Spray bar blockage.

chiroracer · 04-20-2018, 10:41 AM

Heard more valve noise on rt. bank just before 5K miles valve adjust and oil change. Also changed at 100 miles always Brad Penn. when I was doing the valve adjustment nothing seemed too far off of .004 but I noticed a dark colored cam lobe on the #5 exhaust lobe, no scoring,just darker. The left bank looked pristine but the right bank were not galled or scored ,just darker colored.
I subsequently found a plastic nugget(packing peanut?) in the banjo fitting feeding the cam housing. I changed the oil adjusted the valves and started it up and it sounds fine.

My plan is to run it 1000 miles and check it again and see if it" heals"

Any thoughts? I figure if it starts to make noise I will refinish cam and rockers on this bank anyway if it doesn't work out.

Trackrash · Trackrash's Garage

I agree with your plan of action. Except, I would probably check things after a few hundred miles.

My concern would be what if there is more debris in there? I would also want to figure out how it got there.

Did you drop the sump plate and look at the screen? Probably should cut open the filter as well.

jpnovak · 04-21-2018, 05:14 AM

WHy not spray clean the cam oiling passage and make sure all the spray bar holes are open? Just takes some solvent and some air pressure.

chiroracer · 04-24-2018, 09:11 AM

Thanks,I found the offending piece (large)located in the banjo fitting. the spray bars ended up testing OK.

chiroracer · 04-24-2018, 02:01 PM

I did not end up removing spray bars just cleaned them with carb cleaner and compressed air purge with no additional debris. I think the chunk was a packing peanut about as big as a pea that was in the oil supply line. other oil/ sump looked good. I will pop that valve cover in a couple hundred miles to check it out. Keep fingers crossed for me. I have a spare engine I can slap in , as one does if need be. I can't be without my 911.
I have a spare everything come to think of it. Thanks guys!

Henry Schmidt · Henry Schmidt's Garage

If the spray bar exhibits no external damage (dents from broken rockers being foremost) , we just remove the plugs, clean with an appropriate bottle bush, replace the plugs and go.