As I go through the issues with my car it’s time to look at my running too cold issue (haven’t seen this often with a Mk2). The gauge is between 30 and 70 on the gauge, which I assume means 50? If I am in a traffic jam it does go up to 70 so the gauge will move that far.

The car has a couple of mods, a straight port head and manifold and an oil cooler.

Any ideas’s?

 

As usual after asking the question I assume the answer is simple. Either no thermostat or its stuck open? Still waiting for the new gasket before I open up the housing.

 

Apart from the thermostat, there's also the temperature sensor (sender). They tend to become 'tired' with age and read low. It's worthwhile checking the temperature with another device such as an infrared sensor.

 

Thanks. Used my IR thermometer. Right next to the sensor, exactly 70 degrees. Must be a slow sensor. I will get one on my next order from SNG.

 

The worst situation is when the temperature sensor starts reading low while the thermostat starts to stick shut. All seems fine until disaster hits. With our old Jaguars it's likely to be limited to boiling over, but, with systems that run at higher pressures, a water hose may explode.

 

after a recent engine/trans rebuild i noticed the temp was registering way, way too high on my mk2 3.4l. turned out it was the temp sensor.

beware! it appears that british cars (and possible others) from the 50's and 60's used what looks like the same temp sensor. i found, much to my dismay, that although most look almost identical, vendor's descriptions of which engines and cars they are designed for is often inaccurate. i ended up buying three before i found one that FIT (wrong threads, too many threads, too few threads, etc.) and registered the correct value.

and ya, a XK engine running too cold? ...never.