1998 V70 NA - Emissions code P0440 -Emissions code 3

[scot850]

Thanks for the suggestion. If/when the light comes back on I will have to jack the car up and look. So far so good it has not come back on but temperature may affect it and I know lengths and type of driving also.

Fingers crossed but no high expectations!!

Neil.

[scot850]

Almost funny. Had a phone call from the young lady who said that after nearly 2 weeks all was well. No check light. Then about an hour later a text, 'Engine check light has just come back on! Jinxed it!'

I did not know that this had been an on-going issue for several years and 2 garages had had several looks at the issue and not fixed it. I am leaning toward the purge valve or check valve is intermittently sticking as it has taken 2 weeks and a lot of mixed driving before it came on. Doesn't help the temperature is all over the place. +9C today and possibly -33C next week!

I will have to find a way to get this up high enough to get me and the stomach under the car to check the pipework to the rear and then see about making a smoker system.

Neil.

[befarrer]

Blowing into both pipes there is no resistance. That makes me think the Evap purge valve by the RHS of the top of the radiator is faulty or jammed. It as I understand it should be closed when not energised. Is that the correct assumption?

This was my issue. It's easy to check the valve, it's 2 wires, connect to battery positive on one negative on the other, if it's normally open, adding power should close it, if normally closed, adding power should open it. If adding power does nothing, it's a dud. The one on the rad going from the charcoal can to the intake should be normally closed, and I believe the one going from the charcoal can to the fuel tank should be normally open.

[scot850]

You are correct. The valve by the radiator is supposed to be normally closed. As I was able to blow down both tubes makes me think it was faulty. When I removed it and tried again it was closed. Sprayed loads of carb cleaner into it (one end takes air from intake manifold and is not filtered). Then energised it many times and it was repeatable as operating as it should. But maybe it is just intermittent?

I am going to Pick and Pull this morning as there is a 98 V70 that should have the same system based on the Vin#.

I can get the OEM Bosch valve from Rock Auto delivered by courier for under $50 worst case. Easy to swap out.

There is a filter near this valve on the pipe to the carbon canister. Does not look particularly dirty but maybe it is and is marginal for air flow?

OK, I need to also check the one to the fuel tank. Any idea where it is?


Neil.