Why does my engine not reach normal operating temperature, too cool, temp gauge is about 1/4, 1/2 is normal, with lower engine temp the heater takes longer to warm the car. Could the problem be the thermostat or a problem with the heater core? the car is a 2001 Volvo V70 (5 Cylinder) with 96,000 miles. No previous problems with cooling system.

It is likely that the thermostat is stuck open. Remove and replace. They are very inexpensive.

That is pretty much normal, the heater blower fan acts like the radiator does and helps cool the water passing through it by extracting the heat from it. then once the car inside temp warms up it goes back to normal. Nothing to worry about.

No one ever said new means good. Try another thermostat. Make sure it is the recommended temp for the vehicle. I would spend the extra money to buy a dealer thermostat. What controls temp is restriction of flow thru the system until a set temperature is reached and the thermostat opens. Has to be a thermostat.

Possible bad sending unit or shorted sending unit wiring.

It could be a plugged heater core or heater control problem. I assume the blower is working, but the air is cold. The first thing to check is the coolant level, make sure there is coolant in the resivoir. Next see if the temerature gauge reaches the normal operating temperature range. If the gauge reads cold most of the time, it would tell you that the thermsotat is faulty and not allowing the engine to reach full operating temperature. If your car doesn't have a temp gauge, the blue cold engine light might stay on for an extended period of time. The thermostat is supposed to not allow coolant flow in the radiator until the engine reaches operating temperature. If you drive the car for a couple of minutes, from cold start, the radiator or upper hose should be cool until the engine reaches operating temp.

I would suspect either the temp guage or the coolant temperature sensor being inaccurate. The new thermostat is probably working good, or else you wouldn't have a very warm heater. If you have electric radiator fans, you might check to see if they are running all th time. Electric cooling fans should only come on when the temperature sensor reaches a predetermined coolant temp, or when the a/c or defroster is turned on. If the fan runs all the time, the engine would not reach normal operating temperature.

To test your new thermostat, do the following
1. Make sure your heater is off.
2. Start your engine and allow it to run for 6 to 8 minutes so it can reach the normal operating temperature.
3. Turn your heat tmperature select all the way up, and then turn the fan on high. You should hear the thermostat click when it opens up to circulate the coolant through the system. You may also notice your temperature gauge reading lowering.

The only pressure you may have in the radiator/cooling system is very minimal and caused by the coolant heating up.Whenever pressure starts building , it is purposefully relieved through your coolant reserviors overflow hose. Thats why you should never fill your coolant reservior all the way up. It needs to have 3 or 4 inches to allaw for expansion.

I hope this helps you.

I assume you are talking about your engine temperature gauge reading? I had a problem with my 1996 Caravan thermostat (V6 3L). It can get stuck wide open and never allow the engine to operate at the specified temperature. On my vehicle, the thermostat has a metal tab that would prop the valve wide open if it failed. I think the thought of the designer was better to be stuck open than full closed I guess. Anyway, my vehicle temperature would never reach normal range with it stuck open. For my vehicle it is 195 F. This time of year, it would take a very long time before your engine would reach normal running temperature. The interior heater would also take a long time since the engine is also cooler. If your vehicle is newer it can also cause the engine check light to come on because this would affect the emission control systems and keep your engine in a cold engine mode loop...

Not knowing a lot of details of your situation, I would check:

?· The gauge is working correctly and plugged into the temp sender near the thermostat.

?· You have the correct fluid level (Please be careful checking this)

?· Your heater core and engine radiator not clogged with sediment

?· Flush out your radiator and heater core

?· Replace your engine thermostat with the specified temperature range your vehicle requires (parts store tech can help you obtain the correct one)

Good Luck.

if the engine is not reaching operating temp, then the heater is never going to blow warm air. I would start with checking temp of engine, if its not warm enough (180f) I would replace the thermostat

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