Yellow Engine light on dashboard

Brian23

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As normal the yellow engine light comes on then goes off on starting, but after a run today it came on, as I parked and would not go off. When I used the car a few hours later the same. At start goes off after run comes on. Any easy fix or MB diagnostic? Is this an engine management problem?
Brian
 

television

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You do need to pull the plug top front of the engine on the cam shaft plug to see if it is oily,,if it is do not drive anymore till you get the blocker that stops the oil from getting into the wiring harness and into the engine
 

100%Bitch

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This might sound a bit silly, but have you used supermarket petrol?

I had my light come on for no apparent reason when I used ASDA petrol once. I kept filling up with Shell V-Power and all was wel after a couple of fill-ups. MB could find anything wrong with it.
 
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Brian23

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What car, petrol or diesel, what light, glow plug, abs, etc.

The car is a 1999 230SLK Petrol. The light looks like a small amber engine. It goes out when starting and sometimes comes on when idling. Could it be some kind of pressure switch that need replacing?
 
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Brian23

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You do need to pull the plug top front of the engine on the cam shaft plug to see if it is oily,,if it is do not drive anymore till you get the blocker that stops the oil from getting into the wiring harness and into the engine

I will check that
 
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andy@pcd-ltd

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The quickest and easiest thing to do would be get it stuck on a star machine and the fault codes read out and go from there
 

Alex Crow

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three common causes on this motor. oil in wiring as has been said (usually causes problem when oil gets to O2 sensor), (p0410) secondary air injection and air mass related faults. no point guessing any more, needs to be plugged in.
 
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Brian23

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You do need to pull the plug top front of the engine on the cam shaft plug to see if it is oily,,if it is do not drive anymore till you get the blocker that stops the oil from getting into the wiring harness and into the engine

I take it that when I look for the plug it is obvious where it is? and the blocker is an easy fit?
Brian
 

wiltsandy

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I take it that when I look for the plug it is obvious where it is? and the blocker is an easy fit?
Brian

You may not need the blocker as you have an early engine and I don't think they suffered from the leaking cam sensor like the later engines do. I may be wrong though and I'm sure SAMUNIT or one of the other 'techies' will correct me.

The plug you're looking for is under the front cover at the top of the engine. Take the cover off and it'll be obvious. Remove the pug from the sensor and check for oil in it.

My guess is that your O2 sensor has gone and that's why the management light is coming on when idling or after a short while.
 

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I have also heard that maybe not on the early engines the 111973, the later ones are the 111983

If the engine performance is down then the MAF can also turn on the lamp

Still worth checking the sensor,just squeeze the release button on the plug and have a look
 
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Brian23

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Took off the cover, the plug did have some oil on it. Took it to MB and they took it in the workshop, but seemed to think that it is ok and is nothing to worry about. So I'll give it a good clean at the weekend and keep an eye on it. The light has not come on again since the weekend, so we will have to see how it is on a long run. thanks for everyones help. I will check the MAF.

**Also what are these Blockers and where do they fit??
Brian
 
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Brian23

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You do need to pull the plug top front of the engine on the cam shaft plug to see if it is oily,,if it is do not drive anymore till you get the blocker that stops the oil from getting into the wiring harness and into the engine


Took off the cover, the plug did have some oil on it. Took it to MB and they took it in the workshop, but seemed to think that it is ok and is nothing to worry about. So I'll give it a good clean at the weekend and keep an eye on it. The light has not come on again since the weekend, so we will have to see how it is on a long run. thanks for everyones help. I will check the MAF.

**Also what are these Blockers and where do they fit??
Brian

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television

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Took off the cover, the plug did have some oil on it. Took it to MB and they took it in the workshop, but seemed to think that it is ok and is nothing to worry about. So I'll give it a good clean at the weekend and keep an eye on it. The light has not come on again since the weekend, so we will have to see how it is on a long run. thanks for everyones help. I will check the MAF.

**Also what are these Blockers and where do they fit??
Brian

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You just unplug that lead, plug in the blocker and the plug that you took out goes into the blocker
 

wiltsandy

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Took off the cover, the plug did have some oil on it. Took it to MB and they took it in the workshop, but seemed to think that it is ok and is nothing to worry about. So I'll give it a good clean at the weekend and keep an eye on it. The light has not come on again since the weekend, so we will have to see how it is on a long run. thanks for everyones help. I will check the MAF.

Brian

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If there was any trace of oil in the plug, irrespective of MB say I would put a blocker in the loom. It's only about £18 and is money well spent to stop any future oil ingress into the loom and eventually finding it's way up to the ECU!

**Also what are these Blockers and where do they fit??

It's a short loom with a male connector on one end and a female on the other that are hermetically sealed to stop oil passing through the pins and into the cable. It connects between the cam sensor and existing loom.
 


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