overheating and struggling up a long hill

[martialllaw]

How many kms on the car?.

290600Km

[spot01]

290600Km

Ok, so it's only mid-life, but it's in the range where people have had viscous fan clutch issues develop - I hate replacing things unless sure they are the cause, but these clutches seem to be difficult to diagnose properly due to their "fluid" nature - there are quite a few threads on them if you want to read up on them.

[TIAB]

I just had exactly the same experience, have not taken the van away for a while 2.5T, done the gap a few times no problem. Yesterday headed off and when we hit the highway started offer heating, so much Aircon shut off. Checked fluids, Fan, Etc, no problems. It would only take 5 min to overheat at highway speed but slow or stopped would cool back down a bit.
Pulled radiator out and found at least 40% blocked channels, as well as plenty of rubbish externally. decided to put whole new unit is as plastic tanks don,t take the heat too well and have done 180k.

Doing test run tomorrow and will let you know.

[TIAB]

All good, drove up our mountain with a passion and needle only just moved so radiators can get blocked, could have solved with rodding but decided on all new.

[Doowrag]

I just had exactly the same experience, have not taken the van away for a while 2.5T, done the gap a few times no problem. Yesterday headed off and when we hit the highway started offer heating, so much Aircon shut off. Checked fluids, Fan, Etc, no problems. It would only take 5 min to overheat at highway speed but slow or stopped would cool back down a bit.
Pulled radiator out and found at least 40% blocked channels, as well as plenty of rubbish externally. decided to put whole new unit is as plastic tanks don,t take the heat too well and have done 180k.

Doing test run tomorrow and will let you know.

same here on the weekend towing about 950kg it heated up to 3/4 on the gauge, air con switched off then it would come back down and kick the air con back in. this was about a 20 minute cycle for about an hour till i got to my destination. i have the radiator getting pulled out today to check.