[AndrewJ]

So, I just did my first long trip with Harold yesterday, I drove from McKinleyville to San Fransisco, a distance of about 275 miles. It wasn't a big deal until I got to the mountanous portion of the trip. After an elevation gain of 1800 feet in 20 miles or so, the car started acting kinda funny.

The temp gauge was showing normal temps, but the motor wasn't making enough power to climb the steeper grades. The only thing that seemed to help was kicking the heater into high gear, sucking some heat out of the engine bay.

I think I'll be cutting out a vent in the airdam for the return trip. That'll give me an opportunity to rig up a variable open-close vent using a manual choke cable. I've kinda been wanting to try that anyway.

But before I do that, does anyone have any ideas as to what would cause the motor to loose power in that situation? The coolant temps weren't abnormally high, but due to the high load and low speed it's not unreasonable to think that under-hood temps were higher than normal.

Oh, and by losing power I mean that I was unable to keep up a "reasonable" speed (50mph) even after downshifting into 4th. By downshifting to 3rd I could keep about 42mph.
I can keep 50mph on my "calibrated" test hill all the time (it's a similar grade to the hills I had trouble with), though that's the only hill on a 10 mile drive.