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Can someone offer they’re opinion on the chain? 1st pic is the exhaust side and second pic is the intake side. This is a 2005 c230k with just over 100k miles. Does it look stretched enough that it needs to be replaced?
Check the slack between the intake and exhaust sprockets. If the chain is loose (ie it can be lifted off the guide), it needs to be replaced.
The sprockets have a computer controlled internal adjustment (won't explain here) that shifts the timing as needed. Therefore the marks will be slightly off most of the time.
Check the slack between the intake and exhaust sprockets. If the chain is loose (ie it can be lifted off the guide), it needs to be replaced.
The sprockets have a computer controlled internal adjustment (won't explain here) that shifts the timing as needed. Therefore the marks will be slightly off most of the time.
the chain is tight and the sprockets are in good condition. Appears to be normal wear. I do however get the slight noise at cold start that goes away in about 2 seconds. Reading through the forums, everyone is like, you must replace the chain immediately...
Are you sure it's the chain that's making the noise?
Chain life seems to be hit or miss. There are people here with 300k km on the original chain. I had mine inspected a few years ago and was told there was plenty of life left. Factors affecting chain life include driving style (higher revs = higher stress) or using the wrong type of oil. Always stick to the approved list.
Last edited by slammer111; Sep 28, 2020 at 10:40 AM.
Are you sure it's the chain that's making the noise?
Chain life seems to be hit or miss. There are people here with 300k km on the original chain. I had mine inspected a few years ago and was told there was plenty of life left. Factors affecting chain life including driving style (higher revs = higher stress) or using the wrong type of oil. Always stick to the approved list.
the chain has about 110,000 miles on it. Car sees routine oil changes about every 7500 miles and use quality synthetic. Liqui moly, Mobil 1, Castrol syntec. It’s driven moderately, not aggressive or gently.
At tdc, these are the timing marks. Exhaust is slightly off and intake is spot on. The camshaft locking tool fits on correctly like this. Rotating to align the exhaust cam, brings the crankshaft dampener to about 10 degrees. Is that enough to warrant replacing the chain?
How are the teeth on the sprockets looking? Specifically the ones on the intake gear. Can you post a photo?
I didn’t photograph the teeth on the sprockets, but rotated the engine by hand several times while looking at the teeth. They are all intact, not worn down to nubs or anything. No evidence on the teeth that the chain is skipping. They all look to have normal wear pattern
If you are sure the chain is showing 10 degrees of stretch, then it would be worth it to replace the chain. I was told by my indie that ~7 degrees is when it's time to do the job.
Just looked back at my photos. Looks like my indie also measured the chain stretch by lining up the mark on the exhaust cam, then taking the reading off the crankshaft pulley.
Couldn't tell you why your chain is so stretched based on your maintenance and driving style. Wondering if it may also be caused by either a bad batch or a bad supplier. When I had mine inspected at some 180k km, I only had ~4 degrees of stretch. I too also drive my car moderately aggressively, with the occasional Italian tuneup.
Last edited by slammer111; Sep 28, 2020 at 10:55 AM.
If you are sure the chain is showing 10 degrees of stretch, then it would be worth it to replace the chain. I was told by my indie that ~7 degrees is when it's time to do the job.
Just looked back at my photos. Looks like my indie also measured the chain stretch by lining up the mark on the exhaust cam, then taking the reading off the crankshaft pulley.
Couldn't tell you why your chain is so stretched based on your maintenance and driving style. Wondering if it may also be caused by either a bad batch or a bad supplier.
did you replace the chain yourself or have it done professionally? I am contemplating doing it myself, but a little apprehensive due to a mishap several years ago. Replaced the chain tensioner and quickly discovered I received a bad part when I cranked the motor and the chain jumped because the tensioner didn’t maintain tension. I have done timing belts on volvos before with no issues and other repairs from minor to major. I’m also concerned about some of the posts where people are having misfire issues after replacing the chain
At the time the indie actually just reassembled the car (new valve cover gaskets) and told me to come back (much) later as my chain hadn't stretched enough to warrant a replacement. Several years later, I'm still on the original chain at 235k km. At the rate I'm going, I think I'll get the job done at 300k.
I probably will let the indie handle it when the time comes. While the job itself doesn't seem terribly difficult (like 80% of most maintenance jobs), the main thing stopping me is the price of the required tools. No point spending all that money on a kit that I might only use once. For some $200 more, I might as well make sure it's done properly. My indie has the required tools, as well as a tech who has done this specific job multiple times.
For all critical parts, I recommend either a dealership or a reputable brand (Febi etc.) sourced directly from a reputable source (absolutely no Amazon or eBay). Nothing more frustrating than dealing with defective parts in the middle of a job, or having a newly installed part fail prematurely.
Have you looked at the M271 timing chain threads started by other members here?
Last edited by slammer111; Sep 28, 2020 at 11:36 AM.
At the time the indie actually just reassembled the car (new valve cover gaskets) and told me to come back (much) later as my chain hadn't stretched enough to warrant a replacement. Several years later, I'm still on the original chain at 235k km. At the rate I'm going, I think I'll get the job done at 300k.
I probably will let the indie handle it when the time comes. While the job itself doesn't seem terribly difficult (like 80% of most maintenance jobs), the main thing stopping me is the price of the required tools. No point spending all that money on a kit that I might only use once. For some $200 more, I might as well make sure it's done properly. My indie has the required tools, as well as a tech who has done this specific job multiple times.
For all critical parts, I recommend either a dealership or a reputable brand (Febi etc.) sourced directly from a reputable source (absolutely no Amazon or eBay). Nothing more frustrating than dealing with defective parts in the middle of a job, or having a newly installed part fail prematurely.
Have you looked at the M271 timing chain threads started by other members here?
I have. And I’ve purchased the tools to do it as well as practiced on a junk motor. Just a little gun shy I guess.
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Wondering if it may also be caused by either a bad batch or a bad supplier. When I had mine inspected at some 180k km, I only had ~4 degrees of stretch. I too also drive my car moderately aggressively, with the occasional Italian tuneup.
