Evaluating valve adjustment time by sound
 

It's major-service time for my car, as there are a variety of things that it is due for, including an oil change. My valves were last adjusted 10,000 miles ago, on the day I picked the car up. I understand 10k-15k is the appropriate interval for checking the valves; I drive it about 4-5k per year.

In April I had an emergency brake caliper rebuild done by a good 911 mechanic in Nashville (Wicky Lawrie) as I was on my way to Atlanta. After pulling my car into the shop, he commented that the valves sounded a slightly noisy to him and it might be worth checking them. To his ear, one cylinder was also noisier than the rest. In his opinion it wasn't urgent, but he was picky enough about that that if it were his car he would do it because listening to it would annoy him.

So as I prepare to put my car up on stands for a bit to change the oil, check the plugs, replace some fuel lines, rebuild the other front caliper, work on the pedal cluster, etc. I ask myself whether I should check the valves and adjust as needed. It will be my first time and I am not afraid of the task, but all the same, if I don't need to do it now I'd just as soon not. Partly because I'd have to order a gasket set and feeler gauges, etc. which means waiting another week. For all I know they're all within spec, just on the loose side (I recall the spec is .04 +/-.02, which is a pretty big range)

Should I just do it, or is there any harm in waiting until my next oil change? I did take a video of the car idling that I will upload, though it may be a bit hard to hear the valves over the high idle (car is cold), fan and exhaust.

I am kinda pissed off at Rawknees for posting the tolerances. All of a sudden valve lash is a whatever the hell you want. Get an 0.006 and a 0.002 feeler gauge. Little one goes and big one doesn't and you are done. Screw the 0.004 feeler gauge or the Kirk adjustment tool.

They need to be at 0.004. If you can't pull that off pay your wrench.

That said, clackity clack is better than silent.

More rant: If by chance your 0.002 gap goes south to say -0.001, your valve does not close. Bad things.

You are in Chicago. I say gear up for a winter project.

Side note, I see pictures of donuts and beer being posted by Rawknees to discredit me.

I do call the mega competent wrench, Rawknees, a pin head now and then. Order of magnitude? You decide.

http://forums.pelicanparts.com/uploa...1497129655.jpg

Go easy on him, I'm hanging with his Mom right now.

Oh, don't blame likes-to-be-on-his-knees for it. For all I know I recall it from the manual, or a man i a trenchcoat in a parking garage at night. All the same, .004 +/- .001 is pretty different from, say, .004 +/- .0001. If I am a touch high, I'm not going to worry about it, even as I am going for .04 on all valves.

As for how they are now, as you say, clackity-clack is better than silent. I do not tend to slack on maintenance on my cars, but I don't want to do something unnecessary, either.

As for winter projects, my unheated garage and my hands' intolerance for cold means nothing much gets done in winter unless it is unusually warm.

Carv'in into Rawmeatrono Bob! Has serious ring to it.

Ott... I say if the other work is being done, why not check valves and get it done. Downstream you'll probably be glad you did it.

I stand down and don't want to start no trouble.

http://forums.pelicanparts.com/uploa...1497131292.jpg

Worked in Naperville for eight years. Friend in Cicero. Same house price as my compound was in Akron. Probably more. No garage at all.

BAB is fixing an airplane.

He'll respond.

Here's a recent pic of him after a haircut.

http://forums.pelicanparts.com/uploa...1497131664.jpg

Ha!

Don't make fun of his small arms.

http://forums.pelicanparts.com/uploa...1497132079.jpg

Small arms means something else must be real big.http://forums.pelicanparts.com/suppo...oilet_claw.gif

Cause you know you must be able to scratch things.

Bobasaurous, please tell her I said "Hi Mom".


Ask Bob's and Karl's moms for clarification! :eek:


This has your name all over it, Bro!

http://img11.deviantart.net/4475/i/2...girlsuzy17.jpg


PS - about the valve lash specs - ol' Bob doubted me about that in another thread, and I promptly pimp slapped him with a text pic of the factory spec sticker.

https://ih0.redbubble.net/image.7309...01c5ca27c6.jpg

No they don't, bub (so says Porsche, Ducati, Continental, Suzuki, Yamaha, Honda, and 99.9% of every manufacturer of an engine with solid lifters (or no lifters at all) - ya' BAB


Agreed - it would be silly to leave the lash "as is" if it measures out at a tight .002, butt that is not what a range like that is for; it is to account for the "judgement" factor of measuring lash with a feeler blade, and to emphasize that the gap is not a critical, precision thing at all, BAB.

I will learn you a thing or two about a thing or three, yet!


And I say again ---->

http://cdn.quotesgram.com/small/30/9...-Pimp-Slap.jpg

^^^

You're the one on the right!

It is possible that a valve or two are now out of spec but these are not quiet engines.....and was said earlier, it is better for the valves to be too loose than too tight. It's your call but, I would adjust them on whatever schedule you choose. I personally do the 15k mile schedule as per my 3.2's original Porsche service record. Cheers

I was trained by Porsche and can say that they were specific about clearance. But not 0.004in, rather 0.01mm which is 0.0039 inch. Or a "tight" 0.004 inch.

So how does one explain the engine decal stating a range? Well, Porsche is a small company and I've found they often have (gasp) some disagreement about the details. The 0.01mm needs to be exact when assembling an engine with new or refaced components.

I have measured these a few days later after just a few miles and yes they will be different from what they were set at. So my belief is that a range is okay and looser is better than too tight. You have to be careful with turning the engine over with removed plugs since carbon fluff can get between valve and seat throwing off measurement.

Yes looser is better than too tight, because if they are too tight, they won't seal properly or long enough, and that is how you burn a valve. Run a burnt valve long enough, and you will eat a valve. Eat a valve, and things get very expensive.

Some people say a tappy engine is a happy engine. It turns out that the tighter they are, the quieter they get, so setting them too tight and having a nice quiet engine is a no no. Over time, you would think maybe the stem would wear, and things would get looser, but if the valve starts to wear into the seat, things will actually get tighter, and this is why you need to check them.

If you don't know with certainty when the last valve adjustment was performed, you need to check it.

Thanks for all the feedback. And the Bob & Ronnie show is, um, entertaining :) I think I'll just leave them be for another oil change unless I feel compelled for some reason to drain the oil and check them this winter.

I was forming a bubble flare today on a brake line and your Mom started crying.

I said, Jeebus, look at that thing it's perfect. Please climb down off of my back right now.

She said, no, it's great, it's just that his Dad used to call him bubble head.

They were tears of joy.

^^^

Mom holdin' the ol' Stones for you afterwards, too, and s**t!

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valves tend to get tighter over time.

you did not say how many mile are on the engine,
I would also look for other signs.
does it smoke when you first start it up.

if so you could be looking at a guide issue,

I know on my worn out 77s motor the "valves" where noisy after an adjustment,
perhaps guides where worn out or something else in the valve train.,
I just kept driving it.

T77911S,

The PO had the engine rebuilt (he did some of the work himself) in 2010, and the top end was redone in 2013 because somehow the exhaust-side valve guides were missed the first time. It saw probably a couple thousand miles between then and my buying it in 2015, and I've put 10k on it since then. So all in all, a pretty fresh engine. 89k on the odometer but the speedo is non-original so it is TMU.

The above-mentioned mechanic mentioned to me that, based on his ear hearing one cylinder that seemed louder than the others, that in addition to simply a slightly loose valve it was possible that the rocker shaft on one cylinder was slightly out of position (he showed me the right and wrong positions on a disassembled head in the shop, and told me how that mistake can happen) and worth inspecting for when I had the covers off.

I think it smokes a little on first startup (I find it hard to notice) but nothing abnormal, given that it has been sitting for at least a week.

On a side note Engine Builders Supply farmed my heads out in the late 90's. The rebuilt heads were sent back with the exhaust valve seals in a separate bag. I asked what the heck? The said you don't need them was the response.

I never dug into it any deeper. Not sure why.

not sure how you miss the exhaust valve guides, they are the ones that go bad.

I will go back to my statement of valves get tighter with mileage to help you answer your own questions.

if you have one that gets noticeably louder over time then perhaps you have another issue.
you could have a plugged oil hole in the spray bar and you are wearing out the cam/rocker thus increasing the gap for example. I have seen this happen first hand.

a shaft off center wont do it unless the shaft is worn and has moved or one end has come out. shafts have come out and the rocker fallen off. again, nothing to do with a valve adjustment but a mechanical failure. also seen this happen.

did a machine shop that knows how to do Porsche heads do the guides?

if you are hearing what you think Is a rocker here is what I would do.
go in and do a valve adjustment. adjust them on the snug side. make sure they are done right.
after doing them, spin the motor over a few times then go back and check them again.
check the head studs. just put a wrench on them and make sure none are broken.
inspect the rocker shafts. make sure they are at least consistently in the same place. you could even put a wrench on them and make sure they do not turn. if they turn, they can move.
inspect the cam lobes and rocker faces for wear.
inspect the spray bar holes for anything that could be plugging them. mainly the ones that face up.
button it back up and run it again.

my 77 was noisy after valve adjustments. I also noticed that after adjusting them the first time they may not be the same when going thru them again.
I just always suspected bad guides and they may be moving around.


one last thing.
did the pistons get replaced?
I have been told:
JE pistons can cause piston slap due to the fact that they do not have the offset that Porsche pistons have.

Yeah, it does seem odd that the exhaust guides were skipped the first time, but that's what happened. I've got records on the rebuilds at home, but this is what the PO (who was on this forum - the car was originally advertised here) wrote:

"Original rebuild was done by an Atlanta area shop that went through a change of ownership in the middle of the rebuild. All was good with it, except valve guides on the exhaust side did not get done. That resulted in bad smoke on deceleration last year. I did the top end myself, except for sending out the heads to Motowerks Racing in Cumming GA. They did the assembly but sent the actual machine work out. The new heads and cams really woke the engine up."

I don't remember whether it has Porsche pistons or not, but I do have that information at home. The PO had the car for 15 years so I've got records back to about 2001.

I do not have an experienced enough ear to say that there might be a misaligned rocker - that was the opinion of the mechanic in Nashville, and he did not even say that he thought that *was* the case, merely that it was a possibility. It was an informal conversation. He did show he how it could cause a little more noise, but I don't remember the explanation.

Thanks for the suggestion below. I will do that when I do take the covers off and check the valves, but I am inclined to do that either this winter or at the next oil change after this one. I'd be be more worried if they were tight!