Clackety clackety clackety clack

[Steve@Rennsport]

Originally Posted by Reiver

Steve,
My experience is pretty shallow but I've listened to 2 other euro 3.0's and they both had a bit of slap/knock in each one. As they warm it goes away but not totally and is only heard at idle.
Another shop owner told me it's pretty normal.
OTOH, what's in the video might be anything as trying to compare recorded sounds always escapes me.

USA/Euro 3.0's should not have any piston slap at all unless they have 2618 pistons (JE, CP, Woosner, etc) in them.

Mahle cast & forged pistons run very quietly unless something is wrong such as piston wear, pin bore wear, etc. New ones are dead quiet.

[Reiver]

Okay Steve, you know a hellava lot more about this than I do.

[evan9eleven]

Hi everyone!

No update other then that I got to run the car a couple hundred more miles before putting her up for the winter. I will have a good listen to the engine with the stethoscope when I get a free weekend, I just haven't had time and and weather has been lousy.


evan

[evan9eleven]

Originally Posted by Steve@Rennsport

USA/Euro 3.0's should not have any piston slap at all unless they have 2618 pistons (JE, CP, Woosner, etc) in them.

Mahle cast & forged pistons run very quietly unless something is wrong such as piston wear, pin bore wear, etc. New ones are dead quiet.

Steve, since my P/Cs are of unknown vintage but are OEM 9:8:1 Euro spec, does that tell you anything about if they are Mahle or something else?

[Steve@Rennsport]

Originally Posted by evan9eleven

Steve, since my P/Cs are of unknown vintage but are OEM 9:8:1 Euro spec, does that tell you anything about if they are Mahle or something else?

Without seeing your cylinders for myself, I cannot tell you precisely what you have, however if they are Euro 9.8:1 pistons, they are likely Mahle ones.

Nikasil and Ausil cylinders have very different appearances as well as markings at the base of the cylinder so if you can take some close-up, high-res pictures, I may be able to ID them for you.

[Sub8]

Nikasil and Ausil cylinders have very different appearances as well as markings at the base of the cylinder so if you can take some close-up, high-res pictures, I may be able to ID them for you.

Steve - hi, top or bottom of engine to id cylinders? Many thanks.

[bavaria911]

Evan,
Photos of the cylinders...as Steve says. What do you have?

[evan9eleven]

Originally Posted by Steve@Rennsport

Without seeing your cylinders for myself, I cannot tell you precisely what you have, however if they are Euro 9.8:1 pistons, they are likely Mahle ones.

Nikasil and Ausil cylinders have very different appearances as well as markings at the base of the cylinder so if you can take some close-up, high-res pictures, I may be able to ID them for you.

Originally Posted by bavaria911

Evan,
Photos of the cylinders...as Steve says. What do you have?

Finally got time to snap a couple pics from underneath the car today... hereby delivered for the great Steve W. to evaluate. Any idea what I've got? I can take more pics if needed. TIA

[Steve@Rennsport]

Those look like Alusils to me, based on the pics.

[evan9eleven]

Thanks Steve! I'll definitely have questions come rebuild time.

Now its just to wait for the snow to melt so I can get the car outside, run it and try out my mechanics stethoscope.

[evan9eleven]

Out came the stethoscope for the first time today: back to trying to find the clackety noise. I'm not sure I know more then before but here is the lowdown:

• The noise is definitely on the right side of the motor (4-5-6)
• No clacking from the chain boxes
• Clacking audible on fan housing but very muted
• Audible on lower right rocker cover but muted
• Clearly audible on upper rocker cover but not loudest here either
• Clearly audible from underneath the heads
• Clearly audible from exhaust flanges but again not loudest
• LOUD from 4-5-6 intake runners next to each injector. On cylinder 4, I can FEEL the clack through the stethoscope wand
• Really LOUD with the wand on the right SSI header
• Barely audible from the underside of the case which leads me to believe its not bottom end

Again, this is a metallic thuck-thuck-thuck-thuck noise, apporximately four times a second at 7 - 800 RPM (idling slowly with oil cap removed, sound is most audible this way.) The clack speeds up according to engine RPM and gets harder to hear with the other noises over 3K but is still there.

You'll recall I've had the right side rocker covers off and checked valve clearances and these were in spec, no rocker shafts out of place, no oil or exhaust leaks. Sounds like a little engine gremlin is smaking something metal inside the engine with ball peen hammer four times a second, and I can't find the little bugger.

Next I'll put the car in the air and run it to better probe around underneath the motor. Thoughts welcome!

[Alan L]

So, here are my thoughts/options. Valve guide loose (probably inlet), small end bush loose, or maybe they did not install the little wrist pin clips properly on #4.
This is just shooting from the hip, but if possible my next step might be to try and look inside #4. Don't know how do-able this is but others will have the knowledge if it is. I'm thinking of those small internal probe type lights/cameras. If it is possible, I would get #4 piston to the bottom and try and inspect the lining of the cyl, looking for marks.
On the upside - I had exactly the same issue (on #2) after rebuilding my engine from the crank up. I could feel it on the cylinder housing. After trying everything else, I reluctantly tore the engine down to the short block looking/measuring for any sign of something wrong. And found NOTHING. Had no option but to bolt it up again.from memory the noise was still there, but finally went away, and some years and about 20-30k later, it is perfect. Go figure.
Alan

[Charlie V]

Could the exhaust flange be leaking?? I found mine warped somehow and caused a leak. Same issue happened to a buddy doing a rebuild. Solution is to remove and file the flange flat. Reinstalled with new gaskets and I used a little high heat silicone. 100% OK now.

[Alan L]

Certainly can make a sound like described - but unlikely to make the vibration he can feel in #4, IMHO.
Alan

[evan9eleven]

Originally Posted by Alan L

So, here are my thoughts/options. Valve guide loose (probably inlet), small end bush loose, or maybe they did not install the little wrist pin clips properly on #4.
This is just shooting from the hip, but if possible my next step might be to try and look inside #4. Don't know how do-able this is but others will have the knowledge if it is. I'm thinking of those small internal probe type lights/cameras. If it is possible, I would get #4 piston to the bottom and try and inspect the lining of the cyl, looking for marks.
On the upside - I had exactly the same issue (on #2) after rebuilding my engine from the crank up. I could feel it on the cylinder housing. After trying everything else, I reluctantly tore the engine down to the short block looking/measuring for any sign of something wrong. And found NOTHING. Had no option but to bolt it up again.from memory the noise was still there, but finally went away, and some years and about 20-30k later, it is perfect. Go figure.
Alan

Thanks Alan, I recall you describing your engine that fixed itself. I'm not counting on that happening, but you have some good suggestions as always. The heads were left untouched when the PO had the rebuild done other then machining of the mating surfaces... so valves/seats/springs/guides have 160K miles on them and possibly a lot of neglegt along the way. I couldn't find any broken springs when I had the covers off, so at some point I'm going to have to do a teardown. Problem is that means a full rebuild 'cause there is no way I'm dropping the motor to do things halfway.

My electrician buddy has some kind of probe camera I can borrow. Not sure if it will fit in a plug hole but its worth asking.

[evan9eleven]

Originally Posted by Charlie V

Could the exhaust flange be leaking?? I found mine warped somehow and caused a leak. Same issue happened to a buddy doing a rebuild. Solution is to remove and file the flange flat. Reinstalled with new gaskets and I used a little high heat silicone. 100% OK now.

Originally Posted by Alan L

Certainly can make a sound like described - but unlikely to make the vibration he can feel in #4, IMHO.
Alan

I can't find any leaks, and this is a metallic clack I can feel. Imagine someone was under the car tapping the engine with a hammer four times a second and thats about what I have.

[Pat RUFBTR]

Maybe a rocker of broken. Good luck. ;-)

[evan9eleven]

Originally Posted by Pat RUFBTR

Maybe a rocker of broken. Good luck. ;-)

I had both covers off on the right side and rockers/shafts are fine, valves are in adjustment. I couldn't find any broken springs but I suppose an inner spring could be gone that I couldn't see.

[dpham6761]

Really nice. Well done.
Cheers,
Resmas

[Pat RUFBTR]

Originally Posted by evan9eleven

I had both covers off on the right side and rockers/shafts are fine, valves are in adjustment. I couldn't find any broken springs but I suppose an inner spring could be gone that I couldn't see.

Not easy to find the cause of this clac clac, it is maybe due to a bad regulation of the game(set,play) of valve too important for the admission 4.