F/Up to 1st valve adjustment...re-adjust needed?

911Freak · 11-16-2009, 11:01 AM

Last weekend I adjusted the valves on my '81 SC 3.0l (930/08)

I measured the clearance on each valve at-least 2-3x.

I believed I achieved the proper amount of resistance on each gap (.004)
I thought I had them all perfect

(also tried the go-no-go back side technique but wasn't confident in the results do to limited visibility and zero prior experience..)

So my issue is now I have a noticeable tapping sound coming from the passenger side of the engine... I suspect it is #5

I did use a long screw driver and noticed the tapping sound was coming from the #5/6 cylinder area...

I'm going to have to open her up again

The oil is new as are the gaskets

My questions are:

Do I have to replace the valve cover gaskets and oil with a new set and another 10 qts? ($60 mistake)

Can I drain just enough oil out of the engine sump to not make a huge mess getting to upper and lower valves and not have to drain the oil out of the tank?

If I use a brand new oil pan can I reuse the oil? If so should I filter it prior to reusing it? If so, what kind of filter? Paper coffee filter?

I'm about to ride over to the garage and start working on her..I'll follow the responses on my BB

Your advise is greatly appreciated as always

jwasbury · 11-16-2009, 11:16 AM

Jack up only the side of the car you are working on and you can remove the lower valve cover without losing much oil.

psalt · 11-16-2009, 11:26 AM

What did that valve measure before you adjusted it ?

911Freak · 11-16-2009, 11:30 AM

Quote:

Originally Posted by psalt

What did that valve measure before you adjusted it ?

Great question!

ALL the valves measured tight..I couldn't get them to "rock" or click when they were closed (prior to adjustment)...also couldn't even get a .002mm blade in...

I expected them to be loose, not tight!

The engine was pretty quiet, but still had that noisy valve noise, now the engine runs much more smooth and seems to have a bit of it's power back... except for that noisy tapping sound

911Freak · 11-16-2009, 11:30 AM

Quote:

Originally Posted by jwasbury

Jack up only the side of the car you are working on and you can remove the lower valve cover without losing much oil.

Do I still drain some oil off out of the bottom plate? Or just go for it?

Thanks!

cmcfaul · cmcfaul's Garage

Been there done that recently. you can re-ue the gaskets if you don't tear them when removing them again. You don't have to drain all the oil out if you jack up only the side you are working on and making all the oil go to the other side of the car. There will be some drippage but at lease you don't have to drain and refilll with expensive oil again.

Make sure you tighten the lock down screws and re measure

chris
73 911 E

911Freak · 11-16-2009, 11:46 AM

Quote:

Originally Posted by cmcfaul

Been there done that recently. you can re-ue the gaskets if you don't tear them when removing them again. You don't have to drain all the oil out if you jack up only the side you are working on and making all the oil go to the other side of the car. There will be some drippage but at lease you don't have to drain and refilll with expensive oil again.

Make sure you tighten the lock down screws and re measure

chris
73 911 E

Thank you!

I'll report back what I find etc

Gunter · Gunter's Garage

Quote:

Originally Posted by 911Freak

ALL the valves measured tight..I couldn't get them to "rock" or click when they were closed (prior to adjustment)...also couldn't even get a .002mm blade in...

They may not have had any clearance at all; not good. Did someone maybe set them that tight to mask the tapping noise?

I expected them to be loose, not tight!

Valves tend to reduce the clearance over time by settling deeper into the seat

The engine was pretty quiet, but still had that noisy valve noise, now the engine runs much more smooth and seems to have a bit of it's power back... except for that noisy tapping sound

Tapping could come from rocker shaft moving out of position, damaged adjuster foot, broken spring, worn guides....................eccessive clearance. Make sure you have the right sequence when adjusting.

There may be a little more power because the compression improved by setting proper clearance. (If there was no clearance, the valves couldn't close completely robbing you of HP and increasing the possibility of burning the valves, especially the exhaust ones)

I smear a little grease on both sides of the gaskets so they never stick.

And I re-use them all the time.

psalt · 11-16-2009, 12:05 PM

ALL the valves measured tight..I couldn't get them to "rock" or click when they were closed (prior to adjustment)...also couldn't even get a .002mm blade in... I expected them to be loose, not tight!

Don't be surprised if all the valves are adjusted correctly after you open it up. The normal pattern is for the valves to close up as the seats wear, not get loose with age, and often the adjustment is to open up the clearance back to spec. It is a misnomer that "noisy valves just need to be adjusted" and chasing noise by closing down clearances is a bad idea. The 911 specs are very tight and should be considered minimums. The purpose of the valve clearance is to give the valve some time to sit down and give off heat. It is not about heat expansion, hot clearances are bigger. All mechanical valve trains make noise and often it is caused by worn guides, stems and rockers. Expecting the engine to be silent after a valve adjustment is unrealistic, expecting the same noise or more is more likely.

dshepp806 · dshepp806's Garage

Quote:

Originally Posted by psalt

ALL the valves measured tight..I couldn't get them to "rock" or click when they were closed (prior to adjustment)...also couldn't even get a .002mm blade in... I expected them to be loose, not tight!

Don't be surprised if all the valves are adjusted correctly after you open it up. The normal pattern is for the valves to close up as the seats wear, not get loose with age, and often the adjustment is to open up the clearance back to spec. It is a misnomer that "noisy valves just need to be adjusted" and chasing noise by closing down clearances is a bad idea. The 911 specs are very tight and should be considered minimums. The purpose of the valve clearance is to give the valve some time to sit down and give off heat. It is not about heat expansion, hot clearances are bigger. All mechanical valve trains make noise and often it is caused by worn guides, stems and rockers. Expecting the engine to be silent after a valve adjustment is unrealistic, expecting the same noise or more is more likely.

+1 on that,..THAT's how I'll go into into my upcoming adjustment....will be damned sure to look closely at the rockers and other assemblies....much data here to be found on those rockers, feet, etc....

all input on that's welcomed...will help assessment of everything related to these items mentioned.

good luck,