733I interior water leak + speedometer

[newbe]

I have a very nice 733i just purchased. Two bothersome problems though...A mysterious water leak making the floorboards wet. At first I suspected the heater core but there are no signs of coolant in the water.
Any ideas? Next the speedometer doesn't work...I've read something about an SI board but have no idea where it is located. I haven't been able to find a service manual for this model yet.
Any help would be appreciated

[jeff '84 733i]

For the wet floorboards, you have to unclog a couple of drains. If the floor is wet in the front, you've got to remove the outside cowling and unclog the two drains on either side of the blower motor. You;ll need a wire coathanger to run down the drains and some water or compressed air to work the dirt out. I was able to repot a houseplant with all the junk in mine. If the back seat floorboards are wet, check the drains in the trak of the sunroof. again, you'll need your trusty wire coathanger. Also check the taillight seals to make sure they are intact. You might get condensation in your trunk and damp floorboards in the back seats.

[newbe]

I appreciate the info...I'll give it a look

[jeff '84 733i]

The speedometer is antohter story. The SI board is for the Service Indicator lights and has a couple of rechargable batteries on the board. If the batteries will no longer recharge you can't reset the Service Indicator lights. Those are the ones on the instrument panel that show whether or not you should change the oil.

What gauges are working and not working? Knowing that will help out in troubleshooting.

[jeff '84 733i]

Since I've experienced the same problem that this guy has, I've just passed on what I've learned. I certainly don't know everything.

Why can't you offer up something else that makes sense without belittling others? And while you are at it, maybe you should ask the fellow with the wet floorboards problem if my advice wasn't appreciated. Why would I not want to share what I know about these cars?

BTW, The water was on the floor, not the dash where the water would be easily seen when leaking from a bad windshield weatherstrip.

[tseran]

The speedometer not working usually is the result of the instrument cluster having cold solder joints. I took mine out and inspected it under the scope and resoldered about a dozen bad solder joints and all was fine...........for a while. Then I replaced the entire cluster, that fixed everything. The instrument cluster software is tied to the OBC software and they have to match. It will still work, but acts wierd sometimes.

Good luck!

Originally Posted by newbe

I have a very nice 733i just purchased. Two bothersome problems though...A mysterious water leak making the floorboards wet. At first I suspected the heater core but there are no signs of coolant in the water.
Any ideas? Next the speedometer doesn't work...I've read something about an SI board but have no idea where it is located. I haven't been able to find a service manual for this model yet.
Any help would be appreciated

[84733ibimmer]

Originally Posted by newbe

I have a very nice 733i just purchased. Two bothersome problems though...A mysterious water leak making the floorboards wet. At first I suspected the heater core but there are no signs of coolant in the water.
Any ideas? Next the speedometer doesn't work...I've read something about an SI board but have no idea where it is located. I haven't been able to find a service manual for this model yet.
Any help would be appreciated

i have the same problem with mine the leak is in the passenger front and my gauges dont work i still havent got in there to try and fix it ill probally try tonite and my window on the drivers side dosent roll up all the way ive taken the door apart but i might need some parts

[bmwstyle]

About the leak in the passenger side, the problem is a drain that is clogged up by mud and leaves or whatever it could be.
You have to take out the box that holds the ECU and you will find the drain.
I had the same problem when it rained or when i washed my car.

Hope it helps.

[gtofan]

I know this a little late but your water leak is probably coming from the A/C inlet at the firewall. The rubber gasket around the copper tubes,especially the small one will develop a gap and water (rain especially) will run down the small tube and drop on the passenger floor. Silicone sealant will fix problem.

[tseran]

Originally Posted by gtofan

I know this a little late but your water leak is probably coming from the A/C inlet at the firewall. The rubber gasket around the copper tubes,especially the small one will develop a gap and water (rain especially) will run down the small tube and drop on the passenger floor. Silicone sealant will fix problem.

Thanks a lot. I inspected the hoses to the heater core, at the firewall, and found the leak. I was not looking forward to taking the dash down so this really helped a lot. Thanks again,

Tony

[gtofan]

That's great you found it, definately look at the A/C lines going into the firewall also. They are on the passenger's side and look at the rubber seals around the lines, especially the small line. It should be a snug fit, you can check with a paper clip and see if you can easily fit between the copper and the grommet, if so water will get in. I would seal it anyway, you can use any of the automotive silicone sealers but not gasket makers. Good luck.

[gtofan]

I had my speedo stop working in mine also a while back and the problem was the old batteries leaked a little and corroded the circuit board which was right on my signal wire for the speedo. I used a jumper wire for a temporary fix but a new board is in the works. The instrument cluster is easy to remove, any probs let me know.