Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help




Go Back   PeachParts Mercedes ShopForum > Technical Information and Support > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #16  
Old 01-27-2003, 02:43 PM
Registered User
 
Join Date: Oct 2002
Location: Vanersborg, Sweden
Posts: 99
Hello friends,

Thank You again for all Your really good help and all the advices. I cant thank You enough and I really appreciate it.

I ordered new rails, a tensioner and a new chain earlier today. The rails were cheap but the chain was about 120 USD and the tensioner about 190 USD. Probably because the sales tax here in Sweden is 25%. Anyway, I thought it probably be well spent money if it cures my car.

Some of the stuff needs to be sent after from Germany so I probably have to wait until this weekend before I can get busy with the fixes.

Im thinking of borowing a fiberoptic setup the have a look through the spark plug holes at the pistons for any signs of contact between the valves and the pistons. It probably works great as well to see when the number 1 piston is at TDC so that I can determine if the harmonic damper is out of alignment.

One thing that I wanted to ask about is if there is any good way of checking if the tensioner is OK or not? The reason is ofcourse if I should try to save the 190 USD.Also I would like to ask how this Mercedes tensioner works. All the other tensioners that I have seen, be they mechanical or hydraulical, they only elongate and never retract. But when I rotated this engine by hand I could clearly see that when i started to put load the wrench the tensioner elongated with about 1 1/2 inch and when I released the pressure it retracted by the same amount. I might be completely wrong here but wouldnt that mean that everytime You start the car, and until the oil pressure builds, You would have a lot of slack causing the chain to slap the rails?

Well, I guess that was all for now. Ill let You all know how it goes with my replacement and the fiberoptic inspection.

Thanks again,

Mikael
Reply With Quote
  #17  
Old 01-27-2003, 04:23 PM
Registered User
 
Join Date: Oct 2002
Location: Colorado Springs
Posts: 481
Tensioner

Michael Your tensioner is bad. The tensioner should hold pressure so you do not have slack when you start the car. The fact that there is slack could be what has caused your problem to start with. The clattering sound on startup is the first sign you need a new tensioner. By the way those prices are high a new febi tensioner is @us$60 and a chain is US$80
Good luck this weekend.
m
__________________
Martin Ingram
Colorado Springs
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)
Reply With Quote
  #18  
Old 02-05-2003, 12:23 PM
Registered User
 
Join Date: Oct 2002
Location: Vanersborg, Sweden
Posts: 99
Hello again Friends,

Let me tell You that standing outside when its below freezing, snow is falling and wind is blowing, changing cam chain tensioner and all the rails, is not what I would recomend as recreational fun. Anyway, most of it is behind me now.

I changed all the parts and following the hints and help I got from the list earlier it was no big deal except for some fasteners that was rather stuck. I also checked that the crank timing was at 0 degrees when No 1 cylinder was at TDC to eliminate that possibility of error. Also I found that 2 of the rails were broken instead of 1 as I wrote earlier.

Finally when I got it together enough, I rechecked the timing between the crank and the cams. Now the 2 timing marks on LH and RH cam align exactly at the same time but the crank is still at 14 - 15 degrees.

My assumption from this is that I should change the timing of the cams by 1 tooth which would give me a timing change of 20 degrees between the cams and the crank (there is 36 teeths on each cam i.e 10 degrees betweeb each. The difference of 5 degrees is probably because the chain is not so much stretched when I rotate it by hand as it will be when the engine is running.

Now this is me guessing and I was hoping for input from all of You if my guesswork is correct or not.

As soon as I have Your input, I hope that my next tread will be that of a smooth running engine and no tapping noise. I will ofcourse run a compression check as soon as i got the covers on but Im waiting with that until Im sure that I got everything timed and togheter.

Many, many thanks to all of You.

Mikael Westerberg
1984 500 SEL
Vanersborg, Sweden
Reply With Quote
  #19  
Old 02-05-2003, 12:55 PM
Super Moderator
 
Join Date: Apr 2000
Location: Falls Church, VA
Posts: 5,316
To get everything to line up, the chain needs to have its slack on the right side where it would be taken up by the tensioner if the engine was running. It needs to be tight between the right and left sprockets.

If you have everything positioned like this and you are still off, then try repositioning the sprockets to get the marks to line up. Turn the engine over a couple of turn by hand to verify that you are not having any piston-valve contact.

Then crank the engine for a few seconds with the coil wire unplugged. You should build up oil pressure in the tensioner, and the chain will tighten. Do one final check of the cam marks - you should be dead/spot/right on at TDC and good to go.
__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe
Reply With Quote
  #20  
Old 02-06-2003, 07:15 PM
hoggy
Guest
 
Posts: n/a
Chain rails

Mikael

I thought I was lucky. changed the chain rails last weekend, not too hard a job if you follow the procedure from the link you have been given, the only thing I would add to the procedure is a 6mm bottom tap for cleaning the threads out in the pivot pins, before you insert the puller, I made a small slide hammer which made the job a bit quicker. I also had two broken chain guides and the bits no where to be seen, chain stretch is about 10 degrees with the new guides ( not 28 like yours ) but will be changing the chain and tensioner anyway, my car (500se) has done very similar mileage to yours and I also needed to change the valve stem seals, this can also be done with very little expense and without taking the heads off, Im actually looking forward to doing the chain job, the thought of a six foot long chain emerging from the depths of the timing case while the new one is being fed in really tickles my fancy ( Im a mechanical nut )

Good luck
Reply With Quote
  #21  
Old 02-10-2003, 01:43 PM
Registered User
 
Join Date: Oct 2002
Location: Vanersborg, Sweden
Posts: 99
Hi again,

I now have everything back togheter. New cam chain, new chain tensioner and new rails. As I wrote earlier the new parts took me back from 27 - 28 degrees of stretch/ wear to about 15. Following the advices I also changed the timing by one tooth putting the timing on 5 degrees before TDC and with some cranking to pressurize the tensioner I was at 2 -3 degrees before TDC.

Now, I did double and triple check the timing marks everywere but when I started the car the noise was terrible and it was running very poorly. Took it apart again and changed one tooth back and voila now it is running like before.

I dont think anything was damaged because of the one tooth change and I have been running the car today. The slight stumble at idle seem to be somewhat better and the performance is noticeably better. I still have the tapping noise but Im not terrified by anymore as I were when i saw the 27 - 28 degree stretch the first time.

Now the strange thing about all this is that for some reason the timing marks on the cams cant be right - can it? I did check that the crank timing was at 0 degrees when the No1 cylinder were at TDC. And with everything lined up according to the advices the car did hardly run.

My assumtions is that the timing marks on the cam must be off for some reason. I havent yet made the compression check to see if something was damaged in the process but will do so. I also think I read somewere that the no1 intake valve should start to open 12 degrees after TDC which should be quite easy to check.

Any thought on this?

Best regards,

Mikael
Reply With Quote
  #22  
Old 02-10-2003, 02:52 PM
Super Moderator
 
Join Date: Apr 2000
Location: Falls Church, VA
Posts: 5,316
To be sure of the basics:

- The notches on the thrust washers lined up with the marks on the cam towers.

- The little "0|0" mark on the balancer under the pointer.

- The chain tensioned fully, no slack between the sprockets.

Under these conditions, mine lined up perfectly with the new chain.
__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe
Reply With Quote
  #23  
Old 02-10-2003, 05:42 PM
Thomaspin's Avatar
pindelski.com
 
Join Date: Jun 2001
Location: CA
Posts: 531
Are you sure the Woodruff keys have no offset?

Mikaelw - when you had the cam gears removed, did you check that the Woodruff keys which locate in the slot on the cam shaft and on the gear wheel are straight?

MB sells them in various offsets up to 10 degrees and it's possible a previous owner/mechanic compensated for bad timing by installing offset keys. Offset can be positive or negative, depending how you install these.

With a new chain and tensioner, you should be using straight keys on both cams, not dog-legged ones. Offset keys would continue to return a timing error.
Reply With Quote
  #24  
Old 02-11-2003, 03:31 PM
Registered User
 
Join Date: Oct 2002
Location: Vanersborg, Sweden
Posts: 99
Hi again,

Heres the things that I checked after I had the new parts installed:

1) Cam alignment: Both cams align very nicely with their respective marks on the thrust washer. There is no visual difference between when they align but they both align at the same time.

2) Crank alignment: I checked that the timing mark on the crank (harmonic damper) shows O when when the No1 piston is at TDC.

3) New tensioner was installed and I cranked the engine for about 5 seconds to pressurize it.

4) As far as I could see the Woodruff keys were straight (I did not remove them for inspection but looked at them in place and there was nothing suggesting that they were of the offset type.

At this point I did check the crank to cam alignment and when the cams aligned with their respective tower the crank was at 2-3 degrees before TDC. I had rotated the engine by hand several times to make sure that there were no contact between the valves and the pistons.

I thought everything looked fine and put the rocker covers etc back on and fired the engine up. There was a terrible noise as if I ran a couple of valves in the pistons and the engine was running very poorly.

At this point I realized that things were not quite OK so I took the rocker covers of and moved back the cams one tooth each. This were how everything lined up after I changed the tensioner, rails and the chain. At this point the crank (harmonic damper) showed 15 degrees after TDC when the cams were aligned with the marks on the tower. My fear at this moment was that I damaged some valves but thoght that I now was in the middle of how the car was before I took it apart and how it was moments before when I started it.

Therefore I put the rocker covers and all other parts back on
and started it up. It now ran as it did before I changed all the parts. I drove it to work yesterday and today and it runs slightly better than before. The idle is still a bit uneven at times and the response is noticeably better (not sigificatly better). I still have the tapping/ knocking noise which doesnt get better or worse at different rpms or load conditions. If I run the engine and pull one by one of the ignition cables off there is no change to the tapping. This makes me think that one of the hydraulic elements need replacement

My conclusion is that it must be something wrong with the timing marks on the cams or everything should have been fine the first time I started the car up after the parts replacement. I dont know if that is possible or if there is something in the process that I overlooked.

This is why I wonder at what number of crank degrees the intake valve should start to open. If I understood the valve timing procedure correctly the degrees should be checked at 2 mm of intake valve lift but Im not sure what the reading of the crank should be?

Or is there a smarter way of confirming if the cam timing marks are correct.

Any and all hints are appreciated.

Thanks/ Mikael
Reply With Quote
  #25  
Old 02-11-2003, 04:04 PM
Registered User
 
Join Date: Oct 2002
Location: Colorado Springs
Posts: 481
Michael,
i sent you the pdf for checking the valve openings and timing information. I would check make sure those match up with your engin and specific cams.
m
__________________
Martin Ingram
Colorado Springs
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)
Reply With Quote
  #26  
Old 02-11-2003, 08:39 PM
Super Moderator
 
Join Date: Apr 2000
Location: Falls Church, VA
Posts: 5,316
OK, I realize that this suggestion is far-fetched, but Mikael's last report has bothered me and I am really stretching for a reasonable explanation.

Assuming that there are no offset keys in the cam(s).

All I can come up with is that the distributor drive gear may be off a tooth. This is the gear right below the left cylinder head. When it is installed, or the chain changed, it needs to be lined up to a mark in the crankcase. This is to allow the distributor to be set relative to #1 TDC. With the cams correctly set relative to TDC, which was a CHANGE from the way it was before, the ignition timing was changed relative to the valve opening and started firing with either the exhaust or intake valve open when the car was started.

The result is a lot of noise and a poorly running engine. Mikael sets the cam timing back and thus restores the ignition timing relative to the valves which makes the engine run better. By some miracle, in the current position, the valves are not hitting the pistons.

I am not suggesting that you pull the front cover off to check this, but take a look at where the firing point is with the cams and crank in closest agreement - the way you had it before.

All I can think of other than some wierdness like a wrong part somewhere in the valve train.

Offered almost apologetically.
__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe
Reply With Quote
  #27  
Old 02-12-2003, 03:11 PM
Registered User
 
Join Date: Oct 2002
Location: Vanersborg, Sweden
Posts: 99
Hi Martin & Chuck,

I really appreciate Your help. If You ever come to Sweden, by all means, look me up and let me buy You a cold one and start the barbecue for with a couple of nice T-bones on it.

The only reason why I did not check the valve timing as per the specs that Martin provided me is that I dont have the valve adjusting screw No# 116 050 11 20 and I didnt think I would get correct readings doing the check without that. I kind of hoped that by miracle there would be an easy check for me with the available tools.

Anyway, since I suspect that one of the hydraulic compensators is damaged but havent found which one yet(causing my tapping noise, I guess I better bite the bullet and head down to the dealer tomorrow and buy the valve adjusting screw to be able to check the timing properly and get some leads on this.

Ill get back again as soon as I have had a good chance to look at this.

Please remember - if ever in Sweden!!

Thanks again/ Mikael
Reply With Quote
  #28  
Old 03-18-2003, 06:59 PM
hoggy
Guest
 
Posts: n/a
Tapping Noise

Mikael

Did you manage to cure the tapping noise and if so how did you track down the offending hydraulic unit. I still have the same problem after replacing the chain, guides, tensioner and many attempts at isolating the hydraulic unit thats making the din.
Reply With Quote
  #29  
Old 03-21-2003, 02:08 PM
Registered User
 
Join Date: Oct 2002
Location: Vanersborg, Sweden
Posts: 99
Hi Hoggy,

Im afraid i didnt track down the tapping noise origin yet. After I changed the tensioner and the rails and the chain the noise was still the same. Im waiting for spring time to set in at the moment so that its more comfortable to work outside. Once its warm outside I will take my Jag out and spend some time with finding the source of the noise. I have been listening a lot with my stetoscope and Im pretty sure that the noise comes from one of the 4 front hydraulic compensators on the passenger side cylinder bank.

Ill get back with more info.

Cheers/ Mikael
Reply With Quote
  #30  
Old 03-23-2003, 06:27 PM
hoggy
Guest
 
Posts: n/a
Tappet Noise

I finally tracked down the noise on my car, not good news, I made a partial valve cover so I could run the engine and isolate the valve set making the noise. You need this as the engine pumps an amazing amount of oil to the heads and this ends up all over the floor. The valve set in question is number 1 exhaust but could not stop the noise no matter what I did, I eventually removed the rocker arm and the valve springs and pushed a piece of hose over the valve stem so that I could lift it up and down and found that the noise is coming from the valve making contact with the valve seat. This could mean two things
1. The exhaust valve is slightly bent.
2. I think the most likely The valve seat is loose in the head.

So Im in for a heads off job to rectify it, not really looking forward to that and it looks like I will have to purchase some special tools to do the job. I have been through the hydraulic lifters a good number of times now, so if you have a problem with them let us
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 10:20 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page