Rocker Arm Wear

[Roger 911]

'84 3.2, stock motor, 103K miles. I'm chasing down a ticking sound that does not seem to be solved by valve adjustment. Was expecting to see a broken valve spring, but so far I have not found any. However, after removing a couple of the rocker arms, I was surprised by how much they were worn. Below shows the #2 and #3 exhaust rockers next to a new one. Both are deeply dished, #3 even more than #2. As you can see, there appears to be about a 1mm dish on the pad. Is this normal wear for a 3.2 with just over 100K miles? I replaced cams on a 2.4T motor many years ago and I don't recall the rockers having that much wear, but I can't say for certain. Could this be the source of my ticking sound (which appears to be coming from the left, 123, side of the motor)?

Any thoughts are appreciated. Thanks.

[proporsche]

Roger, you have major problem with lubrication.I would absolutely suggest to check you squirt tubes on your camshaft housings-mainly left side!! Do not install new rockers until you find the problem.

Make sure all the little lubrication holes are clear..........

Ivan

ps. i do have a feeling your camshaft is gone ...check that for sure

[Neil Harvey]

OUCH!!!

Second engine today posting issues with rocker arms.

There is nothing normal about this. As already suggested, you have a major issue with lubrication. And, I ca be sure your camshaft(s) are junk too.

These early rockers are cast and the base material is particularly full of inclusions. Its normal with the process of casting and the material used. This works as the sliding face of the rocker arm is hardened and ground smooth, But the hardness is not very deep. When the lubrication goes away, heat builds up and the wear is accelerated. Then the damage starts and its all over. The oil is there to remove the heat.

All of that junk material worn off the rockers and cam lobes is suspended in the oil and some will be trapped inside your engine. Not good. What do you do? From a professional standpoint, the engine needs coming down, checking and repaired with new parts etc. But from owners point of view, risk will be taken and the offending parts replaced and the engine run again.

However, you do have a chance to know more, here. As suggested, the cam deck(s) will need to be removed and the oil tube removed and cleaned. I also suggest the oil holes be opened up some. Once the cam deck is removed, its quick to remove the head and cylinder and pull the rod and check the bearings. I would. It will not get better. Engines are not like the human body. They do not heal with medication and time.

I also suggest you check the engines oil pressure running.

We have been coating both the cams and rocker for years now. Just a little insurance and the coating helps lower the friction and heat built up with these sliding rocker geometries.

[proporsche]

nice, what are you coating it with??

Ivan

[Roger 911]

Is it safe to assume that this is also most likely the source of the ticking coming from the left side?

[john walker's workshop]

It's coming apart anyway, and you'll find out in the process.

[Arlo911]

Originally Posted by proporsche

nice, what are you coating it with??

Ivan

Probably a DLC coating

[Roger 911]

Originally Posted by john walker's workshop

It's coming apart anyway, and you'll find out in the process.

If I can be pretty sure that these abnormally worn rockers are causing the tapping noise, then I'm less inclined to worry about broken piston rings or rod bearings, etc.

[proporsche]

yes you can be 200% sure it is your tapping noise but you have more problems than tapping Roger...deal with it the right way

Ivan

[Roger 911]

Originally Posted by proporsche

yes you can be 200% sure it is your tapping noise but you have more problems than tapping Roger...deal with it the right way

Ivan

Yes, I appreciate that. I fully intend to replace the cams and rockers, after ensuring that the lubrication system for the left cam is clean and functioning. The exhaust lobe for #2 feels bad. It has a bit of a lip running around the outer edges of the lobe (like a worn brake rotor), plus there is a discernable ridge running horizontally across the lobe. I can absolutely see where this ridge, if anything, would create a loud ticking sound. Good news (at least a little), is that I removed a rocker from #5 exhaust and it looks great and the lobe looks and feels fine (left one in the pic). So it does appear to be isolated to the left cam and rockers.

[john walker's workshop]

One lobe bad is all it takes to ruin a cam. Some work ahead of you.

[Roger 911]

Originally Posted by john walker's workshop

One lobe bad is all it takes to ruin a cam. Some work ahead of you.

I know. I replaced cams in a 2.4 many years ago. It will give me an excuse to upgrade to 964 cams!

[Roger 911]

I found the source of the cam/rocker wear. The cam oil line restrictors were clogged with some sort of reddish black flakes. They appear to be scaling of some sort, not metallic. When I installed the motor eight years ago, I also installed the 964 Turbo oil restrictors, which I had run successfully for 10+ years in a 2.4L motor. While it's possible that these deposits could have caused issues regardless, having the much smaller diameter (2.5mm) restrictors didn't help. When I put it back together, I will reinstall the stock 6mm fittings.

[proporsche]

well looks like a water pump silicone some unpro mechanics use to work on these engine..I do not mean you but somebody must have used it on your 911.I have encountered this problem on several occasions..
this is 993 but same story..make sure you flush everything 2x or 3 x the oil tubes and change the oil and filter before you get into bigger problems....

Ivan

[Roger 911]

Originally Posted by proporsche

well looks like a water pump silicone some unpro mechanics use to work on these engine..I do not mean you but somebody must have used it on your 911.I have encountered this problem on several occasions..
this is 993 but same story..make sure you flush everything 2x or 3 x the oil tubes and change the oil and filter before you get into bigger problems....

Ivan

Could be some sort of sealant. I got the motor eight years ago with 85K miles. It was from a totaled car that appeared to have been well cared for, ran well, good compression, etc. However, the whole experience of the crash (front end), removal, shipping, and installation, could have loosened up deposits in the engine. It ran great for years (still ran great when I removed it!). It was really only last year that I noticed the ticking noise that wouldn't go away. But based on the wear, I'm sure the oil flow had been disrupted for years. I only drive it 2-3K miles a year.

Yes, the engine is out of the car now. I will be replacing cams and rocker arms. I'll blow some air through the spray bar and check it. I hope when I pull the cams I don't see extraordinary wear on the cam bearing surfaces, implying damage to the cam housing bearing surfaces. We'll see!

[RetroSC]

Just beware that whatever was blocking those cam oil line fittings has been circulating through your entire engine's oil system, so it could be blocking something else. If it were me and I was that far in I'd just tear it all down so I was sure to get everything clean.

[Roger 911]

Originally Posted by RetroSC

Just beware that whatever was blocking those cam oil line fittings has been circulating through your entire engine's oil system, so it could be blocking something else. If it were me and I was that far in I'd just tear it all down so I was sure to get everything clean.

Oh yes, that thought has crossed my mind. We'll see what the cams look like when I get them out. I'll also cut open the filter and take a look inside.

[proporsche]

yes i`d like to see the filter too;-) Just flush the engine with thinner oil 2 x ....i imagine you will be fine...

Ivan

[Solamar]

Originally Posted by Roger 911

I found the source of the cam/rocker wear. The cam oil line restrictors were clogged with some sort of reddish black flakes. They appear to be scaling of some sort, not metallic.

Not metallic or not magnetic?

I hope not - but the pieces look like rod or main bearing bits from a spun bearing.

[Roger 911]

Originally Posted by Solamar

Not metallic or not magnetic?

I hope not - but the pieces look like rod or main bearing bits from a spun bearing.

No, not metallic or magnetic. They are actually translucent if held up to the light, reddish brown tint. Deposits of some sort.