Overheating Question

I was towing about 5000 lbs of rock in a trailer today. I was stopped on a hill (uphill) and had the car in drive, but my foot on the brakes. I noticed my temp gauge went up from the normal half way mark to about 3/4 way to max temp. I shifted the transmission to neutral and the temps dropped after a minute or so.

1) Why would the water temp shoot up in drive vs neutral if I was stopped?

2) Could there be any damage to the engine if it was 3/4 for about 3-5 minutes?

Thanks!

 

No damage to the engine!

In drive the engine is trying to overcome the static friction of the torque converter, but has less air-flow because you're stopped. In neutral it's spinning freely.

 

Where you still on the hill when the temps dropped?

My truck idles higher in P and N.
But not much more. Not enough to blow that much more air across the engine, but maybe.

Have you checked the fluid level in the radiator?

 

I was still on the hill when the temps dropped. Fluid level normal. It was a hot day (about 100 degrees) - hopefully everything's fine.

 

I’m in agreement with no damage done. You gave the cooling system and transmission a good work out. If the temperature needle was buried in full hot and you floored it the rest of the way up the hill, that can possibly cause damage.

If you haul that much weight in hot air regularly, you might consider adding a transmission cooler. Even if yours has a towing package, it could extend the life of your transmission. I put one in a different vehicle that had a thermostat controlled fan, worked good, it was a b&m.

 

This was a one time thing - just to remove the gravel from my back yard. Thanks for the input guys!

 

See, that could potentially be a problem because the temp gauge needle on these trucks are designed to go to to half and stay that way until you have overheated it. If you see anything above half there is a good chance you were already at 230+ degree territory. Maybe even 250-260+ degrees.

Do yourself a favor and when you tow, leave it in 4 when going up hills, this is especially true when in steep terrain for extended periods of time. A real temperature gauge (and not just going off the OE dummy gauge) may be a good thing to look into as well. Especially if you tow often.

AEM makes a direct plug in X series gauge (it should be PN:

$188 30-0300 X-Series Wideband UEGO AFR Sensor Controller Gauge

30-0300) to the OBD2 plug which reads the temp output directly from the PCM. This way you have absolute direct information of your coolant temperature at all times.