Is this a thermostat problem?

[dpd]

Hi Delica.ca,

Recently my L300 has not been blowing heat into the cabin. Heater blows air but it's cold.
When this happens, I also notice the temp gauge climbs way higher than usual.

It happens intermittently. When the heat does blow hot, the temp gauge is normal, everything is fine.
And it seems like it sometimes goes from broken, to working, when I hit a big bump :)

Does this sound like a thermostat that needs replacing?

Thank you!
David

[dfnder]

That sounds like you are low in coolant, make sure the engine is cold before you open your rad cap and be sure to check your overflow that it is up to level as well. The overflow tanks have been know to leak and crack with age so keep an eye on it. Good Luck as it sounds like it has been an issue for a while and these vehicles are known to have issues if overheated.

[dfnder]

That sounds like you are low in coolant, make sure the engine is cold before you open your rad cap and be sure to check your overflow that it is up to level as well. The overflow tanks have been know to leak and crack with age so keep an eye on it. Good Luck as it sounds like it has been an issue for a while and these vehicles are known to have issues if overheated.

[glenn]

X2 - check your coolant.

[dpd]

Thanks for the tips. It has only been an issue for a few days of driving, and it was low coolant. A bit puzzling and I didn't check that first because I topped it up fairly recently. Time to find the leak...I have some WVO gear that is coolant heated and it is probably somewhere in there. I'll also check the wvo tank for coolant coming out of the heated pickup, I imagine that could be bad to get in the engine.
David

[nxski]

Could be time to replace the water pump.

[dpd]

Good idea, I got a new pump with my timing job at CVI about 3 years ago but you never know.
I'll go there if I can't find the coolant leak in the wvo hose tangles.

[glenn]

Also watch for coolant escaping out of the reservoir on longer trips. Your cooling system may be fine, but the cooling system can become pressurized from engine pressure via a cracked head, or bad head gasket - which leads to coolant being forced into the reservoir and onto the road. The longer the engine is running, the more pressurized it becomes.

I learned this the hard way. If there is no sign of a coolant leak, this is a possibility.