Loss of Full Boost Pressure

[ATinOf]

Not a noob per se, but it is my first post here!

First the history - cars done 57K, last 9K with me, running fine no engine or box error codes, but then gearbox issue popped up stuck in 5th gear; since i'm not one to shy away from a bit of work - stripped out engine and box and undertook a full refurb on the box; new seals, gaskets, frictions, vac checked spools; put it all back together (3 faults traced: output shaft double seal compromised exchanging fluid with transfer box; bushings quite worn on intermediate shaft; tubular seals to valve body not holding pressure) Beside these faults and the fact the sun gears are slightly out of specified tolerance for axial play the box is in excellent shape. While the engine was out and since it had a puddle of oil in the valley - I replaced the fine oil filter; oil filter housing seals; top oil cooler seals; camshaft adjuster seals; vac pump seal. While I was at it and since the front end was all gummed up with black stuff I replaced the front pulley crank seal, the idler pulley, tensioner pulley and aux belt. I broke the PCV hose behind the inlet manifold so replaced it; I broke the oil breather hose so replaced it (they were brittle). I did trap a vac hose putting a rocker cover back on (nearside airbox pipe) but it seemed good at the time so reused it; I have since bought one to replace it with but haven't yet replaced it. She fired up first time on reassembly, no fluid leaks, and gearbox issues are no more, so I promoted myself to chief mechanic and sipped some beer.

So whats all the fuss about? I am getting an error code (ignore the date I hadnt reset the clock when test driving);

000665 - Boost Pressure Regulation
P0299 - 002 - Control Range Not Reached - MIL ON
Freeze Frame:
Fault Status: 11100010
Fault Priority: 2
Fault Frequency: 2
Reset counter: 255
Mileage: 91008 km
Time Indication: 0
Date: 2008.04.04
Time: 18:52:16

Freeze Frame:
RPM: 3103 /min
Load: 84.7 %
Speed: 103.0 km/h
Temperature: 96.0°C
Temperature: 51.0°C
Absolute Pres.: 1000.0 mbar
Voltage: 13.335 V

and not reaching full boost; watching the boost bargraph in the DIS it looked like it was getting about 75% and topping out (and never had that issue before the work); clearly i'm going to change the suspect vac hose but you guys know if there are other elements I should look at? Graph attached, if the attachment works?



By the way I have hundreds of photos depicting the work above step by step which I will share at some point if you guys want it; when i get the time!
And no I'm not going to demote myself, I still think I earned the beer

[douglas96]

Hi,

It may be a long shot as it would be a different fault code I would expect, but it may be worth checking the vacuum hoses that attach to the diverter valves on the bottom of the air filter boxes are connected. The one on bank 1 side of the engine is a bit of pain to connect I find. I verify that it is with a borescope just to be sure! Also check to see if the diverter valves on the bottom of the airboxes do not leak and that the springs are relatively strong. (Unlikely as it ran fine before, but you never know!)

The breather hoses are a bit of a pain and have a reputation for breaking!

It does sound to be vacuum related though, so hopefully the new hoses fix it!

Well done on the work!

Out of interest; how did you get the engine out? Did you lift the car once the engine was ready to be removed, or was the engine lifted out of the engine bay?

[ATinOf]

Thanks for the tip I'll check those out when I replace the vac hose

I dont have the luxury of a car lift so the car was up an axle stands and the engine/box was dropped six inches and came out the front end with an engine crane. Not for the feint hearted.
Hope this pic works...

[douglas96]

Very nice! I just wanted to know as I haven't heard of anyone doing it that way yet, but it's good to know that it can be done without a 2 post lift!

Thanks

[Jim Haseltine]

That's something I like to see. My tame mechanic and his mates keep telling me it can't be done at home. Mind you, they said the same about the coolant pipes.
I'd take a look at the fitting and security of the clips on the charge hoses, you only need one to be a little loose for pressure to leak.

[P300]

Wow - good work! I'm not that brave

[rs6danbar]

How long did this take?

[ATinOf]

Thread back on track; I have finally gotten round to whipping off the suspect vac hose (that I had trapped and salvaged) to try and resolve the loss of full boost - this suspect vac hose was n/s from the solenoid rubber mounted on the front of the inlet manifold to the recirc valve on the n/s air box. Had a bit of a fubar moment - I had ordered 07L 131 056J having sourced the part on 7zap without realising the pics on 7zap are l/h drive; so I had ordered the wrong side doh.

Ordered the correct part 07L 131 055J and I changed this out this morning. Once it was off I vac checked it and it tested good, I also vac checked the recirc vave and it lifted off its seat and reset fine. I then checked the off side vac tube and recirc valve and that lifted off its seat and reset fine.So at this point I'm thinking that wasn't the problem, but I got the vac pipe and that side is off now so I may as well fit the new one no? So its now on, and the suspect vac pipe that tested good anyway is on the used but good shelf. Its too bl##dy hot to strip off the other side though so I'll just put that new vac pipe into stock.

I'm thinking I haven't fixed the problem but a test drive will tell. I will log the obvious blocks on the test run. Will update you later.

[Jim Haseltine]

Whilst buggering about changing my discs at the weekend I thought 'While I'm here...' RH inter cooler hose was loose and as for the amount of oil in there, well, somebody didn't think to put a catch pan under it so I spend an hour or so removing what seemed to have been about a litre of oil from my drive. When I did the left side I was more sensible but there was only 300ml in there.
Fair number of broken metalastic mounts under the engine, one of which is going to have to be drilled out.

[ATinOf]

Ok so that's interesting; aside from the fact my low pad warning prevents me from seeing boost on the DIS; I managed to get it to show for a brief moment before the low pad warning kicked in and it is still not achieving full boost on the bargraph. But, having cleared DTCs before I went out I have no fault code up this time (least net yet, it may pop up after a few more miles).

Logging the data as below this can also be seen; driving a little exorbitantly (if that's spelled correctly) shows the actual boost only achieving some 1350 or so with a setpoint of some 1620 or so; even though N75 is attempting to control it.



So no the vac pipe change has not affected this so its nothing obvious from the work done getting the engine out and back in. Further diagnostics required. Any pointers for blocks to check would be appreciated. I guess fuel trims is the next port of call?

Also can you log and graph data from both engine controller 1 and controller 2 from VCDS at the same time? I cant seem to get it to do this.

[ATinOf]

OK time to own up. Here's me not even bothering to check the bottom IC hoses thinking I wouldnt have forgotten something as simple as that; had the car up for a pad change so had a quick look and yes; id forgotten to tighten one of the clips, doh

Boost sorted, test driven and all well, now back to them pads

[douglas96]

Good job it was a simple fix then!

[Erwan35]

Not a noob per se, but it is my first post here!

First the history - cars done 57K, last 9K with me, running fine no engine or box error codes, but then gearbox issue popped up stuck in 5th gear; since i'm not one to shy away from a bit of work - stripped out engine and box and undertook a full refurb on the box; new seals, gaskets, frictions, vac checked spools; put it all back together (3 faults traced: output shaft double seal compromised exchanging fluid with transfer box; bushings quite worn on intermediate shaft; tubular seals to valve body not holding pressure) Beside these faults and the fact the sun gears are slightly out of specified tolerance for axial play the box is in excellent shape. While the engine was out and since it had a puddle of oil in the valley - I replaced the fine oil filter; oil filter housing seals; top oil cooler seals; camshaft adjuster seals; vac pump seal. While I was at it and since the front end was all gummed up with black stuff I replaced the front pulley crank seal, the idler pulley, tensioner pulley and aux belt. I broke the PCV hose behind the inlet manifold so replaced it; I broke the oil breather hose so replaced it (they were brittle). I did trap a vac hose putting a rocker cover back on (nearside airbox pipe) but it seemed good at the time so reused it; I have since bought one to replace it with but haven't yet replaced it. She fired up first time on reassembly, no fluid leaks, and gearbox issues are no more, so I promoted myself to chief mechanic and sipped some beer.

So whats all the fuss about? I am getting an error code (ignore the date I hadnt reset the clock when test driving);

000665 - Boost Pressure Regulation
P0299 - 002 - Control Range Not Reached - MIL ON
Freeze Frame:
Fault Status: 11100010
Fault Priority: 2
Fault Frequency: 2
Reset counter: 255
Mileage: 91008 km
Time Indication: 0
Date: 2008.04.04
Time: 18:52:16

Freeze Frame:
RPM: 3103 /min
Load: 84.7 %
Speed: 103.0 km/h
Temperature: 96.0°C
Temperature: 51.0°C
Absolute Pres.: 1000.0 mbar
Voltage: 13.335 V

and not reaching full boost; watching the boost bargraph in the DIS it looked like it was getting about 75% and topping out (and never had that issue before the work); clearly i'm going to change the suspect vac hose but you guys know if there are other elements I should look at? Graph attached, if the attachment works?



By the way I have hundreds of photos depicting the work above step by step which I will share at some point if you guys want it; when i get the time!
And no I'm not going to demote myself, I still think I earned the beer

HOW DID YOU GET THE GRAPH LIKE THAT? WHAT DEVICE DO U USE?

[ATinOf]

Logged the data to a file in VCDS, exported it to Excel; sorted the chunck of data I was interested in and charted it in Excel. I assumed thats how we all do it? VCDS has a graph facility but it has limited functionality.

[c3nturi0n]

I had a similar issue over the weekend driving out of Austria... at one point I tried to overtake and kicked down at which point I noticed small drop in power, MIL came on. Car continued to run fine and 1100 miles later I arrived home safely .

I did quick VCDS scan last night and I got the following two
- P0299 (on both banks)
- Knock sensor 1 (G61) - P0328 - signal too high - intermittent

any hints or clues or what could that be related to?

ps. MIL was erased, codes did re-appear and I can confirm that car runs and drives smoothly.