2nd Gen JCW Most liked posts in thread: Need Help:Turbo Boost error 2885

OK, let's see what we can do here. I started off with having the dealer do a diagnosis. Right now, I cannot find the receipt from the dealer but they stepped through all the potentials for the P2885 code that MINI has in the checklist.

They checked and replaced several elec sensors all of which did nothing. The good thing for me was that I didn't pay for any of these parts. They put my originals back on after each test. Once they eliminated all the elec parts they were down to the turbo. That is where I took over.

So, I started with easy tests. I bought a hand vacuum pump at the parts store, Attached it to the wastage actuator, ( it is the shiny housing and threaded rod below the turbo with a vacuum house ). Use the hand pump to check to see if the wastegate is holding. (See video above). The wastegate is inside the turbo housing on the exhaust side.

In order to visually inspect the wastage I purchased a cheap USB flexible scope camera and used my laptop to view inside the turbo. To do this just remove the O2 sensor on the top of the catalytic converter. This will give you a view of the wastegate, the exhaust turbine wheel, the catalytic converter honeycomb.

In my case the wastegate was clearly broken and not holding vacuum. While it is possible to get just the exhaust housing and not a complete turbo, (Check out JMturbocoopers.com) I found that my turbo had leaking oil seals and was using oil to the intercooler and also the catalytic converter. In the end I replaced the turbo, the IC, and the cat.

Nathan has been after me for some time to write all this up but I have not gotten around to finishing it. Maybe I will get back on it.


Ultimately, I let go of that car as it was starting to nickel and dime me with the common N14 problems. As much as I loved that JCW and all that power, I let it go.


I now have a awesome R53 (Thanks Chuck:beer). Check the link in my sig line.

 

I picked up the car this evening and started to plot my plan for for figuring out why the car is throwing the charge-air pressure deviation error.

Before I put the car in service mode to get the catalytic converter off to inspect the waste gate for proper operating, I thought maybe I could capture some log date that might be of use. I have a bluetooth OBD2 device and Torque running on my tablet so I hooked it up and took a drive.

Here is some of the interesting log entries. I could use some education on vacuum and boost so feel free to teach me what I should be seeing.

I noticed that at idle the vacuum was bout -24. Then when accelerating thru the gears it showed boost and the value topped out at about 10. Even then the boost would fall off drastically even though I still was accelerating and I was not yet in top gear.


Here are a few of the rows of data for comparison.

Column 1
Wed May 29 20:12:33 EDT 2013 -10.88
Wed May 29 20:12:34 EDT 2013 -2.9
Wed May 29 20:12:35 EDT 2013 0.29
Wed May 29 20:12:36 EDT 2013 6.96
Wed May 29 20:12:37 EDT 2013 8.27
Wed May 29 20:12:38 EDT 2013 9.72
Wed May 29 20:12:39 EDT 2013 -10.59
Wed May 29 20:12:40 EDT 2013 7.11
Wed May 29 20:12:41 EDT 2013 4.35
Wed May 29 20:12:42 EDT 2013 3.34
Wed May 29 20:12:43 EDT 2013 3.19

As you can see the boost topped out at 9.72 then started falling as I went to the next gear. The boost just kept falling from 7.11 to 3.19.

Does this point to anything in particular?

 

Time for an update.

The code remains. It clears itself if you drive the car easy, but if I get on the gas it comes right back.

The next step in the dealer plan was to pull the cat converter to see the wastegate and then operate the gate under manual vac pump to see if it is ok.

I decided to take the shortcut and use my flexible snake camera and view it from the opening of the top O2 sensor.

Here is a video of the results.

Turbo problems on Vimeo

Take a look at it and tell me if you think this is how it is supposed to look or not. I don't know what it should be. The gate does open and close, but the gate itself is odd looking to me.

 

At first I was going to replace just the exhaust housing which contained the waste gate . Had the oil seals been ok that would have worked but in the end once it was apart I ordered a full replacement and then returned the exhaust housing.

Jmturbocoopers was good to work with. Hey will rebuild yours and ship back also.

I am not schooled in this but will make a guess. Colder air is more dense and therefore will give you more boost because of more air in a confined space. So maybe that is why it feels normal. Part of the reason why the larger aftermarket inter cooler helps. They lower the temp of the air.

I'm sure if I am wrong someone will be along to set it straight.

Even when it feels ok, can you force it to go limp by stomping on it and going wide open throttle? I was able to reproduce the cel at will if I jumped on it. I would build boost and then it would drop. I could see it on my scangauge boost.