Running cold issue. Tricky one-thoughts needed
 

My silver '8 has been running a little "cold" recently. I originaly thought "ok, time for a new thermostat, water pump & belt".

I had the above sorted yesterday using all OEM parts and the problem still persists. Mainly during motorway use, and it seems to run even cooler when using the a/c cc.

I have no problems with heat in the car, heaters work just fine, no water leaks, water levels are fine and system was bled properly, taken for a warm up run and then re bled to be safe.


The needle isnt jumping around arratically which makes me think it's not a temp sender fault. Could anyone point me in a few directions of other parts that could be to blame for this odd temp behaviour. :-(

Bex

not sure bex but love the new sig pic! +++

Awesome sig pic, not sure about the engine. Ben/Mike/Physce/A8Doc will probably know.

Could still be temp sender, but if it's going to a normal place whilst idling/town traffic, and then dropping when going fast, it may not be.

Maybe the fan staying on when it shouldn't. Does it behave with the climate off or set to econ mode?

Thanks for the sig comments chaps +++ :D I have a few new pics I rather like. ;)

Yes I think it does go back to the normal 90 (middle of dial) during town driving.

I will confirm later but I am pretty sure that when using econ, temps remain normal.

I will update a little more tonight after work. +++

I was thinking the fan may be staying on-but I cant hear it when I pop the bonnet :Confused:

Can you put VCDS on it and check the temperatures from the senders.
The drawings show you have twin electric fans. If one were not switching off that might cause the problem. But running cold usually means thermostat issues of temp sender issues.

Hmm, ok maybe I ought to think about ordering a new temp sender, it goes up and down so gracefully that I really don't think this is the culpret :(

I will try to get plugged into VCDS later. Not sure whether the guy will know how to access the temps from the senders.

Could you advise on how to access this in VCDS?

Just to add, I am going over to my friend with VCDS within the next 2 hours, and he has asked whether anyone knows which number measuring blocks are for the temp senders?

That probably means more to you guys than to me :D

just cycle through the ones for the engine as they may be different from my PF D2.

Temp readings seem normal on idle, couldn't test it running at higher speed (when it actually runs cold) because the laptop battery doesnt hold its charge and has to be connected to the mains constantly.

:( I am going to order a new temp sender anyway. I will keep you all updated +++