jeebs

Been a while since I posted on the forum but hoping someone can give me a clue what to look at. Starting last week I noticed that my 89 was running warmer than normal. Nothing too bad, but was getting up to 215 or so when it normally never gets above 210 even in traffic with the a/c on. Last weekend as I pulled into my driveway I noticed that the coolant had started leaking out.

After checking all the hoses and overflow tank for leaks/cracks, I pulled the radiator and discovered that the draincock had broken and wasn't sealing. Installed a new draincock, put the radiator back in the car, filled it with coolant, but it was still running warm - now getting up to 225 when idling with the a/c on. As an fyi, the radiator is only a year old.

I thought maybe the thermostat had stopped working, even though it was only a year old also. Installed a new AC Delco thermostat (195) last night, but the coolant temp still got hotter than normal when I test drove it. Plus while I was driving the Check Engine light came on (Code 33 when I checked this morning).

I think I can figure out what's causing the Code 33, but would appreciate any ideas on what else may be causing the car to run warm. The main fan seems to be running fine, and I don't see any coolant leaks (nor has the coolant level gone down). But after replacing the thermostat and making sure it's got plenty of coolant, I'm stumped. Again, I appreciate any advice on what else might be causing it to run hot.

65Z01

Have you pulled the radiator shroud to check for debris and/or obstruction in either the A/C condensor or the radiator??

Also, think about checking for exhaust gasses in the coolant; this can be done at the radiator cap opening.

hooked073

Your temps sound dead on to me...

Jon Hekking

Your temps really don't sound that bad. You could also make sure you don't have an air bubble in the system. I don't think you have a problem though...............

Jamie Lennartson

My car has all new radiator and high flow water pump and everything water wetter etc...
Takes longer now but it will get up to 225 =227 and fan kicks on and it's perfectly normal!

Driveing i get 180s...

If you want it to run cooler you have to get the kit to make the fan/aux fan come on sooner.

Letting any motor idle it will get hotter and hotter until the computer tells the fan to come on that is any car!

jeebs

Thanks to all those who replied. However, I'm still having some issues and the temps are growing hotter.

65Z01 - Yes, I made sure to clean out the shroud area when I pulled the radiator. There was minimal debris since radiator is only a year old.

Hokies83 - The main fan is running the whole time since I've got the a/c on, but the temps keep climbing.

In the original post I mentioned the temps were climbing to 225, but I should have mentioned that 225 was reached right as I arrived home or work - at the end of my drive.

Last night the coolant temp hit 240 (per the dash gauge) as I pulled into my driveway. (As an aside, at what temp is the the pusher fan supposed to turn on? When I checked it in my driveway, it was running and I assumed it should have come on before the coolant hit 240.)

My commute is mostly city driving with a fair amount of stop lights and traffic, but the past few weeks traffic has been MUCH lighter than normal. So the car is actually idling and sitting in traffic for LESS time than itnormally does, but I haven't seen the coolant temps this high since the old radiator bit the dust. Any other ideas on what else I should check?

Relic

I spent a fair amount of time and effort on my 87. It was running warm, and for 2 reasons, crap in the space between the radiator and condensor and the radiator was old, and not flowing well. Clean the space, new, slightly bigger radiator and my car runs much like yours. I have a 180* t-stat.

Driving around, it stays pretty close to 182*. If I stop, the coolant temp rises. If I stop long enough, it hits 232* and the fan comes on. That's how GM designed it. The fan wouldn't come on at 232* if they didn't expect it to get there. Once the fan goes on, it drops to under 220*. If I start moving, it drops down below 200* pretty fast.

I'm pretty sure that's how these cars ran out of the box.

Relic

I have an 87 and there is only one fan. It comes on around 230* If you get to 240* that's too hot. I think you have 2 fans?

If the fan is coming on, and you have a new radiator, and t-stat, it can only be the water pump?

94z07fx3

Temps sound good.

It would be helpful if you would let the car idle AC off and note the fan on temp and note the fan off temp then post them here. A healthy system should be able to cycle the fans on and off at idle this time of year.

Another thought is that the pressure caps are cheap and they don't last forever. <--- I'm not saying your cap is bad.

RRT vette

The temps sound ok to me. The 240* is a bit much and would be the starting point of me observing the temp very closely while driving in traffic. Just double check for any leaks under the car after you drive it and make sure you've gotten most if not all the air out of the radiator/block.