Pre-LCI E85 replacement thermostat?

[Zedebee]

My 03 2.5i takes an age to get up to temperature and “normal” seems to be about a third on the gauge instead of a half. No other problems - car starts and runs just fine - so I am guessing the thermostat is simply stuck open.

I am on a bit of a shoestring with this car. Any recommendations for which part(s) to get from AUTODOC and anything else I should be doing (preventative maintenance-wise) at the same time?

I also need to replace a failed oil pressure switch and O2 sensor which have thrown codes but not causing any other issues .

[enuff_zed]

I fitted a Febi Bilstein thermostat from Autodoc on wifey's 2.5i. The full plastic assembly. Been ok for a couple of years at least.
Sorry can't remember the price.

[SonnyA85]

you could get new coolant too if you wanted from autodoc although probably not necessary if been replaced within the past year or so. it's hardly expensive though for coolant. so long as it's G48 i think the spec is it's fine. i used febi bilstein coolant.

[Zedebee]

I fitted a Febi Bilstein thermostat from Autodoc on wifey's 2.5i. The full plastic assembly. Been ok for a couple of years at least.
Sorry can't remember the price.

This one? Looks like £35 on a good day. I’ve not heard of any issues with the water pump (unlike the N52), so I’m guessing it’s best not to disturb that.

5C69A159-6618-4ED0-949D-515CA86C684B.png (195.82 KiB) Viewed 256 times

[enuff_zed]

Depends how far you want to go. They do leak water out of the tell-tale hole under the shaft when the bearing seal fails.
You need about the same amount of dismantling to get to that too.
But it goes on................... while you're in there you could change the belts too, oh and while the thermostat is off it's easier to get at the vanos...........

Depends on your budget and your trust in fate.

[bigwinn]

I fitted a Febi Bilstein thermostat from Autodoc on wifey's 2.5i. The full plastic assembly. Been ok for a couple of years at least.
Sorry can't remember the price.

This one? Looks like £35 on a good day. I’ve not heard of any issues with the water pump (unlike the N52), so I’m guessing it’s best not to disturb that.
5C69A159-6618-4ED0-949D-515CA86C684B.png

I took a water pump off the 3.0 which had done 140k and not a micrometer of play in it at all

However John next doors car same age and fewer miles was approx 2-3k off failing

Give it a wiggle with the belts off see what you think

[bigwinn]

Thermostats Ive used several from Autodoc, Febi, Akabus and Meyle if I recall- all good no issues

[Billbob10]

I fitted febi bilstein also recently just been to france 1100 miles with no problem

[Jakg]

I *think* Wahler are OE.

I got one on eBay NOS for £15.

I'd replace the surrounding bolts, too - only a couple of quid on eBay.

I only changed mine because I got it cheap and was tracing a coolant leak - it wasn't the problem in the end, but the seal was clearly weeping a little but only visible when removed.



And in addition to new coolant, I'd get a metal bleed screw in case you round yours off - if you really want to go cheap and can wait they are like £3 on Aliexpress.

EDIT - IF your worried about coolant loss, I'd also check the expansion tank and coolant temp sensor seal.

I drained and refilled my system several times chasing leaks and wasted a lot of coolant in the process - it would've been cheaper to do it all at once.
The coolant temp sensor seal is a common leak point if disturbed but a new seal isn't expensive (apparently! I didn't know they were available when I did mine).
The expansion tanks are known for blowing up.

[Zedebee]

Thanks guys, helpful info. @jakg, it’s just the thermostat I think, no coolant less as far as I can tell.

Just trying to think of a few things to make up a decent AUTODOC order now!