Overheating in drive throughs

[GeoffM]

Today I had the privilege of discovering my car is overheating at drive throughs.
I ordered some water, poured it in the overflow tank, and drove away.
As soon as I started moving, the temp dropped again.

Several miles later, I was sitting at a light, and it did it again.
The RPMs dropped in the tell tale way that says the fans are coming on.
I didn't hear if they came on or not, but I did see my temperature spike.

I haven't had a chance to look at any of this yet.
Does what I described sound like a clear cut problem?

[illinois_erik]

bench test your thermostat, did your fans ever kick on? bench test the sensor/switch..to me though it sounds like the radiator has just seen its best days, filled with crap. if you can afford the down time, fill it with vinegar and let it sit a weekend then flush it out..or just buy a new one, stock style or all aluminum, theyre about 100 bucks on ebay, i got an all aluminum one double core with a lifetime warranty for like 90 bucks then i got a half sized aluminum triple core for my swap car for about 120 shipped

[Joey GT-R]

Your thermostat is probably getting stuck closed and as the car is running it is getting unstuck and cooling the engine, try replacing it and see what happens.

[GeoffM]

Two replies for thermostat, I'll give that a shot when I get to work on it tomorrow.

I'm also thinking of the fans, I'll sit there and watch them if that's what it takes.
Thanks for the advice guys

****I may have a coolant leak. If I do, it's very very small. So small, that I can't find where it's coming from, because it's only dripped less than a 1/4 cup (I think) in the week I've noticed it.
If I had low coolant, it wouldn't cool back down when I drove it, so this is irrelevant, correct?

[illinois_erik]

Two replies for thermostat, I'll give that a shot when I get to work on it tomorrow.

I'm also thinking of the fans, I'll sit there and watch them if that's what it takes.
Thanks for the advice guys

****I may have a coolant leak. If I do, it's very very small. So small, that I can't find where it's coming from, because it's only dripped less than a 1/4 cup (I think) in the week I've noticed it.
If I had low coolant, it wouldn't cool back down when I drove it, so this is irrelevant, correct?

Oh also, trapped air in the system can cause an overheat, burp her well after tinkering. good luck

[oyajicool]

I would check the rad fan operation first before getting into thermostat if it was my car.

[jhondayaaj]

Definitely the fans first. Make sure t stat opens up and a few minutes later the fan should kick on. Both of them. I would rev the engine up at about 2500 rpm at the throttle cable to help it open quicker and the fans to come on sooner. But make sure both fans work and are blowing strong and pulling in towards the engine and not pushing. Good luck.

[HondaFan81]

I agree on first checking or replacing thermostat as well. If not, than I agree with looking into the fans. However, you indicated they worked in your statements.

I can tell you our Accord radiators need to be like less than half-full to overheat (50/50 coolant mix). If overheating is due to coolant level, it would have to be a significant leak or small leak over long period of time.

Regardless of outsome, to note condition, I'd inspect your coolant hoses and radiator condition. If you notice any white/green colored powder near any joints, it may indicate a coolant leak. Radiators deteriorate in our state from road salt, so check it out.

[oni_cb7]

If you have AC, then turn on the AC button and both the fans should be working. If not, then you have to figure out if the motor on the fan is broken or not.

[SilverShadow]

Sitting at a Drive-thru or traffic light and the car overheats brings back memories. I drove the wagon from L.A. to Vegas and this happened on a over 100 degree weather. I had to turn the heat on the entire trip and back!!! When I got back, I got a new radiator for 120 and the car ran perfect. Ran for another 3 years with no problems. Car was stolen last year.

[GeoffM]

I ran power to the fan on the passenger side, and it came on.
I was trying to get to the connector for the one on the drivers side, but while I was over
there I noticed no coolant in the rad. I added about 1/4 gallon of water.
Bled it, and sat there and waited for a leak or the fans to come on.

After several minutes of waiting, I decided that it's not the heater core, or the heater lines.
I do see a few drips on the ground, but can't for sure say that's the muffler.

I also took it up to my old autozone and put a pressure tester on it.
(Scariest thing I did that day, opening the rad cap while hot)

I upped the pressure till I saw something leak. It turned out the top rad hose was loose.
Fairly decently loose, as I turned the screwdriver at least six times to get it tight again.

That was all yesterday. It was raining, so I couldn't check for more leaks.
If it stays dry today I should be able to. Hopefully I'll hear the fans kick on as well.

[Losiracer2]

I recently had an oil cooler coolant hose leak on me, the one right behind the oil filter and oil cooler. That was a bitch to get off from underneath the car, so don't rule out hoses in weird spots that could leak.

Our cars are getting to the point where everything, rubber related should be replaced or will leak no matter where you live.

Make sure you don't over tighten the Top rad hose to the rad, that spout is plastic and does break if the plastic is brittle enough. That's why I had to get a new radiator because of that piece breaking on mine. Kinda sucks because the old one was a dual core and now all they make are single core replacements. Unless you buy a Koyo or something pricey.

I think I got mine at O'Reilly auto for 80 bucks with a lifetime warranty.

[HondaFan81]

Any feedback?

Loose upper radiator hose clamp is significant! What were you thinking? If that clamp has loosened up on you before, replace it.

Get some 50/50 coolant mixture back in your coolant system. Like I said, our Accord radiators typically are less than half-full before they overheat. I've fixed quite a few coolant system related problems to our Accords on people's cars, including my bro's.

I agree with replacing ALL coolant hoses on our cars every few years. I have noticed on newer Hondas with blue coolant fluid, the hoses last much longer, they do not degrade from inside-out like the older green fluid. We have 2 newer Hondas with blue fluid and if you keep car until 300K miles...you only have to replace all coolant hoses at like 150K miles. Amazing and much appreciated!

[GeoffM]

Nothing yet. It looked like I had another puddle under it at work today, but I was in a hurry and couldn't get underneath it and see if it was new.

This was the first time I've had to tighten it, but I never re tightened it since I put it on.

I'm looking for spring clamps, but encountering a good amount of debate between the two.
Any advice?

I'll try to park inside tonight and put some cardboard under it to see if it's still leaking.

[AAPOQ]

Oh also, trapped air in the system can cause an overheat, burp her well after tinkering. good luck

Pardon my ignorance, but how do you burp a car?