Knocking/tapping sound

[lovedavdubs]

Symptoms:

Knocking/tapping sound, On drivers side of the engine. Especially Loud when the van has just been started. Sound tapers off a little after 20sec. or so, but is still loud.

Slight loss of power. Especially at lower speeds. (hill climbing)

I discovered that a mechanic put too much oil in during a routine oil change. I also found part of the valve cover gasket in one of the pushrod tubes @ cyl. #4. The engine has good compression throughout. (#3=115, #1=120, #4=125, #2=125)

The sound seems to be coming from cylinder #4, but this cylinder's compression reading was fine. If I have decent compression can the lifter, (hydraulic tappet) as the book calls it still be bad?

I just started the van up with the valve cover off to compare the rocker movement. Just by looking, I found that one of the rockers at the #4 cyl. didn't plunge as deep as the others. I'm assuming its clogged up with the same valve cover gasket material that I found sitting inside the tube earlier. Any opinions or other assumptions? Is this something I can just pull out, unclog, and reinstall? Or do I need to buy a new one?

[weinerwagen]

Are you sure it's not one of the hydro lifters making some noise? Re check the clearances, DONT FOLLOW BENTLEY's recommendation.
Bentley wants you to tighten down the valves too much, too tight, causes loss of compression.

These engines tend to do some tapping when they are cold and with miles on them. Just use good oil, maybe change it more often, but they are bad about lifters making noise...
_________________
Retired attorney--Tort King.

[lovedavdubs]

Maybe I wasn't clear enough. The lifter is what I'm planning to pull and clean. I'm not sure how to check the valve clearance though. But this is no ordinary tap.

[wayoutjake]

As far as rocker settings... check out this post by dave menche...

Jason L
85gl 2.1
Louisville, KY

Joined: 10 May 2004
Posts: 199
Location: Fresno, Cal driving a BIG OLD SWIFT TRANS TRUCK
Posted: Wed Jun 02, 2004 10:47 pm Post subject:


so when you inviting Karl and his family, my kids, the dogs, cats and westies up the hill to enjoy some cooler weather......

btw, did you hear that Karl had a slight booboo with his 65? "Slight" being the operative word....

aint those o rings fun? I put my 1.9 together countless times before I finally figured it all out....the lifters take forever to pump up babes.....
so leave them loose an let it run....forget EPA rules, let the engine run while those lifters pump up, sometimes they will take 1/2 a day....

keep running the rack on the valves, if you get a dead miss, loosen the valve up, let it run with sloppy valves for a while til the lifters decide to pump....then only 1/2 a turn
forget Bentley 2 cranks.,....one max, you get them too tight you get a dead miss....

I used a compression tester on one engine, first try was 30 lbs, then loosened the valve by one turn, got 60 lbs of compression, loosened them up another turn, got 150......
play with timing...
they are rough runners btw, but timing, vacuum lines, make sure the intake is snug, they do come loose off the head, I found WD-40 located some leaks.....
valves, leaks and timing, you are in an area where you can bump the timing up a bit, without worry of smogging issues,,,,,find a spot that that beast likes the timing at,

so much for Bentley.....




dave menche
Samba Contributor

[lovedavdubs]

So on a hunch I swallowed the lump in my throat and got to removing the lifters on the driver's side. This is the first time I've ever done work like this...(SCARY) I started with cyl.#4 first. That's ware the tapping seemed to be coming from. 1st. I pulled the one nearest to the bumper. I was able to compress it between my thumb and middle finger, so at the time I thought that meant it was good. So when I pulled the second one and found that I could not compress it this way I figured it was clogged. So I proceeded to disassemble it...Oops. Then I realized after reading the book that when fully bleed, you should not be able to compress the lifter by hand. So I disassembled the first lifter I pulled out, cleaned them both real good in degreaser, reassembled them, and bled them while submerged in a cup of fresh oil. After this process, I found that the lifter that I was able to compress with my fingers was no longer compressible this way. I then slid them back into the motor and put everything back together the way it came out. Ok time to adjust the valves...Now I'm lost again. mother @#$&er! I started it up real quick just to see if every thing was in working order. It was REALY loud for a few seconds, but then setteled down to a light tap. What's the best way to adjust the valves on an 82 Aircooled motor? I've read conflicting opinions.

[Randy in Maine]

Do this, go to www.type2.com click on "library" and then "L" like lifters and read the rap by John Anderson on adjusting hydraulic lifters on a type 4 engine. Very informative.

Worked for me.