Hey guys, I've been getting P0440 (Major leak detected in the Evap system) recently. It started after I got my yearly emissions inspection done. The inspection station pressure tested my gas cap as part of the inspection, and it tested ok (however it is not a factory Volvo cap, rather a replacement OEE cap). I've also noticed a strong fuel smell recently in the passenger compartment when the engine is cold or the car has been sitting for some time then started, but only from up front. After driving a few miles it tends to clear up. When the code first showed up I didn't have the smell.

The first time it happened, I cleared the code with a cheap Autozone scanner (about a week and a half ago, was at ~12-15 gallons in the tank) and it came back today. I've looked for vacuum leaks, and can't find any.

I'm no stranger to the cause(s) of this code, however I am unfamiliar with Volvos. What I am wondering, is this a common occurrence with the 850? What normally causes the issue? I'm leaning towards a dead purge solenoid, but I am curious...would the aftermarket gas cap, even though it tested ok, cause this issue? I believe I remember reading somewhere in my research before purchasing the car that these 850's are finicky about their gas caps, is this true? Again, no vacuum leaks that I can see/find/hear anywhere around or going to the charcoal canister.

For clarification, this is the 3rd time the light has gone off, all 3 times have been after the gas cap has been removed (twice for fill up, once for inspection) and all 3 times the light has gone off while traveling at ~45 mph on the highway (no more than 25% load). Not sure how many miles in between each reset as the odometer gears are stripped, but as far as intervals this last time took about 10 gallons of fuel before setting off again (~200 miles?).

Thanks!

-Z-

 

Anyone? Bueller? Bueller?

 

You got a leak in Evap system; there's not a predominant common cause that I'm aware of (hasn't happened to me as yet..) but I would ck around the valve and canister first if it were me. Bottom line, diagnose the problem and fix it. Evap system is pretty much same regardless of vehicle manufacturer.

BTW: who's Bueller?

 

it's 2019 not sure if you will read this? The P0440 is not any of these problems. I've replaced them all. I became obsessed wirh fixing my V70. I believe it's a computer malfunction. Designed by the tech to get people to trade car. I've had my 98 V70 from 42,000.00 mi. It now has 166, 000. Mi. The ABS goes on & off. The check engine P0440 has been on 9 yrs 136,000.00 mi I've had switch transmission wk done. All codes all clear for that. Also, summer time window & lock malfunction. The locks and windows work perfectly 60° and under. When it's 70° and above locks & windows work occasionally. My car has been worked on buy a certified Volvo mechanic who specializes in big rig Volvo

 

not sure why you'd say that your evap leak code is a computer malfunction... Sounds like you just never found the root cause. Common causes are the J-tube, cannister, gas cap or purge valve (just did that this year on my son's S40 to fix theproblem) but there's also a hose that goes all the way from the intake back to the cannister by the right rear wheel. You'd need to inspect that line as well if the other repairs didn't solve the issue.

 

Can confirm- just fixed a similar code (P0455) and the evap purge hose between the charcoal canister and evap purge vent had been cracked/torn. I had service record from one of the previous owners that said the same thing had been fixed a few years ago. Turns out they didn't bother with a hose clamp on the charcoal canister, they just ziptied the old vacuum hose back on. Zip tie tore the hose over time and by the time I got under yesterday, it was completely disconnected. $7 later new hose and rivets and we're squared away!