Check Engine Light - DM code 5 - EGR valve

[RicardoD]

My Check Engine Light is on. I have a 1994 E500. I used the DM button and LED and its code 5: Exhaust gas recirculation inoperative

I cleared the code and it came back on after a couple of trips to work. So I think its real.

So far advice I found on this board is here:
http://www.500eboard.com/forums/showthread.php?t=8766

In my experience, the most common problem is a vacuum leak/broken hose from the manifold to switchover valve on the passenger-side fender or from the switchover valve back to the EGR valve. Next would be the EGR valve itself, then the switchover valve last. If it's none of those, then you may have a blockage in the secondary air tube...but unless you have a ton of miles, that's not likely, IMO.

Anyone else have any tips as I start to figure this one out. I assume EGR valve is under air filter unit somewhere. Anyone with a photo of where to look?

 

[gerryvz]

It's a common code on the .036, Ricardo. I've had it for the past couple of years on my own car. I just keep resetting the CEL when it comes up. I need to get off my butt and fix it. I get codes 4 and 5 pretty regularly. I'll be watching this thread. Perhaps this weekend (after I redo the G-wagen steering system) I'll take a look at it.

Cheers,
Gerry

 

[RicardoD]

Gerry, I'm a pretty good home mechanic, but still pretty clueless about the .036, I should be able to take a look this weekend, and hopefully identify all the parts and hoses. Finally got a chance to look at the factory manual on this, section 14, to help me figure out this system and where all the parts and house are. I should be able to follow up with photos to help others down the road.

http://www.w124-zone.com/downloads/MB CD/W124/w124CD1/Program/Engine/LHIS/14-0030.pdf

and specific EGR valve replacement procedure if that is in fact the problem:
http://www.w124-zone.com/downloads/MB CD/W124/w124CD1/Program/Engine/119/14-7662E.pdf

 

[RicardoD]

More google research before I actually take a look at this over the weekend and inspect all hoses, connections, etc.

http://www.peachparts.com/shopforum/tech-help/26268-m119-egr-clean-out.html#post1119281

Post references removing EGR valve and cleaning passage tube underneath which is integrated into intake. Clogged passage apparently is one way to trip CEL light.

Note there is a gasket underneath the EGR valve assembly so that should be replaced. Picture of EGR valve attached. Part number: 001-140-76-60

 

[RicardoD]

Sometime the problems are very easy. I had a broken rubber elbow fitting that connects to the top of the EGR valve. Time to see if I can find a replacement at my local auto parts store. Pictures attached to make things super obvious and to help other find the EGR valve and location of EGR switchover / change over valve / solenoids. You can trace the EGR valve vacuum line from the valve on top of engine to just behind the right front headlight where the switchover valves are.

I think I broke this rubber hose fitting when I was changing my spark plug wires a few weeks back.

EDIT: EGR Vacuum line rubber elbow part number is: 117 078 02 81

 

[gerryvz]

Keep an eye on it. That's cool though, if it was the problem. Fingers crossed !! Thanks for the follow-up !

 

[RicardoD]

I couldn't find an equivalent rubber elbow at my local auto parts store so I just bought 75 cents worth of rubber vacuum hose and made that work. I cleared the trouble code, and we will see what happens.

The actual Mercedes Benz part number for these rubber elbows is: 117 078 02 81

I may add one to my next part order to get back to the OEM look and HP gains!!

 

[Stevester 500E]

1. Check EGR with vacuum pump. If your engine stumbles when the vacuum pump is applied, then you EGR is functioning to some degree.
2. If the engine does not stumble, Either your EGR valve is faulty or the EGR tube is clogged with carbon.

 

[gerryvz]

I just got back from the wrecking yard, where I snagged some parts for a few folks. One of the cars I got parts from was a 1993 500SEL (W140), which had an M119 and was made in January, 1993. Unfortunately this car had the plastic cam oiler tubes, so alas no tubes for sale from me at this point in time. However, I also had to get the valve covers for 281lxm. I'm going to have them, and a set of M119 valve covers I already own, powder-coated locally.

After getting the valve covers off, I looked at the EGR valve, since it was sitting proud atop the intake manifold, partially under the front edge of the fuel rail. After moving the rail out of the way, I removed the three 5mm Allen bolts that held the valve to the manifold. The area under the valve was very carboned up, so it would be VERY easy to see how the tube passage that goes into the intake from the EGR valve would and could get clogged.

I'm going to remove my own EGR valve and de-coke it, as well as the flexible tube that goes into the intake. I believe that is the cause of my constant codes 4 and 5 that I have been getting on my E500. I will take photos and do a "HOW-TO" on this operation in the future.

Attached is a photo of the thick gasket that goes between the EGR valve and the intake manifold. I removed it from the 500SEL; however it is very inexpensive from MB and aftermarket (Elring Klinger) sources.

I do not believe that my EGR valve -- in and of itself -- is faulty or inoperative. I think the tube that flows from it to the manifold is the issue. In any case, it should be something for folks to watch out for. My car has ~135K miles on the odometer.

Cheers,
Gerry

P.S. I put a "silver dollar" next to the gasket so you can gauge its' size. I'm sure that most folks below the age of about 40 have probably never seen one of these vintage "Eisenhower" dollars before (including gsxr)

 

[RicardoD]

I can report that my broken vacuum line rubber elbow fitting on the top of the EGR valve was the cause of my CEL as its has now gone away. In addition I just received the vacuum line rubber elbow fitting, p/n 117 078 02 81 , so my car has returned to the OEM look. I ordered a couple of elbows as I am sure it may be needed elsewhere down the road.

Gerry, looking forward to you photos on EGR removal and tube clean out. This may be a good PM step for me as well.

 

[nocfn]

Thanks GVZ and 281lxm is my BW screen name, and I did a scrub of the EGR tube on the C126, made a difference but wasn't plugged up.

 

[KoLoS]

RicardoD, I had the same problem, thanks for EGR Vacuum line rubber elbow part number
My engine was working with broken rubber so I was wondering... what was the consequences?
What happens if the EGR were to stop functioning entirely on an M119? Power loss? MPG loss? I assume there will be a CEL, but is that it?

 

[French02chris]

Hello,

I think that I am having a problem with my EGR as well...

I tested the vacuum yesterday using a handpump, and the EGR did hold the vacuum...

However, when I started the car and applied vacuum to the EGR ( with the pump), the RPM had NO change and the engine did not stall...

So, here is the dumb question : am I supposed to "block" the vacuum line going to the EGR ( since it is not plugged in to the EGR anymore), or it does not matter??

Also, how easy is it to clean the tube from the EGR to the manifold? If the manifold needs to be removed, how big of a job is it ( I would need to bring it to the shop, so I need to figure out the expense beforehand ) ??

Thank you all
Christophe

 

[gsxr]

If you disconnected the vac line to the EGR, yes, you should plug the open line/hose.

Search the forum for details but IIRC you can try to use an old speedometer cable to "roto-root" the tube to the intake? Pretty sure you don't have to remove the entire manifold but you might have to remove the ETA, maybe.

 

[French02chris]

If you disconnected the vac line to the EGR, yes, you should plug the open line/hose.

Search the forum for details but IIRC you can try to use an old speedometer cable to "roto-root" the tube to the intake? Pretty sure you don't have to remove the entire manifold but you might have to remove the ETA, maybe.

Ok,
I checked the vacuum while the engine was running ( plugging the open line ), and the EGR is NOT holding vacuum at all...
So I guess that it is time for a new EGR valve??

 

[gsxr]

Ok,
I checked the vacuum while the engine was running ( plugging the open line ), and the EGR is NOT holding vacuum at all...
So I guess that it is time for a new EGR valve??

If you apply vacuum to the EGR valve itself with a Mity-Vac hand pump, and it does not pump down to ~20" vacuum and hold that steady... the diaphragm is probably ruptured, and yes that would require replacing the EGR valve. Double-check this to make sure! The valve is easy to remove, and you can bench test it as well. You can see the plunger on the underside move when vacuum is applied.

 

[French02chris]

If you apply vacuum to the EGR valve itself with a Mity-Vac hand pump, and it does not pump down to ~20" vacuum and hold that steady... the diaphragm is probably ruptured, and yes that would require replacing the EGR valve. Double-check this to make sure! The valve is easy to remove, and you can bench test it as well. You can see the plunger on the underside move when vacuum is applied.

It is really warm outside ( 90 degrees here in Florida ) but I went for more testing :

-If I plug the open line first, then plug the pump into the EGR....it DOES hold vacuum ( @ 20 or so )....However, NO change in RPM and NO stalling
when I release the vacuum from the pump, I can hear the EGR valve clicking ( which is good )

-if I plug the vacuum pump into the EGR, and then plug the open line : the EGR does not hold vacuum....

SO, which way is the correct way?? ( I don't really feel like spending $200 on something that I don't need )...lol


Also before I take off the EGR for inspection, I am ordering a new gasket ( just to be safe, if the old one comes apart)
THanks again for your help

 

[gsxr]

I'm confused - but you should connect the pump directly to the EGR valve itself. The open line won't matter for testing purposes. If you pump the valve down to 20 or so and then release and hear it "click" shut, the valve is probably fine. If there's no change in engine operation, the next check is the tube inside the manifold, which requires removing the valve to access, IIRC? Did you find the thread where someone (Glen or Stevester?) cleaned out their EGR tube?

 

[French02chris]

Hi,
Yes, the pump is directly connected to the EGR valve itself....

I am talking about blocking the open valve line....
2 different tests with engine running :

-When I block/plug the open line first, then connect the pump to the EGR, then pump : the vacuum will hold.

-When I connect the pump to the EGR first, and then block/plug the open line, and then pump : the vacuum will not hold ( actually, you can't even pump vacuum in it )

And No, I haven't find the thread...

BTW, I am also searching for a thread about aftermarket starters....lol

 

[Glen]

I cleaned the EGR tube in the high miler a few years ago. I didn't do a how-to but there are a few posts buried in my owner thread (199).

 

[gsxr]

Yes, the pump is directly connected to the EGR valve itself....

-When I block/plug the open line first, then connect the pump to the EGR, then pump : the vacuum will hold.

This sounds normal.

-When I connect the pump to the EGR first, and then block/plug the open line, and then pump : the vacuum will not hold ( actually, you can't even pump vacuum in it )

I am still confused. What is the difference vs your first test? If the pump is connected DIRECTLY to the EGR valve, with no "T" in the hoses or lines between the pump and valve, there should be no difference in the test or results compared to your first test - the valve should still hold vacuum, nothing changed. Now, if you have a "T" in the hoses and the pump is trying to pull vacuum back through the source line, that is a different scenario.

BTW, I am also searching for a thread about aftermarket starters....lol

Pretty sure the only options are dealer reman ($$$$), Bosch aftermarket reman (~$200 plus core), or no-name eBay 'rebuilders'. I'd avoid used ones unless it was a recent rebuild.

 

[French02chris]

This sounds normal.



I am still confused. What is the difference vs your first test? If the pump is connected DIRECTLY to the EGR valve, with no "T" in the hoses or lines between the pump and valve, there should be no difference in the test or results compared to your first test - the valve should still hold vacuum, nothing changed. Now, if you have a "T" in the hoses and the pump is trying to pull vacuum back through the source line, that is a different scenario.

I also thought that the engine was supposed to stall if the EGR was working properly when applying vacuum??



Pretty sure the only options are dealer reman ($$$$), Bosch aftermarket reman (~$200 plus core), or no-name eBay 'rebuilders'. I'd avoid used ones unless it was a recent rebuild.

Sorry for all the confusion....I redid the testing right now, and either way ( plugging first or second, does not matter)
The EGR hold the vacuum ( I pump 20 ) but the engine does not change RPM nor stall, which after reading online, seems to mean that
the EGR is dirty or the ports are blocked with carbon
When I remove the pump from the EGR, I can hear the click ( the valve is closing)

Also, I just drove about 45 minutes in a 90 degree weather, and when arriving at home and trying to put in reverse, the car almost stall ( but did not, it surged back up to rpm 1000 ).

As soon as the gasket for the EGR arrive ( next week), I will take it out and check it !!!

As for the starters, I am only asking as I saw this one for $104 new.:
Power Select Professional Grade 100% New Starter
http://www.rockauto.com/en/moreinfo.php?pk=6678764&cc=1194656&jsn=385&jsn=385&jsn=385

 

[gsxr]

As for the starters, I am only asking as I saw this one for $104 new.:
Power Select Professional Grade 100% New Starter
http://www.rockauto.com/en/moreinfo.php?pk=6678764&cc=1194656&jsn=385&jsn=385&jsn=385

That starter is probably aftermarket Chinese junk... I wouldn't put it on my car, but that's just me. M119 starters are no fun to replace. A Bosch reman should last a very long time.

 

[French02chris]

NEW UPDATE ABOUT EGR VALVE

my old EGR is bad!!!

So yesterday, I did order a new one from Rockauto.....it is $163 ( yes I took a risk...lol ) https://www.rockauto.com/en/moreinfo.php?pk=1353715&cc=1194656&jsn=2

I received it today :
1- the box says : Made in Germany
2- the EGR inside is EXACTLY like mine : PIERBURG !!!! ( written on the valve itself)
3-the gasket is actually a MB gasket....lol

Well, I guess I was lucky

Later on today, I will install it

 

[French02chris]

So the saga continues...LOL

I did install the new EGR . Then when the car was at running temperature, I use to vacuum pump on it, and the car's idle change ( almost stall ) : which is good.
So, now my EGR is working...

However, yesterday ( it was colder than last week, here in Florida ) my Idle fluctuation came back ( RPM going back and worth 500-700 for a few second when put in gear) when I stopped at the light near my house
BTW, it only happen when put in gear ( if I leave the car in N or P, this problem does NOT appear )

This morning, I checked the Fuel pressure : all good ( even the leak-down test )
-No codes ( except for the airbag quid )

SO, my question : could it be a small vacuum leak somewhere which only happen when the engine is cold ( since higher temperature will expand the plastic lines )???

Or could it be that the LH module is bad??

The issue only happen when engine is cold....as soon as the temp gets around 60 ( engine wise ) , the problem disappears

I am running out of ideas ....everything else is good ( MAF, wiring, throttle body, ignition cables and plugs...etc...etc...etc)

ps : I have ordered some new engine mounts as mine are shot ( I can feel vibrations and rumble at gear when stopped)

 

[RicardoD]

I would like to thank my past self for this post as I had forgotten about this. I am once again triggering a Check Engine light with DM codes 4 & 5. I look in the general area and found another rubber elbow and hose disconnected. I hope this is the source of the problem. I still need to get a little handy mityvac hand pump as I am wondering when the EGR valve will finally give out.

 

[nocfn]

I bet that line is hard. Get a few meters and replace everything off the pierburg valve om PS fender. And make them a bit longer...

 

[RicardoD]

2 years later and that elbow i had to reconnect failed again triggering my EGR code. Just change them all while you are in there. I changed the other one a few years back.

Order a handful of 117 078 02 81 and change these two out as a PM step.

 

[nocfn]

I use the silicone connectors in bulk and just cut to size.

 

[gerryvz]

Yep, it's a good idea to just replace ALL of the elbow connectors underhood. And the vacuum lines, for that matter. I had a lot of brittle lines on the top of my engine when I did my COVID top-end job.

 

[dionphaneuf]

I've had this same CEL (code 5 only) for some so finally got to doing this. I pulled the valve off the motor and unsurprisingly it was quite ugle looking. I used degreaser and brake cleaner to tidy it up, and it seemed to hold vacuum fine (I didn't have a tester at the time, but it would move when sucked on). Next I tried to use various hard wires I had in my garage (including a braided steel bicycle brake line that I splayed out) attached to a drail to clean the egr passages in the engine with mild success. One side of the EGR goes to the drivers side of the car (LHS); at first I could push a wire in about 4 inches, but after a while and with some persuasion I could get around a foot in. The wire would spin but I don't think I was removing much. Reading more about this I ought to remove the ETA the next time I do this. The other side (going to passenger side/vehicle right) was more challenging, I could only get 3-4 inches of wire in here and it's not clear if it's totally clogged.

I reassembled the system and cleared the DM code. I borrowed a mitty vac tool from a friend and was able to clear here the EGR valve actuate ('clicking' on and off). It slowly leaks down from -20 in, but stops at -5 in; if I then release vacuum with the mitty vac tool the valve clicks. I think the mitty vac tool is leaky itself of the hose connection to the EGR is slightly loose, as I can get to -25 in Hg and hold with the end of the hose on a rubber glove, but slight movement immediately loses all vacuum.

In any case, when this vacuum is applied the car doesn't stumble as I'd expect. I'm going to get some carb cleaner and a stiffer cable (speedo as suggested) for the next time I do this, and also pull the ETA to ensure I don't throw tons of crap into Don Roden's finest. I've already replaced the vacuum lines from the EGR valve to the front fender area, and everything is pointing to more cleaning of the engine passages as what's needed next. Is the passenger side passage really that short, or is it likely clogged too? I'd assumed that one goes to the RHS exahust header/manifold, with the LHS passage going to the intake.