Thread: Overheating - TDi300

IME ( RRC with a 350) if you restart kinda immediately the gauge will read higher due to heat soak. It will then go very rapidly down to what it was as the coolant circulates.

Could be air in the cooling system, bad earth to the gauge, etc.

You don't say what the obvious overheating symptoms are.

If it is visibly losing coolant out of the coolant reservoir with reported gauge readings I'd be looking at an air lock in the cooling system.

cheers, DL

Blocked radiator? When was it last flushed or rodded?

Originally Posted by abaddonxi

Blocked radiator? When was it last flushed or rodded?

I agree. This is the most likely cause.

x3 for the radiator being blocked and needing to be rodded.

Forget about the LR temp gauge and get yourself something decent so you actually know how hot it is. I use an Engine Watchdog TM2, but there are other options.

If you overheat a 300tdi it will cost you at least $2K unless you are very lucky - so take it seriously and don't be tempted to think "ah - its OK today so I wont worry too much".

Steve

Getting that squeak from the serpentine belt? Is the waterpump on the way out?

Checked the thermostat? My father had the exact thing. After a decent hill, the temp gauge went right up and he could actually hear the engine boil a little. He pulled the thermostat and boiled it up in the kettle. 95 degrees and it stayed closed. Bought a new one and checked it in the kettle and it opened while the old one stayed closed. Fit new thermostat, problem fixed.

A cappucino thermometer is excelent for checking the opening temps of thermostats.

First up, don't believe the standard temp gauge, they are
Have a read here for alternatives. http://www.aulro.com/afvb/technical-...emp-guage.html

Secondly, after checking the obvious things like the t/stat and radiator, (and make sure the radiator and t/stat bleeds aren't blocked) is the fan clutch working ?

Don't believe that ram air alone is enough in a hard working 300Tdi at speed, when they get warm they need that clutch to engage and force more air through the radiator to keep the coolant temp down.
Quite a few owners have had a similar issue, checked everything to no avail then as a last resort swapped out the fan clutch and solved the problem.

Thanks for the many responses and plenty to work with. I will replace this gauge now as a matter of course.

The radiator has been flushed, water pump replaced and the fan is working perfectly.

I lean towards it being a thermostat and I will now check to see if this was replaced, either way I will replace it and see if this changes anything.

Regards, Baz