CalG

Only marginal Audi interest,but we are a pretty smart group, so I thought to ask here.

My neighbor called the other evening with a question. As the weather has brought some pretty cold air recently, he had replaced the thermostat in his old toyota landcruiser plow rig.

After his work, he observed that the coolant gauge temperture went up well, but then fell again to a cool level with very little output from the cabin heater. Cabin heat the goal!

I speculated that the coolant level could be low, to explain the lack of cabin heat, but that does not match the temperature gauge changs.

My question is "What are the symptoms if the t-stat is put in backwards"? (

Anyone been there?

Oh, neighbor does not recall the orientation before or after replacement, but he did note that the replacement T-stat did not have the bleed hole. (always up!)

TIA

CalG

gondar

The pellet side faces the block (heat source).

If it is reversed,the block temp will overshoot initially.

If the replacement stat did not have a bleed and OE did it, then the new part is not exactly correct. At a minimum I would drill a 1/16" hole, enough to let air through, but better to get the right part.

CalG

If the T-stat where installed reversed, it could bind on the housing resulting in a failed open condition.

I will check with "Bill" (the neighbor) regarding progress and symptoms.

Thanks all

Cal

TwoTonic

they seem finicky with the OEM replacement thermostat used in the old 3FE motor. It's hard to install backwards-- if you have done one before it's pretty obvious what the correct orientation is.

Most likely cause is air bubble in the heater circuit. It should self-resolve after a couple of heat-cool cycles, assuming the reservoir is adequately full.

Stuck open is also possible, but less likely.