I am following the tutorial to the letter and when I rotate the engine, my dial indicator needle does not move!! It appears that with the number 1 valve pointing straight up - which is where you start this procedure from - that is the highest point the valve travels. I have the gauge set up, setting on top of the valve keeper - dial indicator needle set at 0 - and everything is tight. Valve lash removed...

What am I not doing right here?


ryan

__________________
RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE

This is from the FSM - Can someone explain this to me???

7 Insert dial gauge and fasten so that contact button
rests on valve spring cap (arrow) with less than 3 mm
preloading (small dial gauge pointer).
Turn gauge dial until large pointer is on "0".

Caution:
Dial gauge contact button must be exactly perpendic-
ular to valve spring cap.

8 Continue to turn crankshaft in normal operating
direction until small dial gauge pointer has dropped
by 2 mm (valve lift) to 1 mm.

I clearly do not have much experience working with a dial indicator gauge!

ryan

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RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE

Which one are you working on?

Intake #1 is the second valve in not the first.

Also there is no way the the dial indicator isn't moving if you set it up right. It's got to be hanging up on something.

__________________
1984 300SD Turbo Diesel 150,000 miles

OBK member #23

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I am on the second valve - intake #1.

I am just resting the tip of the dial gauge on the valve keeper - reading of 0 on the gauge - with the lobe pointing straight up. I rotate the engine and the valve moves down but not any further up as I move around 360 degrees (I can watch this happen as I spin the engine and I can see that there is no way that I can get a reading on the dial gauge - the valve will not come up any higher to depress the dial gauge lever) - and the needle does not move as I turn the engine all the way around (nothing is 'hung up' either, checked and re-checked, etc.).

Am I supposed to pre-load the gauge as described in the FSM somehow? Am I actually measuring a 2mm rise in the height of the valve keeper - or a 2mm drop in the height of the valve keeper - as I rotate the engine?

ryan

__________________
RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE

Yep, you've found your problem. The gauge, at rest, won't travel "downward". You must "preload" the gauge by .100" or so and than turn the outside ring of the gauge to reset "zero". Then the pointer will move downward when the valve starts to open.

Don't kill yourself to attempt to set the gauge at exactly .100" or .200" preloaded. The rotating outside ring is designed to reset zero just for this purpose.

when you set up a dial gauge, as your instructions stated you need a preload, so the gauge is actually pressing on the valve( the needle moves in the guage, but less than 3mm). Then you move the cover so the needle reads 0. It sounds like you are hitting something, or the valve travel is out not touching the gauge.

__________________
83 300SD Dark Silver Dark brown inside

You need a 2" or greater needle to do this properly. The 1" is too short (but what I used).

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1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
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#1995 E320 Touring
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OBK #42

I am going to look for a 2 inch gauge this morning...

But, once I get a 'preload' - anywhere less than 3mm - I reset the needle to 0 by turning the gauge around, right? Then when do I know the valve has traveled 2mm?

I tried the preload and the needle went around counter clockwise - needless to say - I'm not getting this...!

ryan

__________________
RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE

When the gauge is reset to zero and the valve begins to move, the needle will start to rotate (should be counter-clockwise). 2mm is .080". Stop and read the crankshaft numbers when the pointer moves by .080" (needle should be pointing at "20")

The needle on the dial indicator should indicte a 2mm difference from the original "zero" setting.

BY GOLLY - I THINK I GOT IT!

I have finally got it - measured it several times (following the excellent advice from this forum) and I am measuring 15 degrees stretch on the crankshaft. If you compare that to specs for my engine - 617.912, camshaft code 08 (13.5 degrees of stretch after 20,000k) - I am only showing 1.5 degrees of chain stretch!

Measuring it the other way - lining up cam marks (which I have done numerous times) - I showed anywhere from 3-5.5 degrees of stretch.

I suppose I could be off a little with the 2mm method - only used 1 inch travel dial gauge, so it wasn't EXACTLY perpendicular - but I think I was pretty close. I am assuming I should go with the 2mm lift results...

If so, I think I will leave the chain alone...

Again, thanks for the help!

ryan

__________________
RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE

where I thought I had "things figured out"... Been gone overseas last semester so I really haven't had time to do any follow-up. Got back last month and I have really hard cold starts - car just refuses to fire if even below 30 F. Started looking at the injection pump because I had adjusted it last summer, but I thought I would check out the timing chain again - just to be sure and I also recently picked up a 2 inch dial gauge. Read up again on the procedure and just got done. I am showing the same 3 degrees stretch when I use the "line up the marks" method, but I getting 8-9 degrees stretch when I use the 2mm lift method. I have quadruple checked all measurements - my 2 inch dial gauge sure makes it easier and I have followed the technique "to the letter". I get 22 degree ATDC on the gauge and then I subtract the FSM stretch of 13.5 degrees...for an 8.5 stretch.

I know why last time I didn't get 9 degrees stretch using the dial gauge - I was stopping the gauge at the .08 mark and not the .02 mark - which I figured out after re-reading the FSM and the DIY on this page.

Anyway, why the big difference? Most of what I have read has indicated that these 2 approaches should be similar...

Again, I have done each a dozen times - checking and rechecking everything - and I am getting consistent results!

ryan

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RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE

You must be doing something wrong. One of our forum members was taking polls from everyone (including me) who had tried both methods and the readings were spot on for every single person. It should not be that far off.

Are you remembering to look at the cam code to make sure you are using the right chart? Is the dial gauge perfectly vertical?

Scott

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Scott
1982 Mercedes 240D, 4 speed, 275,000
1988 Porsche 944 Turbo S (70,000)
1987 Porsche 911 Coupe 109,000 (sold)
1998 Mercedes E300 TurboDiesel 147,000 (sold)
1985 Mercedes 300D 227,000 (totaled by inattentive driver with no insurance!)
1997 Mercedes E300 Diesel 236,000 (sold)
1995 Ducati 900SS (sold)
1987 VW Jetta GLI 157,000 (sold)
1986 Camaro 125,000 (sold - P.O.S.)
1977 Corvette L82 125,000 (sold)
1965 Pontiac GTO 15,000 restored (sold)

It's a '78 300D, Engine 617.912 - cam code 08. Dial gauge is about as vertical as I can get it - perfectly vertical is not possible.

I have read, and re-read and checked and double-checked...

ryan

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RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE

If you read post #9, he indicates to stop rotating engine when the pointer gets to .08, while the DIY article says to rotate engine until needle turns CCW to .02.

Which is right?

ryan

__________________
RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE