Thread: Engine temperature slightly higher than normal

Hello,

I own a 99 D2 TD5.

The motor has a TM2 fitted to monitor the head temp. Over the past twelve months or so, the motor has begun to run approximately 2-3 degrees hotter than usual. It has never looked like over heating, it can run at the original temperature(88-89 degrees C) rarely now. But now tends to run at 91-92 degrees C, even at night with cooler ambient temperatures.
I did find a coolant leak on the fuel cooler, replaced the o-rings, all is good there.

The head gasket does have a minor leak, I bleed a few air bubbles out of the system every 7 - 14 days or so.

I was thinking that it is either:

1) The thermostat beginning to fail, although it is a genuine and only been in two or so years
2) The water pump, again, a genuine part only installed for approximately two or so years.
3) The temperature sender on the TM2, which I think is less likely.

The entire cooling system(radiator, all hoses, t/stat and water pump) were replaced all at once, just over two years ago. It has had nothing but OAT(mixed to correct strength with demineralised water) in the system since.

Can it be anything else that is failing/going to fail?

A penny for your thoughts please.

Cheers,

Jason

Thanks sierrafery,

It appears that the viscous clutch on the fan has seen better days and is not operating as it's meant to.

Cheers,

Jason