Mercedes-Benz Forum banner

1 - 7 of 7 Posts

·
Registered
1988 560SEL
Joined
·
18 Posts
Discussion Starter #1
G'day
2614011

I took off the right valve cover to inspect the chain, tensioner, guides and cam oilers. All appears to be fine. But I need to replace the valve stem seals because of smoking issues. I decided to change the chain, tensioner, guides and cam oilers at the same time. I made a video of the inspection: https://youtu.be/1kn-kRE5dv4
The car has travelled appr. 330k kms. I can not find any reference to a previous chain replacement in the books.
Looking a the cam lobes, I see some parallel line discoloration. The surface of the lobes is mirror smooth with no pitting or grooves. Should I be concerned? Thank you for your input.

Cheers
 

·
Registered
1990 420 SEC
Joined
·
157 Posts
To me that cam looks fine. There is the other cam too. On my cars 116 engine just one cam lobe shows scratches. That is on the left had side. There is not much one could do to help the situation except replace it as it gets noisy.
Maybe timing mark offset on right hand cam tells how much stretch there is in the chain. On the other hand the manual does not tell to set timing with offset keys based on the timing marks. If you find a chain link with circlips the chain surely has been replaced. Some suggest to bed the chain sideways to check how much it has been worn. On the other hand if the chain will be replaced who cares if it already has been replaced some time. A lot easier and cheaper to replace the chain than crank shaft sprocket and cam sprockets.
 

·
Outstanding Contributor
450slc5.0cab 280sl5sp 280se4.5 500seAMG +250seStkW108 350sl4spdX3 500secEuro
Joined
·
22,160 Posts
Not much to see in the video. All I can see is that your oiler tubes aren’t falling out.

27mm socket on the crankshaft pulley, and rotate clockwise, righty tighty. Bring the camshaft timing marks into alignment for each of the camshafts. Wrote down where you are on the harmonic balancer. Do this multiple times, as a single reading is never reliable.if your stretch on the passenger (right, or left when looking at the engine from the front of the car) is more than 5 degrees ATDC on the harmonic balancer, then the chain has enough stretch to replace it. I’m cheap and never in a rush. So I do parts one at a time to see the effect of each. First do the chain. Roll it in. By the time you start rolling it in, you are nearly done. Typically the camshaft sprockets hope next, but in some cases, if there’s no obvious wear, and the timing is lined up after replacing the chain, I don’t replace the sprockets. The sprockets are easy too though. Since guides and oiler tube connections are cheap, those should get done while you have it open. Your guides are getting brown, and show they’ve been in there a while. They are probably the most difficult part because the pins can stick. A puller or a correct size nut bolt and washers are required. The puller is cheap and easy though, and definitely recommended. Finally, the tensioner and valve cover gaskets are the controversial parts that need to be inspected to see if they need to be replaced. If there’s slip in your chain on the tensioner side, it definitely needs replacement. It’s the most expensive item.
 

·
Registered
1988 560SEL
Joined
·
18 Posts
Discussion Starter #4
Thanks Heikkif and Fonzi for your helpful posts. I have already purchased a guide pin puller on eBay. I just came back from a Family reunion in Germany and managed to get all the bits very cheap (minus 19% Goods and Services Tax) while over there. I will do all the work when the next service is due in April.

Although the cam lobes look good to me also, I just wonder what these light brown parallel stripes are on the otherwise mirror smooth surface.

This is the puller I purchased

2614086
 

·
Registered
1988 Mercedes 500 sec
Joined
·
443 Posts
hoping to do this in the near future how many guide pins are there, is the tool essential and will it pull out all the guide pins
 

·
Registered
1990 420 SEC
Joined
·
157 Posts
There are 6 pins to be pulled out when replacing upper chain guides which can be replaced without removing chain cover. That kind of tool pulls the pins nicely. People say it is possible to pull the pins with a sliding hammer or just a long 6 mm screw, a nut and a socket or a piece of steel tube. The screw goes trough the socket or the tube.
 

·
Registered
1991 420 SEL
Joined
·
136 Posts
I think for the $35 or so I spent on that tool it was worth it.

Also, here's a little cut and paste from a previous post:

"The timing tensioner guide rail (the 'banana') pin, the pin that holds it in place - isn't threaded and isn't obvious. After some minor panic I read here and elsewhere that there's a little hollow pin under a plug. Did I say it's not threaded? You have to stick something through it and catch the edge of it, then pull it out. Apparently the manual calls for a 'cant bolt' - but I couldn't find one :doh:

What worked on this clean vehicle - I took a 16 penny common nail and ground the head down a little to fit. If it hangs up going in, don't force it, I suggest grinding it down a little more, just in case it doesn't work you'll want to be able to remove it! Then bend the last 3/4" or so of the pointy end at a 90 to have something to pull on."

This worked for me.

Good luck.

Pete
 
1 - 7 of 7 Posts
Top