OK, so I'm thinking about changing the timing chain... - Page 3 - PeachParts Mercedes-Benz Forum

shane83SD · #31 03-18-2004, 10:53 PM

Hi Lietuviai,

Look in this thread, gsxr described it and has a link to his site.
Smoking, carboning, poor cold off idle with little to no blowby. What could it be?[/URL]

lietuviai · #32 03-18-2004, 11:01 PM

Oh yeah, I know that thread. I've got some of my own replies and questions in it.
Thanks.

leathermang · #33 03-19-2004, 06:15 AM

240Joe,
Now the problem becomes obvious....

"I said he should at least check it the quick and dirty way before he changes it. " -240Joe

You have never done this live... you are ' armchairing' it...

The fact is this is about a 10 minute operation. The fact that it is only this amnout of time.... and that THE FACTORY SHOP MANUAL PRESCRIBES IT IN THESE CIRCUMSTANCES makes it a no brainer...

240Joe · #34 03-19-2004, 07:13 AM

Leather,

Now I know you have lost it. I've checked chain wear every time my valve cover has been off on my 80 240d and my 83 300d.

Yes, the manual method doesn't take that much time, but it does take equipment that the normal do-it-yourselfer doesn't have.

Please quit sandbagging it and read to us what the manual says you need to do that job.

My way is much, much easier, and almost as accurate. And as I said before, he has absolutely no idea what his chain condition is.

Changing chains is way overrated. I think this witchcraft got started by the guy who continues to repeat the 3kmile oil change, and will remain nameless. Even people that have chains with 7 or 8 degrees of stretch indicate that if IP timing is corrected with the worn chain, very little different is noticed in performance with the new chain.

When you adjust your IP timing by the drip method, you remove the affect of chain wear. The only performance factor is then the late valve timing...and that's where the offset key comes into play.

240Joe

leathermang · #35 03-19-2004, 07:36 AM

Space saved for answer next to question...back with pictures....

In the meantime... someone please email me and tell me how to post more than one picture in one post... several people have done this lately... and this would be a good time for me to do this....

In the meantime....

Changing chains is very over rated... PARTICULARLY if the old sprockets are left on the engine.

The offset keys are designed to be used as per the factory shop manual instructions.... that is what they are made for.... the question now is why you believe the shop manual on this....but not when they say " in special cases, eg, during complaints about performance,check and adjust begin of opening at intake valve of 1st cylinder" (sic)

What are these " extrodinary" tools which you believe are necessary for this job... but are beyond what most DIY's would or should have ?

How much do they cost ?

Will they be something which the DIY will ever use again ?

240Joe · #36 03-19-2004, 08:42 AM

If you tell me I need a dial indicator to do the job, and I don't have one, even if it costs $20, most people start thinking it's just easier to change the chain and forget the "extra" step.

That's like recommending a compression test....what a worthless piece of advice that is. First, most people don't have the tools, and then when they get an answer, which may be wrong, they don't know what to do with it....

If you have to buy every tool the manual calls for, you should sell this car and buy a rice box, it will be much cheaper.

My way is better....it is no cost, almost as accurate, and will allow him to focus on the real problem, not some imaginary problem.

I have been consistent in saying I think this problem is IP timing or injectors, but it's too easy to rule out the chain with my quick check.

End of story.

240Joe

leathermang · #37 03-19-2004, 09:19 AM

Ok,, the more you write the closer we get to the problem....

But the simple stuff first....

Yes, one needs a dial indicator to do this fast and easy....

Even at your assumption of $20 (which is high)... lets see..... how much does a chain and the associated things cost... how much labor would it be ?.... I think you really really underestimate the intellectual abilities and the energy of our forum members....

I suspect from what you have said that you do not have a Mercedes shop manual for the 617.952 engine... am I correct on this ?

A compression test by itself only tells certain overall things... a leakdown test is usually necessary to know what to do next....

What kind of test is available other than compression and then leak down... do you just look at an engine and toss a coin to determine whether and where it is worthy of being worked on or discarded.... I really think that was a wild statement " compression test being worthless"..... and hope some of the old guys on the forum will speak up....

lietuviai · #38 03-19-2004, 01:46 PM

I am on the verge of being an old timer and by some in this forum I may be considered an old timer since I have worked on cars for almost 25 years now.
I don't know about diesels but with gassers a compression check is very important in diagnosing the condition of the valves and rings, if there is a crack in the head(not mine, thank you), or blown head gasket. I would think the same philosophy would apply to a diesel as well. The thing is, it's usually much easier to do a compression check on a gasser.
But please, before we end up having a "fight"

here let's remember that we're trying to solve a problem that I have with my car.

leathermang · #39 03-19-2004, 02:07 PM

"I would think the same philosophy would apply to a diesel as well. "
That is exactly correct... and even more so because the actual ignition ( after glowplugs go out ) must be caused by the compression.......
I am a very conservative guy machine philosophy wise.... yall may can tell that... I hope you can... and I hope that enough people have first hand knowledge and trust in what they have learned in the past to recognize how outlandish 240Joe's attitudes and statements are....
I have just been saying that at that point , if you are wanting to check the timing,chain,cams, etc... when you are at the place where you would look at the mark on the cam... as 240Joe suggests.... that you have done 95 percent of the work necessary to DO IT Correctly.... as the shop manual says if you have any performance complaints with the car....
You already have the valve cover off.... found the marks on the crank pulley.... it does not make sense to not zero out the distance on the number one intake valve.... measure the movement of that valve to 2mm... .and then look at the crank numbers...

lietuviai · #40 03-19-2004, 02:24 PM

Leathermang, I too am as conservative as possible in regards to working on cars and spending money as well. What you're saying makes sense, it doesn't take that much more work to do it right. I like doing things right especially if it doesn't take much more effort to do it. I don't have a dial indicator but maybe it would be possible to duplicate the amount of prescribed valve travel by trying to insert a 2mm feeler gauge between the valve and the cam.

240Joe · #41 03-19-2004, 02:29 PM

Leather said

"and I hope that enough people have first hand knowledge and trust in what they have learned in the past to recognize how outlandish 240Joe's attitudes and statements are...."

I think you must be referring to my assersion that 3kmile oil changes are unnecessary. I stand by my words.

Outlandish???? You mean telling him to do a basic test that will cost him nothing extra is outlandish..... I think not. I think your advise is dangerous, expensive, and, yes, useless!

If he would listen to you, which I hope no one ever does, he would have to purchase a compression gage for diesels, a dial indicator, have his alda torn apart and probably not be able to get it back together, have some compression readings that mean absolutely nothing, and still be no closer to solving the problem.

240Joe

leathermang · #42 03-19-2004, 02:36 PM

You have hit on something correctly....
However, I want to address the dial indicator issue.. since it was misrepresented so badly....
I have an $18 mitutoyo which I have had for 10 years.... last year I was in Harbor Freight and they had one on sale ( Enco) for $6... yes , not a typo... SIX DOLLARS.... I got it, got out a bunch of things and measured them with BOTH units.... they both measured the same.... no difference which I could determine.... so we are talking less than half a thou ( as machinists say).....
Maybe one is more shock resistant than the other... but they are both AGCD certified... the standard measure.... so I would not hesitate to suggest Harbor Freight or Enco direct... and they are useful for lots of other things.... so with stand and extension we are talking $20 or less....how much is your car worth... or how much is it worth to be able to make a much better informed decision with regards to your next step on your engine ?
Ok,,,, what you do is run up your adjusting cap nut so it touches the cam with NO distance between them....
Then you are looking for that point when the cam has pressed the intake valve 2mm...
So a dial is just the easy way....
You could also make a jig which was at a certain place to start... and use feeler guages to keep checking until you get the distance traveled by the valve.... a dial indicator is just easier to read... and if you only use it on MB's ... you could get one with a metric reading face....

Rick Miley · #43 03-19-2004, 02:41 PM

Greg, you left out a piece. What is the reading supposed to be on the harmonic balancer when you the the 2mm valve movement?

240Joe · #44 03-19-2004, 02:43 PM

Leather,

Why do you insist on wasting his time.

lietuviai...please just look at the marks and tell us what you see.

If you listen to leather, you're going to need a full up machine shop, two master machinists, an engineer or two, probably a manager to run your shop, and a huge bank loan to pay for it all.

Stop listening to him...period...there I said it.

240Joe

lietuviai · #45 03-19-2004, 02:50 PM

Looks like my feeler gauge idea won't work. The cam needs to turn an amount that would provide precisely 2mm of valve travel to be able to coincide with the amount of timing chain stretch that would be indicated on the crank pulley. If only I lived in CA right now. My dad has all the dial indicators and stands that I would need. Looks like I have to make a trip to Harbor Freight. I hope those DI's they have aren't made in China.