Lambda sensor type

[wiltsandy]

Can anyone please confirm which type of Lambda sensor Mercedes fitted to the 230K (SLK R170) engine - Zirconia or Titanium?

I'm still getting the low volts code thrown up as a result of oil in the loom so am going to change the sensor first. If that doesn't fix it then a new loom will be next I guess.

There's no oil in the intake piping or MAF and I cleaned the MAF yesterday so am pretty certain it's not that side of things that's causing the fault code to be generated. I've also cleaned out the spring loaded valve in the upper breather system.

 

[television]

It will go away eventually they all do, if you just have the lamp on sometimes but the car drives OK does it matter

 

[wiltsandy]

The car drives fine with no obvious problems - it's just that I'm fed up with the light coming on and re-setting it.

Having previously cleaned all the other connectors and also taking the ECU apart yesterday to clean that out too, I'm pretty confident that the problem now lies in the O2 sensor or that part of the loom.

Maybe I'll give it a few more days/journeys before taking the plunge.

 

[racall]

where is the O2 sensor located??

 

[wiltsandy]

where is the O2 sensor located??

It's in the downpipe on the drivers side. Access is easy from above.

The connector is clipped to the top of the bellhousing, behind the engine block.

 

[owenrich]

Hi Wiltsandy, is the electrical connection to the 02 sensor at the bellhousing connector? If so does it just pull apart? I can't help with the Lambda sensor type, looked everywhere but no info as to what type, sorry. Another question, sorry, but how does the MAF come apart? As you see I'm learning by example!! Cheers. Owen.

 

[wiltsandy]

Hi Wiltsandy, is the electrical connection to the 02 sensor at the bellhousing connector? If so does it just pull apart? I can't help with the Lambda sensor type, looked everywhere but no info as to what type, sorry. Another question, sorry, but how does the MAF come apart? As you see I'm learning by example!! Cheers. Owen.

Hi Owen,

The electrical connector for the O2 sensor on mine is just pushed into a spring clip on the top of the bellhousing. I just unclipped it and then pulled the connector apart.

I ended up buying a universal zirconia sensor from ebay for £16.50 as I thought I had nothing to lose. With the universal ones you have to re-use the old connector so I cut it off the old one and soldered the new sensor to the old lead, obviously matching the colours up. Have done about 80 miles since changing it yesterday and so far no ECU light!

As for the MAF, I just took unplugged it and removed it along with the intake pipework. Once off the car, remove the two torx head screws that hold the MAF to the pipe adapter and it pulls out. I sprayed mine with carb cleaner as that's all I had but I sprayed from the opposite side to the way the air flows through it so that it would wash any gunk out. Not much came out and it wasn't very dirty to start with but there is a noticeable improvement in the pick up now.

Hope this helps and let us know how you get on.

 

[owenrich]

Hi Andy, thanks for your reply. You are obviously handier than me, but then I now live in a flat without any "real" tools so it's difficult! The O2 connector on mine appears to be a turn type to lift the flanges and guess what it won't turn. I found the MAF thanks to the Russion diagrams from here, thanks guys. Took the MB engine plastic covers off and decided to just spray the connectors with electrical contact cleaner from Maplins. How many connectors, male/female, on the engine loom have you found? I did as many as I could see including the four in the ECU and fingers crossed it will start in the morning!! Hope the universal sensor does the job. Have you tried http:/ryououki.no-ip.com/r107/ a good site for the SLK R170 class. Cheers. Owen.

 

[wiltsandy]

Sounds like you might have a different connector to mine then Owen. Maybe it's something to do with the age of the vehicles; what year is yours?

I've only cleaned the O2 sensor connector and the four on the ECU as the connector on the MAF was dry. I've also taken the ECU apart and holding it with the connector rail at the bottom, washed it with contact cleaner in an attempt to remove any oil. There wasn't much on it but there was a coating on the connector rail.

After putting it all back together I put a small piece of kitchen paper under each ECU connector to soak up any further oil that might migrate to the end of the loom. It's really easy to undo the connectors every so often and change the paper!

Having fitted the Starter Line though there certainly appears to be less oil in the loom so maybe I've caught it in time.

The car won't be used for a couple of weeks now but I hope that when I get back to driving it the ECU light will stay off!

Just ask if you want any more info.

 

[wiltsandy]

Just noticed that yours is an '03 200K.

According to http://www.lambdapower.co.uk/partsearch/az2.asp?manu=Mercedes it looks like we should have the same sensor with the same plug: http://www.lambdapower.co.uk/partsearch/connectors.asp?conn=47.

Mine definately just pulled apart - try yours again.

 

[owenrich]

Hi Andy, just typed a long reply, tried to post and had to refresh and lost it!! ****** annoying and this happens a lot, am I taking too long or is it just how it is? Thanks anyway would like to keep in touch. Cheers. Owen.

 

[wiltsandy]

Hi Owen,

I can't answer your queston about how the forum works I'm afraid. You'll have to ask someone with more knowledge about that side of things than me :lol:

Hope you get your car sorted soon. I'm on holiday in Spain now but will still be keeping an eye on the forums to see how you're geting on.

 

[owenrich]

Alright for some! Hi Andy, just off to MB to collect a new gearstick! Old on had the paint completely worn away, didn't think the "paint" would last very long, hey ho more spending, but in a good cause. Have a great holiday. Owen.