1981 911SC Starter solenoid needs a hammer whack to work, just the solenoid?

[acorad]

Starter solenoid needs a hammer whack to work, can I replace just the solenoid?

I've searched all the 911 tech threads on starter solenoids, and some say that we can replace them, but there is no mention that I could find to any source selling the correct solenoid.

Any ideas?

[Otter74]

If you live in a metro area that offers you these kinds of places, you could take it to a shop that rebuilds starters and alternators and just have them repair or replace the solenoid. Otherwise it’s probably going to be easier to just put a new starter in. I’m in the middle of that now, after my starter started exhibiting the same behavior last fall.

[acorad]

Originally Posted by Otter74

If you live in a metro area that offers you these kinds of places, you could take it to a shop that rebuilds starters and alternators and just have them repair or replace the solenoid. Otherwise it’s probably going to be easier to just put a new starter in. I’m in the middle of that now, after my starter started exhibiting the same behavior last fall.

Great suggestion. I live in the LA, CA, area. I'm sure there must be some rebuild shops near me.

Andy

[Alan L]

You can pull the solenoid apart and fix it. Done several over the years of various makes.
The ususal problem is the high load contacts inside get burnt and won't carry the full load. Hitting it probably settles the contacts a bit more. Or it could be sticking in movement. A clean out and inspection of the throw out lever would fix that. (never had that issue) .Not to much else to go wrong with them.

Edit - that is presuming it is the solenoid. You can test that by jumping the terminals . If everything then works, it is the solenoid - not doing its job. It could be the starter itself - worn brushes etc. Only a bit of homework will fix it.

[acorad]

Originally Posted by Alan L

You can pull the solenoid apart and fix it. Done several over the years of various makes.
The ususal problem is the high load contacts inside get burnt and won't carry the full load. Hitting it probably settles the contacts a bit more. Or it could be sticking in movement. A clean out and inspection of the throw out lever would fix that. (never had that issue) .Not to much else to go wrong with them.
Alan

Thank you for this, I watched one of the rebuild videos and I'm sure I could do it.

But some of the commenters said a DIY rebuild would only last a year or so. Our host has some new ones by WOSPerformance.

What do you think?

Andy

[acorad]

Originally Posted by Alan L

Edit - that is presuming it is the solenoid. You can test that by jumping the terminals . If everything then works, it is the solenoid - not doing its job. It could be the starter itself - worn brushes etc. Only a bit of homework will fix it.

I used a multimeter on the 12 o'clock yellow wire to the solenoid, and it read over 13V with the key turned to start. Reconnected the yellow wire via its spade connector, and the starter only began spinning after I banged on the solenoid with a hammer.

I can jump the terminals if the multimeter test was not conclusive.

Andy

[Alan L]

Multi meter not much use. You need to jump the terminals - that isolates the issue.
You aren't rebiilding the solenoid - you are repairing it. Yes, it is possible the internal contacts may be so stuffed, it won't last. But generally not. I have done dozens over the years. One vehicle I am still driving that is over 30 years old. I fixed the solenoid about 3 yrs ago - erratic engagement - click, click, not start, click, finally start. Hasn't missed a beat since. I wouldn't be surprised if both my porsches haven't had the same treatment - I have certainly had P solenoids apart before.
They can last for many years more if a decent job is done. The cost is nil.
Just a Q of whether you are in a mind to fix what is fixable, or choose simply to replace. I generally go down the former route. If that finally fails, I know I have good justification to throw new parts at the problem.
Alan

[acorad]

Thanks Alan, I'll give it a shot, hopefully this afternoon.

Andy

[Alan L]

Get a piece of stout (ish) insulated wire. Doesn't have to be like jumper cables. Put the ends briefly across the two terminals with nuts on them. These are the terminals that transfer the power direct from the battery to the starter. You are bypassing the solenoid initiated bridge (which bridges internally across these two terminals) . That will confirm the high load side of the circuit is working OK - battery and earth connections etc, and the starter itself is OK.
Do it 2-3 times to make sure the result is not a fluke. If it works perfectly every time, then it is the solenoid internal bridge that is letting you down. You should be able to confirm that by now jumping from the input terminal (the one where the battery cable is attached) to the yellow wire spade terminal - remove the spade terminal. There are two - one to the CSV, and one powers the solenoid. You are looking for terminal #50. They are usually marked on the plastic body, but if you can't see that mark, just test both til you are sure of the result. If it is the CSV one you will just hear a click from above the trans. You are now putting 12V from a verfified circuit, to power the solenoid. If it does not perform properly, you have verified the problem. If it is the bridge contacts, you should hear it clunk, but no engagement of the starter.
Alan

[acorad]

So I just got home and the car started right up, no problem.

I guess I have to wait for the problem to come back to do the tests?

Since I need a jack to lift the car high enough for me get under to hit the solenoid with a hammer when it doesn't crank, I'm hesitant to drive the car anywhere and park it because if it doesn't start I'll be stranded.

Andy

[Bob Ashlock]

Classic 'gummy' solenoid problem. Take apart, clean and lube with light oil so it slides in the barrel easily again.

[Alan L]

It is sounding like the solenoid, but can't be totally sure. Could be the yellow wire circuit, Ign barrel, etc. But a sticky solenoid, and or dirty contacts inside would seem the likely issue.
So one thing you could do to try and test this is as follows. Undo the nut on the output side of the solenoid and remove the elec tab from the stud. This feed goes to the starter motor. So the starter is now disabled. It seems the starter is probably not the culprit - but no confirmation right now. But to put the solenoid to some more scrutiny you can do one of 2 things. Turn the Ign key to start multiple times. Can you hear the solenoid engaging - clunk. The starter won't fire - you have disconnected it.
If that is not definitive, jump the solenoid terminal with the battery feed on it to the appropriate yellow wire terminal. That will engage the solenoid - if it is able to engage. If it is sticking, there will be no clunk. You can do this test multiple times until you get a defintive answer as to what is going on.
Or, if you feel adventurous - just do as Bob suggests, and while you are in there, clean the inner terminals.
Alan

[reclino]

I rebuilt my starter on page 19 of my 930 build thread.

https://forums.pelicanparts.com/911-930-turbo-super-charging-forum/848849-barn-find-1986-911-turbo-19.html

I describe a bit about each component including detailed pictures. It requires a bit of soldering to get the solenoid to bits, but it's not that hard. The Bendix clutch can also be taken apart and lubed, though I was able to find a NOS Bosch bendix to replace mine.

[David Inc.]

A new starter is less than $300, how much are you going to save getting it rebuilt vs. replacing?

[917_Langheck]

Originally Posted by David Inc.

A new starter is less than $300, how much are you going to save getting it rebuilt vs. replacing?

Well, that's a bit of a nonstarter.... There are no new Bosch starters for that money - they are either repops, or rebuilds, and both are known junk - or they are a high torque, which some don't like the sound of, or others wouldn't use because it's not OEM.

Personally, I went with the IMI 101N, because paying $600.00 for a Bosch starter is ridiculous, and rebuilding the original is fairly easy, especially when you can take your time and still enjoy your car knowing it's going to start.

[David Inc.]

Yeah I went with the hitorque available through Pelican. It seems to be the way to go for everyone, and genuinely is stronger (though I don't know if more durable) than the OEM.

[acorad]

Thanks all, I just ordered the WASP hi-torque through Pelican. I'll install it and then rebuild the old one at my leisure and keep it for a backup.

[proporsche]

acorad..you can replace the solenoid by yourself-that would take you about 15 minutes once you have the starter out.To get it out jack up the car use jack stands-safety 1st- after you disconnect the battery remove the upper allen head nut with 10mm allen wrench from your tool kit or 10mm socket -what ever you prefer- i use the L shape 10mm Klein tool.
Use a bear hug to reach the upper nut legs towards the end of the car.
If you want to rebuild your starter ,i have used these guys for over 20 years-when i lived in LA...here is a phone number.818 442 9082..
BNR PARTS ALTERNATORS AND STARTERS.
They are in Panorama city not far from you.BTW i used to live in Agoura Hills back in 1987-88 ..

Ivan

[acorad]

Thanks Ivan, I would love to do that. What solenoid would I replace it with?

I googled around but could not find a specific solenoid.

Andy

[proporsche]

Andy...once you have the starter out remove the solenoid .There are 2 types only after you remove it you will see what kind do you need.There is a difference on the shaft size.
one number is 302058 and the other 302032...58 is the one with larger shaft-coil..