Coolant thermostat

[Murphybarnes]

Just looking for some confirmation of the bleedin' obvious please.
My temp guage has always hovered around the five to twelve range and only hits bang on twelve occasionally on long runs. Recently it is struggling to even hit that. It took a twelve mile journey to get some decent heat in the cabin today.
I'm going to book in for a new thermostat but just wondering how a fully functioning system should perform. Should the needle reach vertical pretty briskly and then just stay there. Mine rises and drops slightly depending on how I'm driving.
Cheers for now.

[henrym3]

On these cold mornings my gauge is at 12 by 2/2.5 miles and never moves from that position. You sound like your thermostat is partially or fully open. 12 miles to get decent heat is way to much mileage.

[marinaman]

gauges tell lies !

ours was always in middle at 12 o clock  one day i was just running tests and even after hours running it was only 65c according to diagnostic
put a new stat in and gauge still sits at 12 o clock but diagnostic shows temp at 95c

[Smeeagain]

[quote="Murphybarnes"]
Just looking for some confirmation of the bleedin' obvious please.
My temp guage has always hovered around the five to twelve range and only hits bang on twelve occasionally on long runs. Recently it is struggling to even hit that. It took a twelve mile journey to get some decent heat in the cabin today.
I'm going to book in for a new thermostat but just wondering how a fully functioning system should perform. Should the needle reach vertical pretty briskly and then just stay there. Mine rises and drops slightly depending on how I'm driving.
Cheers for now.
[/quote]

Access the hidden menu (each th forum) and the you can check the actual temp as your drive rather than working off a gauge on the needle. Mine sits at around five to twelve and the temp is only 70 degrees summer and 65 degrees now so is most likely fully open but doesn't seem to be doing any harm so have left it for now
see

[Murphybarnes]

Thanks for that. Just back from work. Gauge wasn't as sticky today, bit milder. Got it up to its usual five to twelve and temperature was 68°c.

[Murphybarnes]

Anybody know the normal operating temperatures?

[marinaman]

somewhere round 95c i think thats what someone told me on here,  same prob i had  get a new stat in and you be back to norm

got mine from Ebay, but sent wrong one  think there 2 sorts depending on engine,  its one of the bolt holes in a different place  thats all it was, bit fiddly to do but look on You tube there a few vids of doing the job,

I didnt remove the air pipe down to the turbo as i thought it be a sod to put back.so i struggled , bashed knuckles etc.  got it done and found i had dislodged it anyway  so i could have made job 10 times easier

just pulls and pushes back on but watch for the liitle pipe half way down, you will know when you see it.

[Murphybarnes]

Would normally have a bash at it but to be honest my sausage fingers in sub zero temperature in fading light kinda sways me towards my indie. Thanks to everyone for all the info. I'll close this with the final cost at some point. Will be of interest to others in the same predicament.

[Smeeagain]

Yes please advise cost and manufacturer used for the part. HenryM3 has good thermostat info

[marinaman]

got mine from Ebay car parts seller,  Mahle branded and was £38 if i remember

[Smeeagain]

Thanks. Mine sits at 65-75 (depending on outside them, ei cooler in colder weather), and had been like that for a good 10 months but everything else appears one. Im usually of the school of if it aint broke don't fix it, i.e. the car runs one, so what are the reasons for me to replace it (bear in mind that is is colder than hotter and not overheating or boiling off)?

Smee

[henrym3]

As you say "if it ain't broke don't fix it" but yours is broke and needs fixing. Your car will run forever with an open thermostat,  but it's taking longer to warm up and it's using more fuel, it's just not as efficient.

[Smeeagain]

But im not seeing any increase in fuel consumption or is it minimal?

[pcdee]

[quote="henrym3"]
As you say "if it ain't broke don't fix it" but yours is broke and needs fixing. Your car will run forever with an open thermostat,  but it's taking longer to warm up and it's using more fuel, it's just not as efficient.
[/quote]Also, I do believe that the dpf will not regenerate by itself if the temperature doesn't meet the requirements for regeneration

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[X5Sport]

It’s an E53.  No DPF fitted to that series.

Smee, once the weather turns much colder then you may see an increase in fuel consumption but not drastically unless the stat is stuck fully open, then it will take a lot longer to warm up and that will also keep the gearbox on ‘cold’ mode resulting in it holding the gears for longer.  Mine used to pretty much ignore 6th until fully warmed up.  That will increase fuel consumption I think.