merc clk 230 o2 sensors need advise

[drivinggod09]

can anyone advise me on this i have a 230k clk on x plate had oil leaking from camshaft adj into ecu causing 02 sensors to mess up stopped the oil leaking into ecu and cleaned out but from the ecu to the 02 sensors in exhaust is still oil causing the sensors to mess up again is there anyway to stop the oil so it dosnt get to the sensors but stays in the loom or to clean it out while its on the car merc said needs a new loom as they dont bother cleaning them anymore and 6 hours labour at 100 plus vat was thinking of using silicone on the actual wires before 02 sensors to make a oil tight seal or running the car on ramp with o2 sensors disconnected if poss and dispursing oil with spray untill the loom runs clear any ideas cheers
rob

 

[television]

The oil will stop coming out after a short while, normally the oil goes down into the MAF, gets burn and this contaminates the O2 sensors, this could well burn off eventually and the light will go out again

We use hot glue gun to seal this type of thing,, even if it slowed it down the oil will go away.

Just wash the MAF as in the DIY

 

[drivinggod09]

cheers malcolm i will clean the MAF next week chances are it needs 2 new 02 sensors again i thought that the oil running down the wires from prob the ecu area is contaminating the o2 sensors as when i unpluged the upstream one it was really coated in engine oil and must have been pushed into the actual sensor that sits in the exhaust

 

[television]

No it cant go in via the O2 sensor,, I think that it could well go away on its own,,some cars did during the contaminated fuel crisis you could leave it if the car drives OK as the O2 sensor would have weakened the fuel to resolve it.

See if you are getting more MPG

 

[drivinggod09]

i think if it can get that far it can go anywhere the sensors must be dragging it up to them im getting 26mpg now where as the normal is around 30mpg showing it drives fine but isnt the ecu making it run rich which will burn out the cat im wondering if there is anyway to take the sensors out of the equation but trick the computer into thinking they are still there

 

[television]

This could be oil on the MAF.

When the O2 sensor has something on it ,,it thinks that the fuel is too strong and not the other way around, the only thing that turns the warning lamp on is the O2 sensor as the settings are stored stored

 

[star]

If i read this correct, you have oil in you wiring loom which originated from the camshaft adjuster, did you replace the wiring loom, if not, oil will continue to drain down to the o2 sensors messing up the readings. Did you fit the modified loom to the adjuster to stop this? It will also take a long time for the oil to completely disapear from the loom IF ever and so continue to show O2 sensor faults. The repair of silicone at the end will not work unless you can seal each individual strand of copper inside each wire???

 

[drivinggod09]

no havent replaced the loom just had it cleaned and blown through when the cam shaft adjuster was leaking there was oil in the conections under where the diagnostic computer plugs in now there is very little the only oil i can see now is running to the 02 sensors which i thought must be getting inside them the light stayed off when i repaired the cam adjuster and had new o2 sensors but came back on after about 100 miles havent fitted the modified loom yet but on order from mb ive just bought some spray that evaporates oil and is safe to use on electrics and ecu. i was thinking of fitting new sensors and sealing each strand of copper wire to prevent it reaching the 02 sensor element cheers for the reply star motor services

 

[type49]

I agree with Star. I pressume you have stopped the original oil leak, else you are wasting your time. The problem is, the oil leaks through the cam adjuster & gets into a red/green wire. This wire has a soldered joint inside the engine wiring loom. This joint is a main ignition feed & splits here to go to various other places, enabling the oil to spread. It can go straight to the engine control unit & fill up a connector plug. This plug then just lets the oil spread even further & can go as far as the oxygen sensors. In theory, if the leak has been cured, the oil may eventually stop filling up the oxygen sensor plug but how long you will have to wait for this is anyones guess. If it does cure itself, the warning light will not go out untill cancelled via Star type diag computor.

 

[drivinggod09]

thank for the reply ive cured the leak into the loom at the cam adjuster just got a backlog of engine oil in the loom which is at the 02 sensors will try cleaning the maf next week what harm will it do running the car with oil oil in the sensors as it runs fine just down a bit on mpg dont want to buy new sensors untill the oil has drained from the system will it burn the cat out or do any damage to the valves through over fueling

 

[television]

Contaminated O2 sensors under fuel and not over fuel so you are OK dont forget the the oil cannot do any harn on the O2 sensor part of the loom and cannot enter them. the only oil on them is the oil that has gone into the air intake and through the engine

 

[drivinggod09]

just looked at how to clean th MAF by parroit of doom but there is another diagram by another user that looks very complicated looks like something is unbolted from the engine which one should i follow

 

[television]

just looked at how to clean th MAF by parroit of doom but there is another diagram by another user that looks very complicated looks like something is unbolted from the engine which one should i follow

Parrots ifine for what you are doing

 

[drivinggod09]

cheers malcolm will do polished the car yester day and in the night some dirty little bastard has put a 10 inch scratch down to the under coat right along the rear quarter if ever i catch one of these little twats i will break there thieving vandalising grubby fingers im so annoyed now

 

[television]

cheers malcolm will do polished the car yester day and in the night some dirty little bastard has put a 10 inch scratch down to the under coat right along the rear quarter if ever i catch one of these little twats i will break there thieving vandalising grubby fingers im so annoyed now

So sorry to hear that it is a sickening feeling, why do they do it god knows

 

[drivinggod09]

malcolm just a quick one you say my car will be under fueling but i drive about 250 miles per week motorway driving and it has now gone from giving me near 38mpg to 23 mpg no change in driving style surely then the car is over fueling because of the oil in o2 sensors and the chrome exhaust tip has become more black since the mpg went down i know as soon as i put new sensors in and reset it will go back up to high 30s but only for 2 months max before they become contaminated again also cleaned the maf out this week there was very slight oil in the air pipes i presume from the supercharger any ideas

 

[colechelle]

feel like im butting in here but this is more of a common problem then people know, i fitted a blank plug to a 203 about 3 years ago, chap refuses to have a loom put in it, but every 6 months he turns up and in goes a new o2 sensor, everytime i unplug it, its filled with oil, and i mean a lot!! you need a new loom fitted, otherwise this will be a problem for years to come,

 

[television]

Is any more oil coming down the wiring loom

 

[drivinggod09]

when i unpluged it didnt seem to be any more oil in it yet thats after driving back to barracks 120 miles away and doing a bit of running around

 

[television]

Oil is not conductive and if it goes into plugs externally nothing will happen

Its when it goes into the MAF and gets burnt that it goes onto the O2 sensor