I have had a couple of problems with my cooling system lately. Car will idle great with no overheating, but as after driving awhile it may overheat at a red light. Seems as if while driving the car doesnt normally overheat. I stripped my interior down a few months ago, just hooked my heater controls back up this past weekend. I noticed again the car would idle fine with the heat on, but if I turn the heat on while driving the car wants to overheat. Sometimes the fan runs when it should, sometimes it doesnt. First known problem is a loose connector on my thermistat. When its disconnected my fan runs constantly, and my car overheats. This makes since to me, seems as if the thermistat closes when this is disconnected. I do not understand why the car runs hotter with the heat on. Could someone point me in the right direction?
Is your fan reversed maybe? It should be pulling air into the bay, not pushing hot air from the bay through the radiator.
“One thing I’ve noticed over the years is that if you drive into London at 6am, half of the cars on the roads are Porsches and Astons. Whereas if you go in at ten to nine, they’re all Renaults. Simple solution, then. You want a nice car? Get up earlier and do more work.”
Havent checked that. I did notice that there are two fans, one that pulls air into the engine bay, and one on the other side of the radiator that pushes air. I have never seen the one that pushes air turn on. Ill check the fan direction later today
The other fan is probably for your AC and only comes on with AC turned on. I believe somewhere it says it may come on if you're overheating and the primary fan can't keep up, but I have never seen this happen, even when I was overheating.
It sounds like you're not getting enough air over the rad to keep it cool when you're not moving. Check your cooling fan and if it's not coming on as the temp rises (certainly as you begin to overheat) then you need to fix your fan. It could be the motor, the relay, fuse, or the temp switch in the thermostat housing that turns the fan on.
Your heat was probably helping keep everything cool, as since you messed with it, maybe your heater core isn't doing as much cooling for the engine and now the broken fan is exposing itself.
did the overheating start before or after interior was stripped? what shape is the coolant? when the car is warm you can grab the upper and lower hoses to help figure out if it's a thermostat. also feel the radiator top to bottom and side to side, if the top is hot and bottom is not (or vice versa) the radiator is most likely the culprit. also works to feel upper and lower heater core hoses as well. remember it's a system with a flow pattern and you can follow the heat or lack thereof. the fan closer to the bumper is for pushing air into the condensor, the fan in the engine bay is for pulling air through the radiator. all else being equal i have never seen a fan running backwards. but it's not out of the question, i suppose. by the way it's a good idea to head for the original "dual-stage" thermostat if you're thinking about changing. and by loose connection on your thermostat, i think you might be thinking about one of the sensors in thermostat housing? i have disassembled all the connectors and replaced the wiring due to corroded original wires. i would bet it to be the radiator, though. when you're driving you are basically forcing air through the entire radiator surface (and also building up some extra heat. so when you stop you are not driving air through the radiator anymore. and also the radiator fan does not run all the time, only when it is triggered by the switch(one of the sensors in the coolant stream. and also if the cooling fan does kick on it's only on one side of the radiator and is only pulling air through that side.
There are some differences between the Gen 1A and Gen 1B cars. I know firsthand, I own two 1A's and one 1B.
BTW, NO means Normally Open, and NC means Normally Closed, if you didn't know. These thermoswitches control the on and off of the cooling fans.
The 1st Gen A and 1st Gen B are a bit different. In the Gen B cars, the two thermoswitches are NO type switches
1: NO then closes contact after 207 degrees F
2: NO then closes contact after 226 degrees F
Gen A cars:
1: NC then opens contact after 177 degrees F
2: NO then closes contact after 226 degrees F
I think I have that right, please correct me if I am wrong. I found out the hard way you cannot simply swap the switches from the 1st Gen A and B, they are not the same and operate differently.
Basically, you can fart into your intake and get more than 1 hp difference into your car. Hell, I've had a 5 hp fart.
"Trapped in time. Surrounded by evil. Low on gas."
I thought I could get more chicks with a clean engine.
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.