Dash Temperature Gauge Fluctuation w/ Heater On
#1
Dash Temperature Gauge Fluctuation w/ Heater On
Hey guys- kind of scratching my head with this. I have a 97 D1 with about 95k miles.
This summer I had a fluctuating dash temperature gauge after a long road trip. Took the truck into the shop and also told them I have been hearing the waterfall sound behind the passenger side dash. Asked them to pressure test the coolant system and check heater core.
Was told everything was fine following replacement of fan clutch- pressure ok, no coolant leaks or anything dripping out the bottom of the truck. I was told the insides of the heater core likely collapsed but wasn't leaking. This didn't really make sense to me (limited technical knowledge of cars in general), but the truck ran great and I could run AC, while driving 70+ mph up hills, etc no problem.
Now, since winter is coming i have run into a new issue. While driving with the heat on I noticed that the temperature gauge in the dash start to climb above the 1/2 mark, but instantly goes back to normal when I shut the heat off.
any ideas??
This summer I had a fluctuating dash temperature gauge after a long road trip. Took the truck into the shop and also told them I have been hearing the waterfall sound behind the passenger side dash. Asked them to pressure test the coolant system and check heater core.
Was told everything was fine following replacement of fan clutch- pressure ok, no coolant leaks or anything dripping out the bottom of the truck. I was told the insides of the heater core likely collapsed but wasn't leaking. This didn't really make sense to me (limited technical knowledge of cars in general), but the truck ran great and I could run AC, while driving 70+ mph up hills, etc no problem.
Now, since winter is coming i have run into a new issue. While driving with the heat on I noticed that the temperature gauge in the dash start to climb above the 1/2 mark, but instantly goes back to normal when I shut the heat off.
any ideas??
#2
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TDRover (11-21-2014)
#4
X2 regarding the grounds, having just gone through this. Specifically, the grounds behind the LH and RH footwell side panels (E200 and E201 in the Rave electrical manual), and the grounds under the hood on the inside of each fender well, one by the ECU and one by the airbox.
The waterfall sound is air in the cooling system, and you're hearing it in the heater core. Classic Brit engineering, the heater core is the highest point in the cooling system. Go through the bleed procedure with the front passenger wheel up on a curb to ensure that the corner of the radiator with the bleed cap is the highest point in the cooling system.
The waterfall sound is air in the cooling system, and you're hearing it in the heater core. Classic Brit engineering, the heater core is the highest point in the cooling system. Go through the bleed procedure with the front passenger wheel up on a curb to ensure that the corner of the radiator with the bleed cap is the highest point in the cooling system.
Last edited by ajnolin; 11-20-2014 at 01:34 PM.
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TDRover (11-21-2014)
#6
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#10
The 'waterfall' sound from the heater core could also be a tell-tale sound of a mildly leaking headgasket. I've had a few cars that had such sounds for several months ..and one day the headgasket finally let go. Heads redone and new gaskets and sound never came back. Not uncommon. Sniff in the resivor for combusted gases. Do a check with strips. Is your rig using any coolant?