[Mart1000]

Well for the first time I've had a problem with the car (bear with me)...

Last week whilst on the way down the M11 late at night, the car lost a lot of power. No smoke, no chugging or misfire. Just power loss. Engine sounded fine and kicked down normal but I couldnt get it much above 80 (on a private stretch of course lol). I pulled over, stopped the engine. Started straight up and power was restored. No EML shown or fault on I drive. It also did it the following night.

Yesterday morning I was again on M11 (it's only ever done this on straight runs) it happened again. Switched off and on, power restored. Rejoined motorway, and loss of power again, so I limped her to work.

I then got home and looked through my service history to see when it last had fuel/air filter change. Now this is weird, my car has a full BMW history, and has NEVER had the air filter changed going by service book. Fuel filter was done 50k ago, so I booked a diagnostic and filter change this morning.

The head tech showed me the air filter and it was shocking! Totally full of shit (never realised they were so big on these too!). He said he had to Hoover out the air box too.

These are the codes that were read: (sorry if this is going on a bit)

4212, 4222, 4232, 4242, 4252, 4262. These codes are for individual glow plugs. Tech explained that this is actually common on these cars and no concern.

The other code was 3F25 which is charge-air tube monitoring. He said this is normally an obstruction or split in the intercooler pipe. He's checked and they are fine. I asked if the air filter could cause a drop in pressure due to airflow bieng reduced, and he said its possible.

I also enquirer about gearbox update, which I will be having soon as it won't wipe my map. Talking of maps, the week before this started the car was remapped. I don't think this is a coincidence, my way of thinking is that the increased pressure and needs of airflow is beyond the capacity of the blocked filter, and the car just goes into limp.

Sorry about the long post, anyone else had this?

[zltm089]

Hmmm...did you get any misfires?

A remap can highlight lots of stuff that wouldn't be apparent on a std map...especially an aggressive map...

I will be changing a spark plug aswell...

[Mart1000]

No misfire, strange noises/smells....nothing. It was still silky smooth, gearbox was fine, it was as normal, just with a massive lack of power...

[Mart1000]

All I can do at the mo is see if the fuel and air filter solution has worked. Fingers crossed that was the problem!

[Mustard3]

My air filter was the same as you describe yours after only 20k miles from being changed at service....assuming the dealer did actually change it.

It was after my Evolve remap that my car started to show power loss problems. Not a fault with the map at all but the extra boost / stresses must highlight & exacerbate any weakness.

[Mart1000]

What was the diagnosis of your power loss?

[Mustard3]

Originally Posted by Mart1000

What was the diagnosis of your power loss?

Still haven't gotten to the bottom of it. The symptoms are not quite the same as yours though. I've booked it in with a BMW specialist Tuesdays after everything I tried failed.

[Mart1000]

The air and fuel filter were changed last week, and it's been bang on since then.

The air filter was unbelievably shitted up and the air box needed hoovering out.

Still can't believe that with a full BMW history the filter has never been changed!

Oh well, all is good in the world again...

[kaishang]

Originally Posted by Mart1000

What was the diagnosis of your power loss?

Shortage of Viagara.