I have done over 65.000km and have already changed one m.a.p. (Manifold Absolute Pressure) sensor and it seems like im gonna be changing the second one too. Has anyone had issues with this specific sensor?

 

Yes I have.

Just interested in what has pointed you to the map sensor? In my case it was very difficult to trouble shoot and diagnose this sensor as the problem

 

Well i had issues of lack of power especially in over boost (at 4000rpm) also Auto Start Stop wasn't functioning. Changed one of the two m.a.p. sensors and all was fine. What issue did your have that led to the map sensor?

 

The car had a 2885 boost implausibility code, and would not boost properly, and kept going into full engine power mode not available. When we looked at the car there was a leaking recirculation valve. When we fixed that the car stopped throwing codes and going into full engine power mode. However, it still would not boost properly, it would only boost to a manifold pressure or around 25psi instead of 35psi (it is a JCW). The weird thing is the car threw no codes at all.

We were scratching our heads for a long time trying to figure out what was wrong. Eventually I had a hunch that it might be a fault pressure sensor sending wrong information to the ecu.

On the basis of the hunch I changed the sensor, and presto the car boosted normally again. Changed it back and it went into sluggish mode. Changed back and it fixed it again, so definitely the sensor.

The one I changed was the combined temp / pressure sensor BTW.

 

Thanx for the contribution! Let me ask, did you experience a "on" and "off" situation with that sensor? In my case, by saying "on" and "off" i mean, that one day it could be working ok but the next day it could have the issue and vice versa!

1. Btw what exactly is sluggish mode?
2. The m.a.p. sensor (manifold absolute pressure) im talking about, is it also known as the combined temp / pressure sensor?

 

By sluggish mode I mean not boosting properly, lack of power and acceleration, but no codes

Yes, it was the combined temperature and pressure sensor.

This was not on and off in my car. It was not working all the time

 

What do you recon could be the reason for this on and off thing in my car?

 

Uh... 35psi

I hope not for your stock turbos sake as well as your engine. 2.4bar would be all bad...and quite frankly not happening on stock tune (Limp Mode, Fuel Cut) hell the stock BPV or WGA would never allow you to hold that much boost, or even allow you to spike to it.

 

If you read my post fully, you would have noted that I said "boosted to a manifold pressure of 35psi".

The stock JCW has 19psi boost and 21psi overboost which is an absolute manifold pressure of 33.5psi and 35.5psi (ie boost + atmospheric of 14.5psi)

The thread is about replacement the manifold absolute pressure sensor, therefore I was talking about manifold absolute pressure, not boost.

The car was stock, and running the boost levels mini designed for a factory JCW

 

robbo mcs, what else should i should i be looking to check for solving this strange "on and off" issue (that one day it boosts normally and the other day there is loss of power and back to normal again later)?

oh and one other thing, did you change both of the map sensors or just one of them?

 

I have changed both sensors at some stage in the life of the car.

You really need a decent code reader and need to see what codes you are getting to take it further. It could be one of hundreds of things literally.

Also something that can either monitor or datalog parameters would be a huge help, eg what manifold pressure you are achieving.

Do you have a decent code reader or access to a garage that does?

 

There is access to a garage but i have no idea what code reader they are using!
What code reader brands are considered to be decent or more than decent?

 

I use bavarian technic at home or when I am competing.

My mechanic uses the autologic system.

Both of these read all BMW codes and shadow codes. Any decent mechanic working on BMW's will have software that can read the codes. Without that you really are guessing

 

thanx, what are shadow codes?

 

See if you can get some comparision data from a similair JCW on how fast your turbo is spooing up. The boost plausibility error means the turbo is not spooling up quick enough for the ECU. That means either a boost leak (you'd probably hear that but easy to test for) or you turbo is on the way out.

How do I know this? I've already been down the path your going. The culprit ended up being the turbo, more specifically the waste gate on the turbo was leaking by.

My turbo is at G-Pop Shop in Springdale, Arkansas for repair an upgrade right now.

 

Thanx scottab36 but let me ask, if what you say is true and it is the turbo, is it possible one day to be working fine and the other day to have boost issues?
And also what do you mean by saying, leaking by? I should see any oil somewhere? Is that what you mean?

 

I know that once I started having issues (P2085) I replaced just about every sensor including the MAP, MAF, IA Temperature and both O2 sensors. Things would seem to work for a bit and then the problem was back. I pressurized the intake system to 22.5 PSIg and had no leaks. I also replaced the BOV.

The issue first started with the tune I was running but as the turbo degraded it then showed up while running the factory tune. We were then able to compare the turbo response with similar MINIs to ferret out the problem. It was not boosting fast enough. I got my hands on a turbo with about 8K miles on it and the problem was gone.

This problem is also much more prevalent in warm weather since our ECUs use a torque demand to drive boost. Simply put, when it’s warmer out the engine requires more boost to meet the torque demand requested by the ECU and the turbo cannot keep up.

My MINI has always had an appetite for oil but it's been consistent over the years. I saw no oil issues withing the turbo.

 

and as we speak about this, today i got a CEL, not blinking, it just lit-up in the speedo dash!

 

Got it. Sorry for the misinterpretation/misreading of your post.

 

...and yesterday CEL light shut off, *** works again and boost is back! Then i checked it with an error code machine and P2187 came up (as a pending error), any thoughts on the matter?