Hello all,
My v70 threw a code the other day. When I read it it was P0455 (gross leak in the EVAP system)--ok so I figured the gas cap was loose. Sure enough, I checked it and it seemed to not be fitted tightly. I removed it and put it back on to about 6-8 clicks. I erased the code and things were fine for a couple of days. Yesterday, I get the CEL again and so I read it this time as P0440. (EVAP system failure). I did erase it and drive to work without any more CEL but now I'm wondering if the fuel cap has just become old and unable to seal properly or if there is some other vacuum line that has become old and leaky. Does anyone know where common leaks on this system are (besides cap)?

Thanks,
Mike

Mike, Is this a 1998 V70? If so, you may want to check to see if you have a filter below your EVAP valve. From what I understand, this filter was not installed on all 98 models and its necessary to keep the gunk from clogging the EVAP valve which will trigger code P0455. Anyway...if you look at your EVAP valve, there should be a filter attached directly below it. Its white and about the size of a 35mm film container. If you dont have it, you need it. If you do, you probably just need to replace it. Its a good idea to clean out the ports of the EVAP valve with some carb cleaner while your at it. Good luck.

Thanks. It is a 98. There is no flame trap. I have withing the last few months cleaned the vacuum housing and replaced some vacuum lines at this junction as I was hoping a malfunctioning PCV system was the source of my RMS oil leak. It didn't hurt but had to replace the RMS anyhow. I don't think the PCV system is linked to the EVAP system, is it?

Not the flame trap. Its a filter. It should be on the line between the evap valve and the charcoal cannister. It keeps the residue from being sucked into the evap valve & clogging it, which will trigger the p0455. If you dont have this filter, which is possible since you have a 98, then you need it.

You talking about the flame trap? Since his car is a non-turbo, it could have it, but Volvo quit putting it in their cars in late '96. Volvo mechanics take them out and throw them away. I sort of doubt that's what the problem is unless I misunderstood what you were talking about. Of course, the area where the normal flame trap would go can get clogged too. A smaller vacuum line links in from a larger one at this spot.
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1998 S70 T5 Emarald Green Metallic, 2004 V70 2.5T Ruby Red, Previous Owner of Black '94 850 Turbo Wagon. My cars have been running so well lately they've got me worried.

Like you said, it could be just the old seal on the gas cap, but it could also be clogged PCV system hoses or the nipple on this system which is at the base of the large hose that goes from the MAF to the turbo (several visible connectors at the base of this hose). Check under the car and see if you have blow-by at the turbo's side...an indication of this issue. Make sure it's not the turbo's oil return line leaking...also a common issue, but would not cause the vacuum line failure notice. Also, another possibility is the oil trap being clogged. Either of these are messy and a real PIA to deal with. If you have a good indy mechanic, get him to check these for you. I'm currently in the middle of changing out my PCV system hoses as well as my oil trap on my S70...not setting any codes, but I have the blow-by at the side of my turbo, so decided I should do this...It's several hours of work as the intake manifold has to come loose to get to the oil trap under it. Good luck.
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1998 S70 T5 Emarald Green Metallic, 2004 V70 2.5T Ruby Red, Previous Owner of Black '94 850 Turbo Wagon. My cars have been running so well lately they've got me worried.

Thanks, MIJ.

The car is a normally aspirated v70 sot the turbo return line is n/a in this application. The emission hoses and the PCV were inspected and some of the elbows were replaced about 2 months ago while the rear main seal was being replaced. I an inclined to guess that it is at the tank. Do you know if Volvo used some of those weak rubber elbows on the vacuum lines to the tank itself? I haven't crawled under yet to have a look but figured others have had this issue.

Thanks,
Mike

Try the fuel filter...if never changed, it should be anyway. Not expensive at all...Bosch makes the one in your car. www.fcpgroton.com sells it for pretty cheap.
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1998 S70 T5 Emarald Green Metallic, 2004 V70 2.5T Ruby Red, Previous Owner of Black '94 850 Turbo Wagon. My cars have been running so well lately they've got me worried.

Thanks.
I actually have a new in box Volvo fuel filter sitting on the shelf; however, I cannot see how that would have any effect on the EVAP system--are you surmising that if it is somewhat clogged that the tank would build up excessive pressure??? If it were that clogged, would it not create driveability problems at high RPMs as the fuel pressure dropped in the fuel rail (fuel starvation)?

What starts as a lack of "fuel sending" can be registered as a vacuum problem somewhere else. These systems are all inter-related. However, I would check out the filter mentioned in the vacuum line system first, which unfortunately I know nothing about.
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1998 S70 T5 Emarald Green Metallic, 2004 V70 2.5T Ruby Red, Previous Owner of Black '94 850 Turbo Wagon. My cars have been running so well lately they've got me worried.