W203 C180 Lambda Sensor help required

[TazCBR1100XX]

As this is my first post on the forum I'd like to say - Hi all :wink:

Now for the serious stuff

My wife owns a W203 2001 C180 Classic Auto 2.0 (new shape - well, it was when she bought it anyway). Recently there has been an engine management warning lamp on which my Son diagnosed while I was away using the very nifty U480 Scanner I bought. There were three codes stored, one of which was P0135 (O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 1), and there were two others. He can't remember what they were and as he hit the Erase button to try and clear the codes, I now have no way of knowing what they were as only P0135 comes up now.

I've checked around a few places to find out what I need to buy as this is all new to me, and the latest information I have is that there is a Diagnostic Sensor and another Sensor (can't remember what it was called though). Having not looked under the bonnet yet due to lack of time, I haven't got a clue which one I need to buy, and at prices exceeding a hundred quid I'm not going to just go out and buy one of each unless I really have to :roll:

So, the question is - where the hell is Bank 1 Sensor 1 and is P0135 telling me exactly which Sensor I need to buy and I'm just being thick and missing the whole point of Bank 1 Sensor 1

When I phoned Euro Parts they told me there is a 4 wire sensor which comes after the CAT but there are two different ones listed under Bosch for my vehicle (both at around £139.31 incl VAT), and there's another Sensor in front of the CAT (very cheap by comparison at only £88.13 incl VAT :roll: ) The two different listings for the one after the CAT are D3 and D4 (something to do with Euro 3 and Euro 4 whatever they are).

As it appears that there are some real tech-heads on here I hope someone can steer me in the right direction to solving the problem so my wife will stop bleating about how much petrol she's having to put in the car (which is only a fraction of what I have to put in it as she always leaves it empty when I want to use it) :roll:

I've also got one or two other things which need sorting but I'll put them on separate threads so I don't get confused :Oops:

Thanks in anticipation

 

[Ellsy Tanners]

You will have engine oil in the engine wiring loom which will have come from the camshaft adjuster solinoid. there are many threads about this so do a search and see wots been said done about it.
There is an adapata plug to stop the leaking oil, but there are diferent opinoins about wot is neccesery to be replaced. I allways replace the wiring harness and the o2 sensor and the plug adapater and new soliniod. see wot the others recommend.

 

[TazCBR1100XX]

At last I've got a chance to do the work on the C180. However, I could do with a little bit of advice from someone who knows what he/she is talking about (i.e. someone who is not me) before I get stuck in (and get dirty hands in the process) :evil:

There are a couple of questions:

Question 1
Do I need to replace the camshaft adjuster magnet (and O ring) and the O2 sensor as well as installing the starter line mod?

Question 2
There is a plastic cover at the front of the engine which looks to be similar to the one on the left as shown in the link below with a 1 in a circle

http://www.detali.ru/cat/oem_mb2.as...620716.633&CT=M&cat=68Z&SID=15&SGR=060&SGN=03

It's just a plain plastic cover which appears to have a few plastic tags holding it to the cylinder head cover, but I can't see any screws holding it down even though it does feel quite tight. Do I have to remove ALL the cylinder head cover just to get this piece of plastic off, or will it pull off - I haven't tried tugging too hard cuz I don't want to break it if it doesn't just pull off. The connector on the end of the camshaft adjuster magnet is just below this plastic cover, and it doesn't really make sense to have to take the entire cylinder head cover off just to unplug something I've tried looking in the WIS thingy that someone pointed me to, but it doesn't really show anything as far as I can see (or do I mean "can't see")

Question 3
Once I get access to the wiring for the camshaft adjuster magnet, I need to unplug the existing wiring connector and replace it with the starting line modified cable. As I haven't seen what's under the cover yet, do I actually remove the old wiring or leave it in place? i.e. Is the starting line mod a replacement for the existing wiring or is it in addition to the existing wiring?

I don't want to go through the pain of replacing the wiring harness if I don't need to. There are quite a few threads relating to similar problems to this but some of them are a couple of years old so I'm not sure what the current opinions are now that people know much more about the problem.

Anything else I need to know before I start?

 

[TazCBR1100XX]

Does anyone know the part number for the wiring harness that needs replacing? Not the starter line mod because I've already done that, the other harness that holds the oil when the magnet leaks.

Also, when I replace the magnet, what do I need to do to ensure it doesn't leak again? Is there an O ring or a seal that needs replacing? If so, do you have a part number?

Thanks

 

[TazCBR1100XX]

Finally I have extinguished my engine management warning lamp, and increased fuel mpg figures dramatically.

I've replaced the Camshaft Magnet, replaced the o2 Sensor, and installed the Starter Line mod - job done.

I checked the ECU to see whether or not the oil had contaminated it, but couldn't find any sign of oil anywhere in that area. There was a fair amount of oil in the plug for the O2 sensor, but I dabbed it away with cotton buds and hopefully it won't be a problem now that the new parts have been fitted.

Actually doing the job was much easier than I anticipated (with a little advice from the Essex area - thanks very much), but I didn't change the engine harness (that can wait until I know for sure that I have to change it).

I can't believe how much better the car is running at the moment and even when I boot it the fuel economy is still way better than before I changed the parts. My wife hasn't noticed any difference, but then again she only drives it every day!

I'm going to change the MAF over the next few days as the car has now done over 100k miles on the original one, and I'm also thinking of changing out the sparker HT thingies on the spark plugs just in case they're also not operating at maximum performance. Once that's all done I'll be getting it booked in for a full check on the star diagnostics and see what's left over.

I really can't thank people on here enough for giving me the information and the confidence to actually start doing things on the car.

 

[bouncer]

Just a thought to remember. The lambda sensor compares samples of oxygen in the exhaust stream with a clean sample from outside the exhaust. it does this through the gap between the wires and the insulation. If this gets blocked with oil then you will have the same problem.


sTeVe

 

[television]

Nice to see what you have done, the old loom may leak an odd bit of oil for a time as it runs between the copper wires and the plastic, but once it is all gone thats the end of it.

I would leave the MAF until it needs one. When you do cheapest from Bosch