DIY: Thermostat & Waterpump (Video)

[DreamTime]

Wait, actually I think I got this. My neighbor dropped off a big box of tools he thought I might need before he left town last night. I should be good to go.

Just letting the engine cool off overnight before I get started. Wish me luck tomorrow everyone!

[IamFODI]

Thanks for this DIY, lagwagon! Super helpful. Great tips at every step.

My thermostat was REALLY seized in the housing. I looped some huge zip-ties through it and applied as much force as I could with my own muscles -- e.g. looping a jack handle through the zip-ties, standing on that, and then yanking up on the housing with big bursts -- and it didn't budge. Tried some fairly aggressive penetrating lubricant, hoping it'd also eat away a bit at the seal, and still got nothing. I only started noticing progress after cutting away as much of the old dried-out seal as I easily could, and then using some more brute force to walk the thermostat out one side at a time. Once the seal came loose, the thermostat came out pretty easily. Had to clean the housing pretty thoroughly after that to get all the zip-tie shavings and chemicals out of it.

[8k_v8]

Great DIY

Any tips on cleaning up the top of the water pump? Worried about debris getting into the reservoir when scraping residue off.

Thanks!

[Deadmon]

Fantastic DIY video! Changed out the thermostat, belts, pulleys and water pump recently.

The best advice I can give is to really use an offset wrench for the tensioner and have another person help you with putting the belt on/off.

[shimmy23]

Does anyone know the torque specs for this DIYER?

[shimmy23]

Just finished this job. I did coolant hoses, thermostat, sensor and water pump. I bought the FCP kit which consisted of OEM and OE spec parts. Overall, the job wasn't very complex. The lower coolant hose gave me the most grief. It was extremely challenging to remove since it was stuck on!

Not sure you really need a torque spec on this job. None of the bolts were very tight. I think BMW recommended 10NM, which is barely any force.

[ETM3]

Just did this with water pump, thermostat, sensor. Pretty straightforward since I’ve taken off the plenum before. Trouble spots were getting the belt on, off, thermostat removal from the housing. For these an offset wrench helped with tensioner, and for thermostat removal scrape all the old rubber gasket first, then take big pliers, vice grips as the base and turn it and wiggle it out from the housing. Also, had a brain fart and took an hour realizing that there was a cover on the tensioner pulley that needed to be taken off first 🤦. Haven’t seen this mentioned anywhere. All in all not bad took 4 hours for me.

[Mimmer]

jw when you put it all together with turning the screw on the coolant tank. is that a must and can you just add coolant only, confused on the letting air in part...

[IamFODI]

Originally Posted by Mimmer

jw when you put it all together with turning the screw on the coolant tank. is that a must and can you just add coolant only, confused on the letting air in part...

When I did this job, I didn't touch the screw because BMW's procedures don't even mention it AFAICT. Everything went fine.

A few years later, a friend of mine worked on my car's cooling system and used the screw pretty much as described in the video. Also went fine.

IDK what the pros and cons are to each method. With the second method it seemed to take less time to bleed the system and get the coolant level right, but I guess I can't be sure.

[Mimmer]

Originally Posted by IamFODI

When I did this job, I didn't touch the screw because BMW's procedures don't even mention it AFAICT. Everything went fine.

A few years later, a friend of mine worked on my car's cooling system and used the screw pretty much as described in the video. Also went fine.

IDK what the pros and cons are to each method. With the second method it seemed to take less time to bleed the system and get the coolant level right, but I guess I can't be sure.

when bleeding did you turn the car on? I saw a video with jusst turning car on without engine and waiting 12 minutes after stepping on gas pedal for 10 seconds with heat on. thne rechecking...

[IamFODI]

Originally Posted by Mimmer

when bleeding did you turn the car on? I saw a video with jusst turning car on without engine and waiting 12 minutes after stepping on gas pedal for 10 seconds with heat on. thne rechecking...

Yeah, I ran the engine. Haven't tried the method you described.