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535i Andrew

Water paths. Nearside engine bay

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When washing the car at the weekend, I aimed the hose (garden hose not at full flow) on the scuttle panel grills to give the yellow grommet a clear out.  Water ran out clear from behind the panel over the grommet.  All good.

 

The area between the heater cover and the nearside inside wing looked at bit claggy so I pointed the hose in there to flush out any debris, beneath the bonnet strut/explosive strut.

 

image.jpg

 

Thinking that it would drain out into the wheel arch area.

 

Let it run for a few moments and I then heard running water splashing on the ground.

 

I traced it to just in front of the rear wheel.

 

image.jpg

 

Double checked and sure enough on 2nd run of the hose water was exiting the sill in front of the nearside rear wheel when aiming the hose in the area in the first picture, very little was running out in comparison at the front wheel.

 

This doesn't seem right.  Water running along the sill, the full length of the car. That would mean the area in there is kept nice and damp a perfect location for rust.  

 

Has anyone else noticed this?  I am assuming its not normal and something elsewhere is blocked and this is if you like an overspill channel of some sorts.

 

The car was parked on a slight slope, nearside rear being the lowest point.

 

Referencing this post

 

I wonder if the water in mine is not escaping from above/behind the wheel arch liner (Picture 6 that Matthew took in his post with the wheel arch liner removed) and is tracking along some trim where you see two black pipes bend thru 90 deg and then disappear heading to the rear of the car?

 

Further investigation is required.

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That water runs out of the hinge well on to the top of the car's underbody cover and as the car was on  slight slope the water went all the way to the rear of the car. Nothing to worry about. 

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Thanks Matthew.  

 

I thought it would make its way out in the front wheel area, i.e. flow around the top side of the wheel arch liner and exit in front of the sill behind the front wheel rather than flow to the rear of the car.

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4 minutes ago, 535i Andrew said:

Thanks Matthew.  

 

I thought it would make its way out in the front wheel area, i.e. flow around the top side of the wheel arch liner and exit in front of the sill behind the front wheel rather than flow to the rear of the car.

Next time you pour water down the hinge cavity look down between the engine and the inner wing (where you’d go to remove the yellow grommet cover) and you’ll see the water trickling down on to the car under cover. 

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Just now, Matthew Ashton said:

Next time you pour water down the hinge cavity look down between the engine and the inner wing (where you’d go to remove the yellow grommet cover) and you’ll see the water trickling down on to the car under cover. 

 

I did just that, I saw a trickle (on the chassis beneath the cover) on to the underbelly when putting water down the scuttle grills nearer towards the centre of the engine bay. 

 

This was a torrent on comparison, which got me thinking, but I guess its making its way on to the same panel just nearer the outside of the car. 

 

I've always meant to take the wheel arch liners off to check the drains as outlined in your post linked above and some of the other guys posts.

 

 

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I had my rear wheel liner out to do the spring (unnecessarily) and it wasn't too bad a job to get out. Bitch getting back in mind. I was surprised how much crud and cobwebs were behind it! Worth doing every now and then I think, as in every few years if the car is a keeper  (does anyone keep cars these days?)

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20 minutes ago, nashdm2 said:

This is very strange Andrew, I look forward to your further investigations.

 

Yes, I think its strange that the water should travel along the underside of the car thus keeping it nice and damp and attractive to corrosion......

 

My E60 suffered from corrosion on the rear brake lines in the area under the front passenger footwell and sill on that side right where the water is flowing in the F10.

 

An investigation is required, I'll keep you posted

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30 minutes ago, 535i Andrew said:

 

Yes, I think its strange that the water should travel along the underside of the car thus keeping it nice and damp and attractive to corrosion......

 

My E60 suffered from corrosion on the rear brake lines in the area under the front passenger footwell and sill on that side right where the water is flowing in the F10.

 

An investigation is required, I'll keep you posted

 

I think you’ll find the water travels on top of the under tray as I mentioned. It isn’t a sealed unit and once dry I don’t see why it would attract corrosion. 

 

I checked the waterway when I did my investigation a few years ago and the water clearly drains on to the undertray so when the car is at an angle with the rear lower the water will run to the rear. Design at work. 

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18 minutes ago, Matthew Ashton said:

 

I think you’ll find the water travels on top of the under tray as I mentioned. It isn’t a sealed unit and once dry I don’t see why it would attract corrosion. 

 

 

At this time of year up at these latitudes I have my doubts it will dry out and keep the surrounding metal work above the plastic tray nice and damp.

 

I don't live in the tropics like you, lol. :D

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13 minutes ago, 535i Andrew said:

 

At this time of year up at these latitudes I have my doubts it will dry out and keep the surrounding metal work above the plastic tray nice and damp.

 

I don't live in the tropics like you, lol. :D

 

But that then goes for any area in your car that gets wet through driving in adverse weather - wheel wells, engine bay, inside the doors. The undercarriage is probably one of the better corrosion proofed areas of the car. 

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Matthew, are you suggesting that the water goes down onto the engine tray and then makes it way out and down the underside of the car with "water tension", much like when you pour water out of a glass at a narrow angle, it will not pour nicely but stick to the glass on its way down? Hope that makes sense?

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2 hours ago, nashdm2 said:

Matthew, are you suggesting that the water goes down onto the engine tray and then makes it way out and down the underside of the car with "water tension", much like when you pour water out of a glass at a narrow angle, it will not pour nicely but stick to the glass on its way down? Hope that makes sense?

 

And then dries. 

 

I think there is too much “overthinking” a none issue with this one. These cars aren’t going to rust away as a result. The water evacuation from the scuttle panel is distributed across the under tray and on top of the wheel arch liner making its way out to the road. 

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