Engine overheating

2003 PONTIAC GRAND AM
200,000 MILES • 3.4L • V6 • 2WD • AUTOMATIC
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DRUMAN22
  • MEMBER
  • 1 POST
I’ll try to be quick but thorough. A few weeks ago I hit a raccoon with my car one morning while driving to work. I didn’t know at the time that the impact broke the mount on the top passenger side radiator from the frame and bent the radiator back about 4-5 inches up from the bottom. Two days later the radiator must have shifted back causing the lower coolant hose to going to the water pump to contact the water pump pulley which cut a hole in the hose. The engine overheated very quickly because of lack of coolant. After towing it home I replaced the hose and thermostat and quite a bit of coolant. When test driving it would hold temperature at first but then rapidly start overheating again boiling out the coolant and water in the process. It runs fine, no misfiring or backfiring. No coolant in the oil or oil in the coolant. No noticeable coolant leaks anywhere. Once warmed up the system builds and holds pressure and maintain normal running temperature while idling for 30-45 minutes. 10 minutes into driving it overheats again. Tried a few known methods to correct the issue with no success. Thoughts?
Sep 11, 2020 at 7:09 PM
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KASEKENNY
  • Experienced Mechanic
  • 18,907 POSTS
If the engine does not overheat sitting still but does overheat when driving then you most likely have a restriction or an air pocket. I would start by using a laser temp meter to find out if you have hot spots around the cooling system. Basically it should be pretty even temp except for the upper and lower hoses of the radiator. They should be different temperature due to the radiator cooling it down.

Once we know where and if there are hot spots we can determine if that is an air pocket or restriction.

Let us know what you find and we can go from there. Thanks

Here is a guide that covers some of this material:

https://www.2carpros.com/articles/symptoms-of-an-overheating-engine

Sep 12, 2020 at 6:15 AM
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