ibkevin

Boost maxes at ~1 bar. My Profec has recorded as high as 5 psi.

All vac lines, except the evap control and hvac sensing are, are one year old Purosil silicone.

I looked and did find a loose side fitting on the Tial, she got the Locktite blue treatment.

Jack, a smoke machine might me a little tame for around these parts, I'm thinking a tank of propane and a hose to look for intake leaks.

Dal Heger

You said that you tested the recirculation valve, right? When the diaphragm is torn it sounds like a turkey call and it won't hold boost pressure, it just all recirculates back into the turbo intake.

Take the damn thing off and blow through all three of the holes, if any of them leak it's bad, replace it!

Damnit, check the simple things first!

It's not a small leak, a K27 can move enough air to pressurize the engine to over 2 bar all the way up to (and past) redline. Do you have any idea how much air that has to move? It's a BIG hole.

Dal.

jacklet

what kind of shape is your cat in?

ibkevin

Dal, just checked the BOV again, a 2yo Bosch 0 280 142 102, still good. Suction on the nipple produces strong postitive valve operation.

I think some more shop compressor time, eliminating the brake booster and AOS circuits is in order this evening followed with secondary circit testing with a vac pump.

Dal, I owe you a beverage or six of your favorites

Jack, she had better be pretty damn good, at about 200 miles.

jacklet

turbo fubar'd? you must be pullin your hair out-offer a sacrifice to the p-gods?!! many sorrows to you

Dal Heger

Right, but did you give all the ports a blow job?
And yes, I'm serious.


Whoa, those are dangerous words, I might take you up on it! Hmm, road trip for beer? Yea, I'd go for it.

No problem, I wish it was something simple, but it looks like like it's gonna be a head scratcher.

Damn, I just thought of something else... A hole in the intercooler? FOD? Does the car idle and run ok otherwise (when not on boost)?

Keep the info coming.

Dal.

Zero10

I'm kind of confused on the direction you are heading with your troubleshooting.
You have noise and boost loss.
So, remove the pipe coming from the turbo, make some adapter to fit your air compressor into it (perhaps an old fuel filter?... don't know the outlet size of the compressor on a K27), and listen for leaks. If it makes that kind of a racket on boost, then it should be very obvious when you do this test.
Sounds to me like a loose hose clamp on one of the intercooler pipes. I did the same thing, and it would seal fine under vacuum, and only open up on boost. Made kind of a farting noise, but higher pitched. Perhaps could be described as the same noise you are talking about.

ibkevin

Dal, I aint afraid to do oral on a BOV! Especially, mine!

Yes, car runs ok, just changed the oil two days ago and I was rough but "milky free".

Zero, yes, old fuel filter (in this case it's an old Purolator in German with a 928 p/n) and I agree- it should make a huge racket. The AOS seals did just that, but they are pre turbo. Tested and confirmed.

While searching bascics, I found the KLR vac line open. Since it's buried in a tight spot at the back of the cam tower with all the "mods' lines. Judging by the idle and run after the re-connect, it was not the problem.

If someone can host a Quicken (that's what my cam runs) file, I will shoot one in the morning.

I feel pretty stupid right about now!

ibkevin

Could my EBC be limiting boost? It had good "seat of the pants" zoom with the k26.

ibkevin

Not creating boost without an obvious loss of vac sounds like a WG control problem, correct?

jacklet

whats the # of your wastegate spring? with the controller off the spring should be your max boost

ibkevin

.8, dual port.

jacklet

try turning your ebc off and let the wastgate dump with spring pressure you have a strange problem

DDP

Like he ^^ said but just run a vac line from the banjo directly to the side port of the WG, nothing in between. That will rule the WG and boost controller out. I had a similar issue with my motor a little while ago. I heard a loud shreaking sound on boost and I had a bad intake leak. It turned out to be the line running from the IM to the brake booster, at that T junction one of the hose clamps was wrapped around the hose it was suppose to be AND a hard brake line. So it never sealed. It was on the back side of the hose so it was not in plain sight. When the car would idle it made a hissing sound (like a leak) that sounded like it was coming from under the IM or from the AOS. Probably not like your problem but the point of my post is that you may be looking for one thing and it will turn out to be coming from a completely different location. Keep your eyes open. Good luck.

ibkevin

That's good advice! Tim at SFR suggested the same thing.

This is where my Tial post comes in, because I can't maintain vacuum on that side port..