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Valve Adjustment time!
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Posted 10/1/2006 4:27 PM
Dieselburns
Expert




Date registered: May 2006
Location: New York, Long Island
Vehicle(s): 78' MB 300D 87 Chief Cherokee
Posts: 2251
2000
Valve Adjustment time!

Well finally I get some time off so I can work on Charlie Brown. I got most the tools I need to do this procedure. I was wondering if you diesel guys have and tricks on doing a valve adjustment on a non turbo diesel engine? My step dad has a wierd way of doing a valve adjustment on a diesel engine, thats just keep geting me confoosed... Any help would be appreciated.

Any way im also polishing the valve cover and sanding down the air filter housing so I can spray paint it black. I want Charlie Brown run as smooth as a cadillac!


#46713
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Posted 10/2/2006 10:27 AM
BenzDieselTuner

Date registered: Dec 1899
Location:
Vehicle(s):
Re: Valve Adjustment time!

having the wrenches helps alot........
#46814 - in reply to #46713
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Posted 10/2/2006 3:12 PM
Dieselburns
Expert




Date registered: May 2006
Location: New York, Long Island
Vehicle(s): 78' MB 300D 87 Chief Cherokee
Posts: 2251
2000
Re: Valve Adjustment time!

Yea I notice that!

What a bitch it is!!!

Do any of you know where I can get them besides buying them of line, bec Ive tried a lot of hardware stores and pepboys and they dont have them!
#46839 - in reply to #46814
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Posted 10/2/2006 10:40 PM
iNeon

Date registered: Dec 1899
Location:
Vehicle(s):
Re: Valve Adjustment time!

I got a set from mercedes source and they were homemade, I don't recommend it-- The factory tools were 90, theirs were 70.

They're for sale if you want them
#46912 - in reply to #46839
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Posted 10/3/2006 7:43 PM
Dieselburns
Expert




Date registered: May 2006
Location: New York, Long Island
Vehicle(s): 78' MB 300D 87 Chief Cherokee
Posts: 2251
2000
Re: Valve Adjustment time!

4 days and Im done! I know I took a while, but I was busy. So today I put everything together when I got back from work, Turn the key and the car started just fine. I cehck for leaks and all was fine. I took a test drive and man things got better. Though I have a feeling that I didnt tight the lock nutz tight enough so Im kind of worried... Anyway when i came home after my test drive I turn the key to the shut off position, and here we go again my car didnt shut off... sigh* so I check all the lines but it was getting dark and im tired. So tomarow I will check to make sure all the vacuum lines are conected where they supposed to be...

You should see how many scratch marks I have on my arms for adjusting valves with regular wrenches, it was a bitch...
#47018 - in reply to #46912
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Posted 10/4/2006 11:33 AM
BenzDieselTuner

Date registered: Dec 1899
Location:
Vehicle(s):
Re: Valve Adjustment time!

damm, at least u got it all done......i need to do mine, but iv been putting it off......

at least i have the wrenches....
#47136 - in reply to #46713
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Posted 10/9/2006 4:46 PM
TheDon

Date registered: Dec 1899
Location:
Vehicle(s):
Re: Valve Adjustment time!

i need to make some custom wrenches.. the bent ones suck .. you cant get minute adjustments.. for example i was hung up on intake #3 for 30 minutes because the wrench would not go onto the nut, i tried everything minus small pliers which i did not have.. so im making two stubby wrenches for adjusting then use the bent ones to tighten everything up
#47946 - in reply to #46713
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Posted 10/10/2006 1:50 AM
BenzDieselTuner

Date registered: Dec 1899
Location:
Vehicle(s):
Re: Valve Adjustment time!

cool
#47986 - in reply to #46713
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Posted 12/14/2006 4:21 PM
hipine



Date registered: Jul 2006
Location: US, CO, Bailey
Vehicle(s): 460 1980 280GE w. 617A
5000
RE: Valve Adjustment time!

Sorry to dig up an old thread, but this is my first look at this forum and I thought I might have something to add here.

1- Do the adjustment with the engine at operating temperature.  This is a lot more "consistent" set of conditions than doing it when everything's cold.  You don't need to get near any "hot" parts anyway, so it's not a big deal.  The operating temp specs on my 617a are 0.15mm intake and 0.40mm exhaust.

2- Go slow when bumping the engine to position.  Use a remote starter switch so you can make small pulses to the engine with the starter and wait for it to stop bleeding compression (you hear a little hisss) before you bump again.  Use this technique to get the cam lobe pointing STRAIGHT at the oil pipe a-top the cam towers to be sure you're completely in the base circle of the cam.

3- Use a "go/no-go" approach.  Make sure that for each valve the spec gauge is a "go" - can be slid between the rocker face and cam lobe, preferably with a little "drag" - and that the next size up (0.20 intake 0.45 exh at 617a op temp) is a "no-go" - doesn't go into the gap at all.  My normal way of lashing valves is to "feel" the drag on the feeler gauge and set all valves to an even drag.  But I find that access to the gaps on the 617a engine is a little tricky and interferes with my confidence in my ability to feel small differences.  So I fell back to the method I use on my Honda motorcycles where access is restricted - go/no-go.  At least this way there's an upper boundry on the gap.

4- Use the right tools.  With the wrenches I got from Performance Products, the job was a breeze.  Didn't take me any longer than it used to on my 280, and that one didn't even have lock nuts!  I think a GOOD set of tools makes a big difference, as well as nuts that aren't buggered up from being exposed to short-cut methods and tools.  The most important tool of all for a speedy, consistent adjustment is the one that holds the retainer while you adjust the nuts.  If you don't have that, the valve stem turns and you don't get consistent adjustments from turning the nuts.  If the nuts are badly beat up, consider replacing them.

5- Be patient and persistent.  I was amazed at the difference in idle and running smoothness that was made by getting the valve lash closer to exactly the same on all cylinders on my 617a.  So much so that I'm going to go in there again as soon as the weather warms up and try to get it REALLY good. 

Anyway, that's my limited experience.

#56711 - in reply to #46713
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Posted 12/15/2006 1:30 PM
Bruce280
Veteran




Date registered: Nov 2006
Location: Athens, AL
Vehicle(s): 83 280GE, 81 300GD
Posts: 138
100
RE: Valve Adjustment time!

Nice write-up, Dave, and timely advice. I'm about to attempt my first valve adjustment this weekend.
#56783 - in reply to #46713
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Posted 12/17/2006 1:03 PM
hipine



Date registered: Jul 2006
Location: US, CO, Bailey
Vehicle(s): 460 1980 280GE w. 617A
5000
RE: Valve Adjustment time!

Well, I took another crack at the valves yesterday with good results - a noticably even smoother running engine at idle and running, as well as a little bit better power and response.  I did a couple things differently over last week's adjustment.

1- I ran the motor up to full operating temperature before starting the adjustment.  That meant not just getting the water temp up to 190*F but also letting the oil temp and oil cooler go through a full cycle.  My oil temp gauge (sensor near the turbo oil outlet at the back of the oil filter housing) says that the temp rises to a max of 180*F before the thermostatic element opens the cooler line, and then is cooled to 140*F before it starts to rise again.  So figuring that the valve gear takes as much of it's temp from oil as water (maybe more), I let the oil temp go up to 180, down to 140, and start coming up again.  In yesterday's 50*F ambient temps, that took a good 25 minutes of driving.

2- I used English feeler gauges instead of Metric ones.  I was thinking about this a little and decided that if I was going to use the go/no-go method, that I'd like the bracketing values to be as close together as possible.  Metric feeler gauges (at least the ones I have) come in increments of 0.05mm.  They go like, 0.10, 0.15, 0.20, 0.25, etc.  If you do the conversion to English measurements, the equivalents are approximately 0.004", 0.006, 0.008, 0.010, etc.  English feller gauges however are in 0.001" increments.  Roughly 1/2  the step size of the metric ones.  So, since the metric valve lash spec for warm intake valves is 0.15mm, I did the conversion 0.15 x 0.03937, came up with 0.00591 and got myself 0.005 and 0.006" feeler gauges to use as go and no-go for the intakes.  Doing the same with 0.40 yields 0.01575 so I grabbed 0.015 and 0.016 feeler gauges to use as go and no-go for the exhaust.  Knowing that my actual target value was close to the no-go gauge, I then made sure that for each valve the "go" gauge was an easy loose fit, but the no-go gauge did not even start into the gap. 

The number junkies here (and I'm the king of those, I think!) will notice that we could shoot for an ultra-precision gap by using the metric gauge (.00591) as the "go" and the english (.00600) as the no-go.  And just for grins, I might actually try that some time.  But I'm not sure I have the patience to try and hit a target that's 90 MILLIONTHS of an inch wide using a couple jam nuts!

The result of what I DID do yesterday was a nice, smooth running engine at idle and at speed, and even running at a little bit lower exhaust temps for a given situation because the engine was operating more efficiently, getting more power from less fuel at any given time.  In theory, it should help with easier cold starts too, but I'll have to wait till 6 am tomorrow, when it'll be about 5*F ambient to try that.

All the best,

-Dave G.



Edited by hipine 12/17/2006 1:08 PM
#56927 - in reply to #56783
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Posted 12/19/2006 4:40 AM
ForcedInduction
Regular




Date registered: Sep 2006
Location: Federal Heights, CO
Vehicle(s): 1980 240D 3.0VNT
Posts: 89
50
RE: Valve Adjustment time!

hipine - 12/16/2006 11:03 PM

1- I ran the motor up to full operating temperature before starting the adjustment. That meant not just getting the water temp up to 190*F but also letting the oil temp and oil cooler go through a full cycle. My oil temp gauge (sensor near the turbo oil outlet at the back of the oil filter housing) says that the temp rises to a max of 180*F before the thermostatic element opens the cooler line, and then is cooled to 140*F before it starts to rise again. So figuring that the valve gear takes as much of it's temp from oil as water (maybe more), I let the oil temp go up to 180, down to 140, and start coming up again. In yesterday's 50*F ambient temps, that took a good 25 minutes of driving.

 

Valve adjustments are supposed to be done with the engine cold. 

#57109 - in reply to #56927
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Posted 12/24/2006 9:34 PM
guage



Date registered: May 2006
Location: RIGHT OF THE LEFT
Vehicle(s):
100
RE: Valve Adjustment time!

I wonder why the manual gives specs for a warm motor also?
I also like to use the second red arrow to measure/size the gap.Because the rocker arm is spring loaded and
has constant pressure against the cam lobes.

Edited by guage 12/24/2006 9:55 PM




(cam position for measuring #2.JPG)



Attachments
----------------
Attachments cam position for measuring #2.JPG (32KB - 2 downloads)
#57592 - in reply to #46713
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Posted 12/25/2006 7:21 AM
ForcedInduction
Regular




Date registered: Sep 2006
Location: Federal Heights, CO
Vehicle(s): 1980 240D 3.0VNT
Posts: 89
50
RE: Valve Adjustment time!

guage - 12/25/2006 7:34 PM I wonder why the manual gives specs for a warm motor also?

 

Because they figured somebody would try to do it on a warm engine so they planned ahead insted of issuing a TSB or letting mechanics guess.

 

 Doing it with a cold engine gives more accurate results because everything is the same temperature. It may only take 30 minutes to do a valve adjustment, but by that time the valves have cooled significantly and the gaps can be slightly different from when you started.

#57612 - in reply to #57592
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Posted 1/1/2007 11:34 PM
hipine



Date registered: Jul 2006
Location: US, CO, Bailey
Vehicle(s): 460 1980 280GE w. 617A
5000
RE: Valve Adjustment time!

ForcedInduction - 12/25/2006 5:21 AM....It may only take 30 minutes to do a valve adjustment, but by that time the valves have cooled significantly and the gaps can be slightly different from when you started.

 

I wondered about that too, so I re-checked #1 after I'd gone through 1-5. After finishing the setting as above, #1 still passed the go/no-go test. For me the recommendation came froma trusted MB mechanic with 30 yearson the joba nd 20 owning his own MB specific shop, but the proof was in the pudding. A better running engine when set warm than when set cold. But of course, YMMV. The best way is to DIY and see for one's self.  

Of course, the caveat has to be given that, as evidenced by the specs (wider for warm engine than cold) the gaps do close up when the engine is colder and open when it's warm (the aluminum cam towers grow in length faster than the steel valves do as they heat up), so setting cold is the best way to guard against the possibility of gaps closing up too far if you accidentally set them wrong.  It's not unheard of to set an exhaust valve to intake specs by accident and end up burning it.  The chance of causing trouble in this way is a little less if the gaps are set with the engine cold. 

Be careful out there!

-Dave G.

#58142 - in reply to #57612
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Posted 1/3/2007 1:36 AM
ForcedInduction
Regular




Date registered: Sep 2006
Location: Federal Heights, CO
Vehicle(s): 1980 240D 3.0VNT
Posts: 89
50
RE: Valve Adjustment time!

If it works well for you, then more power to you. I might try my next adjustment warm to see if there is much difference.
#58281 - in reply to #46713
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Posted 1/4/2007 4:50 AM
DesertStar
Expert




Date registered: Apr 2006
Location: San Diego, CA USA
Vehicle(s): 85-280GE/95-G320/08-G500
Posts: 2156
2000
Re: Valve Adjustment time!

TheDon - 10/9/2006 1:46 PM

i need to make some custom wrenches.. the bent ones suck .. you cant get minute adjustments.. for example i was hung up on intake #3 for 30 minutes because the wrench would not go onto the nut, i tried everything minus small pliers which i did not have.. so im making two stubby wrenches for adjusting then use the bent ones to tighten everything up


If you end up making your own, watch for when you bend that the chrome plating doesnt chip(at the bend). You dont want small pieces of metal falling in your valve train. Mine did (flaked) so I just wrapped that portion of the wrench with electrical tape.
Mike
#58384 - in reply to #47946
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Posted 1/9/2007 4:25 PM
VWBusMan1

Date registered: Dec 1899
Location:
Vehicle(s):
Re: Valve Adjustment time!

Hey guys I really appreciate the tips as I plan to do the next one myself. Just paid $240 for a valve adjust on my 300CD at 2.5 shop hours. Did I get hosed or is that about the going rate?

Anyway, I suspect once I start doing it it will only get easier.

Happy trails, Mark
#58949 - in reply to #46713
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Posted 1/10/2007 11:49 AM
BenzDieselTuner

Date registered: Dec 1899
Location:
Vehicle(s):
Re: Valve Adjustment time!

that is unfortunately the going rate for a valve adjust....
#59021 - in reply to #46713
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