cooling problems

[dman726749]

ok, so i have recently changes my coolant, and after i changed it i now have a problem. When i get on the interstate the temp gauge sweeps up pretty high and then slowly returns to normal. I have burped the system several times thinking it was just air, but i think i have ruled that out. In every day city driving it runs cool and the gauge never really moves. I have done some searching around and its seems like my culpret is eitehr the t-stat or fan clutch. I plan to start by replacing the t-stat on friday (first day i will have a chance to do it) and go from there...just seeing if there was soemthing i was missing or some other advice someone had to offer..

Thanks in advance

 

[BrooklynBay]

You said that you started to have a cooling problem only after replacing the coolant. Are you using the same brand of coolant, and mixture as you had in there before? Take a look at the chart below:

 

[dogfriend]

If your fan clutch is bad, it would have more of an effect at low speeds or stop and go driving. It wouldn't cause a problem at higher speeds because you should get plenty of airflow even without a fan.

I would vote for the t-stat sticking.

 

[Josh]

On a 90 degree day my truck runs around the N and the O with an occasional trip to the R. I replaced my tstat with no changes. A cold running truck can also cause bad milage due to the ECU staying in open loop. I'm still trying to figure it out.

 

[BrooklynBay]

When you changed your coolant, did you use any flushing chemicals with the engine running for a while? Maybe there is some corrosion in the radiator that has to be flushed out. It is a good idea to install a flush tee that connects to a garden hose to pressure wash the whole system. Just emptying out the old coolant, and refilling it doesn't get everything out.

 

[gijoecam]

Assuming he's running a 50/50 mix or something remotely close to it, it's the thermostat, guaranteed. It's not opening all the way and can't dissipate the heat generated when you accelerate onto the freeway.

 

[dman726749]

welp it wasnt the t-stat guess its onto the the fan clutch....or possibly the rad cap or drive belt....but i am learning towards the fan clutch pretty heavily...now just to find the time to fix it all.....

 

[Josh]

If the t-stat wasnt opening all the way it would overheat driving around town.

 

[gijoecam]

Not necessarily.... it depends on how 'open' it stops, and how much heat the powertrain is generating. When mine failed, it was totally fine at cruising speeds, but when accelerating from a stop light or onto the freeway, it would spike, then creep back down. When the engine generated more heat while accelerating, the t-stat wouldn't open any further and it would overheat. Then, once up to speed, it would slowly creep back down as it wasn't generating as much heat and could cool itself off.

Now, assuming we can rul out the new thermostat, we need to start looking elsewhere. I'd start with the simple stuff first. The cap *could* cause the same issue, but I neglected to mention that before. (KISS slipped the brain) The fan clutch is easy enough... it's only one nut (and turn it the same direction the fan turns when the engine is running). It's also easy to troubleshoot. With the engine up to operating temperature (and the hotter, teh better) shut the engine off and pop the hood. The fan should not spin freely on the clutch when it's hot. If it does, then yes, the clutch is likely on its way out.

Good luck, and keep us posted!

_Joe

 

[Josh]

good explination. My bad.

 

[Supersnizzz]

I just had the same thing happen to me two days ago, and a new radiator cap solved all of my problems. Turns out it wasn't holding much suction to the overflow tank and randomly would seem to be low on coolant.

 

[BrooklynBay]

10 steps to a clean cooling system.

Draining coolant doesn't loosen up all of the rust, and dirt in the system. It is recommended to do a system flush. Here is the procedure:
1. Attach a flush tee in one of your heater core hoses.
2. Open your radiator drain **** valve, and drain your coolant. Close the valve when you are finished.
3. Attach a garden hose, and remove the radiator cap.
4. Flush with water until the water coming out is clear.
5. Add some cooling system cleaner, like the one from Prestone. Put back on your radiator cap, and flush tee cap. Run the engine until it is hot. Keep your heater on throughout this entire procedure.
6. Drain your cooling system, and reconnect the garden hose. Flush your system again until you get clear water coming out.
7. Drain your radiator. Add some coolant, water, and anti rust. Prestone also makes anti rust.
8. Run your engine with the radiator cap off, and check the coolant level in the radiator. You will see the level drop when you start the engine. Add a little water if necessary to obtain the proper mixture. Put the cap back on.
9. Run your engine for a few minutes, and check to see if you have heat coming out of the interior vents.
10. Wait until your engine has cooled down to open the radiator cap. Check your coolant level once more, and the level in your overflow tank. As a extra precaution (optional) you could use a radiator pressure tester like the one made by Stant to check for any leaks. It is best to do this at the end, and not the beginning. If there is some area that was sealed from leakage because of a sludge build up, it will be more noticeable at the end.

 

[dman726749]

Not necessarily.... it depends on how 'open' it stops, and how much heat the powertrain is generating. When mine failed, it was totally fine at cruising speeds, but when accelerating from a stop light or onto the freeway, it would spike, then creep back down. When the engine generated more heat while accelerating, the t-stat wouldn't open any further and it would overheat. Then, once up to speed, it would slowly creep back down as it wasn't generating as much heat and could cool itself off.

Now, assuming we can rul out the new thermostat, we need to start looking elsewhere. I'd start with the simple stuff first. The cap *could* cause the same issue, but I neglected to mention that before. (KISS slipped the brain) The fan clutch is easy enough... it's only one nut (and turn it the same direction the fan turns when the engine is running). It's also easy to troubleshoot. With the engine up to operating temperature (and the hotter, teh better) shut the engine off and pop the hood. The fan should not spin freely on the clutch when it's hot. If it does, then yes, the clutch is likely on its way out.

Good luck, and keep us posted!

_Joe

yea, i read the same thing in my repair manual about the spinning the fan, and indeed it does spin freely, so that seems where my problem lies....next day off i guess i know what i am doing....

 

[Josh]

I tried replacing my radiator cap but no joy. It was 93 today at about 70% or so humidity and the temp gauge sat on the leading edge of the N and with a/c was between the N and the O. :fire: I'm starting to wonder if my temp sender for the gauge is bad?

 

[dman726749]

ARRRGH fan clutch and rad cap didnt solve the problem.....what else could it freaking be?????? when i get on the interstate the temp goes way up then comes down...


could it be a slipping drive belt? bad tensioner allowing the belt to slip?.....

i am really getting tired of throwing money at this stupid problem.

 

[dogfriend]

I would test the thermostat. I know you replaced it, but your symptoms really point to it.

Other more remote possibilities:

Blockage in the cooling system.

Head Gasket problem (not likely, as you would see other symptoms too)

 

[old mechanic]

Since you did not have this problem until you changed the antifreeze did you by chance spill any antifreeze on your belt or pullys when changing the antifreeze or when adding antifreeze?

 

[dman726749]

Since you did not have this problem until you changed the antifreeze did you by chance spill any antifreeze on your belt or pullys when changing the antifreeze or when adding antifreeze?

could have but its been over a month of driving it everyday so if i did, i am sure it isnt the problem....guess i will get another t-stat and try again....

 

[shamaal]

No offense, but I've heard these can be installed backwards.

 

[Arnie897]

Remember this?

http://www.explorerforum.com/forums/showthread.php?t=137190

I ended up with a new radiator....and it finally solved the problem.