This is a 2003 V40 1.9t (same as S40 but a wagon) I'm posting on S40 section since it's more popular. Been having rough idle issues for a while, also had a long start issue. Put a new fuel pressure regulator in and fixed the starting issue but not the idle. Replaced some worn looking vacuum line but didn't help any. Next thing I noticed was the idle control valve hose has some cracking so I was going to replace that. Over the last week when turning the car off the fan would keep running for a few minutes. Saw something saying replace the thermostat and/or ECT. But today all of a sudden it went from bad to horrible. Car revved up for a minute after starting. Now it just cranks and cranks but won't start. Please help this is my girlfriends only form of transportation

 

Is it throwing any codes? From the description, it could be dozens of things. What's the mileage, and has it ever had a timing belt change?

 

It does have a few codes

P0128 coolant temp below thernostth regulating temperature
P0420 catalyst system efficiency below threshold bank 1
P0442 evaporative emission system leak detected small leak
Took it to a mechanic, he didn't find anything. I don't think he knew much about volvos.
It has 126k miles. Is the timing belt a 100k maintenance thing? The car was bought with 119k miles so I guess it's possible they never did that.

Edit: just went to her house, the car started right up :/

 

She just drove the car and apparently it accelerated on it's own for a bit

 

the codes are telling you that 1) your vacuum leak is likely in the evap system - I'd look all the way back to the charcoal canister for any torn/cracked hoses. You'd be smart to also replace the IAV hose if its suspect. Look at other posts as there's other hard to see hoses that can cause a vacuum leak 2) the cat efficiency is saying there's too much of a difference between the front and rear O2 sensors - this can be due to an exhaust leak (any noises from the flex pipe?) or the O2 sensors or the cat itself. If you have a hole in the flex pipe, you might as well replace the cat and o2 sensors all at once. If you don't sense an exhaust leak, I'd leave this for after you sort out the vacuum leak and temp sensor issues by clearing the codes after your other repairs and see if it returns 3) the coolant temp sensor needs to be replaced. My bet is this is the cause for the start/no start experience where the vacuum leak is the cause for the bumpy idle. this is an easy DIY job with the hardest part being figuring out how to unhook the connector (kind of clips backwards). The ECT sits in the thermostat housing so you need to pop off the two bolts holding the cover and top hose to get it out of the way. Its a tight fit that will likely require an open end wrench going like 1/16 of a turn at a time. you can pop open without draining the radiator - you may lose about a cup or so of coolant. THis is a good time to replace the thermostat/gasket and the overflow reservoir cap. I'd also inspect the upper radiator hose for any leaks/staining as this is a common cause for coolant leaks. Finally onto the timing belt.. These cars have a 10 years/105K miles service interval so it should have been done in 2014. You have an interference engine so if the belt goes, so do all the exhaust valves. If you don't see any signs that the works been done (ie a conti belt vs Genuine volvo is a good sign) you will need to have it done including belt, idler and tensioner. Some people opt to do the water pump as well but its not required unless its showing signs of wear. These cars have a VVT gear on the exhaust cam so that will add .5 hours to the shop quote vs the older Volvos.

 

Funny that you mention the hose right below the ICV. I was doing some work on my car over the weekend (rear main seal!) and noticed that there was a huuuge crack in this hose on the underside. Very hard to spot. Called the dealership thinking that they would have to order me a replacement but nope, they had one on hand (30637166). They don't have much on hand unless they are common failure points so I'm guessing this is a common issue.

Also, way back when I had an issue where I would crank repeatedly without being able to start. It would start if I pressed the gas to the floor though. I took off the ICV and soaked it with brake cleaner, dried it and put it back on. Totally cured the issue.

 

Thank you both for the advice! I will check out those things when I get the chance. Question tho, where is the charcoal canister and the idle control valve located? The rear torx 30 bolt holding the thermostat is completely stripped out so I'm not sure what I'm going to do with that.

 

pretty sure the canister is in the right rear (back by the fuel tank).

re the ICV: https://www.matthewsvolvosite.com/fo...ic.php?t=41823

for the torx bolt, you may need to hit it up with PB Blaster, tap a few times, more PB Blaster then try again. If its totally stripped you may need to pound in a hex socket or a triple square to see if it will bite (lol, God knows why these manufacturers go for these odd bit types)...