1998 V70: CEL with no code; bogging down at idle

[scot850]

That valve is likely the roll over valve. Those can fail but very often. Di you check if the evap carbon canister is under the rear of the car or at the front behind the LH headlight under the fender cover? The P0455 - large evap leak you have had is mostly caused by a hose at the carbon canister splitting with age. If at the front it will be fairly obvious once you get access but at the rear it can sometimes be hidden as they split on the top-side of the hose which runs to where you are replacing the hose you show. Like you say it is just a vent hose and should not affect the cars running. If the roll over valve is bad it will prevent a vacuum being pulled during the evap testing, but more likely the issue id the 'J' pipe at the carbon canister.

In either case, not sure it will affect the cars running but will through the code.

Neil.

Neil.

[S Carlson]

That valve is likely the roll over valve. Those can fail but very often. Di you check if the evap carbon canister is under the rear of the car or at the front behind the LH headlight under the fender cover?

This car's canister is under the rear of the car. The valve is #9 in this diagram, which they're calling the "vent valve". I replaced hose #11 with the heater hose from my junkpile. Hose #11 appears to be going to the filler neck, where it seems like it joins into the filler neck. But maybe it doesn't.

The P0455 - large evap leak you have had is mostly caused by a hose at the carbon canister splitting with age. If at the front it will be fairly obvious once you get access but at the rear it can sometimes be hidden as they split on the top-side of the hose which runs to where you are replacing the hose you show. Like you say it is just a vent hose and should not affect the cars running. If the roll over valve is bad it will prevent a vacuum being pulled during the evap testing, but more likely the issue id the 'J' pipe at the carbon canister.

The J pipe is #10 in that diagram, right? I put my hands on it and couldn't feel a split, but I will see what the CEL says.

In either case, not sure it will affect the cars running but will through the code.

Yeah, that was my thought after seeing it was only on the "outside" of the canister, and not between the canister and the engine. So there may be some other buggered hose somewhere. Or it's another problem entirely. Who knows!

I wonder if my car would have the vent hose above the tank like in the thread linked below. I have no idea.
viewtopic.php?f=1&t=60269

[scot850]

What you are showing is an AWD rear evap system and fuel system, but it is very similar. #9 is the hose I am talking about. When I removed mine on a 2000 V70 FWD, the hose looked sound from underneath, but on removing it I found 2 hidden splits on the top where you can't see. It may be ok, but that is the normal hose that fails.

The breather hose you replaced runs up to a filter on the filler neck near the top.

Over filling the fuel tank can flood the carbon canister and it will cause issues.

Neil.

[S Carlson]

What you are showing is an AWD rear evap system and fuel system, but it is very similar.

I got this diagram from the Volvo Cars Mall of Georgia online parts catalog, and they list it for 2WD and AWD, emissions codes A, D, J, and 7. Mine is emissions code 7. The brackets (#18 and #2) I think are the only difference.

#9 is the hose I am talking about. When I removed mine on a 2000 V70 FWD, the hose looked sound from underneath, but on removing it I found 2 hidden splits on the top where you can't see. It may be ok, but that is the normal hose that fails.

Do you mean #10? Because #9 is the valve.

I will try to check it more thoroughly tomorrow morning. I may just buy two new hoses for back there (part numbers 9443308 and 9443309), to have the problem thoroughly fixed and move on with my life (and other Volvo problems!)

I tell ya, these Volvos have so many more variations than the old SAABs I'm used to working with!
I guess this is my tank diagram (again, emissions code 7) so maybe I should be looking at hose #34 as well.

[dalel]

Just last month I had the rollover valve hose on my 98 V70 replaced after years of ignoring occasional P0455's. I don't know enough to explain it but my MPG is up about 3.

[scot850]

#10 looks like the one that runs down to the roll over valve. There is another shorter one that runs from the carbon canister (#27) to the roll over valve if I recall correctly. Been a while since I had a FWD.

#10 in the previous (AWD) diagram is similar to the one I am thinking about that runs to the roll over valve.

Neil.

[S Carlson]

All right, I felt around the J-hose (#10 in first diagram) and thought I could feel a crack. So, I took it off and found out it had a ton of cracks in it. I replaced it, again with heater hose, but with some pre-bent copper tube inside it to prevent it kinking when bent into a J-shape. I figure that stuff will be at least as good as Üro Parts, which people say fails after a couple years. Plus, I don't feel bad tearing it all out when I need to replace or repair the shut off valve.

I also replaced the short hose from the purge valve to the hard nylon line that runs under the car, using fuel hose for that, and put a short section around the hard nylon line where it unwisely is routed touching the oil filter so it's getting rubbed and might develop a hole there.

We'll see if that's enough. I don't think the hard line has a hole rubbed in it at the oil filter (yet) but the codes will tell me.

[scot850]

Fingers crossed!

Neil.