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You are here: Experts > Shopping > Vintage Cars > Vintage Cars > 1978 SLC noise
Expert: Ron
Date: 9/24/2008
Subject: 1978 SLC noise
Question
QUESTION: I have a 1978 450 SLC. It has upper engine noise. (clattering). I removed the Cam Covers and discovered that everything is clean. The dipstick shows clean oil, as clear as new.The oiler tubes are clear. The plastic fittings are intact. I removed the Oilers and there is no oil coming from the holes in the side of the cam bearing supports. The rockers are all loose when the cam is off of them. It seems that all the lifters are collapsed.
Is this a sign of the oil pump not producing pressure? I find it difficult to believe that all 16 lifters are out at the same time or that all 10 oil passages are clogged at the same time.
What do you suggest?
ANSWER: what does your oil pressure guage say in the car at idle?
Clatterring at start up would suggest timing chain issues. How many miles?
Have the valves been adjusted to spec?
have you visualized the cam lobes and oiling process through the oil fill hole?
Let me know
Ron
---------- FOLLOW-UP ----------
QUESTION: Haven't checked the gauge. The clattering is the loose rockers as the lifters are collapsed. (No oil) Don't know about the adjustment. Don't the lifters need to be pumped up to adjust the valves? There is no oil being pumped out of the holes in the cam bearings where the oilers attach. This true of all 10 places
Answer
The 78 has hydraulic ball studs, and it sounds like you have a sticky stud (or maybe several sticking studs). Try cleaning them all first and de-gunking them in some type of carb cleaner, then re-oiling and re-installing them.
If it isn't a tapping but more of a rapping, you have bigger issues. Usually the bottom end on a 4.5 is bulletproof unless it was run low on oil or overheated, .
Before you go and replace the ball studs, try a quart of Rislone oil treatment. I have heard this to be effective
one of my fellow MB listserve guy gave me this information:
The cam shouldn't have a mirror finish on it (although this is almost always common on the lobes themselves), a mirror finish typically indicates wear through the hardened surface - the non-raised parts should at least have this visible. Inspect all of your lobes, none should be flatspotted or have angles at the tips, it should be a smooth curve - not a sharp one. The plastic oiler tube bits are cheap and available in a kit.
Flat rockers almost always mean the lobes on the cam for those are flat too. Closely inspect the lobes that were on those. Flat rockers WILL cause a loud top end.
hope this helps
Ron
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