Evap Emission System Leak Detected (Large Leak) P0455

[drgian]

the 2001 Volvo XC continues to keep thing interesting around here. I was driving with my wife and daughter making sure they understood how proud they should be of me for the head gasket job when the check engine light came on.

I didn't find much about this code on this forum, looking around there are posts about replacing gas caps or hoses, but I wanted to ask here. I don't see anything obvious, no holes or hoses hanging off anywhere. And no other symptoms.

Any suggestions?

Thanks,

drGian

[v70+xc70]

Did you recently fill up?

Did you forget to tighten the fuel cap correctly? Thought so.

Tighten it up, clear code or just wait a few days.

[JRL]

If that doesn't work, visually check the GAS CAP GASKET. If it looks OK and is seated evenly, your next step is to smoke the car.
You should find the leak in about 2 minutes if you do this properly.
Note the mileage and number of starts it takes for the code to come back (if it does after you tighten the cap and reset the code), yes do that first.
Remember always at least 3 clicks of the cap, it's very easy to forget that one time another.

[drgian]

I've only put 1 tank of gas in this car since the rebuild and that wasn't recently. However, yesterday I drove her from once side of Michigan to the other (with my heart in my throat) and filled up and burned up 1/4 tank. I did check the gas cap, it's newer and the gasket is fine. I made sure it's nice and tight this time and I cleared the error before I left home and it didn't come back yet. If I get it again I will let you guys know and you can tell me how to smoke the car (I don't smoke, but I know some potheads that maybe can help me).

[hoonk]

The black plastic vent line to the purge valve may be loose, purge valve is mounted to the left upper corner of the fan shroud on a 2001, plastic vent hose snakes along the the right side of the subframe then across and up to the valve.

[drgian]

All hoses look OK, and I just put a bunch of miles on her and I haven't seen that code again so fingers crossed.

[JRL]

Also the J-hose near the tank.
Common with Volvos and usually an easy fix whatever it turns out to be

[8pack]

I had a cel for small and large leak for 1 year on 2 separate occasions. Once around 70 k I think and again around 180k. The light was intermittent but on hot days almost always came on. In both cases it was the leak detection pump failing and in both cases it took about a year before it actually threw a code for the LDP. Was very frustrating as all indications were it was somewhere else in the system and the second time I was convinced it was a cracked vacuum line somewhere given the age of the car but it wasn't.

If you can't find it anywhere else, that is my bet.

[JRL]

If these leaks are not obvious and you double check the gas cap (common problem, you need those 3 full clicks) and the J-hose, the easiest way, BY FAR, is to smoke the car.
This takes about 5 minutes and if there is a small crack somewhere it WILL show

[drgian]

how does one smoke the car?

[RCFLYER]

I had to smoke my 2001 V70XC today, I have a P0455 code. Youtube shows how to make an inexpensive smoker out of a paint can a smaller coffee can, a small compessor some fittings, vacuum line, charcoal and some mineral oil. Works great. But use one briquet instead of three my can got very hot and melted the O-rings. I disconected a line on the purge valve and injected the smoke into it, Smoke poured out of an outlet next to the fuel filler tube under the car. I'm guessing the leak diagnostic pump might be stuck open. I 'm going to replace it.

[RCFLYER]

I had to smoke my 2001 V70XC today, I have a P0455 code. Youtube shows how to make an inexpensive smoker out of a paint can a smaller coffee can, a small compessor some fittings, vacuum line, charcoal and some mineral oil. Works great. But use one briquet instead of three my can got very hot and melted the O-rings. I disconected a line on the purge valve and injected the smoke into it, Smoke poured out of an outlet next to the fuel filler tube under the car. I'm guessing the leak diagnostic pump might be stuck open. I 'm going to replace it.

I realized my 2001 V70XC does not have a leak detection pump next to the charcoal canister. It has a shut off valve.
This shut off valve is in the open position when the car is off. So during the smoke test it's going to let the smoke through and out the vent tube next to the filler neck under the car. So I ran the test again this time using a heater hose, plug and a few hose clamps to block the vent tube. I loosend the fuel cap till smoke poured out, then tightend it. Sure enough there was smoke leaking from the J tube next to the charcoal canister. I replaced the J tube ran the test again this time it held pressure. I use a small compessor for airbrushing. If your using a big compressor make sure you turn the regulator down.