BMW parking sensors

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testbloke

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I bought my BMW at three years old. Noted in the service history it had had a parking sensor replaced.
A month ago I got same failure. Managed to get an eNay obd to diagnose, got genuine painted part from eBay Germany and luckily it was the one above the exhaust so managed to swap it without removing bumper.
Bit of a pain but in the end sorted for £80 total where the BMW bill would have been over £500.
Not great two failures in four years but hey ho .......
Had car jet washed on Friday on way home, parking sensor failure on Saturday.
So it seems my £34k BMW cannot be jet washed, counting the days till I can get shot of it and go back to Japanese build quality.
 
Jetwashing is fine. Unless you force water into places it shouldn't go. Like parking sensors, which are notorious for being damaged by pressure washing. Who jetwashed it?
 
Jetwash patios.....

wash cars with sponges...
 
Local car wash place. Have used them for years with Honda without an issue
 
The handbook from my car says specifically that you shouldn't let a jet washer anywhere near the parking sensors.
 
boogie man said:
The handbook from my car says specifically that you shouldn't let a jet washer anywhere near the parking sensors.
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Yes, said this in my handbook from my previous BMW I had, said using a jet wash was fine, but not around the parking sensors...
 
testbloke said:
Had car jet washed on Friday on way home, parking sensor failure on Saturday.
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Would suggest like this has caused the failure, unless you've been extremely unlucky...it's not the one you've just replaced that's failed again is it ?
 
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Still to check but logically (and for fixing hopefully) it will be the same one. The inner number is cut away for the exhaust leaving this sensor completely exposed to anything coming off the wheel or to jet wash when doing wheel arch liners.
If it's the same one it will be getting large amounts of silicone which will hopefully keep it good till I can get shot of it
 
boogie man said:
The handbook from my car says specifically that you shouldn't let a jet washer anywhere near the parking sensors.
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I worked for an automotive electronics company. All electrical items outwits the cabin have to meet standards regarding resistance to water ingress, this is why most sensors etc are potted with a rubber like substance.
The sensors are not failing due to water pressure from the front but ingress from the rear. As I say no issue with Honda for six years and also wife's various Mercedes for six years.
 
testbloke said:
Still to check but logically (and for fixing hopefully) it will be the same one. The inner number is cut away for the exhaust leaving this sensor completely exposed to anything coming off the wheel or to jet wash when doing wheel arch liners.
If it's the same one it will be getting large amounts of silicone which will hopefully keep it good till I can get shot of it
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Hopefully (from an ease of replacement) it will be.

I'd be tempted to stay away from Jet washing them - even if it's only for a few months - for peace of mind / to make sure it doesn't cause a further issue...
 
You have to remember jet washers push out water at over 100bar some of them.
To expect an item like that to be resistant to that kind of water pressure you are kidding yourself.
BMW or Honda, maybe its a slight design flaw but I would suggest you switch to a soft wash car washer not a jet washer.

I would never point a jet washer at a car unless you have a low pressure diffuser fitted to the nozzle like a foamer.
 
Yes I will be avoiding in the future. The same company make the sensors for BMW and Honda and many others.
It's the time to failure (again) that's annoying. Probably playing on it a bit to get shot, never liked this car much.
 
Mr Bump said:
You have to remember jet washers push out water at over 100bar some of them.
To expect an item like that to be resistant to that kind of water pressure you are kidding yourself.
BMW or Honda, maybe its a slight design flaw but I would suggest you switch to a soft wash car washer not a jet washer.

I would never point a jet washer at a car unless you have a low pressure diffuser fitted to the nozzle like a foamer.
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Not kidding myself it's a requirement. I kid you not we had ecu,s for gm under 16 feet of water for a week and after drying the mating connector they had to fire first time.
Sixteen feet of water was the Japanese md's koi pond which gave the required water pressure. Other tests included 1000 cycles in salt water where even the label had to scan once the salt crystals were chipped off. This was legal requirements.
Compared to this, one wash with a jet wash and fails is pretty crap.
 
testbloke said:
... we had ecu,s for gm under 16 feet of water for a week ... Compared to this, one wash with a jet wash and fails is pretty crap.
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If the jetwash works at a pressure of 100 bars, that's the equivalent to being more than 3000 feet under water. Still think it's crap?
 
Mr Bump said:
Jetwash patios.....

wash cars with sponges...
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No, you wash cars with lambs wool mitts or microfiber mitts, sponges will just scratch the car with any grit or dirt on the car. It's perfectly ok to jet wash cars, just don't direct the full force of the jet close up and direct onto parking sensors.
 
testbloke said:
I imagine that pressure drops dramatically asks you move away from the tip.
What is the pressure of rain hitting it at 70mph?
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Assuming that the raindrop is 4mm in diameter and that contact with the car accelerates it uniformly from rest to 70mph in a distance of 4mm, the pressure exerted is about 3 bar. Or about the same as being under 100 feet of water. Still miles short of what a pressure washer can deliver.

Next question?
 
StewartR said:
Assuming that the raindrop is 4mm in diameter and that contact with the car accelerates it uniformly from rest to 70mph in a distance of 4mm, the pressure exerted is about 3 bar. Or about the same as being under 100 feet of water. Still miles short of what a pressure washer can deliver.

Next question?
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Mass would have to be taken into consideration, the raindrop being significantly more. Anyway it's the same sensor and ingress from rear again do definitely due to the hole in the rear bumper. Just good old fashioned bad engineering.
I will fashion a cover so it doesn't happen again for the next owner
 
testbloke said:
Mass would have to be taken into consideration, the raindrop being significantly more.
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Sorry, are you suggesting I can't do the maths properly? What figure did you come up with? We can compare our calculations if you like.
 
testbloke said:
So it seems my £34k BMW cannot be jet washed, counting the days till I can get shot of it and go back to Japanese build quality.
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A little anicdote.
Must have been mid 80's when I was working for Wincanton as a driver.
The local depot got half a dozen of what was then state of the art, electronic gearboxed tractor units, ( the make escapes me for now)
First one through the truck wash, and that was as far as it went, it never came out the other side under its own power :D
 
Cobra said:
A little anicdote.
Must have been mid 80's when I was working for Wincanton a:Ds a driver.
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That's a tad scary I used yo chat to a lot of Wincanton lads on CB radio was a 19 monitor :eek:
them and the Red Angels (Shoreham Transport) in the days before mobile phones
 
Cobra said:
A little anicdote.
Must have been mid 80's when I was working for Wincanton as a driver.
The local depot got half a dozen of what was then state of the art, electronic gearboxed tractor units, ( the make escapes me for now)
First one through the truck wash, and that was as far as it went, it never came out the other side under its own power :D
Click to expand...

At least it was under warranty!
 
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