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Join Date: Oct 2007
Location: Idaho
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Scored cam-can I still drive - help

I figured I would start a new thread but this is related to the tappet noise thread.

I adjusted my valves and changed the oil a couple of weeks ago. The car had been sitting for 2 months without being driven and about 2 weeks without oil and valve covers on.

I had 8 qts of oil in it when I started it after adjusting the valves. It might have been too low combined with the rockers and cam being dry but one of the cam lobes on cylinder 6 is scored and the rocker was loose to about .004 using the backside method. Usually using this method you shouldn't be able to slip in a .003 feeler guage.

My question is, can I drive the car at a DE this weekend? I know I eventually need to have the lobe polished and get a new rocker but I would like to wait until winter if possible.
Old 04-15-2010, 02:37 PM
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It would be a good idea to check that the cam spray bar is not clogged down at the last hole that oils and cools the #6 valvetrain and cam lobes.

It's very common in 930's.
Old 04-15-2010, 05:22 PM
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My little valve clatter needs a valve adjustment turned into this... 5 and 6 cylindar spraybar holes clogged. Didn't take long to wear in from when I first heard the valve clatter, I consider myself fortunate to get it when I did, couldve been a lot worse.

bad rocker?
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Old 04-15-2010, 05:57 PM
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Before I put the cover on after I was done, I used a thumb tack since I had one in the garage, to poke in the hole and it seemed very clean and was already open.

I actually drove it about 200 miles after I heard the clatter since I never expected it to be worn. I assume that if it was clogged that it would have been totally gone after time. I wonder if letting it sit without oil for 2 weeks with the covers off let everything dry out. I did have a rag on it instead of the cover.

So if it is not clogged, do you think I can drive it or do you think that the scoring will get worse since it is not polished now?
Old 04-15-2010, 06:38 PM
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I guess I got my answer. I drove this moring for a few miles and the rocker noise is back. So I guess I need to do my first engine drop to remove the cam and rocker.
Old 04-16-2010, 09:28 AM
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Before I did the engine drop I drained the oil and found brass particles in the oil. I didn't expect that for sure. I was hoping that the brass was coming from the rocker but the rocker is not brass and it seems to be in pretty good shape.
I sent the cam to web cams and the rocker also to be reconditioned.

I still can't explain the brass particles in the oil. Are the only brass parts in the engine the bearings? I pulled the distributor hoping the gear on the end was brass but not so. I sure don't want to split the case if it is not necessary.

Things I did before the brass in the oil were

Adjust valves
Changed oil
Removed AAV
Removed and reinstalled recirculation valve assembly
Test fit new IC
Replaced a couple of vacuum hoses
Had valve covers and fan powder coated
Stated car with 8 quarts of oil instead of 11

Before this I had no issues.

The cam scoring may be due to contamination on the feeler guage during backside method of valve adjustment. I kept it pretty clean however and since it is only #6 exhaust I can't believe this was the cause.

Was 8 quarts of oil way too low? The oil pressure was fine.
Old 04-24-2010, 11:30 AM
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There's no problem running the motor on 8 quarts of oil.

Are the brass particals like dust or flakes in the oil? Are they magnetic?
Dirty brown oil can make silvery dust sized metal particals appear brass colored while suspended in it because of the dark amber or brown oil.

If it's brass flakes that sounds like the middle layer of rod or main bearings being worn away. The distributor drive gear on the crankshaft is also brass I think.

Have you checked to see that oil is squirting upwards from the 3 holes in the cam spray bars?
It will squirt upwards around 4 feet at idle and make a mess so it's alot easier to take the upper cover off, clean it completely and dry it, slide it back on the studs and crank the starter motor with the fuel pump relays removed until you see oil pressure on the gauge and then stop.

Then slide the cover off and look to see there are 3 equally sized oil wet spots on the inside of the cover above where the 3 intake vales are.

It should look something like this.
Old 04-24-2010, 11:50 AM
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I think they are like small sliver like shavings. They are small, some just tiny dots and some are as large as 1mm. I didn't check to see if they are magnetic but I took some out of the oil and put them on a rag and they look like shinny brass.

I should check the distributer drive gear assuming I can see it through the distributer hole. I guess there is a remote possibility that when I took the distributer cap off the check the rotor position during the valve adjustment that something got slightly jambed so it would cause more wear to the drive gear but I doubt it.

I ran the car for 200 miles after the valve adjustment and then noticed the valve clatter. The clatter could have been there before the long drive but I didn't notice it.
I took the cover off and noticed the scoring.
I needed to drop the engine and noticed the brass shavings in the oil.

So for 200 miles the car ran fine with no smoke etc.

I didn't check the spray pattern but there was oil all over the rockers when I checked them again and the intake for 6 is not affected.

I have since cleaned the spray bars but I am still worried about the shavings.
Old 04-24-2010, 12:25 PM
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They may appear brass-like because of the small amount of brown oil covering the particles suspended in oil. Light will play funny tricks....
The only way to be sure is to clean the particles in solvent to remove oil covering them. Use a magnet to confirm.

Take a look at the case oil drain plug. It's magnetic and you should see a silver paste covering the magnetic pole in the plug. That silver paste is more than likely the material of the cam lobe(s) and rocker arm(s).
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Old 04-24-2010, 01:20 PM
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The drain plugs were cleaned from my last oil change 200 miles before I discovered the cam scoring. I expected the plugs to contain the shavings but both plugs were still clean.

I saved some oil so I will try to filter some and look again. I am planning on sending some in for analysis also.

I'm getting pretty bummed out...
Old 04-24-2010, 01:40 PM
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I got some of the shavings and they wouldn't stick to the drain plug magnet so I guess that confirms they are brass. The distributer drive gear looks good so it must be from a bearing.

My thought is that the cam got contaminated during the valve adjustment and scored it which sent the steal particles into the case and shaved some brass bearing/s. Just a guess though.
Old 04-25-2010, 03:34 PM
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Speaking of shavings, what's the usual/normal amount to see on the drain plugs? I just changed my oil, and saw some on there. But then, I've always seen some, before and after my rebuild.

Hope this isn't a hijack...
Old 04-25-2010, 06:50 PM
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I have had metal shavings on the magnets each time also which is always kinda scary. The brass is new this time.

Last edited by forwheeler; 04-25-2010 at 08:06 PM..
Old 04-25-2010, 08:00 PM
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Steel metal shavings on the drain plug should go away after a couple thousand miles in a rebuilt motor.

If you see them every time you change the oil it can be a sign that the cam cam thrust plate shim set is wrong and the cam sprockets are not aligned correctly to the intermediate shaft.
If thats so then the inside edge of the chain links rub on the sides of the idler sprocket, cam sprocket, and intermediate shaft sprocket teeth as they rotate and scrape little bits of steel off the sides of them.

You can see if thats been happening by looking for excess wear on the sides of the idler sprocket and cam sprocket teeth when you take the chain case covers off.

A little magnetic paste like sludge stuck to the magnets is usually normal, but continuos shavings are not good.

There's also a chance the motor had a major failure in the past and someone didn't flush out the oil lines and coolers when they rebuilt it and the stuff in the coolers and lines is still moving around with oil flow.
Old 04-26-2010, 08:44 AM
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I should clarify after reading Jims post. What I see is a thick blob of dark paste on the drain plugs. Not too much I'm guessing. I'll take pix next time.

Anyway, sounds normal.
Old 04-26-2010, 10:30 AM
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Yeah it is more fine particles in paste in mine to normally.
Have you ever removed the pan from an automatic transmissions and seen all the "fuzz" on the magnet in there? Doesn't give me a warm feeling but it seems normal.
Old 04-26-2010, 10:41 AM
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Automatic transmissions have wet multiplate clutch packs. As they wear the material has to go somehere.
Old 04-26-2010, 11:22 AM
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