OM642 EGR clean

[onefortheroad]

I changed this today - the one i removed did not have a washer neither did the one I bought - would it cause any issues fitted without this washer?

105 in your photo.

 

[onefortheroad]

Can I do the inlet port motor trick on my OM642?

That's purely a swirl flap issue fix.

 

[such]

That's purely a swirl flap issue fix.

Ok, nothing to do with the inlet port motor then?

 

[onefortheroad]

Ok, nothing to do with the inlet port motor then?

It's everything to do with the inlet port motor . That's what works the swirl flaps.try it .

 

[Wighty]

Can I do the inlet port motor trick on my OM642?

I don’t know on the W212 …even though it is an updated om642 .

 

[such]

Ok, thanks for the feedback - Alex C did mention possible swirl flap issue when I discussed the EGR fault codes and said there is a workaround for it if needed.
He's on his own for the next couple of weeks so unable to look at it.

Would the car be ok if I still drive it in this limp mode.
Is it worth calling MB assist - I had an A service @MB Colchester last year?

 

[such]

Now i have seen that the coolant needs topping up - topped up with 500mls of water yesterday, now needs at least that again.

 

[onefortheroad]

Now i have seen that the coolant needs topping up - topped up with 500mls of water yesterday, now needs at least that again.

Your egr is probably drinking it ,and straight out of the exhaust

 

[such]

Your egr is probably drinking it ,and straight out of the exhaust

I'll let MB assist shed some more light on it tmrw.

 

[such]

MB tech came out and test drove it. Did not generate any codes. Diagnostics came up with "air mass values out of range at 20-40% open. mass air flow sensors passed test.
He suggested a smoke test on the air intake to check for leaks and to check the EGR cooling system.

I have driven the car since and it is defo down on power and changing gears before 1.5k rev with no real acceleration.

 

[supernoodle]

Afaik the EGRs on these are the simple rotary electronic type, ie ECU only gives a position demand, there is no position feedback like on newer engines. The EGR operation can only be determined from the MAF readings.

So when the tech did the test, where the mass values too or too low? You really need to know to investigate.

You can operate the EGR with icarsoft, assume Carly can do the same. So you can determine if the EGR is moving and there is some gas flow at least.
At idle, I'd expect when you open the EGR fully MAF drops to somewhere close to 50% of the MAF value with EGR closed. For closed value you can calculate like this

What if you MAF reading in g/s?

Hello to you all, I wanted to understand what is the usual reading of a MAF sensor on your car? There seems to be no data on this anywhere. Most people have OBD readers that can tell you what it is with live data. This should help anyone trying to determine if their MAF is bad (like me ). Mine...

forums.mercedesclub.org.uk

I assume when the tech said check the EGR cooling system they meant the exhaust gas side of the cooler isn't blocked, which seems unlikely if the valve was so clean. There is a EGR cooler bypass valve so you can force the gas flow path anyway.

 

[such]

Afaik the EGRs on these are the simple rotary electronic type, ie ECU only gives a position demand, there is no position feedback like on newer engines. The EGR operation can only be determined from the MAF readings.

So when the tech did the test, where the mass values too or too low? You really need to know to investigate.

You can operate the EGR with icarsoft, assume Carly can do the same. So you can determine if the EGR is moving and there is some gas flow at least.
At idle, I'd expect when you open the EGR fully MAF drops to somewhere close to 50% of the MAF value with EGR closed. For closed value you can calculate like this

What if you MAF reading in g/s?

Hello to you all, I wanted to understand what is the usual reading of a MAF sensor on your car? There seems to be no data on this anywhere. Most people have OBD readers that can tell you what it is with live data. This should help anyone trying to determine if their MAF is bad (like me ). Mine...

forums.mercedesclub.org.uk

I assume when the tech said check the EGR cooling system they meant the exhaust gas side of the cooler isn't blocked, which seems unlikely if the valve was so clean. There is a EGR cooler bypass valve so you can force the gas flow path anyway.

Thanks supernoodle - the tech didn't mention if the values were too high or too low, and was indeed referring to blockage on the exhaust side of cooler. The car is due a B service with additional filters which I have already - is it worth changing the air filters to see if this makes any difference? I'll wait for Alex Crow to be back up to speed and then take it in for him to look at and service. Thanks for your help

 

[such]

CEL on today - codes mostly related to stuck open/closed EGR valve.
Cleared codes and went for a spirited drive in sport mode and car ran fine - no power restrictions and no CEL.
I think the MB tech when test driving may have done the same as he said it drove ok with no loss of power, but just poodling along causes loss of power

 

[such]

Well MB indie had a look today and concluded the new EGR valve is not working as it should - something about opening at 9% instead of 5% ( I think) He also needs to eliminate potential MAF sensor faults. Did smoke test and no leaks. Going to look at the MB egr which I removed to see if it was sticking and then refit and go from there. I do hope it's not the MAF sensors as the original MB part is way over £1k.

 

[such]

Original MB EGR valve refitted and car collected today. Actually drove really well. Keeping my fingers crossed for now..

 

[such]

I am now wondering if the original issue was caused by the exhaust back pressure sensor which literally fell apart when I touched it due to the brittle plastic housing? Could this cause the codes indicating egr stuck?

 

[Wighty]

I am now wondering if the original issue was caused by the exhaust back pressure sensor which literally fell apart when I touched it due to the brittle plastic housing? Could this cause the codes indicating egr stuck?

Its a consumable item on the same fuse , so probably yes it can (£60 new)
I changed mine a few years ago just as a precaution.

 

[such]

Its a consumable item on the same fuse , so probably yes it can (£60 new)
I changed mine a few years ago just as a precaution.

I did change it before putting on the Lucas EGR valve.

 

[such]

Ok, just did a quick scan and all original codes have returned
Going in to Alex Crow on Weds.

 

[Wighty]

Ok, just did a quick scan and all original codes have returned
Going in to Alex Crow on Weds.

Let us know how you get on buddy