98 S70, CEL on, this code comes up -> P0455-> Generic Evaporative Emission System Leak Detected (gross leak/no flow). I had small system leak before and that was fixed ( evap valve), where do I start with gross leak?

thanks!

 

Oh, just to add, it is not the gas cap, I had it replaced already.
tech, any thoughts?

 

You need to inspect the lines from the Evap valve to the tank.
They vaccum hoses are known to crack over time when old.
There is one that usually cracks near the fuel filter.
If all is good then it might be the evap valve.

 

this thing is driving me crazy. I replaced cap, evap valve, most of the vacuum lines (even though they were fine) and po455 still comes up. If car is cold it will take about 15 minutes for it to be picked up, once car warms up it becomes pending code. Since I did everything I knew and it didnt help I decided to bring it to Volvo dealer (128 Saab/Volvo in Wakefield, Ma). These guys looked at it, charged me $95 for diagnostics and didnt find nothing wrong. Told me to drive it little more and come back. CEL on again and same code again. They probably think I am printing money somewhere so I can come back and give them some every day[:@]. Anyway, I am going to deal with them tomorrow but it really drives me crazy that I cant find this vacuum leak.

 

You might have a bad hose at the fuel tank.

Do you have access to an air compressor?

 

yep, what do you have in mind?

 

Here is what you need to do. Find a small Air pressure regulator that you can crank down pretty low.

Unplug the hose at the Evap Valve and connect to the regulator with maybe even a Vaccum/pressure guage.

Find the Charcoal canister and crimp and hold the Big hose shut.

Then carefully pressurize system to about 3.5 PSI let it pressurize for about 5-10 minutes.

Then listen for leaks.

I have a pressure guage setup with the regulator and a T Then after the 10 minutes I pinch off the line feeding pressure and watch for the guage to drop.

 

thanks for the advice. I found where the leak was. Big hose going to the canister was cracked. I inspected it before and coudnt find nothing wrong because it was cracked on the upper side and I coudnt see it from underneath the car. When I took the canister down I saw where the problem is. It's fixed now but I lost $95 to a dealership that didnt even diagnose my car. Stay away from 128 saab/volvo in wakefield, thiefs!

thanks tech!

 

I have the same exact problem-code p0455-gross vacuum leak. I followed this topic and found that hose at the canister was cracked too. I was pretty convinced that would take care of the problem after i replace it but cel came back yesterday with the same code..today i brought it to someone whos got volvo scanner and he read code 611-tank system. What about tank system tech, what do you think?

 

I got 2001 Volvo C70, and got vacum leak code, so I decided to connect a pump to the valve hose, and heard some air coming out right away, without even making any pressure. when I climbed to the back of my car, the air was blowing right at me from some quarter inch pipe, which was by filler neck, or attached to it... is it supposed to be like that? because when I close that hole, the tank becomes bigger, and holds air when I pump.. so what supposed to go into that hole?

 

My suggestion of a good place to check... For me this code came on in my 99’ s70 and it ended up being an emission system hose, about a half an inch in diameter that runs between the exhaust (header?) and the engine, it was literally falling apart. It was split down the entire run of the hose. I think this hose is a common culprit because its location exposes it to aggressive heat cycles, and tends to deteriorate faster than others. But its easy to miss at first because it’s behind something. If you pop the hood its easily accessible from above, its under the exhaust (header?) that’s in front of the engine. Unfortunately you cannot purchase just that one hose, you have to purchase the whole hose assembly. Ill link the part.

I was actually able to wrap the entire hose in electrical tape and it made the check engine light go off, but this is a temporary fix as the electrical tape will deteriorate quickly exposed to that heat. But this will work if you have to get it inspected within a few weeks.

Evaporative Emission Hose Part# 1270480
https://www.fcpeuro.com/products/vol...-volvo-1270480

 

Huge issue, frequently unreported and undiagnosed!!!!
I have seen this in hundreds of various Volvos.
CLEARLY A FACTORY DEFECT.
Because the other hoses functionally and visually are fine. Compared with just the one small section that fails prematurely. The rubber also takes out the check valves which can really mess with the brake system. Issue is everyone can clearly see when this hose section looks like it was the victim of a fire, or splits, just touching it frequently makes it fall completely apart!
The insidious nature of this small section of hose is as it fails under vacuum!!! Then with the engine shut off, no vacuum, the hose returns to some semblance of appearing normal. I haven't seen any Volvo from 2000, on, that does NOT have an issue with this hose.
Volvos with code "D" have this issue. All of them. 1270480 Other markets frequently have a slightly different part number, but the same cheep section of hose fails as well.
The only good news is that the OEM hose comes with new check valves, which are very necessary if you attempt to replace the hose without the valves. As you will find out if you don't. If that section of hose has fallen apart, then BOTH check valves are toast.

And here is another part that seems to be affected right about the same time if you notice the failing vacuum line: the ejector 30665561, which can drastically affect the turbo, frequently gets clogged and fails, I have yet to be able to clean this part either.

Do88 makes very nice replacement lines, which is something I personally do on any of these 2000 and on Volvos as a matter of routine! (Hose issue seems to start at about 10 / 8 years of use, regardless of milage!!!)
But I have yet to find decent check valves aftermarket as of yet???? anyone?