If a manual equipped car suspect the clutch interlock switch. My 02 did this and I had the...

I need some help troubleshooting. My 2001 S has not been cranking occasionally (pretty frequently recently). The battery has been checked and is good. The ignition switch has been changed in the last 5000 miles. (I'm not saying that might not be the problem again). The symptoms are as follows. I climb in the car, turn the key to crank and ......nothing. On occasion I'll turn the key all the way off and repeatedly try to crank again and on the 2nd or 3rd time it cranks. On other occasions no luck so I'll climb out of the car, push the car a foot or so, climb back in and it cranks. Our boxsters are not so easy to "tap" the starter and then try to crank because of the difficulty in quickly getting to the starter but I haven't ruled that out as a possibility. The problem is getting worse to the point that it is not reliable if I'm on a schedule which I always am! Any tips on how to troubleshoot this or suggestions on what to do will be appreciated.

the clutch interlock switch and the ignition switch replaced even though the Porsche tech could not reproduce the crank but no start symptom. And he tried by starting the engine or trying to start the engine wiggling the key in the ignition, the steering wheel, and positioning the clutch pedal at various heights above the floorboards to if it was the ignition or clutch pedal interlock switch every chance to act up. After maybe 12 to 15 engine starts over the span of a few minutes, no such luck. Engine cranked and started just fine. Still I decided to throw an ignition switch at the symptom.

The symptom went away for months but reappeared but only very very infrequently. But I got to thinking about it and spoke with the tech about the symptom again. He said there's another possibility and that is the clutch pedal hardware conspires to somehow cause the clutch pedal depress to not be quite enough or due to wear the clutch pedal depress moves the hardware sideways some and the clutch interlock switch is not fully in the engine start positions.

So, you want to be very sure the clutch is depressed all the way down and even if it is the tech told me one might have to adjust (bend?) the interlock switch holder to improve the position of the switch to ensure the clutch pedal arm or whatever contacts it make better contact.

Sincerely,

MarcW.

Thanks MarkW, that sounds like an excellent possibility! I actually thought about the possibility that I may not have the pedal depressed all the way but didn't connect with the switch. I'll definitely check that out tonight!

Then you don't have to worry about it and have the added benefit of not having to get in the car to start it.

I love being able to reach in and start it, then do something else for a couple minutes while both the car and seats heat up. Usually a quick wipe of the rims or windshield. Then off you go!

I just looked and the only momentary switch I can find is one that gets changed at the FIRST part of the clutch travel which seems to me would be the cruise cutoff. Should I not be looking for a switch that gets tripped at the very end of the clutch travel? Can someone send me a pic or give me a detailed description of where this switch is?

the pics are of no value. I need to have the car in the air some so I can get a better sense of where the hardware is.

I have a Boxster shop manual with some drawings of the clutch pedal hardware and some instructions on changing the switch and checking its alignment.

PM me with your email address and I'll make a PDF copy of the appropriate pages and email them to you.

After the new clutch interlock switch is installed the switch must be aligned so that the clutch pedal is depressed the switch's plunger is 'operated' approx. 1 to a max of 2mm before the limit stop of the clutch slave cylinder is reached. There is no info on how the adjustment is to be done but I suspect it might be obvious is one was looking at the mechanism.

Oh, there's another comment: Install the clutch pedal switch. First pull out the operating plunger of the switch out as far as it will go. By means of its self-adjustment function the switch then compensates for the tolerances of the pedals.

Sincerely,

MarcW.

The yellow arrow points to the microswitch that prevents the car from starting if you don't have the pedal pushed in. The red switch is the one that deactivates the cruise control when you push the clutch in.

[www.pelicanparts.com]

“Anything really new is invented only in one’s youth. Later, one becomes more experienced, more famous – and more stupid.” - Albert Einstein

While you are aware of it no one else is, at first.

The clutch interlock switch is a safety feature and one that is intended to prevent the car from starting in gear.

Sincerely,

MarcW.

Well the clutch interlock switch may be a safety feature but it's also a feature that prevents the car from starting on occasion! lol

I happen to think the pluses far outweigh the negatives in doing this free hack. The only other person who *might* drive my car would be a valet, in which case he would either a) depress the clutch while starting because he knows that's generally required, or b) depress the clutch while starting or put it in neutral because he knows to start the car while not in gear. Even if he did accidentally start the car in gear nothing would happen. The car lurches forward by a couple inches and then he sheepishly restarts in neutral.

To each his own but I REALLY enjoy being able to just reach in the car to start it. And it totally eliminates the possibily of the car not starting due to that switch not being fully depressed.

Here's the actual pic from my car showing the zip tie in place:

The box under the driver's seat, the box which controls the anti-theft immobilizer, might also be failing.

should be able to hear a audible 'click' when clutch pedal fully depress although it doesn't mean the switch is good. I haven't messed with mine so I can't help with the exact switch location.

dghii
2000 Boxster S 6speed 112k miles

Wow! You guys (and girls?) are all great. I just got home from work, saw all the responses and will attack this tonight or in the morning. Thank you very much!!

I replaced the ignition switch, then after another month, replaced the clutch interlock switch. It was OK for about 6 weeks, then the non-starting reappeared intermittently. The Dealer Tech could never reproduce the non-start so I was REALLY getting fed-up. Finally, while the car was in my garage, the car refused to start after 8-9 tries. I had the car flatbeded to the dealer and they finally reproduced the non-start. The culprit? The clutch interlock switch! The dealer replaced it on warranty with a new and improved clutch interlock switch. It seems the former switch, which was in itself an "improved" switch from the original, was not working properly, so Porsche redesigned it. Hence the improved model within one year.

So that you know exactly what I went through in the starting (or non-starting) procedure, the various icon lights in the dash and my daytime running lights would come on when I turned the ignition, but the starter would not engage. If this is your situation, my guess is, based on my recent experience, that your clutch interlock switch is bad. Get the newest one from the dealer.

Unfortunately, I had the switch replaced two days before I put the car to bed for the winter. I sure hope the problem is solved. I'll know when the car gets woken up around April 1.

Good luck.
Alex

The functionality of the switch can be verified by merely running a wire around the switch. That is, jump it, take it out of the circuit. In my Fiero this can be done with a paperclip.

If bypassing it doesn't solve the problem, other problems could be the starter relay or starter itself.

My Boxster wouldn't start, with same signs, because the immobilizer had a bad connector. I had the immobilizer box replaced. I did try the jump before being flat bedded home.

the shop I'll ask that the interlock switch be replaced as long as I can be assurred the new switch's part number supersedes that of the current switch's part number.

Might be time to have the new washer jets installed, too. These require a $75/jet wiring harness though to fit/adapt the older MY Boxsters.

Sincerely,

MarcW.

Marc, what are the washer jets?

Here in sunny CA the wipers/washers don't get used much and nozzles got plugged up from letting the washer fluid sit.

Then it turns off rainy and misty and wipers get used and the washer nozzles too of course to keep the windshield clean in inclement weather.

To unplug the old nozzles I tried running white vinegar/distilled water through the washer reservior tank, lines and nozzles, even letting the this mixture sit in hopes it would remove enough of the deposits to let the nozzles put out a good spray, but didn't have much success.

Bought two new nozzles, but the new nozzles are not the same as the washer nozzles the car came with from the factory. One difference is the new washer nozzles require a connection to the car's wiring harness. Why I do not know. Heated nozzles? Or perhaps the nozzles use some kind of pizo-electric feature to make the spray? I was told the existing harness has the connections for the new style nozzles (which tells me the new style nozzles may have been an extra cost option for my 02 MY Boxster) but each washer nozzle requires a $75 (at that time, over a year ago) wiring harness section to connect the nozzle to the car's wiring harness.

Sorry for the confusion. I don't know why I referred to the washer nozzles as jets.

Sincerely,

MarcW.

Alex, your symptoms are EXACTLY what my car (an 01S as well) is experiencing! However I checked the interlock switch with a meter and it was fine, but if the problem is intermittent then that wouldn't mean anything. I may try bypassing the switch with a wire and see if that solves the problem.
Thanks, Clay

it -- more luck than skill -- at just the right time and depressed the clutch pedal a bit more and the starter caught and the engine started.

Intermittent clutch interlock switch is my diagnosis, even though the switch is new (less than a year old). Next time I'm at the dealer I'm going to get another switch and replace the existing switch.

Sincerely,

MarcW.