Overheating

My 300tdi 110 overheated for the first time ever yesterday, at least I think it did...

The temperature gauge certainly spiked, so I pulled over immediately and switched off. Flicked the key to put the electrics on and the gauge sat perfectly in the middle. No steam from the bonnet, no strang(er than normal) noises... Feeling brave I started up again and drove gently towards home, it got a bit dark so I turned my lights on, immediate spike on the temp gauge, turned off lights, temp gauge dropped (a bit).

Checked my oil, no white scummy stuff in there, so I'm really hoping this isn't as serious as a head gasket.

Any suggestions?

Any coolant loss?

Water still in expansion tank at correct level and no sign of leaks from pipes?

If all OK would check radiator for blockges/broken fins andstuff caught in fins. With engine running and at temperature rad should be warm all over (no cold spots)

If that all OK check theermostat opening at correct temp (put in saucepan with thermometer)

If that all checks out start checking earths and wiring from sender to gauge

If that all checks out swap out sender

Sounds more like an electrical problem.

zeaphod said:

Sounds more like an electrical problem.

Click to expand...

Agreed

Turns out the problem was 2 fold. Faulty earth screwing with the temp gauge, combined with a faulty water pump. Neither problem is being easy to fix. The earth refuses to earth properly. 19 years and 220,000 miles is making a selection of bolts un-undoable. Tried everything now, time for the angle grinder.

sepweaver said:

Turns out the problem was 2 fold. Faulty earth screwing with the temp gauge, combined with a faulty water pump. Neither problem is being easy to fix. The earth refuses to earth properly. 19 years and 220,000 miles is making a selection of bolts un-undoable. Tried everything now, time for the angle grinder.

Click to expand...

I'd get the guage working well before tackling the (bound to be) siezed water pump casing bolts. You may not have to change the pump at all.