as its full theres no reason for it to.
There is a way to check for a crack though and its not too hard.
Go to AutoZone and rent a pressure tester or take it to a radiator shop and let them do it. All you are doing is putting pressure on the system and waiting for it to drop. If it does then you have a leak somewhere, be it head, block, hose or otherwise.
Keep me informed as to what you do and MERRY CHRISTMAS TO YOU AND YOURS.

[archer of loaf]

I have a 1990 B2200; the radiator had a blockage somewhere in it causing it to overheat in the summer. Radiator was placed but mechanic neglected to put a thermostat in, this caused the engine to run cold. Perhaps your radiator has a problem?