A couple of months ago (when it was still warm out) I had the radiator and thermostat replaced. Last week when I took it to the tire shop for an alignment, that guy said I had a leaky head gasket. I tried Bar's Leaks Head Gasket Fix. After adding the sealant you are to run the vehicle for 20 minutes with the heat turned up and the blower on high. After 20 minutes I went to turn the vehicle off. I noticed it was warm, not hot in the vehicle and the radiator cap was cold. Air comes out warm from the heater vents below and hot from the air vents above. I took it out at 55 MPH for about 10 miles, nothing changed. I cleaned the engine where the supposed leak was before adding the sealant and it's still clean. I am now thinking what the alignment shop saw was splattered radiator sealant from the Summer. Any ideas?

I do not drive this vehicle much and it is cold, but not cold enough, for my wife to notice a lack of heat.

 

Hi there,

The thing to look for here, what did the engine temperature gauge show you? Was it quarter, half way.
These should get to half way after warming up, so if you're not getting up to that temperature there is a good chance the thermostat is stuck fully open, causing the water to flow round too quickly and it's cooling down. (The diesel engines in these are cold beasties, so run pretty cold!).

Also, not wanting to worry you, but those leaky head gasket fixers are notorious for bunging up heating matrix and systems like that, so if the engine is up to temperature and your cabin isn't warming up it could have partially blocked the heater in the cab.

Oh, one other thing, check the air pollen filter, it's in the footwell in passenger side and should have a plastic cover over it, then inside the filter itself. Mine had the plastic cover completely missing which means air was escaping causing the heat to be lost.

 

I am envisaging that the coolant leak was not from the head gasket but from the thermostat to head joint. Had that on mine after changing thermostat, drip from back of head. And Rad sealer stopped it too.

 

I am off to work but will look again at the gauge this evening as it is my wife's vehicle. The cabin filter cover is there. I change it myself once a year. Thanks for the replies. I'll keep you updated.

 

One and done. It was a stuck thermostat. We have heat. As for the leaky head gasket. It was a false alarm. It was blowback form the radiator change and the clamp at the top of the radiator needed a little tightening. That explained the low coolant in the overflow tank. And yes, the temp gauge is now getting into it's normal range.

 

Excellent news, glad you got it sorted and a good result.

It seems these thermostats like to get stuck fully open!

 

All thermostats [design standard] are designed to always stick open Andy M8 !