I'm not ready to call this a knock...

[bills2002]

...more like a really loud tick. I just bought the car and drove it 600 miles with no problems. Put it on jack stands and went through the whole thing (changed fluids, new muffler, new hoses, belt, tires, etc). Before my wonderful mechanical touch ups the car was quiet except for the holes in the muffler. Now the loud ticking (OK, kinda like a knock) seems to be under the valve cover on cylinder 3ish. I did three things that may have affected this area: 1) replaced the 5W30 and cheap parts store filter with 20W50 and a proper Mahle, 2) set the valves to .006 cold and 3) replaced the oil sending unit. The ticking gets a little quieter once I get to operating temp; then it really is just a loud tick. I only replaced the oil sender because they are cheap and the old one looked, well, old. Could the change from a light oil to the 20W50 have uncovered anything?

One more thing...the compression check was 125-130 across the board.

[Mike Self]

It's easy to misadjust one...I usually set at .007 and then use an .008 feeler gauge as a "no go" to make sure I got it right.

You might also check to see if the timing chain tensioner is pumped up properly and isn't allowing slack in the chain...

mike

[TobyB]

Exhaust leaks at the manifold can sound a lot like a valve.

Not exactly the same, but close, and they have the

same 1/2 crank frequency.

Not 'phut' like you'd think, but 'snap'

t

[c.d.iesel]

" A happy valve is a ticking valve "

you may have had tight valves originally,

and now with proper clearence - hearing some 'normal'

ticking which is good - recheck the valves carefully.

[bills2002]

Thank you for the replies; this might be better tech support than I get from BenzWorld.org.

So what I am hearing is that I may have misadjusted the valves or caused something to start leaking in the exhaust when I changed the muffler. I really had to torque the old muffler to get it off but doubt I put enough force to affect the manifold. So I'll concentrate on the valves. I've heard and read conflicting advice. Do I check valve clearances hot, warm, or cold? Also, can't I check valves when their rocker arms are off the cam lobes or does each cylinder need to be checked at exactly tdc?

[colinrichardson]

Cold...

check this out:

http://www.bmw2002faq.com/content/view/21/32/

[TobyB]

There is a hot spec rattling around out there, too-

if I remember, it's just a thou or so tighter...

And yes, start with the valves.

t

[pkbinplano]

maybe the valves are quiet now and you just hear the noisy mechanical fuel pump. Mine tick tick ticks,

[bills2002]

LOL. The screwdriver to the ear trick gave a whir-whoosh on the fuel pump and arm and a loud tock over the cylinder 3 valves. I had a TR-4 before and should know what healthy valves sound like...hopefully. Thanks to all, I'll report out this afternoon.

[TobyB]

TR4's got a pushrod motor...

heh

t

[bills2002]

TR4's got a pushrod motor...

heh

t

Yep, and the tappets are just as loud. It's so much easier with the OHC to figure out when a cylinder is on the compression stroke.

[bills2002]

OK, thank you all for the advice. I readjusted the valves cold to .007 one cylinder at a time on the compression stroke and the knock is a tock now. Lesson learned.