Starter motor won't work when it's "hot"
 

folks,

just got my car (1987 Carrera 3.2) back from the dealer today after a major service (yes, the porsche dealer - huge bill and everything), and i drove it back to my office.

I stopped to talk to some friends for a few minutes and when i tried to start the car again it went "er-gruf" and nothing more. I thought "****. the battery is dead - how can that be?" and called the dealer to chew them out, especially because i got a new alternator and battery about 5000km ago.

they sent down the head mechanic who arrived an hour or so later with a spare battery. Just on the off-chance he sat into the car and - it started straight away.

so - he says "well, it could be that the starter motor needs to be disassembled and cleaned and properly re-greased".....

now - my car lived in germany for 10 years, then holland for several and is now in spain. his idea is that the starter motor won't work when it's hot because the old grease doesn't provide enough lubrication when the starter motor is heated up by the engine and all the metal expands that little bit - but that it will work when it's cold.

can anyone comment on this? ever heard of it before?

hugh

Yep....happens a lot. VERY common on the 914s, less so on the 356s and 911s......MOST times if ya bang on the solenoid it will free it up and start right up.

Replacing the starter with a rebuild does not always help....."I" have pulled the solenoid and lubed it and it corrected the problem. Others use what is called a "hot start" kit.....it supplies more juice at start up.....band aid effect though.

Replace with Hi-Torque
 

Hugh,

The popular permanent (or as much so as possible anyhow) fix is to replace your old starter with the Hi-Torque model sold by our sponsor. Eliminates hot-start problems and probably wouldn't cost much more than to have the old one R&R'd when all is said and done.

HTH,

Here's what my starter sounded like when the Bendix was bad.

Sound Bite

Check the connections on the battery and the starter first!! When stuff gets hot the resistance goes up and bad connections show more. If it still flounders when hot do a clean up on the solenoid and see how it goes. Replaceing the starter motor is the last step.

Alex

Excellent suggestion. And don't forget the ground strap from the tranny mount to the body. A bad ground strap could definitely give you starter problems.

After checking all the grounds and scratching my head for a few months, I finally installed the hot start relay in my 914. Solved the problem instantly. Just a note, while most people think the kit is a band-aid and kind of hack, lots of other non-p cars use starter relays also. So whatever works...

Had exactly the same problem with my 88 model 3.2 Cabrio, my mechanic replaced the starter solenoid (just the solnoid, never opened the starter motor) with a much beefier item off an old model BMW (can't remember which model, will check with him next week). Problem solved ever since. Happens to a lot of 911's out here in the tropics....

Had the same problem around X mas. check the threads. Had it completely rebuilt soileniod and all for $85 in AZ. Not a problem since.

I just put the high torque starter in but haven't been on a trip long enough to test it out (has it solved my hot start problem). But Hugh, one thing I can pass along, given that it sounds like you had a pretty short trip before you encountered difficulty, is that your starter may be on its last legs. My hot start problems all occurred during long highway trips where I'd be going maybe 200-250 mi. at continuous high speed between stops. After these long road trips, the car had to sit overnight before the starter would work. During the trips I learned to park on an incline so I could jumpstart. I never experienced the problem with "normal" everyday driving, until one day recently when the starter quit after a short drive and wouldn't kick in for about 2 hrs., then quit for good. I suspect that a lot of these hot start "problems" are just symptomatic of a starter going bad, or maybe a badly-designed starter, but many 911 drivers don't experience the problem or the symptoms because they don't use the car on a long highspeed trip.

well.. my alarm starter disable unit has a smaller ga. wire than the yellow sol wire.. and a 2 year old hi-torque/racing starter.. I still have some long drive/hot start problems.. I'm going to clean the sol for laughs, and do a 75 amp Bosch relay/big elec contacts.......Ron

SOOOOOOO....THE CONSENSUS IS.......the solenoid......refer back to MY original post....


BANG on the MOFO solenoid......if it starts, that is the freakin' problem.....hate to be pissy and say I be right, but "I" be right.....:eek:

In either Excellence or Pano was a whole article on the up-grade to an aux. starter sol on the 356/whatever.. but IMHO, the factory wiring/electrical sys. on my 911 sucks.........Ron

These Porsche engines do not like spanish, so, tell the mechanic to be quiet when they work on it. Sticky solenoid happens a lot because the flapper boxes for the heat are diverting the hot air into the starter "cave" underneath. For the short, just clean the solenoid plunger with WD40, grease the electr. connections, check the ground strap from tranny to chassis. For the long term, consider a rebuild and adding a starter kit (These kits do provide more juice) SmileWavy

Maybe if you put a cool collar around the starter........ :)

I found my hot start problem to be caused by the drive gear not returning to its original location. The drive gear is extended and held in that location by the solenoid during the start. Release the switch and a spring retracts it. When retracted, the solenoid should be returned to its retracted location also.

In my case, the drive gear was not quite fully retracting, so the solenoid was also not fully retracted. If I removed the started and pushed the drive gear fully in, it would work every time. Disassembled and cleaned and it has worked since without a problem.

You need to check the ground strap,most starter troubles are a bad ground.

well,

thanks for all the feedback.

at least the mechanic is on the right track in general (plus my translations of mechanical spanish seem to be at least somewhat accurate)

i don't rememer him mentioning the solenoid (although he may have). what i understood he said was that they'd take the starter apart and put it back together. I suspect that if the starter is bad they'll be happy to charge me for a new one.

he did also mention cleaning up the ground connectionto the chassis, so it looks like he may know what he's talking about.

thanks all

hugh

good point.. I went overkill on starter ground, LOL.. I'll find the pic if wanted... salt air is a *****......................Ron

Guys, Ron is a "boat guy"...these guys know electrics well. That's because if anything in electrics has a weak point, salt air will find it!