Broken Rocker Arm
 

Hi all,

I recently purchased a 1981 Targa with a 3,2 motor that had the top end rebuild with 4K miles on it since then.

As I was driving it home it was clicking a little bit from the right cylinder bank. I thought, it's been sitting for a while, maybe the valves need adjusting. The noise kept getting louder and the when I got off the highway it was really loud and the engine wasn't firing on all the cylinders. The drive home was approximately 200 miles. Oil pressure was around 5 bar the whole time. (The Targa makes a lot of wind noise!)

I got a friend of a friend to come by and listen to it and he popped of the right upper valve cover. The middle rocker arm fell out.....The other thing he noticed straight away was that the inside of the valve cover was dry. Bone dry, not a drop of oil on it.
His assessment is that the oil line to that side is blocked and the cam ran dry.

Does anybody have a picture of what the inside of a normal valve cover should look like? I pulled the one off the left side yesterday and it is dry also!

All I know now is that I will now be getting some experience with the engine from my dream car! I wanted to do that sometime, not be forced to do so at the beginning!

Thanks for the help!

If it was running dry, you'd see the damaged cam lobes and rocker faces easily. Post a pic of the cam and rocker, especially the rocker face that rides on the cam.

Did the rocker break? Or, was it just loose? The rocker shaft, if not positioned property and torqued correctly, can "walk" out of it's bore.

If it's actually broken, they are designed to break upon valve/piston contact but damage isn't normally avoided. Hope you don't have to go there...

If the rocker covers were dry that's real bad. You say the motor was run like that for a while? The damage from lack of lubricating oil will damage the valve train and cams real fast. If thats really the situation then the top end will need to be removed and repaired.
The cam spray bar on each side has 3 oil holes per cylinder and one of them for each cylinder sprays oil straight up so the oil from it splashes off the inside of the upper cover and splatters all over in there to lubricate all the moving parts and carry away heat. The other two spray bar holes for each cylinder spray oil directly towards the cam lobes and rocker arms.
Oil also goes through passageways in the cam tower to lubricate the cam journals.

The inside of the upper covers should be getting wet with oil sprayed up at them as soon as oil pressure is developed. Oil pressure usually builds up between 1 to 2 seconds of the starter motor being turned over with a good battery.

Just to satisfy myself that there isn't a blockage within an oil gallery inside of the crankcase, I would pull off the upper cover on the opposite side of the engine and see if it looks normal or if it is also dry.

Sorry to read this. Trying to think how oil line to cam tower was plugged or restricted. Was the oil dropped when upper valve cover removed? Curious what oil filter looks like.

What was the oil pressure like while you were driving? If the oil was bypassing the cams I think that it should have indicated as high.

I'll post a couple of pictures tonight of what everything looks like right now.

The intake rocker arm for cylinder five is broken in half.

I popped off the left intake valve cover and it is also dry.

The engine is still in the car, so I don't know the extent of the damage yet. I have a couple of other projects with higher priority right now, so I'm not sure about when I'll be able to drop it out.

As I was driving the oil pressure was near the top of the scale the entire time. What would the pressure be in a properly running engine?

The oil was changed with the filter to Mobil 1 5W-40 shortly before I got the car. I need to drain it and see if there are any filings in there. With the way the rocker arm looked, I would be surprised.

With 5W-40 oil, the pressure shouldn't have been at the top of the gauge, so this is a further indicator of a blockage. I think I would refer to a diagram of the oiling system to see if I could pinpoint where the system is plugged.

I think you should have a little chat with the person you recently bought this car from . . .

^^^what he said^^^ I was trying to reason through how a rocker could break other than valve contact with the piston. There is the fatigue factor. I guess it could break if the rocker seized on the shaft due to lack of oil or maybe a combination of fatigue and resistance on the shaft. I would think, at that point, the lobe and rocker face would have significant damage.

As Mr. Fairman points out, those little holes in the cam spray bar are a favorite place for debris to lodge. Not sure one or a few being blocked would cause the whole system to run higher pressure. The manual says to remove that spray bar and flush when rebuilding. When I tore mine down, I found a little bit of sealant in one hole so I can understand the requirement to R&R the bars.

Good luck! Wait to see some pics here

too many thoughtsat one time
put it in neutral,, have someone turn the key
with the valve cover off, youll see if there is an oil problem.
if you broke the rocker from fatigue, possible
if you were out of oil there should be wear on the face of the rocker and matching wear on the cam lobe.
can you rock the broken rocker
usually if a chain jumps the damage is on the exhaust side.

bruce

I did that once with my 930 right after I got it... Then I spent the next half hour cleaning oil out of the AC condenser and off everything else back there. 3 thick streams of oil will shoot straight up out of the cam spray bars under starter motor speed alone.

ben there, part of the learning curve....
bruce

Oil blockage on opposite sides of the engine is a slim possibility, recent "rebuild" or not.

If the upper cylinder area has no lube, the cams and rockers would show signs of it. Please confirm.

It could be a "simple" and coincidental case of both lube bars clogged and not able to spray or other issues such as:

No oil
Oil pressure relief valve stuck open
Oil pump shaft broken
Oil pickup tube, broken
Intermediate shaft or gear, broken

Conduct more investigation (e.g. chain boxes) to understand the extent of the damage or lack of lube.

Unless there was an implied warranty attached to the sale, there's probably not much legal leverage on that front. But understanding the extent of any damage should be the topic to address. Is this DIY or are you handing this off to a repair shop?

Sherwood

If the engine still runs after a 200 mile trip, I suspect this is isolated to the upper end. If the spray bars were not working both cams and all the rockers would be trash. Rockers do break all by themselves. You might not be as bad off as you think. Just because the cover looks "dry" doesn't necessarily mean it is.

It should be about 1 bar per 1000 RPMs, So at 3000 RPMS it should be at 3. SO yours wasnt right, which means something was likely blocked.


If the squirterd are somhow plugged then it is understandable but If the cam squirters are damaged it is likely from when the engine was reassembled, do the test and see if they spray, if they dont then find out the cause.

A lack of lube between rubbing parts generates much heat and wear, especially in a high load area between rocker arms and cam lobes. Valve guides will also lack adequate lube and they too might exhibit excessive wear. After a few hundred or thousand revolutions, material will have worn from those surfaces and clearances may increase beyond spec. The shorn material is steel particles, bronze in the case of valve guide material. It does not conveniently remain in the valve train area.

After examining the other engine access areas, suggest cutting open the oil filter and see what's in there.

Drain the crankcase and oil tank and see what's sticking on the magnetic drain plugs.

Take your rebuilding/refurbishing cues from the results of those inspections.

Sherwood

Here are a couple pictures of the valve covers, the broken rocker and where it came from. It all looks rather dry in there. Keep in mind that I have only taken the valve covers off and have NOT cleaned anything.

http://cdn04.trixum.de/upload2/2000/...3c8f05d79c.jpg
http://cdn04.trixum.de/upload2/2000/...6e9a4cb8ac.jpg
http://cdn04.trixum.de/upload2/2000/...3c8f05d79c.jpg
http://cdn04.trixum.de/upload2/2000/...38cdeabc02.jpg
http://cdn03.trixum.de/upload2/2000/...77898c1897.jpg
http://cdn03.trixum.de/upload2/2000/...77898c1897.jpg

...and here are the views of a couple of other valves:

http://cdn03.trixum.de/upload2/2000/...1423b0931d.jpg
http://cdn03.trixum.de/upload2/2000/...b9f190eef2.jpg

From the pictures it looks to me like that there is a LOT of "dirt" in there for something that was supposed to have been worked on only 4K miles ago.

It definitely looks like there was lack of oil flow to the top end. That dirt seems to be the metal wearing away.

That is my opinion as well. When I look at all my pictures, it seems that only the #3 intake valve looks clean, the rest are dirty. Although you can see that there is a bit of that black goo there as well. Could that have been built up in the last 4000 miles of driving w/o enough oil in the valve train?

http://cdn03.trixum.de/upload2/2000/...8ab9d59202.jpg

Rocker
 

It's hard to believe you have pressure on the gauge and that much lack of oil.
The rocker face is hollow as is the cam lobe. And all that black around the oil port. I believe you have an expensive diagnosis all the way to the oil pump.
I would pull the oil line for the cam and at the banjo fitting, there has to be junk there.
Bruce

Although I cannot tell for sure without seeing everything for myself, it appears that the rocker arm broke due to lack of lubrication in the pin bushing.

From the rest of the pics, I'd strongly recommend engine disassembly as something is terribly wrong and there may be collateral damage.

This is painful to see... I'm sorry you bought a car with a motor in this condition. It's going to be very expensive to fix right.

If you bought it recently I hope the previous owner didn't just smear wheel bearing grease on the cams and rockers to keep things quiet long enough to sell it and get it out the door...

Cam to rocker and rocker to shaft severely worn from lack of oil. Looks like many of the other rockers will be in the same shape when everything comes apart.
Seems like a lot of ugly things happen to Porsches in Florida.
Bob B

Agree - rocker faces, rocker bushings, cam lobes all show destructive wear from lack of oiling. You can find and fix the oiling problem, but that won't bring back the rockers, rocker shafts, and cams. Better start looking for replacements.

Don't be to quick to just chuck all the rockers except the broken one you might be surprised what can be saved.

Before
http://tapatalk.imageshack.com/v2/14...aced067b2f.jpg

After
http://tapatalk.imageshack.com/v2/14...41f157cac6.jpg

Thanks for all the tips and information. Now I just need to find the time to drop the motor out.
I'll post more info regarding the extent of the damage, when I get that far.

S***! I wanted to drive this car!

Yeouch.

I'm certainly no engine builder, but the first thing I'd have to take a look at would be the banjo bolts that secure the external rubber/metal oil lines to the camshaft towers and make sure they are in fact a hollow banjo bolt and not just a solid bolt!

At this point, you are probably lucky that there was absolutely no oil at all, because that would have carried all that metal back to the sump and into the pump and bearings.
I would be interested to see what you find when it comes apart.

You'd be surprised. In a shop the other day and got to look at a 3.2 race motor with a hole in the case from thrown rod. Lead tech there said, "guy drove it in like this. This is the oil filter." I expected to see oil filter completely plugged. It wasn't. So, may not be as bad as we think. I hope not.

And where did the metal pieces go? Think gravity aided by internal air turbulence.

Was it confirmed the engine was dry (no lube)?
Do you have a method to replace overheated bearings, cylinders, pistons/rings/pins, damaged crank, gears, cam and rocker bearings or to extract metal dust and bits from the engine/oil cooler w/o disassembly?

Sherwood

These pictures absolutely show no signs of oil anywhere.
I feel you're looking at an engine removal from car and a cam housing/head removal from engine. You need to determine amount of damage to cams, rockers, valves, guides. Unfortunately you won't be able to do this inside the car.

Looks like it has starved from oil.
Rocker arm seems to have been going without lubrication. Should not be that dry in there