Temp gets hot pulling hills
 

I've noticed on warm days, my 85 GSL starts getting hot whenever pulling up a hill. Doesn't matter what gear I'm in or how hard I'm working it, the temp guage starts to climb and hits the halfway point (keeps climbing on longer hills, almost had to pull off the road once to let it cool). Then as soon as it levels off or starts going back down hill, the temp drops back to normal. Car never runs hot at idle or on level terrain, only when it has to work to get over a hill. Any thoughts as to what would cause this? Is this normal?

How's your coolant level? Water pump failing and can't push coolant to radiator when car is tilted back?

What happens when the car is idling pointing uphill? Does it still overheat? Or is this only when driving?

Coolant level is good. I flushed and filled it just a few months ago and the level hasn't dropped at all. That's a good question about what it does if it is just idling on an incline, I haven't tried that. I will give it a shot and report back later.

check your timing also. I had a pickup that was overheating pulling hills and it turned out my timing was causing it.

Both good suggestions, though considering the design of our water pumps I'm not sure how one could get weaker in it's water-moving capacity.

I've seen the timing issue before.

Also small possibility that the secondaries are opening under load but not flowing adequate fuel (gummy jet, etc), and you're leaning out some, which can raise temps too.

Does it still pull well as temps rise, or does it get a little anemic?

what about the thermostat?

I would agree with advanced timing, or clogged jets in the secondaries. Both great suggestions...





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this should be +1!

Thanks guys! I will start by checking the timing, as that sounds like the easiest thing to start with. How can I check the secondaries to see if the jets are clogged? I've never been much for working on carbs...

Well... It wasn't the timing. The leading was dead on and the trailing was only off by 1 or 2 degrees. So, how do I check the secondaries?

Are you judging this all based on the stock temp gauge? I've never found them to be very accurate. Might be worth your while to get a good aftermarket gauge, that way you will have accurate numbers to work with.
I'm sure others will argue with me, but I've never found the stock FB radiator and clutch fan to be very good. It will keep it from overheating yes, but the temp (again on a good aftermarket gauge, with actual numbers) varies quite a bit. I ended up getting a big aluminum rad and electric fan, and it stays much more constant even with a/c on going up hills, stuck in traffic etc..

forget that, its bogus! just buy a thermostat. if that doesn't work you need to pull the radiator and have it rodded out.

Stock fan pulls quite a bit of air. When it's spinning full speed at the beginning of the warmup, I can feel the wind from it behind the car. So if everything is in good condition (fan clutch, radiator, water pump, thermostat, fan shroud, and all the oil cooling components) it should keep the temperature at a very reasonable level. The temperature doesn't need to be constant, it just needs to stay within the safe range. :)

whats the out of safe range then? I found if my coolant level isn't at max my temps fluctuate a lot.

I'm going buy a thermostat today and give that a shot. I'll keep this updated. Thanks!

If everything is in like new shape then yeah it probably works fine. Everything gets so corroded over here with the winter salt that by this time in the parts life its pretty much shot. I've never had a clutch fan that worked right, either it didn't spin enough, or was stuck on and sounded like a tornado. Guess I'm just anal about keeping the temps consistant :)

Heres another thought. Weak fuel pump. Going up hill is leaning you out so it runs
too hot.

So lots of things to check.

I would start with the cooling and then move on to the more exotic issues (fuel,
carbs etc).