With the known problems with the aftermarket solenoids for the valves and their propensity to fail I decided to buy a whole new valve for the my show quality BMW M5.
I realize that many of you do not want to spend $300 on a water valve. I am aware of the E46 valve subsitute and this is a pretty good one but if you have a car you want to keep original then an original fit and finish valve is imperative.
The valve was in the $300 range in the fall of 2017. I installed the valve and at that time only drove the car around the block. It was up to temp but not that many miles.
About a week later our group, BMW Classics of Georgia did a Saturday drive on some back roads in the southern part of the mountains and then to a restaurant for late lunch.
We assembled in a parking lot and I was out of the car and noticed water running out from under my car.
The valve was visible leaking but not enough to prevent me from doing the drive. I had another car behind me in case of catastrophic failure.
I kept an eye on the water temp gauge and it was fine. It was also cool outside. Made it home that day with just adding a little water.
So I contacted parts guy and he ordered another valve but told me I would have to bring the car to the dealer and let them do the replacement. UGH, I said but was able to stay with the car and work with a mechanic that was probably about 60 and new what an S38 was. You have to remove the air box on the M5 to replace the water valve. Not difficult but just wanted someone to work on it that was familiar. Of course I was right there watching.
With valve replaced I drove the car 7 miles home and opened the hood to look.
Water running out of the valve just like the previous one.
So the dealer then tells me they won't replace the valve again. This is a quote of what the parts guy at the dealer told me.
"BMW will only warranty a part or accessory 1 time as a spare part warranty. When the second part failed BMW was not going to cover it".
So here's where I stepped in and tried a couple things.
I took the original valve body (plastic) that was in my car and installed the new solenoid. This actually worked for quite a few months. Thought it was over then later this summer it started leaking again.
I drove it that way for a few months with the radiator cap loose to first click. This kept the water in but didn't pressurize the system and force the water out.
Then in December I decided to remove the valve again and see if I could figure out why it was leaking.
I was able to see a potential problem with the seal of the solenoid and how it sits in the valve body.
Basically there is not enough squish of the gasket by the solenoid body to keep it from leaking.
I did some measuring and saw that I could easily remove some material from the top of the plastic valve body and increase the compression on the gasket.
That did the trick and has been working fine for about a month now. I don't drive this car every day but I have (weather permitting) made extra efforts to put some time on this repair.
When you look at the photos I think it will be pretty apparent what I did.
The bottom part of the valve body has another section to it. One of my valves would come apart there but the other one would not unless I broke it open.
Inside this portion is a check valve. It's simply a ball that rides in there and keeps the coolant from going backwards. Not sure how it could ever do this so I removed the check valve. BTW the photo of the valve I used the lower portion is NOT attached. Sorry I probably shouldn't have used that photo.
I removed about .007 from the top of the valve body allowing the seal at the bottom of the solenoid to push down more and not leak.
This is where the manufacturer for BMW did a poor job of measuring.
There is also a possibility that the lower section could leak. This happened on my first replacement so I sealed the bottom section with JB weld so it was sealed tight. It can take the heat where other sealants can not.
Post if you have questions as it seems so simple to me but may not to others.
Also if you have already experienced a faulty valve I would really like to know. I'm gathering data to submit a consumer complaint in my state and also to BMWNA.
BTW I called BMWNA and asked to speak to someone in the parts area for the US. They told me no such person exists and I would have to go to the dealer. It's not the dealers fault.
BMW needs to recall this part and have one made properly.
Sorry for image problems. There's another step to google hosting they don't tell you tell you look it up and then what you think is the URL doesn't work on here in the URL it has to be in the img. Geez!
) so i replaced it and shaved the top of the plastic flange down to make a tighter seal. it’s been working great with no leaks. thanks a ton 