hello gents, this is my first time owning a volvo...it's a 2009. with 135,500 miles...recent repairs include Complete exhaust system..manifold to muffler...manifold cats were heating up and the rest of the system was rusty ...so i replaced. cost me a fortune..i hoped to enjoy this car for road trips this summer but it seems to have the same problem I bought it with.runs smoothly ,but after driving for about 25-40 mins when car is hot..it stumbles and shuts off...it then starts back up on the first try...there are no codes...can anyone offer me some help or advice?

 

First step would be to scan for any codes in all the control units (not just a cheap OBD scanner)

Fuel pressure cold and after 30 minutes? May have to attach a gauge and leave it on until the car fails if it starts up right away after stalling. Haven't check wiring diagram but there could be a failing relay that once hot creates an open circuit, car shuts off, relay cools down, car starts up. Have you driven it till it dies, restarted and then driven till it dies a second (or 3rd or 4th) time in a row? (i'm betting no, I would head back home - nobody wants to drive a car that randomly cuts off!)

If no codes you will need to isolate the failing system. Going to be fuel or spark or both.

 

thanks so much for your response....turns out when it starts to stumble...there is a misfire on 4,5 and 6...also a ticking noise what seems to be coming from the intake....i agree with you that something is resetting when shut off...i'm not using a obd scanner...my mechanic that's working on it has a sufficient scanner...i'd like to find out what's causing the enter ignition bank to start missing...also the noise...ill keep you posted.. thank you again..

 

update, this only happens when the car is driven aggressively... mechanic had it idling for almost 5 hours...ran like a charm..did not shut off...any idea guys?