On a 1996 Pontiac Grand Am I have changed radiator thermostat and it still overheats

Asked by Jul 02, 2016 at 02:07 PM about the 1996 Pontiac Grand Am 4 Dr SE Sedan

Question type: Maintenance & Repair

In November I change the thermostat and then it overheated in last month it overheated
so bad then off to the hose I change that both upper and lower hose and it still
overheated so I took it to a mechanic and he replace the whole radiator assembly it still
overheats when I turn on the air condition it goes down when I turn on my heater now it's
skyrockets to the red line which is really weird is it possible that I need to replace the
thermostat since that seems to be where all the problems initially started back when I got
replaced and if it overheated and I had to get a complete radiator assembly in it and it still
overheats is it possible that when it did overheat that new one was defective or bad

6 Answers

73,935

First thing is to make sure all the air is out of the cooling system. Your mechanic should have used a tool to pull the cooling system down into a vacuum before refilling it when the radiator was replaced. The fact that the temp goes down when air conditioning is selected tells me that the cooling fans are working. But to be absolutely sure, unplug the coolant temp sensor (with the engine off and cold). Now start the engine. The check engine or service engine soon light will come on because the sensor is unplugged. Ignore it. Now check that the cooling fans are both on. They should be. If they're not you'll have to find out why they're not coming on. If they do come on, shut off the engine and plug the coolant temp sensor back in. Make sure your 195°F thermostat is installed correctly as well. Pointy end up. If all this checks out, flush the cooling system using a chemical cleaner such as Prestone Fast Flush. Follow the instructions on the bottle. If that's not solving the problem replace the water pump. The impeller (fan looking thing on the inside that pumps the coolant) may be rotted away. Here's the water pump I took out of my '00 Grand Prix with the 3.8L V6 three months ago. It had an overheating problem as well. I actually did the flush, changed the radiator, and water pump all together. Runs right between 195°F & 205°F now (normal). As you can see the impeller was rusted away so the coolant was hardly flowing at all! HTH. -Jim

73,935

Here's the new water pump. You can see the difference! HTH. -Jim

10

Jim, I only have one fan and yes it does come on so I'm guessing my best bet would be the only 2 things left the thermostat AGAIN and the water pump thank you so much I'll let you know how it turns out.

1 of 1 people found this helpful.
73,935

You're welcome. Glad to help. Yes, please keep us posted. -Jim

5,495

Jim - When I have a problem, I hope someone will help me as well as you helped Rhonda here. Your advice was spot on, understandable, and thorough. She should be going again soon. Nice job!

I have a 2005 pontiac grand am gt and I put a thermostat in it and it still over heats what could be the problem

Your Answer

Grand Am

Looking for a Used Grand Am in your area?

CarGurus has 966 nationwide Grand Am listings starting at $2,595.

ZIP:

Pontiac Grand Am Experts

  • #1
    tenspeed
    Reputation
    7,980
  • #2
    John Saffrahn
    Reputation
    1,630
  • #3
    Tom Demyan
    Reputation
    1,590
View All

Related Models For Sale

Used Pontiac Grand Prix
13 Great Deals out of 2,464 listings starting at $950
Used Pontiac Firebird
8 Great Deals out of 731 listings starting at $1,649
Used Chevrolet Impala
557 Great Deals out of 33,311 listings starting at $1,499
Used Ford Mustang
445 Great Deals out of 42,042 listings starting at $1,488
Used Chevrolet Camaro
526 Great Deals out of 31,057 listings starting at $1,450
Used Jeep Grand Cherokee
1,066 Great Deals out of 67,520 listings starting at $950
Used Honda Accord
925 Great Deals out of 78,230 listings starting at $1,295
Used Chevrolet Corvette
138 Great Deals out of 16,155 listings starting at $3,000
Used Pontiac Bonneville
442 listings starting at $1,500

Used Cars For Sale

2002 Pontiac Grand Am For Sale
106 listings starting at $2,595

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.