F8X Coolant Thermostat DIY! Am I Missing Something?

[XelAbel]

I'm scratching my head here and am on the brink of believing I'm trapped in a parallel universe. Is it possible that there's no DIY guide on replacing the thermostat for our beloved F8X? I've been scouring the forum (and pretty much half of the internet) for a few hours now, and it's been a fruitless endeavor. Aren't we in the age where there's a DIY for even the most obscure tasks? Like, I bet I can find a guide on how to replace the little light bulb in the glovebox, but the thermostat... nada.

As someone who's not a stranger to throwing a car on a lift and diving deep into its guts, I'm just a bit flabbergasted that I can't find anything on what seems to be a basic maintenance item for our beauties.

So, either I've lost my knack for efficient Googling, or there's a major gap in our DIY repository. If anyone has come across a guide, or even some pointers, I'd be immensely grateful. And if not, maybe it's time I make one?

[hC1001]

I suggest you download a copy of ISTA to get the BMW repair procedures. You can also find it online if you register as a user on a specific site that was asked to take down the repair procedures by BMW in the past. You might see links to this site listed in older posts from 2020 and earlier i think...
Ive never replaced it but the thermostat is connected to the waterpump with 3 bolts. You might be able to get to the 3 bolts from underneath but that might require dismounting some stuff like the oil cooler and electric waterpump. Only way to confirm this is to lift the car and remove the underpanels to take a look at the access space. The engine coolant also needs to be drained beforehand.

In ISTA, it says to replace the o-ring when replacing thermostat. There is a bmw special tool kit listed for this as well but not sure how necessary it is... Special tool 17 2 050

The proper procedure might be to remove the coolant pump from the car and then replace the thermostat out of the car.

The tightening torque for the thermostat housing to coolant pump is listed as 10nm. The torque for the coolant pump to crankcase is listed differently on two torque spec sheets in ISTA. The procedure to replace coolant pump lists it as 10nm. The procedure to remove coolant pump pulley list it as 8nm.

Hope this info helps.

[jagus]

Very interested on this one too. I wonder if the fan should be removed first... Hopefully someone has already done the job before and can bring some light...

[Matt214]

Originally Posted by XelAbel

I'm scratching my head here and am on the brink of believing I'm trapped in a parallel universe. Is it possible that there's no DIY guide on replacing the thermostat for our beloved F8X? I've been scouring the forum (and pretty much half of the internet) for a few hours now, and it's been a fruitless endeavor. Aren't we in the age where there's a DIY for even the most obscure tasks? Like, I bet I can find a guide on how to replace the little light bulb in the glovebox, but the thermostat... nada.

As someone who's not a stranger to throwing a car on a lift and diving deep into its guts, I'm just a bit flabbergasted that I can't find anything on what seems to be a basic maintenance item for our beauties.

So, either I've lost my knack for efficient Googling, or there's a major gap in our DIY repository. If anyone has come across a guide, or even some pointers, I'd be immensely grateful. And if not, maybe it's time I make one?

I was wondering the exact same thing. I've done a ton of searching because in my case, I need to replace the mechanical waterpump as well as the thermostat and I'd like to watch a how-to or read a step by step but have had no luck finding one for the F80. I've been able to find guides for all kinds of other BMW versions of the '3' but not the F80. I'd like to know where I can get a copy of the service manual (ISTA) though, if it still can be downloaded somewhere.

[MrSmileyDC]

I changed the water pump and thermostat on a n54 motor before. I’d assume it’s a similar process considering the similarities of the n54 to the s55. Have you checked one of those guides?

https://f80.bimmerpost.com/forums/at...6&d=1406475520

[chetrickerman]

Replacing the coolant thermostat on the S55 is super easy. Drain coolant, disconnect radiator hose from thermostat housing, unplug thermostat, then loosen the 3 mounting bolts. Then the thermostat should come out.

[jagus]

https://f80.bimmerpost.com/forums/sh....php?t=1906580

This is the best that I found to replace the mechanical water pump...

[Matt214]

Originally Posted by jagus

https://f80.bimmerpost.com/forums/sh....php?t=1906580

This is the best that I found to replace the mechanical water pump...

That's of great help, thank you!

[Matt214]

Originally Posted by MrSmileyDC

I changed the water pump and thermostat on a n54 motor before. I’d assume it’s a similar process considering the similarities of the n54 to the s55. Have you checked one of those guides?

https://f80.bimmerpost.com/forums/at...6&d=1406475520

This definitely is a great informational that gives an overview of the S55 systems. I took a look through it from beginning to end. Although it doesn't have any repair steps, it does diagram the layout of the different systems and gives some insight. Thanks for this!

[jagus]

I just replaced the water pump and thermostat on my F80. I did not remove the fan completly, just pushed it downwards to make enough room to work on the water pump.

I did NOT remove the electric water pump for the charge cooler circuit.

The most difficult, I would say that it was to remove the waterpump, as it was stick to the block and I spent like 30-40 mins until I finally managed to detach it.

Regards

[Whiskey7]

Agreed. Upon search, very little if anything found regarding certain F80/82 engine
related DIY maintenance.

TBS - I just did T-stat on an F82 Saturday. Approached from bottom: remove aluminum guard, loosen sway bar, move wire harness attached to frame and you have access to the 3 T-stat housing bolts.

As previously stated, disconnect sensor lead, hose (pull metal retaining clip completely out and disconnect hose). If you are on your back, free shower begins now.
Replacement unit comes complete with sensor, o-ring and housing. Installation is the reverse.

Add coolant into main reservoir, if you did not drain coolant system, air charge reservoir should not be affected.

Bleed system, run and check level.

[XelAbel]

Originally Posted by Matt214

I was wondering the exact same thing. I've done a ton of searching because in my case, I need to replace the mechanical waterpump as well as the thermostat and I'd like to watch a how-to or read a step by step but have had no luck finding one for the F80. I've been able to find guides for all kinds of other BMW versions of the '3' but not the F80. I'd like to know where I can get a copy of the service manual (ISTA) though, if it still can be downloaded somewhere.

*Update* Succesfully obtained ISTA, thermostat ordered (and crank bolt capture Will post pictures/details when after I finish the job.

https://mega.nz/folder/C4kywIja#Bf47WtBUZiEtvHnm5ExbJQ

Here is a link to the ISTA procedure for the waterpump. Will add images and other details to the Mega link as I get them.

[jagus]

The worst is to make enough room with the fan... Good luck