Okay, so i have replaced the thermostat 2 times in the last year and i know for a fact that my radiator works. whenever i drive on the freeway with the ac on the engine begins to rise in temp, then when i turn it off it cools down. I switched the flow so that the ac pulls from the outside air instead of inside, and that seemed to help as well. I think the problem may be that my radiator fans are not kicking in.

Is the anyway to check if the fans are working properly?

PS. I live in AZ so the temp today was like 102.

 

When the engine temp goes up -stop, leave it running, open the hood and look.

 

Let my ask you this, when you say you're radiator is working what does that mean? I recently had a overheating problem. My car would run hot only on the hwy with the AC on or off, and turning on the heat was the only way I could lower the coolant temp. In city traffic the engine wouldn't run hot, only on the hwy. I started with the basic, coolant flush and new thermostat, no dice it didn't help, then I started questioning my radiator. Several years back I had a fender bender and the body shop replaced the radiator. Appearantly the radiator they installed was a single core radiator and not a dual core like the OEM 3rd gen radiators. I guess over the years my single core radiator was slowly getting cloged internally, because looking from the outside my radiator "look like it was working" no leaks no drip nothing.

Personally when you're traveling on the hwy, the air flow that's naturally going through your radiator is A LOT more than what the fans can provide. So once you've confirmed your radiator fans are working properly during city trafic, and you have no leaks, I wouldn't overlook the radiator regardless of how it looks from the outside.

MIKE

 

Hey CandiMan,

how the weather over your state,

I heard that it bad over there,

 

First: Flush the radiator with a high pressure solution. ( about 30 PSI)
Second : definitely check the level of freon in the A/c system
Third : is your car sitting level? I had a car that was sagging in the rear and it would overheat if I turned on the A/C

 

I'm in FL too...and right now unless you're in the panhandle it's not to bad. They better expect a beating from Ivan though. Last weekend in Tampa we got the weaker end of Frances, but it still knocked out power, and there was a lot of tree debris. And car accidents, because of all the traffic lights being out. Crazy stuff

 

Might wanna check your water pump. Mine overheated last summer due to the water pump failing, though I'm not sure if I overheated immediately due to the failure or it was something that took time to kick in.

 

Get ready for this. I had the same thing happen on my ’94 on a trip to and fro St. Louis. Guess what the problem was? A clogged catalytic converter. Apparently, after a while—11 years and 205k miles—the catalytic converter can become clogged. As a result, the exhaust gasses will build up and cause the engine to overheat. This anomaly will only become apparent on long, highway drives. When you stop and let the engine idle, the temp gauge goes down. Weird!

Mind you that prior to my trip, I had already flushed and refilled the coolant—something that I am well experienced in doing. The water pump and thermostat is no older than 2 years old.

How did I find out about this? My father told me! On older cars, this used to be a common problem; however, on newer cars this is quite rare. Also, I had another “old skool” mechanic tell me the same thing. Actually, he said that back in the day, they would just punch a hole in the CC to inexpensively fix the problem.

Was that really my problem? Well, I changed my catalytic converter, went on another long azz drive to Niagara Falls. Car ran like a champ to and fro with the temp gauge sitting slightly below the half mark.

Now, this is not to say that this is your problem, but it may be a troubleshooting tree to investigate after all other options are exhausted (no pun intended).

Good luck and let us know what you find.

 

I replaced the ac compressor, receiver, and recharged the system at the begining of the summer so i don't think that is the problem.

I checked the fans and they seem to be working just fine.

The coolant does leak a little but just when it gets hot.

My car is sitting at the stock stance.

And the water pump was just replaced about a year ago.
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I will have to look into the cc. Tell me did your car still overheat at night on the highways? Because, mine doesn't at all. It stays right at the half way mark.

The radiator has been replaced and has about 40K on it. It's not OEM, but i am not sure if it's dual core. I don't remember the brand, but it is made of metal and not plastic like some cheap aftermarket ones.

I think i have narrowed it down to these two possibilties. Any other suggestions?

 

since you say the coolant leaks when it gets hot, have you ever replaced what is leaking out?....its likely your radiator.

 

If your coolant leaks when it is hot, then you will have to investigate that issue—unless it is coming from the overflow container. When I drove to St. Louis, it was during the day; therefore, I cannot answer your night question. On the way back from St. Louis, I mitigated the overheating by keeping the rpm below 3k (anything above that would cause the gradual overheating condition after about 3 hours of driving). Again, in my case, I replaced the CC and all is well again residing on the right side of 200k miles.

Either way, I DID NOT have any coolant leakage in my situation.

 

Try replacing the radiator cap. I had a similar issue... No leaks with the radiator but when it got hot, it started leaking somewhere... Rad cap changed... No problems since...

 

first of all, did you spot any leaks? if not, then get a prestone radiator cleaner kit. drain your fluid, refill it with water and cleaner kit. drive around for a whole week or two. drain your fluid. now hand flush your entire system starting from the radiator, then unhook one of your heater core, hook up a garden pipe to one of the connector and backflush it. keep your water pressure low or you'll get water flying all over! also, be sure to recycle your toxic waste or you're gonna ended drinking them in the future!

 

also, check your water pump too....you might need to change it if it's all seized up.