running hot?

[johndej]

A few weeks ago I was driving about 200 miles from Richmond to Harrisonburg. I got about 2/3 of the way there and saw my needle creeping up so i took it easy going over a mountain I was coming to at that point, ended up turning on the heat full blast to get the needle to come back down from like 90% up on the gauge. That worked for the rest of the drive so when I got to the burg I topped it off with 50/50 anti-freeze/water (prob actually over filled it, puke tank too). I've driven it the past 2 - 3 weeks and it'll start to get hot after about 20 or so miles of driving and I'll turn the heat on and it'll come back down. It seems to have plenty of coolant (not discolored or anything) and no air in the system (turned the car on, pulled the cap off, topped it off when the coolant drew down some). I'm wondering if the fan or thermostat is working right and if there was a way to get around this (my dad thinks I should somehow be able to maybe wire in a switch for the fan to come on whenever the car starts).

[Oldblueaccord]

Well you did the right thing running the heat to keep it from boiling.

I think I would look at these thing in this order:

1. Thermostat- sounds easy to replace but the bolts can easily snap off in the housing so beware.

2. Radiator-if its old its prolly plugged internally. If you change it change the water pump to since you have the system drained anyway.

3. I guess its possible the guage its wrong but if the heat was very hot then I would say the car is running to hot.

Notice I don't mention the cap or the fans too much. Fans might save you from overheating make sure they work but on my car,5 speed, they never come on so they dont work to keep the car in temp. spec. The cap well I had a leak on my car and drove with the cap loose,no pressure ,for about 3 years before I changed my radaitor out. I just keep it on just enough so the coolant didn't splash out.


wp

quick edit if you turn on the AC button and the HVAC fan on the front radiator fans are forced on. You can pull the AC fuse to keep the AC clutch coming on.

[Toneloc5145]

If you are driving (your car is moving) then your fans essentially are doing nothing to cool the car off. Fans are used during low speeds/idle just to pull in air. Thermostats are very easy to change and cost like 6 bucks at autozone. Your thermostat may be stuck closed.

And are you in Harrisonburg? That's where I go to school (JMU).

[Hauntd ca3]

Your thermostat may be stuck closed.

l (JMU).

or not opening completely

[w261w261]

Have you bled the system (bleed valve by thermostat)?

[bank2me]

Id change the thermostat if it keeps on overheatin check the waterpump, and be careful with the bolts ,I had one snap off in the housing luckily I got it out. Put anti seize on them when putting back in too. Good luck.

[Dr_Snooz]

The cap well I had a leak on my car and drove with the cap loose,no pressure ,for about 3 years before I changed my radaitor out. I just keep it on just enough so the coolant didn't splash out.

I think they pressurize the system to raise the boiling point of the coolant. Don't want it boiling out the top of the radiator.

[russiankid]

Well you did the right thing running the heat to keep it from boiling.

I think I would look at these thing in this order:

1. Thermostat- sounds easy to replace but the bolts can easily snap off in the housing so beware.

2. Radiator-if its old its prolly plugged internally. If you change it change the water pump to since you have the system drained anyway.

3. I guess its possible the guage its wrong but if the heat was very hot then I would say the car is running to hot.

Notice I don't mention the cap or the fans too much. Fans might save you from overheating make sure they work but on my car,5 speed, they never come on so they dont work to keep the car in temp. spec. The cap well I had a leak on my car and drove with the cap loose,no pressure ,for about 3 years before I changed my radaitor out. I just keep it on just enough so the coolant didn't splash out.


wp

quick edit if you turn on the AC button and the HVAC fan on the front radiator fans are forced on. You can pull the AC fuse to keep the AC clutch coming on.

If they snap off, pray you can get them out. I couldn't get mine out so I had to order a new housing.

[johndej]

Update - replaced the thermostat and that seems to have cleared everything up.