We have an 06 S40 and my wife was on the way home from work the other day and a hose popped loose and car overheated. Had to have car towed home. No water in the oil. Reset ECM by disconnecting battery. Car acts like it wants to start but won't.

 

I'm betting there's a 99.8% chance that the problem is NOT electrical. ;-)

Basically, it all comes down to how far she drove it after it started getting hot. Basically, if she dutifully pulled over when the high-temperature light came on, I'd fully expect to be able to fix the hose, fill up the antifreeze and go put another 100,000 miles on the car.

If she drove it until it literally wouldn't go another foot, there are a LOT of possibilities - none of them good, of course. If it still sounds "normal" when you crank it (other than the whole not starting thing...) then there's some hope. If it sound really "lumpy", there could be plenty of internal damage to the moving bits. Warped head, blown head gasket, scraped-up cylinder walls, etc. (short version: you now own a five cylinder door stop).

A quick compression test should tell you what you need to know - if you've got horrible compression on one or more cylinders, you're looking at a rebuild / replacement (the latter probably being a more realistic option).

 

She fired right up this morning. Running fairly smoothly, however blowing smoke out the tailpipe.

 

I'm guessing the engine got hot enough to damage (at least) the rings, and probably scuffed up the cylinder walls. I guess I'd drive it and hope that it just "gets better". It might - Volvos are amazingly forgiving machines... but if it's really blowing smoke, it's only a matter of time before it clogs up your catalytic converter and/or starts fouling the spark plugs. I know there are some snake oil additives that claim to be able to "fix" this kind of damage. I suppose it might be worth a shot if it's a choice of scrapping the car (or at least the motor) or trying the snake oil. You just might get lucky.

And no extra charge, here's some advice for your wife (or teenage kid, bonehead brother, or really anyone born after 1970)… When you see the temperature or oil pressure light come on, that's your car begging you to stop before you kill it. Think of that light as a pair of sad puppy dog eyes imploring you to stop the pain. Yes, there are times when there is a black Range Rover full of European assassins right behind you, but normally you should be able to find a place to stop within a mile or so. It might be inconvenient, but you're normally never more than 10-15 minutes away from the nearest Uber driver who will come whisk you away to your original destination. And you can use part of the $3000 or so you just saved by not melting the engine to pay for the Uber ride and having the car towed home / to the shop. You spouse / significant other / parent / friend or relative who maintains the car will thank you profusely. ;-)

 

Thank you 😊

 

It appears to be steam not oil smoke. Head gasket perhaps ?

 

Unless it warped the head. Or cracked it. There are DIY tests to see if you have combustion gases in the coolant. If you start losing coolant with no apparent leak you pretty much know you have a problem that needs attention.

 

It's sort of good news if it is steam. Yes, that would most likely mean a head gasket, but that's a LOT better than bad rings / gouged cylinder walls. As Hudini suggests above, the blown head gasket can (and often is...) because the head itself warped (due to extreme heat build-up). I would suggest googling some tests for checking to see where the problem is (IIRC, by pressurizing the radiator and seeing if it holds / chasing where it leaks into).

And FWIW, there are snake oil products out there that claim to be able to fix "minor" head gasket leaks, and based on what appear to be legit reviews, some of 'em apparently work at least some of the time. I bring that up only because sometimes the "right fix" (pulling the head, taking it to a machine shop to have it checked / planed, replacing the head gasket - and timing belt while you're there) isn't always possible or prudent (depending on the value of the car).