About a month ago I replaced my water pump and my coolant in my 1991 Buick Riv. It's been running like a peach ever since and has never given me any problems. I can almost forget about my car sometimes, unlike the Honda Civic I had before.

But recently in out Nebraska heat, approaching 90-95 degrees, my temp gauge has been reading high. It usually sits at about 1/2 but it starts approaching 3/4 to the hot. I MUST MENTION THAT IT HAS NEVER OVERHEATED AND HAS NEVER WENT OVER 3/4.

I don't drive like a maniac, at most in stop and go I will push the accelerator to 1/2 way passing people.

Today while driving across town in heavy stop-and-go traffic, it heated up again. I turned off the A/C and turned on the heat to full and rolled down the windows; after about 2 minutes it went to normal.

I about cried when I had to go down a one-lane street in front of 2 trucks going 25mph down a 40mph street. I needed the airflow...

Short version: I have to have the A/C on due to allergies. In stop and go traffic, is it okay for my Buick Riviera to heat up a little more than normal opperating temp? Or is there something wrong?

edit: //
For those who are unaware; The engine coolant also cools the automatic transaxle fluid. I've learned that just a 20 degree increase in temp can cut the life of an automatic in half.

I am asking this partially, because when it heats up past N(ormal)O(perating)T(emp) shift feel is slightly harder.

First: Have you ever replaced your idler and tensioner pulleys?? Mine started running hotter right before mine siezed up. If you haven't...change them now!

Second: Do your cooling fans seem to be running normally? Do they make any noise when you shut the engine off as they stop spinning? If so that may be the issue.

Usually when I have temp problems it's related to something on the drive belt, yours may be different. Good luck.

No odd noises comming from the engine. Still runs smooth and steady.

The electric fan comes on like normal and is inaudible during driving. Occasionally when in the start position with the engine off it will start and won't make any odd noises.

I checked the coolant bleeder above the thermostat housing and i got a trickle of warm coolant, so it's air free. The level was good in both resovior and radiator. The radiator actually looks pretty new.

I would check to make sure your fans are working. Last summer my fans came unplugged somehow and my car kept starting to get hot so I popped the hood and the fans were unplugged.

Worth a shot at least.

i dont know how the 91's are configured but my 96 and the 95's have the fans running with the a/c on. so i just turn it on to cool things down. some cars dont have fans that run with the a/c so it just pulls on the alternator and causes more heat.

if the 91 fans can not be manualy operated, then you may consider adding some watter wetter addative and using more water than coolant. (water cools better than coolant) i use a 60/40 mix year round.
also what t-stat do you have installed? a 180 will keep it cooler but not in sitting traffic.
it is not really bad for the engine to run slightly above normal, in fact you will get beter gas mileage but if your gauge doesnt show #'s then you need to find out how hot it is getting. ~210 is pretty normal for stop and go in summer heat. just dont drive it hard with it that hot.
lastly how is the tranny fluid? if it is old and burnt/brown then change it b/c new ATF will keep the heat down too.

And the tensioner and idler pullies?!!!!! I keep mentioning that because mine shredded the belt and it wrapped around the a/c compressor and then I ended up spending $800 to fix that. Not to mention shredding a hole through my insulation blanket.

Tranny fluid id bright fµ©k red! :-D A fan comes on when I hit the A/C too!

Did you flush the system when you changed the pump? Did you change the t-stat? I'm thinking there is some debris going through the system, even if you flushed it some extra debris could have come loose.

I'd say try a good flush with some of that prestone flush stuff before you go replacing parts.

Ever replaced the water pump? How many miles are on the car?