1989 S10 Overheating Problem

[l884196]

About ready to pull out hair over this...

Initially took truck in due to temperature gauge near redlining. Shop replaced water pump.
Truck ran hot on the way home from picking it up.
I replaced both radiator hoses and new thermostat. No change.
Took back to original shop - they fixed leaks and put in another thermostat.
Truck ran hot again on the way home from picking up.
Have since replaced...
Sending Unit on top of engine
Temperature Switch on left side of engine
Installed new Fail Safe thermostat
Installed new pressure release Radiator Cap
Still overheating
Anti-freeze does not appear to be flowing up from engine and through upper hose (not hot).

HELP!!!!!!!!!!

[MT-2500]

What engine?
It sounds like you need to find another shop.
Are you going to fix it yourself or just figure it out for the shop?
Has it been checked for headgasket leakage with a block ckeck tester?
Has the rad flow been tested?
Does the rad get warm at top or bottom?
Does the heater put out good warm/hot air?
MT

[OverBoardProject]

Welcome to AF

MT is right! Look for another shop!
They had no business replacing the water pump unless it was leaking before performing a few simple tests.

Another question is how far are you driving? Is it far enough where the thermostat should be open allowing the top rad hose to become warm?

I just replaced my thermostat christmas eve and had the same problem. After pulling over I found that it wasn't open... took it out and the water was warm but not hot.
I still haven't figured mine out but borrowed a tempurture sensor an it's in my gauge somewhere. SO as long as it doesn't go any higher I'm not too worried.

[sector95]

Sounds like maybe your radiator is shot..... as in all plugged up. If the coolant cannot be seen to move when the engine is warm and the cap is off, then you've got some severe blockage in the radiator core. Since the pump is new and the T-stat is new, you could safely rule out them. I would try removing the T-stat and recheck your radiator flow. Without the T-stat you should see a good flow thru the rad right away; if not, then you're probably looking at a new radiator. Also, if the fan uses a clutch (the fan is attached a big aluminum hub with fins on it and you can spin the fan when the engine is not running) consider replacing it. They do go bad over time and the failure symptoms are not readily apparent.

And ditto the other guys.... run, do not walk, to another shop.....

mike

[OverBoardProject]

In my case my rad was flushed a couple of months earlier and even though it came from one of my parts trucks it looks like it was fairly new to start with.
I did inspect it when I had the trouble.

So his might not be a plugged rad.

[sector95]

Originally Posted by OverBoardProject

In my case my rad was flushed a couple of months earlier and even though it came from one of my parts trucks it looks like it was fairly new to start with.
I did inspect it when I had the trouble.

So his might not be a plugged rad.

Well, I wouldn't put too much stock in having a radiator flushed...even if it's been done professionally. The chemicals used to flush a radiator these days are first and foremost designed to be environmentally friendly; that means they don't do near as good a job at dissolving the crud built up inside the radiator as they used to. You can't really tell the condition of a radiator by what it looks like as you peer into the cap opening.... it's in the flow tubes where you can't see. And the only way a good rad shop will evaluate a radiator is by flow testing it before and after it's tanked. If the shop didn't tell you this or check it, you got your money taken.

[OverBoardProject]

A high volum water hose is a good way to test the flow though.

The water didn't even slow down while going through my rad.

Plus if I had a heating problem my motor would have had problems. I just made a 400 or so mile trip with a full load. 60 of those miles were in a traffic jam since Vancouver was playing Toronto in Vancouver that day. (what a lousy day to plan on a move)

[Cam1959]

Try not filling rad to rad cap neck, but leaving it few inches below. Worked for me to stop leaks. And temp never goes above 120F.