When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
My water pump took a crap and I also noticed what appeared to be an oil leak on the timing chain cover I decided what the hell since I am draining the coolant anyway lets fix the oil leak.
To my surprise 189k on the clock my camshaft sprocket is missing teeth and my chain is stretched.. Now the expense of the chain and tensioner isn't bad but OMFG $500 for a 1 sprocket?
I've looked on FCP, Pelican and AutohausAZ which is the cheapest out of all of them. Does anyone know of another place I can perhaps purchase both sprockets without breaking the bank? Also the the exhaust side is fine it's just the intake. Would it be wise to just replace both? the Intake is the one with missing teeth...
Items have been ordered now waiting on them to arrive with the exception of the actuators which I'n going to order both. I've been scavenging the internet and seems like some of the guys in SLK forum have found 2 companies that actually make them and have been holding up fine for a few years.
So far total cost
1. AutohausAZ Order
Febi Bilstein Camshaft Adjuster Magnet Seal - 0109972348
Febi Bilstein Timing Chain Kit - 44974
Victor Reinz Timing Cover Oil Seal - 0299973248
$195 to the door
2. FCPEuro Order Mercedes Valve Cover Gasket - Reinz 2710160921 Mercedes Chemical Gasket Maker - Genuine Mercedes 003989982010
$64 to the door
I remember reading about a company from South Africa that makes decent aftermarket sprockets with a much harder material. Might be in the giant timing chain thread.
I actually found him through a SLK forum its merc271.com he sells the sprockets only and I would need to use my original core. There's another they mention CSR Tech Berlin which cost about the same as merc271 but it's complete.
I've tried to contacting both and Merc271 has been the most responsive.
Once I decide which route and receive everything i'll update.
Side note I did order some INA Hydraulic Lifter Tappets Rockers so i'll swap those out as well. It's one of those things since i'm in there...
Something to add to the list of required items is a 27mm Deep Socket in order to remove the camshaft sprockets.
At this point I have removed the sprockets and broken the chain in addition I have removed the camshaft housing as well ( changing the hydraulic lifters preventative) and removed the chain tensioner which appears to have been broken.
The only thing that had my head scratching was placing the camshaft locking tool on at first it didn't sit flush and it felt forced because the camshaft were slightly not dead on. What I did was use a 27mm socket that I had and just moved it slightly so I can tighten the tool down. Did this on both sprockets and worked fine
I need to now drop the pan assuming there is going to be some sprocket teeth floating in there not looking forward to this...
Also the febi kit 44974 I bought from FCP Euro has a bracket for the chain tensioner I don't want to remove the Timing Case If I don't have to. Does anyone know if it's necessary the chain tensioner appears to be identical to the old one.
Fingers Crossed car is on the road again next week!
It's been a few days and I now have my sprockets and have started some of the process of removing the lower timing case cover.
The camshaft actuators I decided to go with are the Ebay Maxpeedingrod brand which when talking to them they said it was designed by German Engineers in a Chinese factory who knows how true this is but they did offer me a 2 year warranty on them which is a lot longer than anyone else I've spoken to.
I've decided to remove the lower timing case because my chain guides have groves in them and need to be replaced. The chain and guide kit is the Febi 44974 which I mentioned but it is in fact a Genuine MB part the guides say JWIS on them and the MB logo and part numbers have been removed see photos. This leads me to believe my chain is also MB part as it has JWIS stamped on the chain. The tensioner is blank but so was the original. Another reason I am removing the lower timing case is because I'd also like to replace the bracket for the tensioner and take a look at the other guides and crankshaft sprocket see if there is any severe signs of wear. I am currently at the point were I need to drop the oil pan which hopefully I can accomplish tomorrow.
Here are additional parts I ordered to replace due to the removal of the lower timing cover these parts should be replaced if anyone decides to do this.
Timing Cover Rear Seal /Crankshaft Seal $17.00
Part # 023-997-84-47
Engine Timing Cover Gasket/Water Pump $6.50
Part # 017-997-49-45
Engine Timing Cover Gasket /Water Pump $5.25
Part # 017-997-50-45
I'll update this thread as soon as I can... thank you
The tensioner bracket has a one way oil valve for maintaining pressure when the engine is off. The reason why the kit recommends replacing it is that the one way valve in the newer version tensioner has been removed in the newer version for some weird reason. If the newer version tensioner is used and the bracket valve fails, then the chain will skip or damage the gears/engine. However, I am unsure of the failure rate of the bracket valve. If one wants to take a chance, one can reuse the bracket and skip opening up the front end. Personally I am unaware of any instances of this bracket failing. See link above for details.
In other words, in the original design both the bracket and tensioner each had their own one way valves (ie 2 in total). The newer tensioners don't have one, so now the bracket valve is a singular point of failure. Replacing the bracket is recommended by Febi but not strictly required.
Fun fact - according to the Febi literature, every single tensioner that leaves the factory is bench tested first. In other words, it is a guaranteed 0% failure rate.
Last edited by slammer111; Mar 1, 2022 at 01:51 PM.
I did read that press release but one of the things that caught me off guard was that the kits that are listed on that pdf are different part numbers than the kit I currently purchased.
Also the new tensioner and the old tensioner look to be identical I'm assuming the non-return valve is internal? In either instances we are taking off the front cover and replacing the bracket and guides also gives us the opportunity to change out some seals and inspect balance sprocket and guide.
Thanks for the input appreciate that there is still some activity in the w203 threads.
Unfortunately I never had the job done so I can't comment too much. However, based on the PDF it looks like the old version tensioner would have a one way valve at the "tensioner tip" end of the base component (the component with the screw threads and hex end). I would open up the old valve and take a look. This would make the most sense as the oil goes in through the little hole at the base then has to travel down the length of the tensioner before coming out the hole at the end.
It won't hurt to replace the bracket as well. However, it also makes the job much more complicated, so there is no wrong or wrong. Personally I wouldn't want to deal with any leaks if for some reason the front panel wasn't resealed properly.
Last edited by slammer111; Mar 6, 2022 at 12:12 AM.
I was able to remove the timing cover without dropping the pan all. I removed all the bolts and that where on the cover and the few on the bottom holding the cover to the pan.
All accessories where removed.
Something to note is replacing the driver side chain guide is a real PITA you need to remove the head for this but it can be done "forcefully" without the head being removed. You have to remove the bottom portion first and rotate and take it off chances are you may snap the old guide which I did.
The tensioner bracket seemed to be in fine condition all though I don't know how to test the valve in it to see if it's working or not. Since I have a new bracket I am just going to replace it in addition the
sprocket seems to be good shape along with the chain. I may replace the tensioner as one of those since I am there scenarios still waiting on availability from the dealer for that part.
I am going to start cleaning the covers and prepping for install soon with new seals and o-rings.
Still going at out after cleaning all the parts and covers and piecing everything back together the conclusion is this. The oil pan needs to come off in order to install the cover back it's an extremely tight fit and good thing we did because there was pieces of the sprocket in the oil pan.
While everything was off decided to swap out the supercharger pulley and oil.
My alternator has indications that it's going bad so I am waiting for that now meanwhile I am detailing the engine bay.
Here's some pics to enjoy.... here's to hoping when everything is on it's good as new...
What was wrong with the supercharger pulley? Didn't know that was a wear item. Does it just come off by removing the screw at the end?
FYI the M271 supercharger requires 136mL of new oil if you're able to dump everything out. Might want to take a look here for additional information. Also be sure to check the crankcase breather hoses (including the $12 hose) and check valve, engine mounts, and other bits. Same thread. Personally I would replace at least the check valve while you have everything apart. That thing is a nightmare to get to.
Last edited by slammer111; Mar 11, 2022 at 03:23 PM.
The pulley has been upgraded to 60mm for more HP. You need to use a pulley puller and than a press to put the new pulley on.
I changed all the $12 hoses about a year ago everything is still in good condition. I have also mastered the removal of the supercharger it's about a 15 min job after the intake manifold and other items have been removed. You have to have the car jacked up get underneath and remove the intake muffler which is the black box that connects the supercharger the air intake it's literally 2 bolts and it comes right off from the top after that. The 3rd lower bolt is easily accessible and comes out in few seconds with a powered ratchet.
The guy I purchased the pulley from said 115/117ml for the Oil. I have also read in many different areas 125ml is whats required...
I thought I had drained all the old oil out previously through the drain plug when I had replaced the PCV but when I actually took it apart it still has some of that cheese smelling oil and was filled to the brim so I put to much in last time and not all of it comes out of that drain hole. MB Supercharged oil Part #000989620109 is exactly 125ml.
I cleaned it out completely and added AC delco supercharger oil roughly 125ml give or take a few it ones full bottle of 118ml and than a small tilt of some extra.
Apparently its recommended to change the oil every 50k miles. So maybe next year i'll service it again.
It's alive! Car is much quieter than I remember could be the new chain and sprocket or could be the alternator that had signs of it going bad that I replaced as well...
Hoping to get another 100K out of this car! On to the next repair!
First, congratulations on finishing! I’m following along since I’m replacing the tensioner mounting.
You dropped the pan. Did you lift the engine and drop the frame per the WIS? Fun times.
Yes I had to lift the the engine up and drop the front subframe axel it was a total of 4 bolts to drop and it sits on the suspension when I dropped it. I used a jack to lift it back up and and torqued back down to specs. You have the WIS same instructions I used in a round about way.
My water pump took a crap and I also noticed what appeared to be an oil leak on the timing chain cover I decided what the hell since I am draining the coolant anyway lets fix the oil leak.
To my surprise 189k on the clock my camshaft sprocket is missing teeth and my chain is stretched.. Now the expense of the chain and tensioner isn't bad but OMFG $500 for a 1 sprocket?
I've looked on FCP, Pelican and AutohausAZ which is the cheapest out of all of them. Does anyone know of another place I can perhaps purchase both sprockets without breaking the bank? Also the the exhaust side is fine it's just the intake. Would it be wise to just replace both? the Intake is the one with missing teeth...
Yes I had to lift the the engine up and drop the front subframe axel it was a total of 4 bolts to drop and it sits on the suspension when I dropped it. I used a jack to lift it back up and and torqued back down to specs. You have the WIS same instructions I used in a round about way.
the WIS also says to remove the steering column link and the catalytic converter. Did you like have to do that?
I removed the steering link and the exhaust connection between cat and exhaust pipe, lifted the engine, dropped the pan. Removed the pan. Removed 11 bolts from the lower chain cover. And I can't get the cover off for anything. The driver's side I can pry off enough to see the lower right guide pin; from your pic it looks like there's one on the upper left. But I can't get the cover off either side; it's like it's bolted in from the top. I can get the bottom left to move, but it's like it's bolted in about halfway up.
Are there any hidden bolts? Prying on this the way i am only means I'm damaging the sealing surfaces. I've been at this for my second day and found the lower right bolt wasn't out. Unfortunately that didn't mean I got this off. My guess is the previous owner used black rtv to seal the cover, and that's about the perfect glue. One more evening and I'm lifting the cradle back, dropping the engine, and sending it to the local charity.
I removed the steering link and the exhaust connection between cat and exhaust pipe, lifted the engine, dropped the pan. Removed the pan. Removed 11 bolts from the lower chain cover. And I can't get the cover off for anything. The driver's side I can pry off enough to see the lower right guide pin; from your pic it looks like there's one on the upper left. But I can't get the cover off either side; it's like it's bolted in from the top. I can get the bottom left to move, but it's like it's bolted in about halfway up.
Are there any hidden bolts? Prying on this the way i am only means I'm damaging the sealing surfaces. I've been at this for my second day and found the lower right bolt wasn't out. Unfortunately that didn't mean I got this off. My guess is the previous owner used black rtv to seal the cover, and that's about the perfect glue. One more evening and I'm lifting the cradle back, dropping the engine, and sending it to the local charity.
There are 2 bolts on top you have to remove the cam actuator/sprocket to get to the one below the driver or passenger side you can see them from up top. I am assuming you removed all accessories I don't recall how many bolts in front hold the cover the together but I did run into a situation because my cover was so filthy i missed one. There is some pry points on the over that I used on top and at the bottom. post some photos i'll see if I can help point you in the right direction.
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
If the newer version tensioner is used and the bracket valve fails, then the chain will skip or damage the gears/engine. However, I am unsure of the failure rate of the bracket valve. If one wants to take a chance, one can reuse the bracket and skip opening up the front end. Personally I am unaware of any instances of this bracket failing. See link above for details.
Does it just come off by removing the screw at the end?
