I'm helping a friend with her 2013 C70 T5 Auto. Shes been driving the car for multiple weeks while its been overheating (terrible, I know), she says the car suddenly went out of gear, revved up freely and then died. I checked it out, found that the heater hoses at the back of the engine are cracked and leaking, obviously the source of the overheating. The car now only cranks but wont start, I pulled the codes and received the following; P0026, P0727, P0303, P0300, P0140, P0304, P0116, so, multiple cylinder misfires, there's no RPM signal, no coolant temperature signal (probably because of the lack of coolant), an 02 sensor fault, and a fault with the variable valve lift solenoid. These all seem semi related to me, the cars dash says Low Power, which could be because they drained the battery using the accessories when they pushed the car to the parking lot its currently sitting in or something else . I read on another post on this forum the importance of the voltage regulator and overall charging system, my experience is all with old ford V8's, and those get similar issues related to the charging system. I'm assuming this is an issue with the charging system, I forgot my multimeter, so I didn't measure voltage at the battery, im assuming its less than nominal. I don't have any expirence with volvo's, so any suggestions from you more experienced guys is appreciated. How can I get the car running again? should I start with a VVL solenoid? RPM sensor? Voltage regulator? Crankshaft position sensor? Thanks!

 

What I'd do is start by measuring battery voltage - I'd expect a battery at 80% charge to be 12.6V - if you find the car below that ie 12.2 or lower the battery is drained pointing to a bad battery or charging system issue. That can also create false positives on error codes. Don't try to start without topping off the coolant and recharging the battery (you can use jumper cables to build up a basic charge). If you get it to start up, measure battery voltage with the car running. it should be in the 14V range. Again lower than 13V is a charging system issue or higher than 15V. Many newer Volvos have a modular voltage regulator that can be replaced without replacing the entire altnerator so check out parts stores for that if you're lookiing to fix yourself. If the car fails to start, then you need to start checking for signs of a head gasket issue (overheating can warp the cylinder head) and make sure the timing belt is sound as well if it spins too freely.

 

You should - BEFORE you start randomly buying or swapping parts -
Charge the battery, maybe glance at the timing belt to make sure it's still there - just bend the top of the cover back slightly
Fill the coolant reservoir with water and leave the cap off - if it was empty - what does it smell like in the reservoir? keep your body/face away from the reservoir and
Spin engine over - does it sound normal? does the water geyser out of the reservoir?
If you don't know what it's supposed to sound like and it's not exploding out of the reservoir - do a compression test
If you have compression, move onto the next reasonable steps - is there fuel pressure, is there a spark - is the cam belt on and aligned correctly -

Sorry I forgot a couple of basic things - make sure there is oil in the engine and transmission first!