I’ve gone through two replacement ‘gear reduction’ starters. Both worked flawlessly when the car was cold. The first had about 12 starts on it, and maybe 2h TSN, when after a 20 min highway drive it was not able to start the engine and just clicked. I let the car cool for ~3 hours, and it fired up. Welsh send me a replacement, and it’s doing the same. Car starts fine when cold, after driving 6 miles, it was slugging to fire up again after a stop. Another 15 miles to get home, and I got clicks upon arrival when trying to restart.
See video - Jaguar XKE high torque starter replacement from Welsh - YouTube
Is there a vendor/brand that is better than what I’ve been getting from Welsh? Just went out to the garage, 4 hours later, cranked fine. No clicking, just turning the engine, and fired up in 3 sec. Any suggestions or advice is welcome. I can’t be letting the car cool for 2 hours every time I want to take it out to restart it.
Sounds ghastly… is it engaging the flywheel properly? Is that the motor or the solenoid clicking?
When cold - works as it should, turns the engine over, without and dings, clanks, scratches. No indication of it not engaging the flywheel properly. When hot, it does not, so that was the solenoid clicking.
See if you can measure the temperature of the starter, in situ, when it won’t work: if you can’t do that, you can approximate it to be about 200°. Pull the starter out, and then heat it up to about 200°, and see if it will work. That will answer your question, or should.
Just a thought from an Aussie that has had starter problems in the past because of a poor battery. “Fully” charged battery often failed to start and all the clicking disappeared when a new battery was installed. I would try a new battery.
You make a good point… Even for an Aussie! 
There have been instances where I have seen hot batteries/hot connections causing fairly large voltage drops, so I think your idea is a good one.
It sounds like the pinion isn’t fully engaging or something.
If there aren’t bits of wombat caught in the pinion I too would try a different battery.
Up here, it’s bullsnake bits!
Here it is - 5 hours later after the engine has cooled -
Engages fully, no clicking from the solenoid.
Thank you for the battery suggestion - I’ll have to go look for a new one - since this is the second starter that won’t spin when heat-soaked, perhaps, just perhaps it’s the battery. But on this cold crank, it’s working as it should. (when cold)
Check your ground strap(s).
Place a DMV on the battery and see what the volts are when trying to crank when hot.
How old is the battery
4 years old or more, replace.
cold cranking amps on battery under 650?
Cables, new , old and clean?
Are you sure your charging and not OVERCHARGING!
Good luck.
gtjoey1314
I don’t see how the battery could be at play since there’s no cranking whatsoever, and when he lets it cool down, it works.
I’ve seen a lot of newer starters (not Jaguar specific) that have some pretty iffy internal wiring connections. I’ve then had it replaced with the same problem. When this happens, try hitting the starter with a mallet. Have you checked the voltage at the starter?
Internal resistance increasing with heat and reaching a ‘tipping point’ resulting in a no crank situation, just spit balling here.
If that is what a „modern gear reduction starter“ sounds and cranks like, I don’t see the advantage (okay, it’s lighter).
If the hot starter works okay with direct wiring, it could be the battery, relay, engine ground, wiring.
You are reporting that it doesn’t crank, so the battery is not even being tested when the car is hot. It suggests a connection on the low current side to or at the solenoid is failing when hot so it fails to connect the high current main starter circuit.
Starting a cold car is harder work than starting a hot car, so I doubt it is the battery itself. You can rule that out in an instant with some jump leads and a second battery in parallel.
kind regards
Marek
I have had '70’s Delco starters develop dead spots when heat soaked and not crank or click yet work fine when cold. In my cases the starter solenoid was out in the open so I could bump the starter by arcing between the battery post and solenoid winding terminal with a screw driver. After bumping the starter past the dead spot I could then always then just go back and start like normal with the key. Probably could have done things similar to this video if my starter was not out in the open. So far I have not had any starter problems with the E but it looks like similar set up.
David
68 E-type FHC
Are you positive the starter pinion is fully disengaging from the flywheel after the engine starts?
I would be looking at connections on the ground side and the plus side. The starter doesn’t get that hot and you’ve had two of them do the exact same thing.
I uploaded a cold start video above - I let the engine cool for 3+ hours, and it cranks near perfect. This led me to believe that all the connections, plus and ground, are fine. But I will recheck again, this weekend.