Z3 1.9 Pre facelift M44 Engine. Lambada probe

UK forum for general and technical discussion about the Z3 roadster
Post Reply
joneseric
Joined: Wed 19 Jun, 2013 19:10
Posts: 20

  Z3 roadster 2.8
Contact:

Z3 1.9 Pre facelift M44 Engine. Lambada probe

Post by joneseric »

I am away from home at the moment and reading up on the Catalytic Convertor / Lambada probe installation on my car.
I have had the dreaded high Co2 MOT fail. Please could somone tell me how many lambada probes my car is supposed to have. I am sure the car has one pre cat probe, but when I look at RealOEM the parts diagram shows both a pre and post Cat installation. Any advice gratefully accepted.

Rgds

Eric
User avatar
colb
Joined: Sat 05 May, 2012 22:46
Posts: 690

  Z3 roadster 1.8 TU
Location: Newport South Wales UK

Re: Z3 1.9 Pre facelift M44 Engine. Lambada probe

Post by colb »

If you check oem using last six letters and numbers of your vin number the diagrams displayed will show a generic picture. If your car is not fitted with a part it will be greyed out in the diagram
Colb
1999 BMW 1.8 Z3
2003 BMW 2.5 Z4
1998 Honda Deauville NT650V
joneseric
Joined: Wed 19 Jun, 2013 19:10
Posts: 20

  Z3 roadster 2.8
Contact:

Re: Z3 1.9 Pre facelift M44 Engine. Lambada probe

Post by joneseric »

Hi-Thanks for your advice, I got my wife to send the VIN and like magic RealOEM says my car has Qty 1 probe - pre cat.

Thanks

Eric
User avatar
BonBon
Joined: Tue 08 Jan, 2008 21:10
Posts: 1227

  Z3 roadster 1.9

Re: Z3 1.9 Pre facelift M44 Engine. Lambada probe

Post by BonBon »

I assume your Cat Conveter itself may be knackered.
User avatar
Robert T
Site Admin
Joined: Mon 12 Jun, 2006 10:35
Posts: 10170

  Z3 roadster 1.9
Location: Cheshire

Re: Z3 1.9 Pre facelift M44 Engine. Lambada probe

Post by Robert T »

CO2 (Carbon Dioxide) or CO (Carbon Monoxide)? Pre-facelift cars did not have a gCO2/km rating, so they are taxed in the over 1.5 litre category, and so I don't think they can test CO2 output. Certainly on my last MOT it just shows CO, HC and lambda. High CO can be that the car was not up to temperature when tested. How high was the HC reading?

Cheers R.

Sent from my SM-G950F using Tapatalk

Arctic Silver '99 Z3 1.9 & Black '59 Frogeye 1275cc
Image
Del
Joined: Sat 19 Nov, 2011 18:35
Posts: 2136

  Z3 roadster 1.9

Re: Z3 1.9 Pre facelift M44 Engine. Lambada probe

Post by Del »

CO (carbon monoxide) measured in the UK MOT. High CO is caused by either overly rich mixture or failed (failing) catalytic converter. If the ECU has logged no sensor error codes I would guess at a failing catalytic converter :(
joneseric
Joined: Wed 19 Jun, 2013 19:10
Posts: 20

  Z3 roadster 2.8
Contact:

Re: Z3 1.9 Pre facelift M44 Engine. Lambada probe

Post by joneseric »

Hi, sorry for late reply, still in the Middle East fixing an aeroplane!

Robert, your correct the car is not plated, and only CO, carbon monoxide is measured.

Both fast idle and idle failed CO. HC was 103ppm and lambda was 1.015, so within the middle of the range.

The car was warm as I had just replaced the thermostat and the gauge was in the middle, also, my wife give it a good thrash to ensure it was warm.

She noticed a misfire around 3500rpm in 3rd and 4th gear, with noticeable hesitation.

Mileage is 62k. I do about 2k a year.

The cat is 2 years old, but it was a cheap one.

No fault codes, I have a inpa diagosntic setup with a 20 pin interface.

So: when I get home, it’s a new Walken type approved cat, new coil and ignition leads, and all pipes on the induction side checked, and not forgetting the MAF sensor.

I wil. Keep you posted and thanks again for the advice.

E
joneseric
Joined: Wed 19 Jun, 2013 19:10
Posts: 20

  Z3 roadster 2.8
Contact:

Re: Z3 1.9 Pre facelift M44 Engine. Lambada probe

Post by joneseric »

An update!

The car had previously been failing the MOT emissions test with high CO. My car was reading 0.5. Today my car was tested and the CO was 0.06, this is a massive improvement.

The effort to get there was also massive and I guess if a garage had carried out the work the cost would have written the car off. Before I detail what i did, which was not out the ordinary, I am a qualified aircraft engineer with quite a lot of exprience in aero-engine-piston etc. I also have BMW diagnostic software and a recently purchased emission testing equipment.

- My first task was to test for airleaks around the induction system, a volatile spray was used sparingly, this resulted in small increases in rpm.

- Find the air leak!. The induction side was almost completely removed and checked for damage. Some pipes where a little loose on their stub connectors, these were replaced.

The following items were replaced as the idle was rough.

- Idle control valve replaced. — Bargin on ebay. OEM part.

- Cam position sensor replaced - Another ebay bargin.

- PCV replaced

Exhaust System

- Cat replaced with Type Approved item.

- All joints fitted with new gaskets.

Result

Lambda - Good

HC - Good

CO - 0.06!! Passed

Rgds

Eric
Post Reply