300tdi overheating

Hi,

I have a 110 300tdi which is overheating!! (whats new!)

When crusing along the needle stays at half way no problem, then on hills with foot down, needle goes pass the red mark . But pull my foot off the throttle at the top and the needle moves straight back to half way.

Then I have noticed that when the revs die down on going up the hill the temp will come down, or even towing a trailer the temp will keep down until the revs pick up again and the temp needle goes up with it!!!

Could this be a problem with the belt slipping as the power steering goes heavy after going through water.

Or am I just hopeing and that they are in fact two different problems!!!!!

check out put of alternator with a voltmeter on red battery terminal and an earth watch reading whilst you rev it ,check rads hot all over core when engines upto temp if not fit a new one ,hot top hose indicates thermostat is open ,check level with thermostat housing plug out should be overflowing

I had this my rad was full of mud ( my rad was only hot on the edges) everyone said it was fecked, just mud, found when I was looking the little y piece from my header tank wa blocked so the coolant couldn't bleed properly,

Have you been messing with the fuel pump at all?

No havent done anything to the pump. Right I'll have to have a look over christmas, and there was me thinking a quick belt chage would sort it out!!!

Right just to let you know, had a look and the results were as follows!!!
worked it until the needle was on the H for hot on the gauge!! Had a look under the bonnet, not that hot, raidiator was fine no cold spots. So had a look at the switch where I couldnt get the cable off. got it in the end where it seemed to have coroded!! Gave it a good clean, and hey 100 miles done and the needle didnt move over half way, problem SORTED!!!!

Thank you guys for the replys, it's now to sort the horn no light flash and the reverse light first (that's annoying me and it's not the switch as I've tested it!!)

Good to know its sorted

I recently had a similar problem, mine was showing on the gage that it was running hot but the engine did not feel or smell hot. I changed the sender unit and the problem was solved. You can get them from Paddocks for a couple of pounds.