XSeries-forum

Hi,

I'm having a few problems with my car. If I'm below 2000 rpm the engine is quite hesitant (fine above that). Also the engine sound like it's hunting at ticker.

I had a look around the internet on various sites, and I think it may be a MAF issue?

I disconnected the connection from the MAF whilst the engine was running and the engine kept running, and the hunting stopped. Would this confirm my suspicion? (engine was cold at the time).

I have no engine light on, and using a fault checker (Carly) there are no errors.

Thanks

Mick

If it runs better and drives ok then you have found the fault.
You could also check the small vacuum pipes as well the tend to split at the ends.

Thanks for the reply Alan, I'll check the vacuum pipes this weekend.

Thanks

Mick

Does anyone happen to know the ID of the various vacuum hoses on the E83?

Haven't had time to check them yet, but it might be good to find a supply of the correct size, in case I find a leak.

Mick

If it helps, use the REALOEM database (BMW Parts on line) with the last 7 of your VIN to pull up the right model. Pipe numbers etc will be listed in various locations/slides.

It’s a copy of the same system that Dealers have.

I have a question for anyone that knows the vacuum system on these cars.

I have a MityVac vacuum pump, I was under the impression that if I disconnected the hose to the EGR valve, and connected the MityVac to the hose and created a vacuum, the vacuum should be constant until I release the pressure. When I tried this I couldn't get anything at all, which makes me think I do have a broken or disconnected vacuum hose somewhere.

Does that seem correct?

Thanks
Mick

Sounds spot on to me.
Can't remember the I'd of the pipe I just bought some that a lot of sellers had the same size.
I put silicone on mine and if you get a size too small it will still fit.
I am on holiday in Egypt at the moment so can't look for the size on realoem I can't remember my vin number.

Thanks for the reply Alan,

I'll check on Real OEM today and see what information I can get from it. I'm off work tomorrow so hopefully I can get the intake manifold off and
check the vacuum pipes for any loose or broken hoses.

Mick

You might as well replace them while you have the manifold of.
I found it was the ends of the pipe that had split and some had come off completely.
It's a common thing they don't last for ever lol.

It looks like the small vacuum hoses are 3.5mm ID, with a wall thickness of 2mm. I've found some silicon vacuum hose with an ID of 3mm and the same 2mm wall thickness. Hopefully that should do the trick.

Mick

Yes that will do the job nicely.
Can't remember what length I got but I think it was about 3 meters and did all of them with a bit left over but it's not expensive.

Well, It's all sorted now. The problem was with the vacuum actuator that operates the swirl flaps, I'm assuming that the diaphragm that moves the arm must have a hole or something. I tested it with my MityVac and couldn't get a vacuum. Luckily I had a spare lying around, I tested the spare and it worked as intended, swapped it over, and all is well.

Mick