98 V70 xc: Problems with air intake/vacuum lines since pcv job Topic is solved

[abscate]

It’s really smart to take the time to understand function so you get these right and not just play matchmaker. Pictures can mislead , are hard to take , and also hoses have usually been replaced and don’t look stock anyway

Erik (NA) and cn90 (turbo) did incredible detailed jobs outlining the hoses with markers in the referenced thread but there are also many other options and variants

Most hoses are single function but the one that isn’t is the evap purge line on a turbo car.

One end of the evap valve goes under the car to the canister.

The engine has to suck on the other end. On a turbo car, the intake manifold sucks at idle and overrun, but is under pressure at boost. The intake snorkel, on the other hand , is at pressure at idle and under vacuum at boost.

So the other side of the purge valve goes to a T, and one side goes to the intake manifold and the other to the snorkel. Check valves are put in do that pressure doesn’t leak from one to the other , these have to between vacuum source and the T.

[erikv11]

... Erik did an incredible detailed job outlining the hoses with markers in the referenced thread but there are also many other options and variants ...

(1) That's cn90's referenced thread, not mine! I did the NA post, not the turbo one. I've been very careful to not reference the NA thread, to avoid confusion.

(2) For sure there are variants, and optional equipment (like with or without the air pump, etc.). As noted earlier in this thread: find the white sticker under the hood of your car!!! If you post up a picture of that sticker we can help you be sure about any small variations in your car.

(3) Great description of how the EVAP vacuum circuit works!

[abscate]

Fixed credit for diagrams above

[CIK7]

"Hose already here" hooks to the "extra nipple" you had that end of it correct.
Then it tees a couple times and has check valves, and a solenoid.
One end goes to the EVAP canister under the fender and you showed in a pic that one os still in place, all good.
The other end goes to a nipple on the intake snorkel *right next* to the PTC.

So to summarize: The line from the passenger side of the IM hooks up to the nipple that is *part of* the PTC, you may have that one in the right place I am not completely sure. But the "Hose already here" goes to a nipple on the intake snorkel *right next* to the PTC. So these two lines end up very close to one another, down there by the turbo.

You're getting there and the car will run better once this is all sorted out!

After figuring out where the evap and ptc/left of im hoses went, I discovered that there was ANOTHER hose out of place (#3 on that topic y'all pointed to, the one I posted a link for). So now I have all nipples and ports covered. I had to buy a new line for #3. Now I realize it doesn't have a clamp yet and needs one, but why would the intercooler hose (that leads to the throttle body) pop off when I jam the gas pedal down? Is it under THAT much pressure to push air through? I don't put the pedal down far very much at all, just occasionally when I want to hear my turbo and exhaust. When that top hose pops off, my engine bogs down, RPMs drop down to 200 or less, makes the engine rough, and eventually shuts off. Can't get it started until the hose is reconnected.

[abscate]

It can run up to an atmosphere of pressure above ambient, so, yes, it needs a very tight clamp to stay on.

[erikv11]

Yes, all of the problems sound like vacuum leaks. Until all of those are fixed, it doesn't make a lot of sense to explore other possibilities.

For the intercooler hose you showed in the picture, the connection *must* have a clamp and the clamp must be very tight. Any air leakage there will cause problems. Check all of the intercooler connections, they all must have tight clamps. Do they all have clamps or do you need some? ...