Overheating

At certain ambient temperatures and usually after a longish fast journey, my 1989 760 GLE estate then refuses to start again - often at a petrol station and once, very embarrassingly , on Eurotunnel. The engine will not turn over and just a faint click is audible when attempting to engage the starter motor. After about 30 minutes it starts normally. I suspect overheating but as this only occurs spasmodically, is there an automatic cut-off/trip somewhere in the engine? Any advice welcome please.

Non Starting when Hot 

First thought is that there may be a bad connection. It is OK when cold but because of the resistance caused by rust/dirt or whatever, the joint heats up when a current runs through it and the heat expands the joint and connection is lost. This is a common problem with Mk1 & 11 Golfs which is solved only by disconnecting every connector in the starter circuit and thoroughly cleaning them. The good news is that there is probably less connectors in the Volvo. Try pulling each connector apart and cleaning both sides and also any earth connection. If that does not fix it then there may be someone else with a proper idea. lol.

Sounds like the starter motor solenoid is on it's way out, or maybe starter motor brushes.

Happened to my 740 '89, exact symptoms. Changed starter for a old 240 B21FT one. Telmo

Sounds like sound advice to start with the starter motor and then work outwards from there. Do you have any problems from cold starts or very damp days?

Pre-engaged starter motors 

On some pre-engaged starter motors when the starter gear is thrown by the solenoid, a bus-bar on the solenoid makes the path for the starter current - and the strike is adjustable by a pair of locknuts. No idea if that is true of the Vplvo, last one I did it on was a Simca 1000. But this does sound as if you are getting "throw" but not atually starter current delivered.

Very many thanks for all your advice. I will get the solenoid & starter motor checked.