Sticky Starter Solenoid on SC only on very hot days

Gunter · Gunter's Garage

After a 3 hour drive on a hot day the starter solenoid would not work. I could feel it taking power but it was stuck. This only happened once. After that it worked fine. Can they get sticky when hot? Also, on the solenoid is terminal #50 (yellow wire, heavy gauge) and another terminal with yellow/blue wiring (lighter gauge). What is this yellow/blue wire for? When I pull it off, nothing seems to be missing. Everything runs with it on or off. Puzzled in the boonies.

Keith S · 08-04-2002, 01:44 AM

My 914/6 suffers from exactly the same problem – I am trying to find out if it's possible to rebuild the solenoid in any way or is it time for a new (exchange) starter? Anyone out there help us? My wife (and probably Gunter's too) is getting tired of push-starting the car....

dickster · 08-04-2002, 03:28 AM

you should (may) be able to separate the solenoid from the motor, and give it a good spray with wd40.

might work.

bob hodges · 08-04-2002, 06:02 AM

The yellow/ blue wire I beleive is for the cold start valve. Perhaps one of our electricans can verify.

Doug Zielke · 08-04-2002, 06:32 AM

Gunter,
In our recent SCWDP get-together, there was a couple with a '77S that had the same trouble. It occured in the heat of the afternoon, after a hard-driving section. If the car was allowed to cool for a few minutes, it would crank over as normal.

One of our more experienced owners commented the solenoid is just suffering from old age. Maybe a good mechanical and electrical cleaning, with some lubrication of the Bendix gear, is all that is needed.

davis911s · davis911s's Garage

Gunter, Mine was one of the 77s that Doug is referring to. I have my starter out and apart, For mine the solenoid works fine so I am going to give the motor a good cleaning and see what happens.

Here is a link to my post about it Starter problems

Shawn

Kevin Stewart · 08-04-2002, 10:11 AM

I had the same problem, it would be for the best if you guys bought a new starter, and it does come with the solenoid, for the small price you guys will save a lot of pizzed off days, i was doing the same thing and debating when a friend say just buy new one, made since, Kevin

RoninLB · 08-04-2002, 10:49 AM

not for nothing Gentlemen, but my starter is no prize either..the best is I live on a sandbar and have had/and friends have had many many cars that are parked outside 24/7/365 without stupid starter problems that my/any 911 has.....so I get my brothers 911 about 8 years ago and within 2 years the 911 starter gives me a problem [my 911 is parked indoors & not a daily driver]..I figure "no big deal". pull it down and see a reblild sticker still on the starter..anyway, I guessed it was the sol because I could easily jump it w/a screwdriver..So I figure WTF, lets get a Tilton that is track stuff and built for higher heat than the Bosch...it's good for 3 years and 10,000 miles and then "here we go again..meanwhile, new ignition sw, extraordinary extra ground strap from starter housing to tranny mount bolt, etc . So now I'm going to take the feed to the sol seriously and do some extraordinary wiring to feed the sol..unless someone has an answer to this stupid 911 starter problem....................Ron

Early_S_Man · 08-04-2002, 11:04 AM

Gunter,

The second smaller wire on the solenoid is to the cold-start valve ... yellow on some cars, but as the diagram shows below ...

Kevin G. · 08-04-2002, 07:46 PM

Guys & Gals -

Had the same experience (solenoid problem) almost a year ago today, when I took my '72 up to Hot August Nites in Reno. Drove all day from LA to Reno via Hwy 395 in the heat of the day.

Stopped in Bridgeport - no start. Trusty crescent wrench across the terminals solves problem. Stopped in Carson City - no start. This time I rigged a wire to the solenoid terminal and ran it into the engine compartment. Bared a small section of the wire lead from the electronics box to the starter/solenoid and wrapped with tape. Now I had an easier fix than crawling under the car to short across the terminals. Worked great, then I wrapped each wire with electrical tape for protection.

Wouldn't you know - the problem never recurred. But the wire is still there waiting for this year's trip.

Watch for a GRed '72 T Targa in the parade Sunday (8/11) - one of only 4 Porsches that I saw out of 5000 cars.

Early_S_Man · 08-04-2002, 08:45 PM

Kevin,

It is very easy to wire a remote starter switch on the relay/fuse/CDI panel ... since the Yellow #50 starter solenoid lead passes through both 14-pin connectors! Then you can remove your 'temporary' emergency backup wire!

Neilk · 08-04-2002, 09:01 PM

This might not be related, but a few months ago I had a couple of hot start problems with my car. I didn't feel like messing with the starter so I started looking at the wiring off of the battery. There were 3 thick wires with ring terminals at the end that connected to the battery. The copper wiring to those terminals were somewhat corroded and in less than stellar condition so I cut them off. I then cleaned the wiring so it looked shiny and corrosion free and used some non correct ring terminals that I had bought at Home Depot to replace the old terminals. Since then I haven't had a problem.

Since your car is 22 years old, why not check the condition of the wiring at your battery? It worked for me.

Watch, next time I drive my car in the blistering heat here in Dallas, I'll get stuck with a bad starter.

RoninLB · 08-05-2002, 12:33 AM

Neil..."not be related"..It's all related, IMO. the sol. feed has so many possible weak areas that even if you repair a current problem it's only a matter of time and circumstance till it may happen again, IMHO.."may" happen again is not good enough..what bugs me also is the long distance run of the sol. feed wire..kinda like a dog chasing it's tail..anyway, I want to find the sol. current draw somewhere before I attack this beast..a novice guess would be between 5-10amps [cold-hot]...and thanks for helping.........Ron

Early_S_Man · 08-05-2002, 07:11 AM

Ron,

I have had a spare starter for about 20 years ... but never needed it ... because I disassemble, clean, and lubricate my starter every two years, regardless of mileage! Only takes a couple of hours, and I pick the time. Eliminates downtime and late night troubleshooting in the middle of nowhere!

I am also thinking of (re)locating a new Optima battery where the passenger-side jump seat is normally. The entire 'jump seat region' will become a storage compartment for spares, tools, & repair 'kits' ... with top and forward hatch covers. A relay will regenerate the starter solenoid signal ... and battery feed and solenoid leads will only have to be about four feet long!

Rot 911 · 08-05-2002, 07:41 AM

Quote:

Originally posted by Early_S_Man

I am also thinking of (re)locating a new Optima battery where the passenger-side jump seat is normally. The entire 'jump seat region' will become a storage compartment for spares, tools, & repair 'kits' ... with top and forward hatch covers.

Warren, sounds somewhat like the battery compartment on an MGB! Without the forward hatch cover that is.

RoninLB · 08-05-2002, 08:44 AM

Warren...clean up the starter/done deal..."regenerate the starter Solenoid signal"..I was thinking along the same line. Not ready to relocate battery/need the space, BUT, an 8ga or 10 ga wire from battery, to a 75 amp Bosch relay/triggered by yellow 50 wire on the down side of alarm starter disable relay output seems doable..and I maintain alarm starter disable..I want a "reverse bias diode" as in the red relay to attach to 50 wire...gotta find the specs. that I will need/misplaced the info. that was just on a post...the rest of the 50 sol. circut is maintained and I installed a huge ground strap from starter mount bolt to tranny mount bolt to "regenerate" stock ground strap...and thanks for comming in on this one....Ron

Gunter · Gunter's Garage

More info on sticky starter solenoid: Because of the long wires coming from the front to the starter, there is a Bosch relay kit available for this problem. It comes with all the wiring and is mounted close to the starter. When installed, the ignition switch activates the relay which then energizes the solenoid. Less current goes through the ignition switch. However, a new solenoid/starter (or cleaning the existing one) may still need to be done because, with excessive heat, it seems to happen now and then. Thanks for all your input.

P.S. There is nothing wrong with women helping to push-start a Porsche, the high heels can really dig into the blacktop. (just don't use a whip).