2007 XC90 3.2l torture device

[rssherwin1]

I went and purchased a smoke testing machine today online it will be here Monday but don’t know where to connect it to look for vacuum leaks in the intake. Can you help me with this?

[chitownV]

Maybe you can remove the air box cover, use a rubber glove over intake tube and poke a hole for the smoke machine hose. Another way is to inflate a balloon/bag inside the intake tube and have the hose pass that. Since the engine will be off, you can get creative.

It’s okay if a little smoke leaks out the intake end with the smoke machine hose inserted, you know that’s not the issue.

If the kit you purchased comes with a cone, try that at the end of the intake tube.

[rssherwin1]

I ran a smoke test and found the intake air piping to be loose (hose clamp). I went ahead and tightened the clamp (will be replacing it) and the P0171 and P0174 went away. My son is driving it this week to see if the code comes back. I’ll keep you posted. Oh, I did do a smoke test after tightening to ensure the intake tube is secure to the throttle body.

[chitownV]

Sounds great! Glad the new part you bought was a tool you can use again.

[rssherwin1]

Well both P0171 and P0174 came back I smoke tested again and found the oil cap (where you fill the oil) is leaking smoke now that the intake tube is fixed. I am going to change the o-ring and check it again. If it’s not this then I’m at a loss for what it could be.

[chitownV]

That is actually one spot that people don't think about and think it should only be replaced if it leaks oil. The oil cap gasket is really cheap and doesn't hurt to change it, whether it's for proper vacuum or to avoid oil leakage in the future. I changed mine about 40k miles ago. This is a common area to look at for the 2.5t engines.

That smoke machine has already been proven to pay for itself by avoiding buying unnecessary new parts and/or paying someone for diagnosis. Without VIDA to help with the diagnosis, let's hope these codes don't back.

Is there a situation where the codes trigger? On idle, accelerating, etc.?

[rssherwin1]

My son said he was just driving down the street when he noticed the light had came back on. I changed the o-ring with one from the auto parts store but I believe that it’s not the exact same size (but it’s close and was worth a try). The old o-ring is compression set and hard as a rock so definitely bad. I am ordering a new oil filler cap it’s $35 (not to expensive) at the dealer and can be here day after tomorrow.

[rssherwin1]

Oh, I put the air box back together and started the car and ran a read for codes and magically they disappeared on their own (normally it requires me clear them) after the o-ring replacement. Maybe the o-ring seals better under a vacuum than under pressure. We’ll drive it tomorrow and see how it does. More to come.

[rssherwin1]

Ok, so it’s not time to rejoice (that comes after a week of road testing) but the check engine light did not come on today. I am still going to change the oil filler cap and intake tube hose clamps as a precaution. The parts were supposed to be in today but the dealer didn’t get a shipment today so when they come in I will swap them out.

[rssherwin1]

Ok, I’m going to call this repair a success. The check engine light is off and hopefully will not return for the remainder of the year. Thank you for helping make this a code effective repair. The smoke tool came in handy and will be a welcome addition to my tools for any future needs.

Next project: Now on to the breaks I will be doing a complete break system service including replacing all wear items hoses fluid and etc. including the parking brake parts as well. It should stop on a dime after that.