treynor
Enthusiast
OK, I'm at my wits end about this one -- maybe one of you will have an idea of what's going on.
I purchased my '01 RT/10 in December '00. Around 2,500 miles I start to notice that the temp gauge, which thusfar has hovered at 190-200 degrees, will sometimes go up to the mid-high hashmark (~225) shortly after the car is started, then settle back down. I don't think much of it (the weather is warming up) until one day at the dragstrip, where I note with alarm that my temps have risen from 190 (right before launch) to 250 on the return road. The little "high water temp" warning light comes on, and the car pukes a little coolant when I park.
I assume the stock cooling system just isn't up to the rigors of 12 seconds of all-out acceleration, and order a Fluidyne radiator. With this installed, the behavior seems to subside a bit, although the temps still climb above 210. Soon, however, I start to see 225 again, usually with an odd pattern of 225 - quick drop to 170-gradual climb to 225 - quick drop. I mention this on the board, and it is suggested that my thermostat is sticking. I order a 180 degree thermostat (which we verify opens at 175 degrees in a *** of water) and avoid driving the car much until we can install it along with the Hennessey heads.
This afternoon when I went to pick up the car, it was STILL exhibiting the problem, only now the temperature goes as high as 250. Suspecting the temperature sender, we grab a pyrometer. Sure enough, the temp gauge reads 250 but the thermostat housing is 185 and the cyl head right by the temp sensor (left cylinder bank, all the way at the front, on the end) is also 185. I let the car cool down a bit repeat the experiment, with the same result -- high temp gauge reading, low actual temperatures read by the pyrometer. We figure the sensor must be bad, and I proceed home, gritting my teeth at the 250+ temps displayed on my dash. I stop a couple of times on the drive home to check actual temps with the pyrometer, and sure enough they're in the 180 - 200 range. Diagnosis confirmed -- bad temp sender and/or bad temp gauge.
However, when I get home I do one final check, and find the thermostat housing reading 230-235 degrees, the temp sender area reading 220 degrees, and the coolant resevoir (the one with the cap) half empty. I check the bleeder fitting on the main radiator hose, and get only steam. What the hell!?! It takes a full five quarts of coolant/water mix before the system is again full and no more bubbles emerge.
On a whim, I checked the oil. Clean as a whistle -- no blown head gasket, which wouldn't make sense anyway as the behavior is the same as with the stock heads on.
The car is now parked in my driveway, and unless I can uncover (and test!) a fix for this problem, there it will remain until Monday when I drop it off at Dodge for them to diagnose and fix. I'm hoping someone on the board can help, as I would have loved to dyno the car tomorrow and report results of the Hennessey heads / CDI headers combo, but obviously cannot until the car is running well.
I purchased my '01 RT/10 in December '00. Around 2,500 miles I start to notice that the temp gauge, which thusfar has hovered at 190-200 degrees, will sometimes go up to the mid-high hashmark (~225) shortly after the car is started, then settle back down. I don't think much of it (the weather is warming up) until one day at the dragstrip, where I note with alarm that my temps have risen from 190 (right before launch) to 250 on the return road. The little "high water temp" warning light comes on, and the car pukes a little coolant when I park.
I assume the stock cooling system just isn't up to the rigors of 12 seconds of all-out acceleration, and order a Fluidyne radiator. With this installed, the behavior seems to subside a bit, although the temps still climb above 210. Soon, however, I start to see 225 again, usually with an odd pattern of 225 - quick drop to 170-gradual climb to 225 - quick drop. I mention this on the board, and it is suggested that my thermostat is sticking. I order a 180 degree thermostat (which we verify opens at 175 degrees in a *** of water) and avoid driving the car much until we can install it along with the Hennessey heads.
This afternoon when I went to pick up the car, it was STILL exhibiting the problem, only now the temperature goes as high as 250. Suspecting the temperature sender, we grab a pyrometer. Sure enough, the temp gauge reads 250 but the thermostat housing is 185 and the cyl head right by the temp sensor (left cylinder bank, all the way at the front, on the end) is also 185. I let the car cool down a bit repeat the experiment, with the same result -- high temp gauge reading, low actual temperatures read by the pyrometer. We figure the sensor must be bad, and I proceed home, gritting my teeth at the 250+ temps displayed on my dash. I stop a couple of times on the drive home to check actual temps with the pyrometer, and sure enough they're in the 180 - 200 range. Diagnosis confirmed -- bad temp sender and/or bad temp gauge.
However, when I get home I do one final check, and find the thermostat housing reading 230-235 degrees, the temp sender area reading 220 degrees, and the coolant resevoir (the one with the cap) half empty. I check the bleeder fitting on the main radiator hose, and get only steam. What the hell!?! It takes a full five quarts of coolant/water mix before the system is again full and no more bubbles emerge.
On a whim, I checked the oil. Clean as a whistle -- no blown head gasket, which wouldn't make sense anyway as the behavior is the same as with the stock heads on.
The car is now parked in my driveway, and unless I can uncover (and test!) a fix for this problem, there it will remain until Monday when I drop it off at Dodge for them to diagnose and fix. I'm hoping someone on the board can help, as I would have loved to dyno the car tomorrow and report results of the Hennessey heads / CDI headers combo, but obviously cannot until the car is running well.
