07xc70 tcv install question

vabob · Post by **vabob** » 03 Jan 2016, 09:27

Hey guy, first post.

I installed a new tcv in the wife's xc70 last week and immediately noticed a hissing sound coming from under the air intake manifold. I poked and prodded a little and noticed if I moved the hose going into the head cover that the noise changed. I buttoned it all back up and came inside to do some research. I see the hose connect to the oil trap box. Could I have installed the new valve in such a way as to create possitive pressure in the pcv system?

A day later she got a error code for lean at idle condition and after looking that up on various forums I see it mostly happens with a clogged pcv/oil trap. I just replaced the whole pcv system 2 years ago and have done 3000ish mile oil changes with full synthetic since then so I doubt the system is clogged.

What are your thoughts?

Post by **scot850** » 03 Jan 2016, 15:08

Did you check which of the TCV ports you have each of the hoses connected to? I don't have a TCV for this car to hand, but the older cars did have a code for each port to let you know which one goes where.

Assuming the valve fitted looks like this one:

http://www.vivaperformance.com/genuine- ... valve-tcv/

Then on IPDUSA website they give a flow chart for which pipe goes where.

http://www.ipdusa.com/products/8900/120 ... 0-v70-xc70

If you go down this page there is an install download file which tells you which pipe goes where.

Neil.

Post by **abscate** » 03 Jan 2016, 18:19

Let's see. If you mix up the waste gate actuator yellow and intake dump blue you would apply turbo pressure to the intake manifold....I'm guessing that would be source of pressure in the PVC

vabob · Post by **vabob** » 04 Jan 2016, 13:34

Not sure if I should start a new thread or not. I think it was just coincidence that found this new issue while I was working on the tcv. I know I told you that when I touched the upper hose for the pcv that noise changed. While I found where the actual leak is coming from. It was not the upper hose, but infact, a vacuum hose underneath the intake manifold. One end has come off and I need to find where it goes to so that I can replace it with a new hose. The reason the sounded changed was because the vacuum line was laying against the upper pcv hose, so when I moved it, it also moved the vacuum hose.

Now can anyone point me in the direction to figure out which original hose was fiber wrapped underneath the intake manifold.

Thanks for the replied above gents, I did use those to confirm that I had installed it correctly.

vabob · Post by **vabob** » 04 Jan 2016, 13:54

Thanks again fellas.

Post by **scot850** » 04 Jan 2016, 14:26

Can you follow the pipe to the other end to see what it is connected to? We can then try to advise where it goes to.

My son is not home just now with our 06 XC70 for me to have a look assuming it is the same (should be).

Neil.

vabob · Post by **vabob** » 04 Jan 2016, 15:25

Standing at the grill, the hose goes downward and to the left towards the timing belt. I kinda lost it after the first few inches. Can't get a visual and my hand is too fat to reach any further than the top of the oil pcv box.

sparky65 · Post by **sparky65** » 04 Jan 2016, 15:44

Do you have a vacuum hose diagram sticker on the underside of your hood? That may give you a clue. I just checked my 01xc and I can't seem to find that hose on my year.

vabob · Post by **vabob** » 04 Jan 2016, 16:33

To be honest, hadn't thought to look. I'll check in the morning when it warms up and gets light out.

Post by **scot850** » 04 Jan 2016, 19:34

Had a look at my son's XC70 and can't seem to see this pipe at all. Can't se any pipes of that diameter in that area at all and definitely not of that type of pipe with the woven exterior. Is you car throwing any codes at all?

The only pipes I can think that may go to the area of the timing gear may be emissions pipes, and they would eventually run to the back of the car. They would/should throw a code if they came off.

Neil.