Last post on Sep 26, 2011 at 10:08 PM
You are in the Chevrolet S-10 & GMC S15 Sonoma
What is this discussion about?
Chevrolet S-10, GMC Sonoma, Heating / Cooling, Truck
#44 of 47 1992 S-10 Chevy pickup 4.3L
Oct 13, 2010 (11:35 am)
I just recently replaced a water pump on my 1992 s-10 Chevy pickup. Before this coolant leaked everywhere. So I tore everything apart, put the new part on, new gaskets and put rubber gasket sealer on the gaskets. I got everything all put back together. I believed it to be fixed because it quit leaking. The next day I drove the truck to school and noticed it to be leaking again. I found it to be a pinhole in one of the lines and fixed that as well. So all said and done I finally believed I got it, but the next day I was driving down the road and my temp. gauge went wayyy up. I stopped on the side of the road and checked the coolant it was all up to specs. So I continued to drive home. The truck drove fine and acted fine, and while i was driving, the temp. went back to normal and the check gauges light went off. The temperature gauge now goes up for a few miles and then goes back to normal while i drive it. I'm really stumped on this one hopefully someone can help me out.
#45 of 47 Re: 1992 S-10 Chevy pickup 4.3L [kushinloud10]
Oct 15, 2010 (8:22 am)
Did you change the thermostat?? That will make the temp gauge fluctuate if it's not working properly. The T-stat should be changed (or at least I did and would) when you change the water pump.
You might also have air trapped in the system, especially since you broke it wide open changing the water pump. That air will cause the truck not to vacuum properly and won't push or pull water from the recovery tank. Try bleeding the system. Or taking it to a shop and having it flushed. They can do a pressure flush that will force any air out of the system...
Sep 25, 2011 (11:27 pm)
i have a 94 s10 4.3 5spd i recently replaced the water pump due to over heating and its still leaking somewhere i've bubbled the system a few times then come out the next day and the coolant had leaked out...is there a soft plug around the waterpump area??
#47 of 47 Re: Coolant Leaks [xjdmoorex]
Sep 26, 2011 (10:08 pm)
I've been there done that with cooling issues on my 4.3 I had a while back. Do you have a pressure tester that you can use to pressurize the system with the motor off? IF not, can you rent one or borrow one from a store or friend. I would do this, even buy one, if it's not too expensive.
Then pressurize the system with the motor off. You do this by replacing the cap with the pressure tester. It pressurizes the system and will expose any coolant leaks. You can then trace them with out fear of moving parts and fans and belts and pulleys and with out the noise of the motor running.
Here are typical problem areas I experienced and found are typical of the 4.3. I did this on a later generation 4.3 (2001) so I am not sure how much will have changed, but the basic block configuration didn't change much. Heads and intakes changed, but not much else. My 4.3 had a lower intake gasket leak. It was spewing coolant into the valley where the valve covers, intake and heads came together. 4.3's are prone to this leak.
Since you also state you overheated, you might have cracked or warped a head. Especially if you have aluminum vortec heads. If that's the case, you'll have to tear down and replace the affected head. The pressure test though will tell you where it's leaking, unless it's leaking internally into the block. If that's the case, your oil will be full of water.