1993 525iT rear wiper issue, cold running

[calmloki]

Search isn't working for me right now, so... today when I tried the rear wiper it went to vertical and stopped - tried this several times with the same result. When I lift the glass hatch I see that the circle with a hole in it is on the left side, whilt the hatch wiper arm pin is to the top of the hatch - looks to me like it's disengaging from the drive circle, which then continues on to the park position. Whatta you think? Loose wiper frame?

Tracking fuel economy and the OBC is claiming 19mpg - not as good as I would like. It's 42F here and I see that the temp gauge is not running a tic below center, but rather close to the blue section. Then at one point it came up to the right spot, then went back down after a bit. Sticky thermostat? If so it seems like a sign that the water pump should be changed as well, yes? What all am I missing?
Tom Walrod

[calmloki]

Ok, so my description leaves something to be desired - but still - don't any of you touring owners work on your own cars? I'm the only one with a failed rear wiper? No pithy words of wisdom?
Scored a 525i heater valve and pump (which I read fail fairly often) as spares at a junk yard today - as well as a replacement heater fan for my '83 533i. $30 total bill. WOOHOO!
Tom Walrod

[Jr ///M5]

Hi Tom,

I'm sure if you're a touring owner, then you are well aware of the wiring harness trouble that occurs in the rear hatch door. I'm not for sure if that is your problem with the rear wiper or not, but the wiring supplies other items that you might not notice yet, such as the license plate light. It seems the hinged area on the tourings are notorious for chomping the wiring harness that is fished through the sides of the rear hatch. You might inspect this wiring harness for frayed wires. Other than that, I'm not much help with the workings of the touring rear hatch and wiper system.

The thermostat is sticking in the open position and causing the engine not to come up to temperature. This can have an effect on the mileage as the engine is not up to optimum temperature to support correct combustion. Start with changing the water pump and thermostat and if the thermostat housing is plastic, change it over to an aluminum aftermarket part. Now is the time for a cooling flush since most of the old coolant will be drained. There is a plug in the side of the block located near #6 cylinder that will drain the rest of the coolant out. Use a new crush washer to reinstall the drain plug with. The plug bolt size is 19mm. While you are doing all this preventive maintenance, check the condition of the serpentine belt and tensioner pully. Both items are inexpensive and easily replaced while doing the water pump and t-stat. These preventive measures should keep you rolling for another 60k miles, as long as you change your coolant every 2 years.

Hope this helps some,
Jr

[calmloki]

Thanks, I appreciate the answer. I am aware of the kinky wiring at the hatch (saw it when I did the hatch struts) but don't think that's the problem - it will take 1/2 a swipe every time I re-engage the pin between glass hatch and metal hatch. Was not aware of the block drain plug - want to change coolant anyway since it is green, rather than the BMW blue or long life orange. I'll check the belt and see what the online folks are going to ding me for all the bits.
Tom Walrod - Touring owner since 1-2-06

[calmloki]

Just to close out the "Complaint, Cause, Correction": a bit more forum searching came up with a message mentioning that glass hatch wiper pin is springloaded. When I checked my pin was pushed all the way in, maybe a 1/4" exposed, no shoulder showing. Worked it in and out with pliers and lubed it up: no more sticking in, wipers work correctly.
Tom Walrod

[rps1072]

Another way is to tighten the wiper lock pin on the underside of the hatch/window. If you have a Bentley, it is on 611-7. This will hold the window closed and insert that pin further into the wiper motor crank.

[Scott H]

Tom, saw you got it working.....posted this anyway so that it would be in the archives at some point for future use.

could be the wiring for the microswitch that tells the wiper when it is parked. I am replacing my touring harnesses as we speak and they were in BAD shape. This was the cause of my wiper stopping in random spots. Most of my rear gate/hatch functions were not working properly when I got the car.....now they all work!

Do any other rear gate items give you fits? inside lighting? lic plate lights? central locking?

[rps1072]

I think the wiring causes an intermittant BRAKE LIGHT warning on the CCM. The license light (one of them) came apart while I was trying to change the bulb, so now I have a bulb loose in a space behind the license plate. I can't get to it--rattle rattle rattle AAARRGH!

[calmloki]

Tom, saw you got it working.....posted this anyway so that it would be in the archives at some point for future use.

could be the wiring for the microswitch that tells the wiper when it is parked. I am replacing my touring harnesses as we speak and they were in BAD shape. This was the cause of my wiper stopping in random spots. Most of my rear gate/hatch functions were not working properly when I got the car.....now they all work!

Do any other rear gate items give you fits? inside lighting? lic plate lights? central locking?

Nope, only problem was not wiping, and the circular portion that drives the wiper pin always returned to the park position. If it weren't returning to park then the microswitch could ell be the problem - maybe a nice way to diagnose the cause of the problem.
Tom

[Scott H]

the gate. The reverse, rear fog, 3rd brake light and lic plate lights can cut off though along with any gate functions like wiper action, central locking, glass opening, gate opening, rear defroster.

The defroster and 3rd brake light wiring is easy to replace apart from the main harnesses.

I think the wiring causes an intermittant BRAKE LIGHT warning on the CCM. The license light (one of them) came apart while I was trying to change the bulb, so now I have a bulb loose in a space behind the license plate. I can't get to it--rattle rattle rattle AAARRGH!