I have a little bit of rattling a about 65 mph. I just changed the oil and it seemed to quiten it for a few days.(15w40 havoline) I am thinking the valves need adj. Car has 207,000 miles(excellent shape)Seems like the dealer said they are self adjusting. Is this true or do I need to go to a (20w50 oil). I use to have an 81 rabbit diesel and always kept the oil changed and valves adjusted.

Their is nothing to adjust on that engine. What you describe almost sounds like a lifter, but I have never heard of one making noise on a 606.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

use synthetic oil and see if it goes away

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'02 BMW 325i
'85 300D 450k
'93 190E 2.6 170k(killed by tree)
'08 Ducati Hypermotard 1100S 6k
'06 Ducati S2R800 14k(sold)

What kind of rattling is it? Interior? Engine? Drivetrain?
My E300 (W210) has an RPM-dependent interior rattle...it comes from the shift lever between 2000 and 2200 RPM. I'm thinking it's worn shifter bushings. Maybe your problem is similar?

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99 E300 TD -- sold
01 540i 6 spd

Probably time for motor mounts if you haven't done them...easy enough to inspect and determine if they are collapsed or not. Alos, the belt tensioner shock bushing can cause some rattling on these but usually that is heard at idle.

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

It sounds a lot like spark knock on a gas engine.
Since it quitened when I changed oil, I am thinking synthetic oil or heavier oil. At one time the PO was running a heavier oil(20w50) pennzoil. Just wonder if thats why. What type of synthetic oil would you recommend.
Thanks to all

Well, I have a pronounced one , and its due to a faulty glow plug harness/plug which has apparently fouled up a chamber pretty good. Hoping that new wiring/relay/ Diesel Purge will eradicate it, OR I'll be popping a prechamber or two this winter. ( or Gps - aaaahhhh!) Not saying yours is a prechamber, but the symptoms can be similar I;m told... the fresh, thicker, oil may just be dampening the noise a bit.

Easiest thing to try is to buy a few cans of Purge and a new fuel filter, rig a feed bottle up, and splice it into your fuel system. Run it through.

I'm just about to do this, and only threw 2 gals of fuel in this am to keep the tank below 1/4 so when the lines are disconnected, I dont get a huge gush of fuel up top.

It could be one of your nozzles not giving a great pattern at rpm. In fact, I'd bet on it. A purge, fresh fuel filter should do it. I'd also check the throttle linkages to ensure the IP rod is going down all the way, ensure it and the air flow are matched.

Oh, yeah, the lifters are hydraulic, no adjustment. I havent even seen mine yet. as the IP timing was spot on (14) , and I assume the chains are spot on too. Cam/valve hasnt been removed yet. ( if the new GP harness and Purge dont work, it will be().

Use a fleet oil. Dino is OK, but Synth is better for cold starts. Rotella, Pennzoil, Delo, etc. They'll say fleet, and typically be a 15-40 weight. ( specifically for diesels - although many of us use the same oil for old skool big block chevies with solid lifters -its good stuff.)

BTW, we dont use 20-50 even in frickin' race cars. ITs WAY too heavy for msot engines with normal bearing clearances. Its made for loose clearnaced race motors, or shot everyday motors. Much too heavy, and doesnt have the wear agents that fleet oil has. Most gas oils have had all the "nasty" wear agents removed anymore. Which is why we DO NOT use them in old flat tappet V8s anymore. Those wear agents are key for good cam/follower wear. Most modern engines use roller tappets. They dont need the addtiives. Our diesels and old solid cammed 7400rpm V8's DO!

Please use them.

No don't run 20W50, I don't think they make one thats diesel rated. Run a 5w40 diesel rated synthetic, like Delvac 1 or Amsoil. Thats probably why, oils that are not diesel rated can't suspend the soot and you probably have some build up in the oil passages of the lifters. They are pumped up by oil and it doesn't take much to clog them. Run a good diesel rated synthetic for 20k miles and it will clear up. Don't use additives or anything like that, the oil will do the job.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200