Starter too slow when hot please advise

Having a problem that when the car has been run up to temprature and turned off the starter is turning too slow to start the car again. I had put a new alternator on the other month to cure another problem so no its not that as getting 14 going into the battery and reading just over 12 when not running and tried another battery to be on the safe side so not that but will start off another car with jump leads. I had this poblem on a 1.8 GTI cabby in the past and just changed the starter which I guess is what will cure it this time but why?????? If it helps its a 2.0 ABF engine in the car, Thanks

Check the electrical connections to the starter motor and the earth wires earthing the engine, gearbox, starter motor and battery to the body.

If these check out okay, its likely the engine is on the 'edge' of its wear and is becoming partially seized at higher temperatures, making it difficult for the starter motor to turn over.

paul_c said

Check the electrical connections to the starter motor and the earth wires earthing the engine, gearbox, starter motor and battery to the body.

If these check out okay, its likely the engine is on the 'edge' of its wear and is becoming partially seized at higher temperatures, making it difficult for the starter motor to turn over.

If engine was on way out would it still start being jumped from another car?

sallyandsean said

paul_c said

Check the electrical connections to the starter motor and the earth wires earthing the engine, gearbox, starter motor and battery to the body.

If these check out okay, its likely the engine is on the 'edge' of its wear and is becoming partially seized at higher temperatures, making it difficult for the starter motor to turn over.

If engine was on way out would it still start being jumped from another car?

It might, because when jump starting, you have the electrical power from 2 batteries AND the alternator of the running engine of the other car - which could be enough to overcome the friction and allow the starter to spin it quick enough to start.

The way to conclusively know would be to turn it over by hand when the engine is cold, then turn it over by hand when its hot, and see if there's an appreciable resistance there.

quick n dirty test if you suspect battery cabling, run a jump lead from battery - to one of the starter bolts. if that sorts it your battery earth to engine is poor. if not do the same but from battery + to the stud on the starter. if that helps its the + cable thats bad

the mk1 engine earth point on top of the gearbox bracket is a bad design choice by vw, later mk2 and mk3 its moved to a stud on the rear engine -> gearbox mounting bolt which is much better. If you still have the mk1 earth point I would move it and also take the battery cabling off a mk3 as its much chunkier. only thing the earth to chassis leg may not reach on my cab I took 2 mk3 battery cables, chopped the 2nsd one down so i had a length with 2 ring terminals and used that to go from chassis leg and joined it to the main earth cable ring with a nut and bolt.

if neither of the above help try jumping the red/black wire spade direct from the battery +, if that helps then the ignition switch or black/red wire is bad. to start with buff up the connection on starter and the red/black wire. to test if its the ignition switch unplug it and jump a wire between the red and red/black, if that helps try a new switch. if not the wire is bad somewhere, follow the red/black as best you can from switch and starter looking for any duff connections. if you cant see anythign you could rig up a relay to give the starter more juice, its a vw approved repair but usually only needed for aurtomatic models

rubjonny said

quick n dirty test if you suspect battery cabling, run a jump lead from battery - to one of the starter bolts. if that sorts it your battery earth to engine is poor. if not do the same but from battery + to the stud on the starter. if that helps its the + cable thats bad

the mk1 engine earth point on top of the gearbox bracket is a bad design choice by vw, later mk2 and mk3 its moved to a stud on the rear engine -> gearbox mounting bolt which is much better. If you still have the mk1 earth point I would move it and also take the battery cabling off a mk3 as its much chunkier. only thing the earth to chassis leg may not reach on my cab I took 2 mk3 battery cables, chopped the 2nsd one down so i had a length with 2 ring terminals and used that to go from chassis leg and joined it to the main earth cable ring with a nut and bolt.

if neither of the above help try jumping the red/black wire spade direct from the battery +, if that helps then the ignition switch or black/red wire is bad. to start with buff up the connection on starter and the red/black wire. to test if its the ignition switch unplug it and jump a wire between the red and red/black, if that helps try a new switch. if not the wire is bad somewhere, follow the red/black as best you can from switch and starter looking for any duff connections. if you cant see anythign you could rig up a relay to give the starter more juice, its a vw approved repair but usually only needed for aurtomatic models

Thanks for that pal