Just replaced the fan clutch and radiator. Water pump is fine: when I gun the engine, a fountain of coolant blows out. So it's still pumping. But the goddamned thing is still overheating after only 15 minutes on the road. Th' hell?
Coolant still bubbling
- Thread starter Charles Austin Miller
- Start date
Sparky
Member
- Dec 4, 2011
- 12,927
Sparky
Member
- Dec 4, 2011
- 12,927
Well I wasn't sure if during that 15 minutes it was a steady temp increase from cold, to normal, to overheat, or it the temp was up to normal then just jumps suddenly.
This time of year it doesn't take long to get up to full operating temp so it may be a bit harder to watch what it is doing and tell the difference. My truck will hit full operating temp in under 10 minutes easy right now.
Are both upper and lower radiator hoses getting warm? There can be a difference between the two but it shouldn't be a drastic difference (one shouldn't be barely warm for example).
This time of year it doesn't take long to get up to full operating temp so it may be a bit harder to watch what it is doing and tell the difference. My truck will hit full operating temp in under 10 minutes easy right now.
Are both upper and lower radiator hoses getting warm? There can be a difference between the two but it shouldn't be a drastic difference (one shouldn't be barely warm for example).
Bow_Tied
Member
Woah, yeah. Definitely sounds like a stuck thermostat, and while you are in there, may want to change the coolant temp sensor since it is so close and easy access at that point.
If you had to change your clutch fan usually a good change that if you can rock it back and forth that the waterpump behind it is junk too. Especially if you smell coolant and can see a little wet under the fan. Some times if they have not been changed or the coolant has been compromised then the internal waterpump pulley could separate and not be pushing any coolant through the system.
If you had to change your clutch fan usually a good change that if you can rock it back and forth that the waterpump behind it is junk too. Especially if you smell coolant and can see a little wet under the fan. Some times if they have not been changed or the coolant has been compromised then the internal waterpump pulley could separate and not be pushing any coolant through the system.
Water pump is only 4 years old. When I gun it, it blows a fountain of coolant. Thermostat is the only thing left.
Mooseman
Moderator
Went through all this with my son's Silverado. Ended up being a clogged rad. Replaced pretty much everything else up to that. Try the t-stat and if still overheating, do the rad.
Radiator was one of the first things I replaced, and I tested it before installing. Ran a garden hose to it and made sure it had good water flow.
I would change out the radiator cap first. I was having similar problems with mine, the upper hose was hot and the lower was cool, changed the thermostat, and both hoses were hot, but it was still overheating and the surge tank was boiling. I noticed that the hoses had no pressure on them when the engine was off and replaced the radiator cap. All is working now.
The thermostat was bad though. I boiled it to check and it never opened. I would highly recommend boiling the new one to make sure it works with all the headache it requires to replace the stupid thing. I have became pretty good at it, but it is still something I never want to do again without a significant amount of cash in hand.
The thermostat was bad though. I boiled it to check and it never opened. I would highly recommend boiling the new one to make sure it works with all the headache it requires to replace the stupid thing. I have became pretty good at it, but it is still something I never want to do again without a significant amount of cash in hand.
Last thing on the list was the thermostat, and it was a devil to get out, as you know. For this job I went ahead and pulled the battery, battery tray and the horns (in addition to the alternator), just to give me more elbow room. The old T-stat appeared to be frozen shut but not gunked-up, and only a trickle of coolant was escaping. Both upper and lower hoses showed signs of bulging. Boiled the old T-stat and the new one side-by-side; the old one remained frozen shut at boiling, the new one (a MotoRad) opened quickly and closed quickly as it cooled. Replaced both hoses, T-stat and radiator cap, filled with Dex-Cool and reassembled everything in about 3 hours (with frequent breaks in the 90° summer heat). Then took the TB on the road for about an hour...absolutely zero overheating, and even saw the temp guage drop at highway speed (first time I've seen that happen in many years). All told, I replaced the fan clutch, radiator, thermostat, serpentine belt, radiator cap and hoses. But everything I replaced NEEDED replacing. Didn't blow any money needlessly.
Nice to see it is working. I didn't use a Delco one because I had a new Duracrap laying around for the other TB and just used it. I guess we will see with time if they last or die off like the others have experienced.