gmc jimmy cooling problem.

NYSpeed Automotive
1

Well i just bought an 88 jimmy. Its has the 2.8.

It has a rebuilt motor, the guy put in an electric fan and it had a bad temperature sender when i got it. coolant gauge would stay pegged at the top.

I changed the temperature sender and sensor and threw in a new thermostat.

Now the gauge is working but the truck goes about 240 then the thermostat opens and only goes down to about 210?

Checked the radiator and its almost all the same temp across the board. The only thing i can think of now is the electric fan is not strong enough or the system needs to be flushed.

Any idea’s ?

2

Those things always had cooling issues stemming from they came with dex cool and people would add glycol (green to it) it would turn the dex cool to jelly and clogg up shit. Try flushing the hell out of it first

3

they had dex cool in 88?

4

These never cam with dex cool. dex cool came in the s10’s starting end of 95.

I am still thinking the system needs a flush.

5

^^^yea, and at 240 that thing should be pissin coolant on the ground. i would put a different guage on it and see what it reads. the stock guage might be off. are you positive the coolant is getting that hot? you could try putting a lower tstat in it and flushing it out. stick to the green coolant.

6

I got the 180 in it. green coolant. used the laser thermometer and it was read 235. so the gauge is reading off only by 5 degrees.

7

I cant say much for the older ones, but the newer one always blow intake gaskets…

8

could it possibly be the bars stop leak i put in there?

The e-fan is the strongest one you could buy.

now that i think about it, you actually need a shroud on the radiator for it too cool correctly

someone on s10planet had the exact same problem you were having. made this. its a piece of sheet metal with a hole cut in it for the fan

http://i97.photobucket.com/albums/l217/neo71665/Truck%20crap/fan001.jpg

9

I was going to make a shroud but the one you posted looks better than the one i was going to make.lol.

could be the stop leak. i will try doing a good flush to it.