in line thermostat

[david2000]

hi to all
today I fitted a in line thermostat to my 75 diesel,started the engine and bleed the system,run the engine temp went up to 96 c and the cooling fan came on then I tried the heater and it was hot the switched the heater off and let the engine come up to temp until the fan came on,then I took the car for a spin down the road temp was between 76 c to 83 c tried the heater it was hot got back home parked the car ran the engine temp was 83 c turned the heater on to 28 c it was hot but the cooling fan came on and I don't know why can anyone tell me why this is
all the best david

[another_clean_sheet]

David, The first thing I would do seeing you have taken the car for a spin is to rebleed the system. I needed to do this after I fitted an online thermostat as I had an airlock in the cooling system.
Mike

[Mickyboy]

Ideally the temp should get to 88 degrees, I have a inline that I fitted and found that I suffered no airlock, what fan have you got 2 or 3 speed ?

Regards mick

[DMGRS]

It sounds like there was an airlock at first, that has now sorted itself out.
The diesels are very cool running - an 86 degree thermostat will tend to sit in the low 80s, and an 88/89 item in the mid 80s.
They're very hard to keep hot!

[Union Wheels]

You can get the diesel to run 95C and back to 85C cycling continually if you fit an alloy housing in the top hose and a 92C stat.

Pete.

[david2000]

hi to all
the fan is a 3 speed and I bled the system when cold and after a test run,on auto the fan comes on but change it to hi the fan go,s off in econ the fan does not come on and in hi mode in econ,in defrost the fan comes on, I have owned the car for 3 years and this is the hottest it has been,the temp gauge never went above half way
all the best david

[T-Cut]

Originally Posted by david2000

- - - this is the hottest it has been,the temp gauge never went above half way

Nor should it. The 'normal' is up to 115C, which is rather warm for any engine.

I thought you were running in diagnostic mode?

TC

[SD1too]

Originally Posted by david2000

... on auto the fan comes on but change it to hi the fan go,s off in econ the fan does not come on and in hi mode in econ,in defrost the fan comes on ..

What you are describing there David is the fan's response to the air conditioning and it is working correctly. It will only respond to engine coolant temperature when this reaches 100°, and you'll have to have the air con. off to hear it starting.

... the temp gauge never went above half way ...

The gauge will remain at "half way" even if your engine seriously overheats (temperatures up to 115°). You have to use the instrument pack diagnostics to find out what the actual temperature is.

Simon

[david2000]

hi to all
yes the fan run continuously for more than 2 minute on demist
today I checked the water level and toped up then I started the car and bled the system no air came out I then connected the t4 and went to the engine overview from cold these were the readings
11.27 water temp cold 6.85 c
11.35 water temp 53.55 c
11.40 water temp 73.55 c
11.45 water temp 79.35 c
11.50 water temp 82.35 c in line thermostat opens
11.55 water temp 87.95 c
12.00 water temp 93.35 c
12.03 water temp 99.16 c fan comes on
while doing this test I tried the atc on auto and the fan did not come on
also the heater was hot

[SD1too]

Originally Posted by david2000

yes the fan run continuously for more than 2 minute on demist

That's fine. In 'demist' mode, the air conditioning will operate with the fan running in slow speed continuously.

11.50 water temp 82.35 c in line thermostat opens
11.55 water temp 87.95 c
12.00 water temp 93.35 c
12.03 water temp 99.16 c fan comes on

I have no experience of the diesel engine David, but from what I've learned on the forum your engine appears to be overheating. Have you inserted the in-line thermostat the correct way around?

while doing this test I tried the atc on auto and the fan did not come on ..

That sometimes happens in 'Auto' mode. It's why we always recommend using 'demist'.

Simon