I have been trying to fix what I thought was an overheating issue. Basically, I'll be driving along the freeway and temp will be steady at 180-190 where it should be, when all of a sudden the temp will fairly quickly and steadily climb up to 210-230 and stay there until I shut the car off. When I shut off the car, the temp would drop back down VERY quickly. It'll drop down to an indicated 160 within literally 3-4 seconds, then finally goes back up to around 180-190 again and stay there.
Twice when this occurred, I was able to stop and shut off the car right away. Like I said, the temp quickly dropped down to like 160 and I could hear a bubbling/gurgling noise under the hood. Once I got to the front of the car I couldn't hear the bubbling noise, and there was no sign of coolant boiling over, and the coolant level was the same.
I figured the problem may be to do with lack of airflow or a clogged radiator, since it occurred on the highway. So I had my current 3-row radiator cleaned and rodded out, and replaced the T-stat with a 180 unit and drilled a bleed hole in it. I filled the cooling system with coolant and distilled water with the front of the car in the air to hopefully bleed any air out. The water pump is a couple of months old and the rad cap is a week old.
I was hoping my problems were solved after having the rad cleaned and replacing the t-stat, but the same thing happened. I was on a pretty deserted stretch of highway, so I shut off the engine and let it coast at 65+mph. Same thing, temp dipped to 160 quickly and came back up to 190ish. I then "push started" the engine back up in 5th gear and was able to get the temp to do this a couple of more times. So apparently it has nothing to do with airflow, since the same thing occurred both at 65mph and at a stop.
There is no rhyme or reason for this. It'll happen when driving steadily at the same speed on flat land. The gauge is a brand new Sunpro mechanical unit. I bought it to temporarily replace the Autometer mechanical one I had, which was also acting weirdly. I honestly don't think it's possible for the coolant temp to drop from 230 to 160 as quickly as the gauge would indicate. It just goes down too fast, and then goes back up. Makes no sense to me at all.
There are no signs of actual overheating. Coolant level stays the same, no boiling over or missing coolant. My electric fan appears to be working correctly, and there are no leaks. No coolant in oil or oil in coolant. No pinging when the temp gauge indicated the car was running hot. I just don't see any signs of overheating. I'd think the gauge was bad, but like I said, I just replaced it.
The ONLY thing I saw which I'm not sure is normal is the level of the coolant in the radiator sort of heaved up and down while the engine was running while hot. But I can see coolant flowing through the radiator and no bubbles.
Does anyone have any clue what's up here? I AM STUMPED and tired of replacing things!
Twice when this occurred, I was able to stop and shut off the car right away. Like I said, the temp quickly dropped down to like 160 and I could hear a bubbling/gurgling noise under the hood. Once I got to the front of the car I couldn't hear the bubbling noise, and there was no sign of coolant boiling over, and the coolant level was the same.
I figured the problem may be to do with lack of airflow or a clogged radiator, since it occurred on the highway. So I had my current 3-row radiator cleaned and rodded out, and replaced the T-stat with a 180 unit and drilled a bleed hole in it. I filled the cooling system with coolant and distilled water with the front of the car in the air to hopefully bleed any air out. The water pump is a couple of months old and the rad cap is a week old.
I was hoping my problems were solved after having the rad cleaned and replacing the t-stat, but the same thing happened. I was on a pretty deserted stretch of highway, so I shut off the engine and let it coast at 65+mph. Same thing, temp dipped to 160 quickly and came back up to 190ish. I then "push started" the engine back up in 5th gear and was able to get the temp to do this a couple of more times. So apparently it has nothing to do with airflow, since the same thing occurred both at 65mph and at a stop.
There is no rhyme or reason for this. It'll happen when driving steadily at the same speed on flat land. The gauge is a brand new Sunpro mechanical unit. I bought it to temporarily replace the Autometer mechanical one I had, which was also acting weirdly. I honestly don't think it's possible for the coolant temp to drop from 230 to 160 as quickly as the gauge would indicate. It just goes down too fast, and then goes back up. Makes no sense to me at all.
There are no signs of actual overheating. Coolant level stays the same, no boiling over or missing coolant. My electric fan appears to be working correctly, and there are no leaks. No coolant in oil or oil in coolant. No pinging when the temp gauge indicated the car was running hot. I just don't see any signs of overheating. I'd think the gauge was bad, but like I said, I just replaced it.
The ONLY thing I saw which I'm not sure is normal is the level of the coolant in the radiator sort of heaved up and down while the engine was running while hot. But I can see coolant flowing through the radiator and no bubbles.
Does anyone have any clue what's up here? I AM STUMPED and tired of replacing things!
Did you get your t-stat in the right way when you switched to the 180*? I know it sounds dumb, but a simple mistake like that can cause all sorts of problems.
