Car Overheats While in Traffic

Hi Austin,

I just watched your video! I live in NW Houston and I’m having the car heat up after I’ve been driving it for half an hour and I need to stop or drive very slow in traffic.

The fans seem to be working and one was just replace two days ago, so I think it’s something else. When the car starts heating up, the A/C starts to blow warmer air and the mechanic said that the pressure was good. Can you please give me some advice?

I was told by a mechanic that the water pump was making a bit of noise, but was functioning.
Thank you.

Usually a restriction in the radiator is the culprit for overheating after a long highway trip, even when sitting in traffic after you exit the freeway.

I would check the coolant level and make sure the radiator and overflow bottle are full, if not you have a leak. If full then either a radiator restriction or some other type of airflow or coolant restriction is possible.

Have you already fixed this? I sold my shop but my top mechanic is located at Christian brothers auto repair on 1488 and 2978 just north of the woodlands.

I can connect you if you need his help.

Austin Davis

Reader Follow Up

Hi Austin,

I think I didn’t explain myself in my e-mail. My VW Jetta seems to heat up only when I’m in bumper to bumper traffic or stopped for several minutes at a time.

However, I just changed out one of the cooling fans and it seems like it did the job. I hope that’s all that was wrong. I appreciate your response. You seem to be very knowledgeable.

I should have asked you this other more pertinent question related to this same car. When I’ve been driving it for about an hour in slow traffic and the car seems to want to heat up a bit, my transmission starts to give me shifting trouble.

The car is automatic, but it seems like shifting to second gear gets difficult. Once I try for a minute or two it get into gear, but it concerns me because I’m worried about the small motor that is tied to the transmission may be failing.

I guess, I need to figure out why the motor is wanting to heat up in the first place even if the fans are working.

My Follow Up

The engine heating and the transmission shifting COULD be related as there could be a sensor that is also heating up and causing the shifting issue.

With any overheating problem I would start like this.

1. Pressure test the cooling system for a leak
2. Check the radiator for a restriction (12 year old SMALL radiator like this I would expect/assume that there is mineral build up at the bottom that needs to be replaced…flushing will do nothing)
3. Check cooling fan operation
4. Check thermostat operation
5. Make sure there is nothing restricting air flow across the radiator
6. Make sure there is not an air pocket in the cooling system that needs to be bled out.
7. make sure the system is holding pressure (upper radiator hose should be hard to squeeze together when engine is warm)

Did you watch my youtube video about this?

See if you can narrow things down and get back with me if you still need help.

Austin Davis

Posted in: Over Heating

About the Author:

Austin Davis, consumer car repair advocate. "Hi there! I love to help people solve their car repair problems and I hope my site was helpful to you today. Thank you for stopping by."
  • Austin Davis

    Great Orson, thanks for commenting. Glad you found the information useful and shared it.

  • Orson

    The seven step process you describe on the second part is really good, there are many things to check if a car overheats in traffic, this I would keep in mind and I´m sending this link to my brother who has a similar problem with his car.

  • Austin Davis

    Thanks for your comment JJ, have a great day.

  • JJ McAllen

    My car was giving me the same problem and the first thing I did was the pressure test to look for a leak and there it was! Also I recommend you search how to pressure test the cooling system for a leak so that you don’t waste any money.