Starter issues, water leakage...etc...finally dealing with those little things

[PorscheNut924]

For years now my 924S has randomly not started sometimes when I turn the key...no cranking or anything. And then it will work fine if I keep trying. After some research it looks like the most common cause of this is the solenoid on the starter motor failing.

A new solenoid is about $30 and a rebuilt starter motor is $177 with a $70 core charge. I suppose it would be a good idea to just replace the whole starter motor while I'm at it?

Is there anything else I should check in the ignition system? I already have a new electrical switch, and replaced the lock switch a while back because it was starting to require serious jiggling to get it loose and start the car.

Also I have a leak into the passenger footwell. While a friend of mine was working on the timing belt a few years ago, I found a big hole under the battery that had been patched with tape and a piece of sheet metal, so he fabricated a real patch for it and it looks almost totally stock again. But it started leaking again and I don't know how to locate the source. Any suggestions? I've thought about looking for some sort of spray-on sealant and just coating the entire battery tray. I've also wondered if the windshield seal could be causing this (I'm pretty sure I still have the original windshield), but there's no trace of water above the dash, it's all coming in from behind it.

Finally, there's a really strange issue. When it's raining heavily, going past about 4,000 rpm's or accelerating quickly will produce a low rapid knocking sound from under the car, toward the back. It doesn't happen when the weather is dry.

[John_AZ]

Originally Posted by PorscheNut924

For years now my 924S has randomly not started sometimes when I turn the key...no cranking or anything. And then it will work fine if I keep trying. After some research it looks like the most common cause of this is the solenoid on the starter motor failing.

A new solenoid is about $30 and a rebuilt starter motor is $177 with a $70 core charge. I suppose it would be a good idea to just replace the whole starter motor while I'm at it?

I keep a couple of used spare starters to troubleshoot and for parts. Usually cheap.
If you buy a starter, get a REMANUFACTURED, not a "rebuilt". A remanufactured starter will have normal worn parts replaced, not just cleaned and painted.

Is there anything else I should check in the ignition system? I already have a new electrical switch, and replaced the lock switch a while back because it was starting to require serious jiggling to get it loose and start the car.

Basic stuff. Clean starter connections. Clean all grounds on engine and inside body.
Next time, gently wiggle the main DME 35 Pin harness wires by the DME (Clarks-Garage suggestion)

Also I have a leak into the passenger footwell. While a friend of mine was working on the timing belt a few years ago, I found a big hole under the battery that had been patched with tape and a piece of sheet metal, so he fabricated a real patch for it and it looks almost totally stock again. But it started leaking again and I don't know how to locate the source. Any suggestions? I've thought about looking for some sort of spray-on sealant and just coating the entire battery tray.

If the battery tray was seriously rotted, the underneath body panel also has holes. Not an easy fix.
Did the new fabricated battery tray cover the passenger side battery drain on the side bottom (tiny hole middle on battery base against side) or the big hole in the front?
Check the drain holes from the top sunroof. Get some thick weed whacker line and run it down the drain holes.
If it is worse when the AC is on, you may have a clogged drain in the blower/evaporator. The drain is by the passenger left toes. Again clean out the drain hole and tube to under the car.

I've also wondered if the windshield seal could be causing this (I'm pretty sure I still have the original windshield), but there's no trace of water above the dash, it's all coming in from behind it.

Finally, there's a really strange issue. When it's raining heavily, going past about 4,000 rpm's or accelerating quickly will produce a low rapid knocking sound from under the car, toward the back. It doesn't happen when the weather is dry.

Only when it rains???
The "low rapid knocking sound" is probably more constant than you realize.
1. Rear wheel bearings
2. CV joints need to be repacked and maybe swapped L to R side
3. TT Torque Tube bearings
4. Change the trans fluid. Catch with a white cloth to check for metal slivers.
5. Check bolts on the trans/TT shaft coupler.

Replied ^

J_AZ

[PorscheNut924]

I think I did mean remanufactured, not rebuilt, thanks for clarifying.

I was thinking of the CV joints, but it really is only audible when it's raining hard enough for there to be standing water on the road. I just had the transmission fluid changed so when I take it back for more repairs I will have them check wheel bearings, CV joints, torque tube, and all that.

Thanks for the suggestions.

[PorscheNut924]

To clarify a bit on the water issue, it is dripping down from behind the dash, not just pooling in the footwell. The place of entry is level with the glove box or higher.

[shadetree944]

I feel for you on the water leaks. My 944 had been sitting in a field for 8 or so years before I bought it and had a tennis ball sized hole in the battery tray. I patched it only to find out like you that age and rust have opened up other areas. To date I have reduced the leakage considerably, but have not completely been able to stop it. I have caulked the space where the a-pillar meets the fender with good results. I THINK the remainder of the water is coming from below the battery drain exit where some seams have rusted. This is about the height of the exhaust headers. More caulking to come.

Hope you solve your problem, and if you do, please post about it so we can know what other tricks water and rust have up their sleeves.