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post #71 of 174 (permalink) Old 12-08-2017, 12:51 PM
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I'll be ordering that at some point today. I was looking at parts on autohasAZ and noticed a part named "Distributor dust shield" It's the orange circle that goes behind the rotor. Mine is in a little subpar shape with a couple chips taken out of it. At $66 seems to be not worth it... Is this a very important piece, and does anyone have experience picking this part from a junkyard? I need a few other non vital plastic parts so a trip to the junkyard is in order anywar. ...
If the damages on that part which are clearly visible in the second picture in post 68 are the only once, it doesn‘t necessarily have to be replaced. But if you can find a better one at the junkyard, you can pick it. What should be in order is the o-ring, the area where the o-ring sits and the surface on the backside of that part, which sits against the aluminum housing.

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... Just to double check, this is the correct seal? The page says i also need a timing chain gasket, is that necessary?
The MB part number is “A 0189977947“ and it‘s about €10 + sales tax here at the MB dealership. Even if I could get one for free from another source without knowing what quality it is, I‘d buy the one from the MB dealership.

That “timing chain gasket“ is only renewed if the upper timing chain aluminum housing (the one the camshaft seal sits in) is taken off . But that‘s not necessary if only the camshaft seal is replaced.
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post #72 of 174 (permalink) Old 12-08-2017, 01:13 PM Thread Starter
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I would of course prefer to go to a MB dealer but the problem with that is getting to a dealership... lol. This part has the same part number and claims genuine mercedes.

One thing I was considering doing (as a band aid of course) is scrubbing the corrosion / residue off the terminals in the cap using a wire brush. My quarter at university is over, and I'd like to head home for winter break. I'd have lots more tools and a sheltered work area. Assuming I was able to get the car started, should I be worried about the engine stalling while driving? In the past once I'm able to get the engine running and up to temp I haven't had any trouble with freeway driving, which is what this trip will consist of. Opinoins?
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post #73 of 174 (permalink) Old 12-08-2017, 02:47 PM
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... Assuming I was able to get the car started, should I be worried about the engine stalling while driving? In the past once I'm able to get the engine running and up to temp I haven't had any trouble with freeway driving, which is what this trip will consist of. Opinoins?
If you get it started you might be lucky and make it home. … However, incomplete combustion of fuel (due to weak ignition sparks) is not good for the engine.
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post #74 of 174 (permalink) Old 12-08-2017, 04:50 PM
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This thread is utterly fascinating; I've read the whole thing now for the third time and it should be required reading for anyone with an M103 engine. Between this and the associated KE Jetronic thread, there's essentially an M103 mechanic's PhD program on BenzWorld. Klasse! Or, as was used in the mid-80s when I lived in Berlin, "Superaffentobelgeil!"

I'm in awe of @codycool55 and his persistence and understanding of electrical testing, and I'm in super-awe of @H.D. and his patient, fantastically thorough and methodical approach to problem resolution—replete with pencil sketches that would make a draftsman jealous. Good show, gents! I love my '89 300SE; of all the cars I've owned in my life—which total seven (I keep my cars for a long time), I must say that my 300SE, which I actually inherited from my late mother, is my favorite. They're heavy cars, and they require frequent applications of TLC and attention to wear items—but they're not outrageously expensive to maintain if you perform maintenance on-schedule and use good quality parts and fluids. Who was it that said "There's nothing quite as expensive as a cheap Mercedes-Benz"?

I'm fastidious about my car running as near to perfect as possible; that's where the real Fahrvergnügen with these cars comes into play because the 126—many argue it's the last great S-Class—was meticulously engineered and crafted in almost all aspects with seriously good materials. I don't know what late 70s Daimler engineering and marketing thinking was vis-a-vis the service life of a 126, but some exterior paint troubles notwithstanding, my looks nearly as good as it did new despite its 183,000 miles on the clock—and of course garaged its whole life helps immensely. Thankfully, my mechanic employs an old-school 126-era mechanic whose daily driver is a 126 420 SEL, so I'm lucky in that he knows the cars quite well, and he's forthright with the difference between must fix vs. ignore it, turn up the radio and just drive the car.

Cody, I empathize with your M103 problems; I'd be super-frustrated were that my engine, so I do hope you get your M103's crankiness resolved. They're great engines with a nearly bulletproof crankcase (or so I'm told), and they deliver impressive power for their size—even if at 177 HP they're arguably a bit underpowered for the heavy 300SE/SEL.

Mine does burn oil, and it does so at what appears to be a slightly increasing rate. I know this is a combination of front/rear seals and, perhaps more importantly, the valve lifter seals—something for which the M103 is renowned. I go through a quart about every 500-700 miles. And I have to press the gas pedal when cold starting to avoid super-long cranking. One question for you: Does your M103 burn oil, too? Or have the seals and valves been reworked. With as many miles as are on yours, I have to think you've already been through this as nearly every M103 eventually develops these oil leaks.

Tangential question for @H.D. : Given that oil makes its way into the combustion chambers, the engine is then also burning minute quantities of it. What are the longer-term ramifications of driving the car this way—and at what point do I need to dig into my wallet and spend a couple of thousand on a valve job/lifter seal and front-rear seal replacement?

Thanks, guys.
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post #75 of 174 (permalink) Old 12-09-2017, 08:17 AM
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Thanks for your appreciation, Strassenkreuzer … … sounds very different from what I experienced in the last 124 forum thread I participated in last summer. I did something similar there and one of the forum‘s most active members called it “superfluous diagnostic procedures“ and no one of the many readers the thread attracted disagreed ... although it led to my pointing to the very part that turned out to be the culprit … and no one seemed to neither understand nor be interested in how it could do that.

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... I love my '89 300SE; of all the cars I've owned in my life—which total seven (I keep my cars for a long time), I must say that my 300SE, which I actually inherited from my late mother, is my favorite. ...
I love to see 1980‘s MB‘s being kept in really nice condition. They were designed with a distinctive engineering spirit. … And the 300SE is sufficiantly powered for nice relaxed cruising in not too hilly area, IMO.

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... Tangential question for @H.D. : Given that oil makes its way into the combustion chambers, the engine is then also burning minute quantities of it. What are the longer-term ramifications of driving the car this way—and at what point do I need to dig into my wallet and spend a couple of thousand on a valve job/lifter seal and front-rear seal replacement? ...
Longer-term oil burning is not good for the cat and leads to deposits on the valves and in the combustion chambers … which, BTW, might be a reason for your cold start problems. Deposits on the backside of the intake valves and in the last part of the intake ports, which are bone dry when the engine is cold, partly absorb the first injected fuel, impeding cold starts. … You might try some Italian tune-up with a good valve-clean-additive in the fuel. …

If you see oil leaking from between the upper front cover (which carries the ignition distributor) and the lower front cover, and the valve stem seals have never been replaced, you might find out that you don‘t have to add oil anymore after taking care of these two things. The valves and valve guides may still be in order. The valve stem seals and the U-shaped rubber gasket for the front cover (and the camshaft seal ring which should be renewed at the same time) are about € 50 plus sales tax here at the MB dealer and it‘s about a three hours job.
If you hear no ticking sound coming from the valve train the lifters are still okay. If you do hear a ticking sound coming from the valve cover and your car was built before March 1989, it might not be the lifters either, but worn camshaft lobes and rocker arms. Up from March 1989 the M103 was equipped with updated camshaft and rocker arms.

H.D.
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post #76 of 174 (permalink) Old 12-10-2017, 10:48 AM
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Quote:
Originally Posted by codycool55 View Post
I'll be ordering that at some point today. I was looking at parts on autohasAZ and noticed a part named "Distributor dust shield" It's the orange circle that goes behind the rotor. Mine is in a little subpar shape with a couple chips taken out of it. At $66 seems to be not worth it... Is this a very important piece, and does anyone have experience picking this part from a junkyard? I need a few other non vital plastic parts so a trip to the junkyard is in order anywar.

Just to double check, this is the correct seal? The page says i also need a timing chain gasket, is that necessary?
You can source that part at the JY for sure. So many M103's to choose from. I got one from an '89 just a few days ago and clearly it had never been taken off. No damage to it. I would not recommend using wear items from the JY but I even took the rotor and distributor cap from this one as it seemed it had been replaced not too long ago and had the OE numbers on them. Less than $20 for an almost new OE rotor/cap/dust shield. Can't beat that price for a spare.
Always good to have a spare of the distributor cap and rotor to swap in if there is any doubt.

I was actually there to pick up some obscure fastener I broke a few months ago and decided to do a case study of this JY car.

It was born in 11/88. Someone had upgraded the valve train oil dripper to save the camshaft with the V shaped washer. The camshaft appeared to not be completely damaged. At 220K miles, it seemed the valve guides were never replaced and it was burning considerable amount of oil. Spark plugs were new (probably replaced with the distributor cap) but fouled with carbon in a major way. It had no chance of passing CA smog test as the Cat would be covered in soot, so off to the JY .....

My '89 got it's first new set of valve guides and complete Head job at 180K miles. A lot of labor but I'm hoping to enjoy my car for the next decade.

Just posting all this to help out the OP.

- Cheers
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post #77 of 174 (permalink) Old 12-10-2017, 04:17 PM
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I love to see 1980‘s MB‘s being kept in really nice condition. They were designed with a distinctive engineering spirit. … And the 300SE is sufficiantly powered for nice relaxed cruising in not too hilly area, IMO.
First off, I assume it's OK to add the comments below to this thread because it has to do with the M103 and carries some similar problems to what Cody is experiencing, so I hope that's OK with those subscribed here.

In any event, @H.D. , I agree with the above comment; I think because the 4-speed starts out in second it can feel lazy, and it does struggle a bit on steep hills unless you kick it down to second. But I recently took it from Los Angeles to Sacramento and then west to San Francisco and then back down along the coast to Big Sur (you can Google it if you like) and back to L.A. Total of about 1,400 miles. She ran flawlessly with only the occasional misfire at idle—which still happens. It's the strangest thing that I can't figure out. The engine seems to run really quite well, but when in Drive at idle—say, at a stoplight—and fully warmed up there is the occasional, what appears to be single-cylinder misfire, and then it's back to normal. Happens very intermittently. Maybe a fouled plug or injector...


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Longer-term oil burning is not good for the cat and leads to deposits on the valves and in the combustion chambers … which, BTW, might be a reason for your cold start problems. Deposits on the backside of the intake valves and in the last part of the intake ports, which are bone dry when the engine is cold, partly absorb the first injected fuel, impeding cold starts. … You might try some Italian tune-up with a good valve-clean-additive in the fuel. …
Yes. I pour in a bottle of a fuel additive product made by Lucas Oil Products; they simply call it "Fuel Treatment" (https://goo.gl/f3AKQG). For the last couple of years I’ve done this with every 3rd or 4th fuel fill. I do worry about the cat; the last smog check passed its nitrous oxide limit by a mere 18 parts-per-million. (In California, the max ppm is 757 and I measured 739). I fear the next one—next year—might fail.

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If you see oil leaking from between the upper front cover (which carries the ignition distributor) and the lower front cover, and the valve stem seals have never been replaced, you might find out that you don‘t have to add oil anymore after taking care of these two things. The valves and valve guides may still be in order. The valve stem seals and the U-shaped rubber gasket for the front cover (and the camshaft seal ring which should be renewed at the same time) are about € 50 plus sales tax here at the MB dealer and it‘s about a three hours job.
Thanks for the guidance on the parts prices and labor time—gives me negotiating power with my mechanic. My 300SE has 183,000 miles on the odometer, and it was manufactured in February 1989—so I guess it has the possibility of a worn camshaft. I pored through my mother’s repair records; she kept every receipt since Day 1) and see if the valve lifters were ever done. In April 2010, at 143,925 miles, it was recommended by her Mercedes dealer, but my mother didn’t evidently want to spend the money. At that time they evidently wanted $1,750 to remove/replace the cylinder head, replace all valves, valve guides and seals and recondition the valve seats. If you’re at all interested and have a few minutes to look at the repair order and notes, feel free to PM me and I’ll send you a link to the redacted/highlighted PDF dealer repair invoice that shows the VIN and the problems/fixes; there’s lots of technician notes there that a Mercedes mechanic probably knows how to decipher.

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If you hear no ticking sound coming from the valve train the lifters are still okay. If you do hear a ticking sound coming from the valve cover and your car was built before March 1989, it might not be the lifters either, but worn camshaft lobes and rocker arms. Up from March 1989 the M103 was equipped with updated camshaft and rocker arms.
At cold start-up, about a third or so of the time I hear a valve or lifter ticking loudly for a few seconds until the oil is pumped into the camshaft drip. After that there is a slight ticking at idle, worse when cold, but nothing loud. As mentioned above, the VIN indicates my car was manufactured in February 1989. I don't know what the current cylinder compression is, but the engine doesn't feel like it's weak.
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post #78 of 174 (permalink) Old 12-10-2017, 07:15 PM
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Streetcruiser, 2/89 is most likely the old camshaft and rockers but you can check that to make sure at the dealership by giving them your engine serial number on the side of the cylinder block. Mine is a 1/89 and had the old. I'm pretty sure anything prior to 3/89 is the old.

At $1750, that would have been a steal at the dealership if they were going to replace the valves as well. What should have been done at that time was to at least addthe V washer to the oil dripper to save your number-1 intake lobe. If that is not there now, I would add that in right away. It is a 10 minute job. When the cover is off the camshaft should be inspected for wear too. If worn that could be contributing to your idle misses.

After I replaced my cam from the donor car my idle misses went away and the car started running a little better. In my case the lobe was worn almost 1.5mm and the rocker was also worn about 1 mm. You need to go in the direction of JY cars if you are adversely effected by the worn cam. OE cam and rockers will set you back $2000 for parts only. I have priced them.

First things first though, you are exactly at the same mileage I'm at, I would strongly recommend opening up the timing cover and taking a look. Takes 10 minutes.
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post #79 of 174 (permalink) Old 12-11-2017, 04:11 AM
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Since it is off-topic in this thread I want to limit myself to this:

Having been manufactured in 2/89 your car is equipped with the old camshaft and rockers, unless you see a “S” stamped in the surface of the cylinder head (upper front corner on the right side), which stands for “Schalenhartguß” (chilled cast iron, the material of the updated camshaft). … But reading that, when standing with the warm engine in Drive at a stoplight, it feels like there is occasional misfire, reduces the likelihood of seeing this “S” stamped there.

I really don’t like to say it Strassenkreuzer, but with what you report I can't help but suspecting worn camshaft lobe(s) and rocker(s). … When the engine runs at very low speed, like it does in D at a stoplight, the worn rocker follows the worn contour of the camshaft lobe the closest, which leads to an insufficient opening stroke of the (intake) valve, thus to insufficient gas filling in the cylinder, which you can feel as a slight misfire. … Probably at least the intake lobe(s) of the first cylinder(s) and the respective rocker(s) is/are worn … which is accompanied by a sound very similar to an early stage of failing lifters.

In that case I suggest to replace the valve stem seals when you replace the camshaft, of course … that’s all in all a 6-7 hours job.

So, the first thing I suggest to do is take the valve cover off and check the camshaft. There is more to say about this issue, but I think we should not use the OP’s thread for that.

BTW, I know the area you mentioned in your last post. I’ve been to the Laguna Seca Raceway several times (grew up in an environment that was heavily influenced by motorsport) ... and I drove along the west coast between SF & LA twice … very nice route. …

H.D.
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post #80 of 174 (permalink) Old 12-11-2017, 08:02 PM
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I had raised the same question to CC55 (The original poster) about the "born" date on his car, back in post 27. It got lost in the shuffle with all of the other ignition issues uncovered. I would still recommend to CC55 to check his serial number/born-on-date/S-mark on the side of the head and make sure he is OK. Second hand cars sometimes have this issue dealt with already so it is best to just take the valve cover off and check (only if your engine serial#/born-on date/S-mark suggest it is the old style camshaft/rocker/dripper). For example if someone bought my car (not very likely) they will see that it has a 1/89 born-on date, old engine serial, no "S" on the head and still it has all the new stuff. Same story with the JY car I encountered last weekend. And another reminder to all:

that 50 cent washer will extend your old valve train material by a bunch, in my experience by 30K-60K miles, maybe more.

- Cheers!
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