Thread: temp rises when going uphill

Originally Posted by dhard

my 300 tdi engine temp rises till it cuts out the air con when climbing steep hills which require the revs to be above 3000 rpm for long periods. The temp then returns to normal very quickly when revs return back to around 2000 rpm. I first noticed this when towing a caravan and just thought that I was working it too hard but just today i hadthe same problem with no van. Any ideas could it be ablocked rad or some other more sinister and expensive problem.

When under load the water flow increases, well it should, it sounds as though your flow isn't, which could mean your radiator is either blocked or your thermostat isn't working properly.

Or it's just really dirty.

Baz.

Probably the thermostat, but no garantee. Check rad & fan too.

That sounds like bad behavior to me. Mine holds the temperature regardless of the load or conditions

Based on bitter experience money spent on keeping the cooling system in tip top shape is worth it. Have it checked out.

the things Id check, in order (not the order of likelyhood but the order ID check them in)

1. the thermal fan coupling if you have one fitted (it should offer a slight resistance to turning by hnd when cold and off and a lot more after youve got it up to temp)

2. the cores of the radiator and heat exhcangers from the outside, if yovue ever driven it offroad or near grass there will be stuff trapped between the aircon condenser and the radiator

3. the condition of the coolant, how well it flows when the engine is heated up, if its carrying any debry or if its bubbling.

4. the thermostat

5. the service history and if thats in any doubt run a chemical flush and replace the coolant.

6. having the radiator checked by the pros.

Somewhere in there another clue will arise as to why your cooking up but as the temp is coming down when you back off the noise its not a fatal problem.....yet.

What Dave said, but get the rad taken apart and rodded out. I've seen these Tdi's overheat when towing with only a 20 to 30% blockage!!!

Also, if your vehicle is a defender, don't discount the old earth problem. Next time you are hammering up a hill and the temp rises, turn on the headlamps and see if it alters the gauge reading. I had a 130 that the owner was sure was overheating, but we manged to prove that with the headlamps on the gauge went UP, and under revs it went up. Fitted a new body earth wire and all back to normal.

either way, get it checked before anything gets damaged....


JC

everyone seems to be thinking on the same track as I am. So I think i might get the radiator flushed out by a professional and have a new thermostat at the same time. May as well get it done properly as they can tell me if it needs replacing rather than to just run the flush thru myself and only be guessing as to wether it was done right or not. I'm pretty sure the viscous fan is ok, twin condensor fans are both ok and the water pump is only 12 months old so it should be ok. So blocked rad or faulty thermostat sound like likely suspects. By the way these hills i'm talking about are pretty steep as in a good 20 mins up 20% gradient. Or for those who know the mt mee area it is ocean veiw rd the road you can turn right ino if you're takeing the scenic route from Dayboro to Woodford. (I usually prefer to take Forest track from lacey's creek rd via jacky creek rd and A break and come out at neurum creek but the handbrake was a bit hung over and couldn't face the potential fall out from this route.)

if your going to get a new thermostat its a DIY and looking at it (and its housing)will give you a precusorary clue as to anything else that might be wrong.

and if you are going to change the t/stat get a genuine parts one as the aftermarket ones including Tridon don't close off the by-pass port properly, leading to overheating