Date: Mon, 27 Oct 1997
From: OCDesign@aol.com
Hi Glenn,
Sometimes when I'm sitting in a traffic jam, the "water temperature" meter rises from the usual 1/3 reading to a bit over the ½-way point. There's about ¼ left before hitting the red zone. I usually don't have the air conditioner on. Is it because there is no wind to blow through the radiator to cool down the engine? On newer cars, the temperature usually doesn't fluctuate that much that quickly. Do you have this problem? I just had the coolant flushed and the hoses replaced.
Also, after driving the car for 1/2 hour during the day, I can feel large amounts of hot air seeping into the cabin, almost like an oven (I live in Los Angeles). Is this normal? Or do you think I need to have the ventilation system checked out.
- Oliver
Oliver -
The P1800 was not designed to cope with summer traffic jams. As far as I know, they all tend to overheat when stopped with the motor running. This is less of a problem if the outside temperature is under seventy degrees.
The first thing to do when the car overheats in a traffic jam is to turn off the air conditioner compressor. It's o.k. to leave the fan on. If the temperature gauge still rises, idle the engine at 2,000 rpm. The increased airflow and water pump speed will help keep it from overheating.
As you might guess, I've had some experience with this in Texas, where summertime temperatures are often over ninety-five degrees. I will have to convert my air conditioner to R-134 soon, and I'm planning to install an electric fan in front of the radiator to handle the elevated temperature in the a/c condenser and, I hope, to cure the overheating.
As for the heat coming from the front of the car, I have this problem, too. Once I got the urge to fix it, replaced all the bad grommets in the firewall, stopped up extraneous holes here and there, and still have the same problem. I think it's just a hot car.
It could be that could be that the engine compartment funnels heat to the firewall by an accident of design. For sure, any air coming through the central vent will get warmed up, because it has to pass through the blower, which is located inside the engine compartment. The only defense, apart from air conditioning, is to close this air vent and use the ones on either side of the underdash instead.
I generally use the air conditioner if the outside temperature is over eighty degrees. Overheating is one reason I have avoided purchasing one of those hood insulation kits for my 1800. In colder climates it would be nice, but not in Fort Worth!
-Glenn.
Date: Thu, 26 Nov 1998
From: johnb@dec.anr.state.vt.us
Oliver,
I saw your letter related to 1800 overheating. I have had a few 1800s and haven't tinkered with them in a few years. I have a 1972 1800 in the barn that at some point I plan to restore.
Anyway, you mentioned that your cabin heats up. I used to have this problem. After lots of searching, I finally realized that the valve which controls the water flow to the heater core didn't seal all the way shut, allowing hot water into the core and thus a little heat came into the cab. The way to fix this is to replace the valve or do what I did, which was to leave the leaking gate valve in place and install a shutoff valve in line ahead of the heat control valve. They are a cheap fix and only require you splice it in the hose coming from the engine with a couple hose clamps. This may solve your problem. Good luck. -John