Hello guys (and gals if any) my first post ever in any car forum. I have a 1998 V70, base model, 2.4 engine non turbo, with 280,000 miles, yep, the guy is still strong. About 2 years ago the Check engine light was on, and gave a P0410 code, back then I Googled the code and sort of narrowed it to be the Secondary Air injection Pump, without any mechanic experience I took the pump off (the pump being below the battery tray) and when I took it off it had some sort of brownish water inside it. I decided to replace it buying an aftermarket pump, (since the Volvo original part was over $300), and the Check Engine was off and problem solved.... Now 2 years after that it gave the same code, I went into the pump again, and yes, it has brownish water inside it again . I checked the 2 hoses connected to it to see if any damage was noticiable, everything looks well. The car runs really well, no change at all neither in the engine nor transmission, at least as far as I can tell. I just traveled from FL to CO last week, the car did fantastic, no troubles at all, just the fact that the Check Engine light has been on for a couple of weeks, I checked the air filter, it has a brownish mark, as if brown water dripped over it, and well the Secondary Air Injection pump full of brownish water. Please any advise as to where or how the water gets inside there. Thanx, sorry for the boring thread.

 

Based on the watermark on your air filter, I would guess that you have reverse flow from the exhaust to the air filter and the water is condensate. for that to get all the way back to the filter, the pump would have to stay off a long time. I wonder sometimes on my own car how often that air pump actually runs. I am not aware of the sound of it, so I just have no idea.


Like all air injection systems, the plumbing incorporates a check valve. It is really obvious right at the top of the engine. It has a vacuum line going to it, so it apparently is controllable. Based on that, it would be hard to say whether it opened and allowed flow to go the wrong way, or whether it just leaked. I bet it leaked, but I am just making that up. I have a similar car but I have not had any codes on the pump, so I just ignore it.

 

Thanx for the comment, yeah, it makes sense, if the check valve is allowing liquid both ways or leaked like you mentioned, then that's probably why I have the air pump full of water, therefore with air and some moist travels up to the air filter, to which leaves me the poop like color on the air filter haha. So the next question would be, change the Check Valve of course, but should I really replace again the Air pump?????? According to a Volvo dealer mechanic, the guy told me 2 years ago that the pump only stays on when you start up the car, and when brought to temperature it stops working, he said that the function of the pump is to REDUCE emissions from the time one starts the car until optimum temperature. He advised me then to replace the pump, since it was the stock one, and full of water, he did not know the life expectancy of the pump. All he knew was how to get rid of the code haha. So final request, any other part I should consider replacing???? Thanx