07 XC70 Won't start below 20 deg F
 

Hi folks. My XC70 2.5L has 145,000 miles on it and generally runs great. It now fairly consistently (though not always) fails to start if it's below around 20F, especially after sitting all night. This used to be more intermittent, and has been getting worse.

It turns over fine regardless of the temperature and I have recently had the battery checked. When it fails, it typically doesn't fire at all or fires very infrequently during cranking. Sometimes when it's cranking away it starts all of a sudden and immediately runs smoothy. I believe I can smell the signs of extra gasoline (rich) in the exhaust in those cases, as I'm backing out of the driveway.

Any thoughts? As I think is obvious, I'm thinking spark or gas, but I don't know this car well, and I've never seen a failure quite like this.

Thanks,
Will

It sounds like a failing relay to me.

Thanks for your reply. Any likely relay suspects in particular?

I don't know how practical this might be, but on one of those extended cranks with no start pull one of the plugs and see if it is wet. If so, then no spark. If dry, then no fuel.

That's where I would start if you do not have access to the diagnostic software to check for codes.

That makes sense. Thanks. As far as codes/errors, various ones appear then disappear seemingly at random on the dash display. My shop, which has tried to fix this problem once, didn't learn anything from the codes.

My favorite is, when it's cranking and not starting, it says: "Reduced engine performance." Yep, that's definitely true. :)