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2008 E350 4M, 2016 Audi Allroad, 2019 Audi Q5
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5,447 Posts
Discussion Starter #1 (Edited)
Have noticed a little dieseling "clacking" noise on my 300TE recently....Does it when warm mainly. Does not do it all the time constantly, but every now and again.

Any ideas what it could be making the sound?

Definitely not a chain or guide issue since I checked and replaced it all a few months ago. Not coming from any pulley's either.
 

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1968 gto (sold) , 91 volvo 740, 89 $300TE, 89 560SEC
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432 Posts
My guess is you have a lifter sticking at times. A stethoscope is invaluable for such noises. I found mine running it with the v/c removed (made one hell of a mess!). I actually disassembled the lifter and cleaned it, soaked it in oil and reinstalled. Tight assed I know, but the noise never came back and that engine was expendable so to speak.....
 

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2008 E350 4M, 2016 Audi Allroad, 2019 Audi Q5
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5,447 Posts
Discussion Starter #4
Would new lifters and cam be expensive? I still have the pre-chilled cam in her. Not much scoring, but if I do the lifters it makes sense to do the rocker arms and everything at once.
 

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'95 E300 DIESEL, '91 600SEL, '92 600SEL
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17,388 Posts
Before you start wrenching I would suggest you do the following at the next oil service interval.

Drain old engine oil. Leave old oil filter in place and refill Dexron ATF until at proper engine oil level. Run engine (but do not drive) for about 30 minutes.

Drain and refill with proper engine oil and change filter. See if noise pattern changes/diminishes. ATF is a great cleaner, and you might be able to revive the lifters temporarily just by flushing them as described above.

If that doesn't work, I would do lifters and ball cups only. Since your old cam is still in decent shape, I would say leave it alone. Do be aware that the bolts holding the cam towers have bad tendency to want to strip out.

Last time I checked a single lifter and ball cup is about $20-25, unless you buy directly from the dealer. Be sure to use INA, who was the OEM for the lifters to MB. So if you do all 12, you're in it for at least $300 and that's before cam and/or rockers.

Be sure to tag which rocker goes with which cam lobe to keep everything paired upon reassembly.

If it were me, I'd start scouring the junk yards for a head in good condition that has the updated chilled cam and other bits.
 

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2008 E350 4M, 2016 Audi Allroad, 2019 Audi Q5
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5,447 Posts
Discussion Starter #6
Just regular walmart brand Dex III?

Its time to change oil right now. I am using Synthetic Rotella-T6 5-40 and just hit 6k so its about time. I want to send this sample in for oil analysis and see if the synthetic shows less wear than the 15-40 non-synthetic Delo 400 or Rotella-T. I have a sample of each so far.
 

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'95 E300 DIESEL, '91 600SEL, '92 600SEL
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17,388 Posts
Yep, just plain cheapo Walmart DexronIII will do just fine.

Out of curiosity, did the noise start after you switched to synthetic??? The synthetic might not have enough ZDP. I'm just guessing here, but just make sure the synthetic stuff is fully diesel rated. It's the sole reason why I'm sticking with Delo400 due to better ZDP content.

BTW, if you're going to start a search for a updated head assembly 1991 was a fine year for the M103.
 
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