defender run hot on high way

[Rangie ute on 38'']

hey all

my fender seems to always sit on the cold line every where it goes from round town to low range work off road punchin it, no matter what thats where it stays untill i get on the high way then hitting 100 it will raise a wisker and if i give it lots of wide throttle and get up around 130 it will cont to rise until overheating just wondering if any one else has the same problem, and why when there is such high air flow volume

[460cixy]

thermostat has it got one? check it

[andrew e]

sounds like a head gasket, i hope not though. check for exhaust gas in the coolant, I had endless trouble with mine and it ended up being a warped block. easier fixed than what it sounds like.

Andy

[RaginRover]

sounds like a head gasket, i hope not though. check for exhaust gas in the coolant, I had endless trouble with mine and it ended up being a warped block. easier fixed than what it sounds like.

Andy

Hold your horses - it is a bit early for that

Hold old is the rig and how many kms? If it is 10 years old and still has the same radiator in it chances are that it is half full of crap. Pull it out and take it to a rad place and get them to pull it to bits and clean it - solder her back up. They will tell you if it is beyond repair - last time I had one done it was $77

Other things like fanhub(not sure if defenders have one) could be stuffed, water pump etc I would start with the rad and go from there

Tom

[justinC]

yup,

Rod the rad out, it is only little and if it is 30 to 40% blocked, this would cause it. Put in a thermostat, diesels produce more power when they are at operating temp.


JC

[mavzilla]

its got a blocked radiator from contaminates fix radiator fix problem
see a peputable radiator shop

[Hally]

What size tyres are you runing my defender use to do the same When ever I did a trip up to double island mine used to get hot if I sat on 110kmh no matter how much I thrashed it in the bush it never went past half way. I was running 31'' which was way to small and with the defender gearing being so short it used rev its tits out

[red90]

Everyone likes to jump the gun. It sounds to me like your thermostat is stuck partially open. Pull and replace and see what happens. If that does not work move on to other possible problems.

[Rangie ute on 38'']

right oh ill check the thermostat this wk end, ive run a variety of different size tyres from 31 all terains up to 35 simex and consistantly same result

[andrew e]

doing a coolant gas test isnt jumping the gun, just eliminating suspects.

Andy

[up2nogood]

With any older car, the first thing to do is remove the radiator and have it cleaned and install a new thermostat and radiator cap.

Or do it every five years if you've owned it that long.


Also check the operation of the fan clutch and replace if necessary, but this causes overheating in traffic, not the highway.


Oh, don't buy cheap crap thermostats. Often it's better to go $genuine$. I say this because I've had cheapo brand ones fail soon after installation.


And you'll never have an overheating problem.