Running hotter after coolant flush

[Rewind351]

Hey guys,

I flushed the radiator and replaced with a 50/50 mix and the car seems to be running hotter than before. Seems to run between 210 and 220 degrees. I burped the system and tried everything I could think of. The fan kicks on at 218 degrees and off at 210 degrees according to my autometer gauge. I thought the stock points were 221 and 200? Any ideas what I could do besides upgrading the radiator? Also, the car usually would run around 190 degrees before the flush. I've had a 180 thermostat in it for a couple years.

Thanks,
RWD

[keg65]

maybe you damage thermostat.
Might try to replace it.

[Rewind351]

Well, I know the thermostat is working because the upper hose gets hot and before the engine get to operating temp the upper hose is under pressure.

It doesn't make sense to me why it would be running hotter.

[Dark04GT]

If it is running that much hotter I am most suspicious about air bubbles. I don't know how to drained it but hopefully you ran the engine and flushed the entire system. If you have a couple air bubbles trapped in there / didn't fill up your system all the way that could explain your slightly higher temps.

If it is running that much hotter I would consider flushing again and using a water/coolant mixture with more water. Water is the portion that does the majority of the cooling. I would run something like 60/40 (water/coolant).

Take a look at this site to double check your draining technique:
How To Flush Your Mustang Coolant

[Rewind351]

If it is running that much hotter I am most suspicious about air bubbles. I don't know how to drained it but hopefully you ran the engine and flushed the entire system. If you have a couple air bubbles trapped in there / didn't fill up your system all the way that could explain your slightly higher temps.

If it is running that much hotter I would consider flushing again and using a water/coolant mixture with more water. Water is the portion that does the majority of the cooling. I would run something like 60/40 (water/coolant).

Take a look at this site to double check your draining technique:
How To Flush Your Mustang Coolant

Thats exactly the approach I took. You are absolutely right and I feared the system had trapped air. I burped the system by lifting the front end so it was highest, and running it until hot with the cap off of the overflow. I'm at a loss. I even increased the water in the system. I'll run it again really good today and see if anything changed.

I suppose it is possible that the flush broke loose crap that is clogging a portion of the radiator so its not cooling properly? That's reaching, but I guess the only way to know would be to get an IR gun and see of there is a cool spot in the radiator?

[02silverstang]

here try this hope it helps

How To Flush Your Mustang Coolant

[Rewind351]

here try this hope it helps

How To Flush Your Mustang Coolant

Seriously?

[Dark04GT]

Thats exactly the approach I took. You are absolutely right and I feared the system had trapped air. I burped the system by lifting the front end so it was highest, and running it until hot with the cap off of the overflow. I'm at a loss. I even increased the water in the system. I'll run it again really good today and see if anything changed.

I suppose it is possible that the flush broke loose crap that is clogging a portion of the radiator so its not cooling properly? That's reaching, but I guess the only way to know would be to get an IR gun and see of there is a cool spot in the radiator?

Sounds like you are reaching with the clogged radiator.

So if the autometer temp gauge is the same and nothing else was messed with during this flush then I wouldn't mess with it too much. As long as the car is not overheating I would drive it around and check the coolant level several times over these next couple of weeks. With the 180 degree thermostat it should not be running that high but being in the low 200's is not that bad either.

If it keeps staying high you could consider a new radiator / thermostat. Other than that I would wait it out, keep the coolant level topped off and see how it goes.

[keg65]

My thermostat got stuck open and that caused mine to overheat. If the water flows to quickly it doesn't have time to cool in the radiator.
I can't run an 180 thermo or it will heat up, but with a 195 its fine.