Thread: viscous fan on a TD5

Originally Posted by kelvo

You say your use to seeing 80-82*C head temp and 91-92*C coolant temp, but what are you seeing when it is 'overheating' ?

I've got my head temp sensor near the back of the head, and this reads within 2-3*C of what my Nanocom reading is.

Without towing I'll see temps of upto 94*C, this is in traffic, slow speed driving, highway. This is with ambient temps in the low 40's.

With the camper on the back it will go upto 96*C on long hills, also if dropping from 100kph limit down to 60kph it will rise upto 96*C But then drop off again. I put this down to reduced airflow through the engine bay and heat soak from the turbo.

My cooling system is standard, original 2003 radiator, but all hoses, thermostat, coolant cap and viscous fan replaced in the last 12 months.

As Pat says I think you're looking for a problem that doesn't exist, hence my previous questions

I'd have to agree with a few here, your temps arent an issue. the info kelvo has posted above is about text book perfect for a TD5 (or any diesel for that matter) as he also mentions, his is stock. As I originally said, I've never had that many failed viscous coupling units. Just some added info, I normally mount the temp sensor (the ones that use an existing bolt on the head somewhere) a little bit further back on the heads, just to get it away from the fan airflow but not too far back that its getting residual engine heat soak. The temps you will read will then be a little bit higher but should be accurate.

I'm not telling you to suck egg here, just some added info...
Any turbo diesel that I fit something like the engine watchdog (that uses the same bolt on sensor) and then show the owner/driver how much temps increase with the right foot pressed down when going up hill and how much it drops by just being a bit lighter on the throttle, always changes their driving style.

Regards
Daz

P.S Another thing I "teach" my customers is.... get used to where the temp gauge needle sits exactly, as in on a Defender TD5, just to the left of centre, a Disco 2 TD5 just above the squiggly line, again just below centre. the moment you see the needle move the thickness of the needle, pull over and turn it off, something is going wrong. Dont get all technical about reving engine for air flow etc, pull over, turn it off. This has saved many a many 300tdi & TD5 head!! :P