81 300sd, 280k, wvo but ive been running mostly diesel. just checked the valve adjustment job I did last week, as I've done a long road trip and wanted to make sure I did it right (it was my first time doing the valves). There were 4 tight ones, and all the others fell within spec. Some were harder to get the feeler gauge through than the others, and I've just had a hell of a time getting them adjusted to the perfect gap which is why there is this slight variation. Anyways they are all correctly gapped now.

Side note: the reason 4 were out of spec was that last week I thought I made them too loose because the engine was running rough. Turns out it was just air in the lines.. Oops!

So I'd been meaning to fix the tight ones and just today got around to it. She fired up fine, and I drove her maybe 500 feet before a slight knocking appeared, which got louder as the rpms increased. It is quite a loud and prominent knock that I have definately never heard before. First thing I thought was low oil but it's fine. I had just driven her about 400 miles yesterday and had no signs of a knock or any engine noise that was out of the ordinary. So my question is: are the valves too loose? What could I have done that would have caused this? All I did was adjust 4 tight valves. I'm afraid to drive the car until I get this fixed. The car sat for about 9 or 10 hours (overnight) before adjusting the valves today. I'm planning on letting it sit in it's current location till tomorrow before trying to readjust them.

is this a clatter or knock?

If the valves are adjusted correctly, valve train clatter is good.

If it is a hammer/knock one of the adjusting lock nuts may have come loose.

NOTE: the adjusting lock nuts can become worn, and fail to remain locked.

As you said checking them again is the best place to start.
Did you get your Valve Adjusting Proceedure from the Factory Service Manual, this Forum or from another Manual like a Haynes or Chilton Manual?

I know in the past I have seen mistakes printed in the manuals before (I have seen more than ounce "Firing Orders" that were not correct) and it is 1 of the reasons I like to have more than 1 source of information to compare.

I have read on this Forum that you need to becarful about rotating the Enigine the wrong direction also. It is claimed that it is possible for the Timing Chain to jump a tooth if the Engine is rotated backwards.

This is easy to check while the Valve Cover is off. Rotate the Engine and line up the timing mark at the Rear of the Chamshaft Gear with the timing mark on the Chamshaft Bearing Tower.
After that look down at the Crankshaft Damper and see what degree mark the pointer points to.
When the Engine was built at the Factory it was lined up to Zero Degrees (Top Dead Center). With the mileage on your car you could have some normal timing chain stretch that would maybe be between 2-4 degrees past Zero (Top Dead Center).

Any large differance in degrees might indicate it skipped a tooth.

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84 300D, 82 Volvo 244Gl Diesel

awesome, thanks for the tip. i will check on the timing chain stretch tomorrow. the procedure i followed was what i read on the factory service manual. i used the specs printed on the sticker by the radiator, 0.1mm intake, 0.35mm exhaust with the engine cold. i adjust with the cam lobe at about 1 o'clock and check the gap btw the lobe and the lifter.

i actually pulled the valve cover right after i pulled the car off the road, and checked to make sure all the adjusting nuts were tight. everything looked fine and nothing came loose.. they were tightened pretty tight to begin with. would it be stupid or a waste of time to try tightening the valves a little bit? i.e. would the gap being too big cause a knock? honestly it sounds like one of the valves is hitting the piston, its a really loud very noticeable hammering that increases in volume and frequency with the rpm of the engine. i only turned the crankshaft clockwise, which is the correct way to turn it, so i dont think the chain would have skipped a tooth. and if it is just worn out, i would have noticed the same problem on the 500 mile drive i did yesterday.

another thing to point out is that right when i finished the valve job i started the engine and let it run for about 10 seconds just to make sure it started okay, which it did, and it sounded fine. then maybe 15 min later i took it for a drive, where as i was leaving the neighborhood and pulling out onto the main street the knock appeared. i immediately let off the gas which caused the knock to not be so loud and potentially damaging to the engine internals, and pulled into the first driveway i could find. i shut it off and pulled the valve cover to check for loose nuts and they were all fine so i put it all back together and started it again, just let it idle for a bit. it idled fine for about 30 - 45 seconds and then the knock came back, and as i gave it gas it just sounded awful.

is there anything else to check besides the timing chain? maybe one of the valves may be adjusted slightly too loose, and the cam is slapping the lifter creating the knock?

To be honest I am not sure what the cause of the Knock could be. Since it happend after a Valve Adjustment you would think that would have had something to do with it; but, it could be somethine else that happend by coincidence.

Is there any chance that it is something like a loose Air Filter Housing banging against something (when mine did this it sounded like something was seriously damaged; almost like a Rod Knock) or the Sheet Metal part that is inside of the top of the Valve Cover (that helps keep Oil out of the Breather tubeing) has come loose?

When the Engine is knocking try rotating the Engine by hand and see if there is a spot during the rotation where it gets hard to turn; if a Valve was Hitting a Piston you would think that when you get to that Cylinder it would be harder to Rotate the Engine than on the other Cylinders.

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84 300D, 82 Volvo 244Gl Diesel

Loose air cleaner sounds like the engine is shaking apart and ready to explode. Get it to knock, press down on the air cleaner, see if that narrows it down for you.

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CC: NSA

All things are burning, know this and be released.

82 Benz 240 D, Kuan Yin
12 Ford Escape 4wd

You're four times

It's hard to

more likely to

concentrate on

have an accident

two things

when you're on

at the same time.

a cell phone.

www.kiva.org It's not like there's anything wrong with feeling good, is there?

i shot a couple videos of what was going on, so you can hear the knocking. i let the engine idle for about 10 minutes, and gave it a few revs and the knocking eventually just stopped, out of nowhere! i drove it back into the neighborhood where i did the valve adjustment on it originally, and i'm hoping that the knock was maybe just due to something that was dry and the engine needed to be run a little to get the oil circulated? im not really sure but it seems to have fixed itself. any thoughts on what this noise was or what it sounds like it could be?

http://www.youtube.com/watch?v=CqsX8loNnLA
http://www.youtube.com/watch?v=YfDiRIHZ0s8
http://www.youtube.com/watch?v=dcNWUXfIakE

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1981 300SD, 270K, two tank wvo system
1985 300D, 288K, california version
1985 300DT wagon, 315k, broken odo

to me it sounds like bad air cleaner mounts.

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1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

well the knocking came back again, and i believe the valve adjustment was just a coincidence. i drove another 600 miles or so and when i was pulling off the freeway after a day long drive last night i heard the knocking at idle. i pulled over and checked the oil level and sure enough, the dipstick was completely dry. last week when i first noticed this knocking noise, the oil was at the low mark (it had been leaking because i didnt have the valve cover bolted tight enough the first time around) and i just topped it off and didnt really think it was caused by low oil. i was convinced it was caused by the valve adjustment because that was the most recent thing i did to the engine.. but the oil is what must have caused it in the first place.

today after adding oil (about 4 quarts topped it off) and searching everywhere for leaks, and letting the engine idle for 15 min or so in hopes the knock would fix itself (as it did last time) to no avail, i decided to do an oil change. turns out the oil fill bolt was so loose i was able to unscrew it by hand. not sure how this could have been, as i clearly remember tightening it pretty good last time i changed the oil. the black paper gasket on the bolt was split and looked pretty bad. i replaced the gasket with a copper one and gave it fresh oil and a new filter. hopefully the bolt was the only place that oil was leaking.. it seems like there are a few oily spots around where the ip bolts to the block, and on the other side of the engine behind/below the turbo, are these common places for oil to leak?

so now that its got new oil i tried letting it idle for another 20 minutes, it heats up but is still knocking. what do i do? i really dont want to drive it while its making this terrible noise. im afraid of rolling a bearing or doing something much worse. and i am certain that this noise is not caused by the air cleaner, as the knock is much louder when im laying under the car than when i am standing over the engine.

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1981 300SD, 270K, two tank wvo system
1985 300D, 288K, california version
1985 300DT wagon, 315k, broken odo

i would invest in a mechanics stethoscope to identify the source

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1986 300SDL, 211K,Dealership serviced its whole life
1991 190E 2.6(120k)
1983 300D(300k)
1977 300D(211k)

When you did the Oil Change after draining the Oil you missed and opportunity to remove the small Oil Pan and inspect the bottom for metal particles or fragments that might have diagnosed a bearing going bad.

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84 300D, 82 Volvo 244Gl Diesel

whats involved in removing the oil pan? do i need a gasket to reinstall it? i guess i could always just drain the oil into a clean container and then pour it back into the engine when im done

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1981 300SD, 270K, two tank wvo system
1985 300D, 288K, california version
1985 300DT wagon, 315k, broken odo

There is a gasket there and the Oil Pan bolts on mine are Allen Head Bolts. On my 300D it does not look like there are major problems to remove the small Oil Pan. I do not know how reusable the Pan Gasket is.

If it was me I would wait to buy the new Oil Pan Gasket after I knew there was no metal in the Oil Pan. Because, if I found metal in the Pan I would not drive the Car and risk more damge until I decided what I was going to do.
What ever you put the New Drained Oil into it might be a good idea to inspect the bottom of that container also to see of any meta fragments
got carried into the New Oil when it was drained.

If you can hear the thumping at idle speeds listen up by the area of the Vacuum pump. I use a 2-3 foot section of a cut off wooden Broom Stick with one end on the part an 1 end by me ear to listen for things (watch out for moving parts like the Fan and the Belts and so forth).

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84 300D, 82 Volvo 244Gl Diesel

Biotour - did you ever get this noise fixed??

Mine makes a very similar noise:

http://www.youtube.com/watch?v=fXS6iyfgvSw

I finally took it to a mechanic, he thinks there is a loose rocker arm or something like that...