I am trying to sort out a cooling system problem on a car I purchased recently. I have noticed that at operating temperature, the temp gauge on the dash seems amazingly steady, absolutely dead center, no matter if I'm climbing a good long hill with a/c running on a hot day, or on level in the cool evening. That could seem like a good thing, but....
I have had two or three occasions of coolant loss appearing on the ground. Once the source was the overflow reservoir, rapid dripping, and that occurred right after I'd topped off the radiator and the reservoir (between the max / min marks) for the first time after acquiring the vehicle. Then I headed off on a short road trip, beginning with a steady uphill gaining about 2000 feet in 15 miles. I replaced the radiator cap at the first opportunity. And didn't see coolant leaking again.
Recently though, on a hot day, after driving about 3 miles, I parked and noticed a steady small stream hitting the pavement, more flow than the first case, appearing in the vicinity of the reservoir but I did not have the opportunity right then to look for the source or confirm if it was coolant or a/c condensate...the a/c had been on. Temp gauge showed normal, as always. Later, at home with the engine cooled down I discovered the radiator needed coolant and the overflow was empty.
Both times the temp gauge clearly showed the very same dead center reading. Thus I began to suspect the temp gauge sending unit was faulty and decided to splurge $10 to replace it to be on the safe side. That seemed like a good start.
I bought a new sending unit at a local Napa store, only to discover that I can't find where the thing goes on the engine. I've studied the factory manual for clues and found none. There IS a sensor right beside the thermostat housing, but looks nothing like what I bought, and I did check back with the store to confirm that I have the correct part, or at least the number on the box is correct. The Napa part is much smaller in diameter, and length, and has one single threaded post on the top of it.
The manual does show a drawing of the "engine coolant temperature sensor" (page 14-67) which matches what I found on the engine, but again this does not resemble the new part.
Did I simply get a box with the wrong part inside? Or is there some other location for the gauge sending unit?
My sense is that the engine is not overheating, but I can't say for sure. The coolant loss like this suggests a head gasket or water jacket problem, but the engine runs great, 25mpg mileage, no visible exhaust signs, and the CA emissions test was sparkling clean, according to the tech "as good as it gets". The test for combustion gas in radiator was clean.
Any ideas on what might be going on?
Thanks for any help.
I have had two or three occasions of coolant loss appearing on the ground. Once the source was the overflow reservoir, rapid dripping, and that occurred right after I'd topped off the radiator and the reservoir (between the max / min marks) for the first time after acquiring the vehicle. Then I headed off on a short road trip, beginning with a steady uphill gaining about 2000 feet in 15 miles. I replaced the radiator cap at the first opportunity. And didn't see coolant leaking again.
Recently though, on a hot day, after driving about 3 miles, I parked and noticed a steady small stream hitting the pavement, more flow than the first case, appearing in the vicinity of the reservoir but I did not have the opportunity right then to look for the source or confirm if it was coolant or a/c condensate...the a/c had been on. Temp gauge showed normal, as always. Later, at home with the engine cooled down I discovered the radiator needed coolant and the overflow was empty.
Both times the temp gauge clearly showed the very same dead center reading. Thus I began to suspect the temp gauge sending unit was faulty and decided to splurge $10 to replace it to be on the safe side. That seemed like a good start.
I bought a new sending unit at a local Napa store, only to discover that I can't find where the thing goes on the engine. I've studied the factory manual for clues and found none. There IS a sensor right beside the thermostat housing, but looks nothing like what I bought, and I did check back with the store to confirm that I have the correct part, or at least the number on the box is correct. The Napa part is much smaller in diameter, and length, and has one single threaded post on the top of it.
The manual does show a drawing of the "engine coolant temperature sensor" (page 14-67) which matches what I found on the engine, but again this does not resemble the new part.
Did I simply get a box with the wrong part inside? Or is there some other location for the gauge sending unit?
My sense is that the engine is not overheating, but I can't say for sure. The coolant loss like this suggests a head gasket or water jacket problem, but the engine runs great, 25mpg mileage, no visible exhaust signs, and the CA emissions test was sparkling clean, according to the tech "as good as it gets". The test for combustion gas in radiator was clean.
Any ideas on what might be going on?
Thanks for any help.
