75 cdt webasto problem
 

Last night I went on a 80 mile round trip, the temp was 5c or lower for most of the time, the problem was that the webasto heater was more or less permanently running for the whole trip! after 40 miles I (carefully) took off the 'radiator' cap and all there was was the slightest hiss and less steam then you get from a cup of tea! now I know these engines are very efficient, but that much? I also noticed that the engine temp gauge was somewhere halfway between a quarter and half, its usually spot on halfway when warmed up, could the temp sensor in the block be faulty and 'fooling' the webasto, or could it be something else, there is no coolant loss that you can notice and if the temp is above 5c(as this morning) the webasto does not come on

The Webasto will switch on when the engine is running and the temperature is below 5 degrees, there is nothing to switch it off apart from its own controls so if the coolant stays colder than normal it may well run on.

I would pull the FBh fuse and see how long it akes for the engine to warm up as sounds like the (engine's) thermostat has had it.

My temp gauge barely varies from the half way mark - even all last winter when it was down to -12C going through Glen Shee.
The gauge pointer passes the blue dot after about 3 miles and reaches half way by 6 in all weathers.
This is how it should be, since the thermostat will not open until the engine has reached operating temp.

Similarly, if the heater was to drop the coolant temp, the thermostat would close.

If the engine takes a long time to reach norml temp and this drops when the heater is on, both are sure signs of thermostat problems as is the fbh running all the time.

Ron

Well to be honest I was also thinking along those lines,my gauge was until recently just the same as yours, and I dont suppose a thermostat will be all that much, think I will have a go tomorrow.

thanks maxi_crawf:D

Running cool!

Quick sell it to an F owner with impending HGF

Now Now!
The KV6 is not immune either!

Ron

Just been looking round for prices for a new thermostat today, only one place said they could get one! and it would be £47 :eek:, is that about right? and where is the thing located on the engine??

maxi_crawf

Yep, that's about right.
Rimmerbros might have some.
Its on the outlet of the water pump round the back of the engine.

Ron

Thanks Ron !!:)

maxi_crawf