ECU flooded with engine oil

John77

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For the 200K it should be beside the air filter with two plugs on the top that are removed by pulling sideways the plastic levers. There is also a torx screw holding the wiring harness.
It depends how much oil there is in it, some have carefully drilled a small hole in the casing otherwise try inverting it and clean the contacts with electrical contact cleaner whilst upside down but I wouldn't want much getting inside it.
Here's a video of someone changing a MAF sensor but at 2:18 he shows removing the plugs from the ECU.
Good luck.


Thank you I will take a look. I do not know if any oil has got that far, but I have fitted blockers and will go from there.
 

John77

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Thank you I will take a look. I do not know if any oil has got that far, but I have fitted blockers and will go from there.


Well took the plugs out on the EClass and SLK and no oil showing, so maybe I have caught it in time. Blockers fitted to both cars, but will check again from time to time. See photo.

CIMG2298.JPG

CIMG2298.JPG
 

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Oldspanners

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Thank you I will take a look. I do not know if any oil has got that far, but I have fitted blockers and will go from there.
The best place to look first is the after cat O2 sensor connector as that is the lowest place on the wiring harness. That will give an idea of how bad it is. I had to clean the connector there four times over a period of months with contact cleaner, compressed air and change the sensor after I was sure it was clear. It didn't look like a lot but enough to upset the readings of the sensor.
It was just noticeable at the ECU but careful cleaning of the area around the ECU pins with a cotton bud soaked in contact cleaner, making sure not to leave any fibres behind (also open up the connector and clean it out a lot more there) and a blast of compressed air a couple of times fixed it so far after four years.
Edit. Just seen the photos looks spot on. Have a look at the O2 sensor. If you have no fault codes, no worries!
 

John77

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The best place to look first is the after cat O2 sensor connector as that is the lowest place on the wiring harness. That will give an idea of how bad it is. I had to clean the connector there four times over a period of months with contact cleaner, compressed air and change the sensor after I was sure it was clear. It didn't look like a lot but enough to upset the readings of the sensor.
It was just noticeable at the ECU but careful cleaning of the area around the ECU pins with a cotton bud soaked in contact cleaner, making sure not to leave any fibres behind (also open up the connector and clean it out a lot more there) and a blast of compressed air a couple of times fixed it so far after four years.
Edit. Just seen the photos looks spot on. Have a look at the O2 sensor. If you have no fault codes, no worries!

Next question. Where do I find that?
 

Oldspanners

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Next question. Where do I find that?
The connector is below the bell housing passenger side(you need to take the splash shield off) with the actual O2 sensor in the exhaust just after the cat.
Edit.
See at about 3:06 for exact place.
 
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John77

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The connector is below the bell housing passenger side(you need to take the splash shield off) with the actual O2 sensor in the exhaust just after the cat.
Edit.
See at about 3:06 for exact place.


Thank you. Interesting tool in the video.
 

Oldspanners

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Thank you. Interesting tool in the video.
Yes good tool, I've one similar but if you have a really seized and faulty sensor (penetrating oil will have little effect on getting the initial movement) its best to cut off the tail close enough to the sensor to allow a full size socket on as the tool can spread slightly and slip.
Of course it's handy for putting the new sensor on!
 

LostKiwi

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I always use a ring spanner.
Undo the connector, slide the ring spanner over and give it grief (with a hammer if necessary)
 

LostKiwi

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Does soaking overnight help??
Does no harm, but don't use WD40 - use Plusgas. Far more effective. Be careful removing it too. If it's really tight all the way it's probably because you're tearing the threads out which makes fitting a new one 'difficult'. If tight work it back and forth with plenty of oil to lubricate it.
 

Dan86

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Hi, i know this is an old thread. However my car wouldnt start upon investigating it i found it to have oil in the ecu. It in the plugs as well. The engine light was on for a whilw tbh before it stopped working.. gutted just before the sun..
 

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Oldspanners

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Doesn't look too bad (I seen a youtube where one was full of oil and had holes drilled in the casing to drain it) but it depends how much is in the loom and if blockers aren't fitted at the cam magnets it will continue.
You need to get the codes read as well and get all the effected connectors cleaned to see if the car will run again and work from there.
 

star

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Not so sure about that, it’s not the oil so much but the lack of pins in the second from left plug?
 

Dan86

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Wighty, firstly before trying to be funny make sure you are speaking sense??? Because there is not meant to be pins there but thanks for your help and constructive comment.
 

Dan86

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Wighty, firstly before trying to be funny make sure you are speaking sense??? Because there is not meant to be pins there but thanks for your help and constructive comment.
 

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Blobcat

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Wighty, firstly before trying to be funny make sure you are speaking sense??? Because there is not meant to be pins there but thanks for your help and constructive comment.
I'd recommend you have a read of the forum, there's lots of great advice mixed with some healthy lighthearted comments. :)
I wouldn't get upset over the comment and note the smiley face ;)
 

Dan86

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Sorry i wasnt meaning to be aggressive just not ideal when my covertible is stuck out in the rain..
I only pulled it out my gagrage then it wouldnt start back up. No starter its seemed. So i ran a wire from battery to starter and it turnt. But does nothing at all when the key is turnt. Im hoping this will cure it. I had the key reprogrammed and still nothing. I wouldnt care as it is an old car but the car was a friends who passed away with the virus so im trying to get it up together in his memory. Ive changed the interior to black leather. Put a new hood on it. So you can see my disappointment. Sorry again
 

Rotorhead500

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No worries, Wighty is thick-skinned! :) You'll have seen a couple of good How To clips on this thread, and a good steer from Star... Hopefully that'll get you back up & running!
 

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