Floor well wet inside car!

[RTTBMW]

Hi,

Well yesterday I decided to look at the issue with the headlight wash wiper that was not working. However, I pulled the bonnet open and I noticed the pasenger front well was soaken wet! So being curious about this and the recent flushing of the heater matrix, have I got a leak somewhere! I also washed the car recently to remove the dust we have acummilated from the dry weather of late!

So I took apon myself to remove the seats, centre console and then the carpet!







I decided to pour water down te scuttle vents to see if water came in both sides.

The passenger side performed I assume as it should out the bottom in front of the floor on the ground.

Drivers side did nothing, so I poured more water in and it decided to leak into the car, but not much!

So off with the wiper and scuttle vent cover, to discover the water channel to the outside has been sealed up with mastic sealant.

I had to spounge out the water to dry this out again!

[RTTBMW]

So how do I remove this heater matrix? Any tips that would be good!



regards


Richard

[BenHar]

Are you sure it's the matrix leaking.

The most common leak is from the valve.

Ben

[RTTBMW]

Hi Ben,

Where is the valve located?

Richard

[BenHar]

On the left hand side of the matrix.

If you search on here for heater valve you will find a lot of useful information.

Ben

[Brianmoooore]

So off with the wiper and scuttle vent cover, to discover the water channel to the outside has been sealed up with mastic sealant.

You sure? It's quite a large hole each side for the water to drain out to the area above the wheel arch liners. Can't see it getting blocked accidentally, and why would anyone block it deliberately?
Have you checked the "elephant's trunk" drain on the bulkhead under the bonnet near the clutch fluid reservoir? These block with general debris.

[Contours]

Could be rust in the firewall where the wires from the fusebox enter the cabin through a grommet located behind the glovebox. If it is, then it's the carpet, dash and loom to come out to sort it. After 30 years of bad weather and if the car is left outside then this is an area prone to rust. I'm in the middle of this at the moment where there is also some rust on the driver's side. A nightmare of stripping but with the Covid restrictions, its a good way of killing time. You would be hoping it is the heater though.

[RTTBMW]

I'll charge up my endoscope camera and take a look! I'll also remove the glove box to check this grommet!

[RTTBMW]

On the left hand side of the matrix.

If you search on here for heater valve you will find a lot of useful information.

Ben

Is that passnger side you mean?

Richard

[BenHar]

On the left hand side of the matrix.

If you search on here for heater valve you will find a lot of useful information.

Ben

Is that passnger side you mean?

Richard

That depends on whether the car is RHD or LHD!

The left hand side looking forward.

Ben

[boiliebasher]

I had this exact issue with my LHD e30 and turned out to be the glove box mounts / fixing points had rotten out and was leaking water in through bulk head! Took me ages to figure that one out!!!

[Brianmoooore]

I had this exact issue with my LHD e30 and turned out to be the glove box mounts / fixing points had rotten out and was leaking water in through bulk head! Took me ages to figure that one out!!!

This one is common, LHD or RHD, and is not caused by water leaking through the bulkhead. The bulkhead is double skinned, and the water is coming through failed sealant at the bottom of the scuttle box. The bulkhead is rotting from the inside out, and the structural weakening is likely to be much greater than it appears.
On a RHD E30, if there are signs of rust around the RH fixing stud for the glovebox, or it breaks off when you try to undo the nut, you have a serious rust issue.

[boiliebasher]

I had this exact issue with my LHD e30 and turned out to be the glove box mounts / fixing points had rotten out and was leaking water in through bulk head! Took me ages to figure that one out!!!

This one is common, LHD or RHD, and is not caused by water leaking through the bulkhead. The bulkhead is double skinned, and the water is coming through failed sealant at the bottom of the scuttle box. The bulkhead is rotting from the inside out, and the structural weakening is likely to be much greater than it appears.
On a RHD E30, if there are signs of rust around the RH fixing stud for the glovebox, or it breaks off when you try to undo the nut, you have a serious rust issue.

In my LHD E30 saloon, the glove box thread mounts are essentially at the same or very similar height and level as the back of the battery tray and the water was leaking in through there. Definitely appeared to be coming through the studs that mounted the glovebox.

As regards to it being a major issue in a RHD car as one of the threads did actually break off when I tried to undo the nut I find it quite a stark contrast to my LHD E30 saloon.

That is literally the only place on the entire car that has any form of rust what so ever and is well above average condition compared to most RHD e30's we are used to seeing in the UK.

Honestly I've gone through the whole car with a fine tooth comb and I can assure you that on that particular LHD E30, the only area of rust on the entire car is at the back of the battery tray where it meets the bulkhead. That's literally it.

It's very interesting to know that had it been similar circumstances on a RHD car, it would be a whole different story....

[Contours]

On a Lhd, you don't have the issues with the fusebox and wiring loom to contend with on that side. Because of the amount of stripping I had to do, I got the area sandblasted which showed up another couple of hidden areas to be dealt with. Wet footwells are a giveaway sign of problems in the bulkhead and while everthing looks great from the engine side the inner panel is where the rot is.

[RTTBMW]

Mine is RHD. I'll take the glovebox out and check this issue! Hopefully not that bad fingers crossed!

[Brianmoooore]

Mine is RHD. I'll take the glovebox out and check this issue! Hopefully not that bad fingers crossed!

You can just about see the area without removing the glovebox, if you force the front edge of the carpet down. If you're extremely lucky, you might find that the large grommet is not properly in place.

[RTTBMW]

Hi,

I took out the glovebox to reveal the plate!



Then I removed the plate to show the firewall in better view. It looks okay to me! The back of the plate I took off had some surface rust! I removed the scuttle vent and looked down inside and I can't find anything amiss!

[RTTBMW]

Where does the rain go when water enters these vents? I can't see how it flows away to the bottom of the car! Especially the driver's side as it does not flow down the bottom of the car! It seems to be bunged up with mastic sealant!

[Contours]

Passenger firewall.JPG

Getting this job done at the moment Richard and just a photo to show the damage on the passenger side to the inner panel where I have removed the wiring and accessory socket . You can see damage at the bonnet pull and after sandblasting this exposed more damage. My car has been outside all of its life so the damage isn't all that bad but still a huge job to sort. You need to check the panel and hope there is another explanation for the soaked footwell.

[RTTBMW]

Well I am hoping after we did the coolant flush with the matrix that it could be the heater matrix is the culprit!

[BenHar]

That grey tuby bit is the heater control valve. I can see that the bottom right corner in the picture has been leaking.

If you search on here for heater valve you will find a lot of useful information.

Ben

[Brianmoooore]

BenHar is correct, there's a definite leak on the valve. The gap between the two parts looks wider on the right, indicating that the rivet on that corner has failed in some way. A simple way of telling a coolant leak from a rain water leak is by taste. Rain water sodden old carpet tastes as you think it might, but a coolant leak is extremely sweet.
That is one of the cleanest insdie bulkheads I've seen for a long while. I don't think there's any leak there. Contrast with the pics. in the next post, which is one of the worst I've seen.
The sealant on the bottom of the scuttle box is essential. It's when that fails that water gets down in between the two skins, and you find that the RH stud of the glovebox hinge falls off when you try to undo the nut. BTW, you should have undone the nuts on the bulkhead to remove the glovebox complete with hinge. The glovebox to hiinge fixings are adjustable and need to be right to get the glovebox to open and close as intended. You'll have to get this right again by trial and error when you refit.
The water in the scuttle box drains sideways through triangular shaped holes into the space above the wheel arch liners. The holes are obvious whhen the wings are off.

[RTTBMW]

The floor of the car and the carpet was slimy green sweet taste. More like coolant than rain! The heater valve is this replaceable! The glovebox side panels had been cable tied to keep them in position. I need screws and fixing threads which I have a pack I got for my 68 mustang when it had bits missing. Can you buy these black screws anywhere specific?

The car I know for sure has been well documented and dry stored for the last 10+ years! I have all MOT's and tax discs, photos from previous owners with prizes at car shows! Starting from Dec 1998! The year I got married!

[BenHar]

The heater valve is this replaceable!

I'm guessing this was a question?

If you search on here for heater valve you will find a lot of useful information.

Go to Quick Links at the top write and select Search. Takes you to search.php

Put "heater valve" into the keywords box and click search. Takes you to search.php?keywords=%22heater+valve%22& ... mit=Search

Look through the posts it shows.

Ben

[RTTBMW]

Replacement BMW heater valve is £155 plus vat. They class it as a sealed unit! I have bought the bits instead to reseal the valve to see how this goes! I suppose I will have to leave the valve open for now! Bought other bits to change out instead! Our local dealer is open for parts now!

regards

Richard

[RTTBMW]

Well, this did not go to plan. The heater valve is completely shot. So I have ordered a replacement along with wiring loom clips to replace.



However, I did like the look when I changed the grill back to chrome!



regards


Richard

[RTTBMW]

Well this weekend I got a few steps further along to getting the car back on the road!

The old heater valve is shot, so out with the old and in with the new replacement.





Now I have serious heat coming through!

[RTTBMW]

The glovebox had to go back in, but I had to clean up the bracket that holds the glovebox to the firewall.

Red oxide, paint and lacquered after removing the rust.





I used the old positions of the plate nuts to align the glovebox back on. Fitted better than the previous effort.