6.0 L engine with 348000 miles on it. Lifter clatter seems to be mostly out of the Left Bank. Would changing the oil pump help or is it deeper than that?
6.0 L engine with 348000 miles on it. Lifter clatter seems to be mostly out of the Left Bank. Would changing the oil pump help or is it deeper than that?
I've never seen an oil pump come apart but if it has over 200k with the original oil pickup tube O-ring, it has probably shrunk and the pump is sucking air.
The oil pan gasket is probably heaving at the oil passages anyway, right?
Sorry knurled I don't understand heaving at the oil passages? The truck doesn't seem to leak any significant amounts of oil, and the clatter is mostly at startup or when it gets to operating temperature.
Is it better or worse after an oil change?
In reply to TRoglodyte :
The oil pan gasket is usually leaking heavily by that age if it's never been changed before. Maybe you lucked out or it is only some production runs.
The oil pickup tube seats in the pump with an O-ring that is poorly captivated. When age and heat make the material shrink, the oil pressure drops to around 15-20psi and the oil in the passages is all aerated, which makes the lifters unhappy.
You need to drop the pan to change the pump anyway.
Is the noise just until the oil pressure comes up, and does the oil pressure come up right away? If so, it's probably lifters.
It's not busted exhaust manifold bolts, right? The will pop cold, and some will seal back up pretty quickly as they warm.
The only other thing I've seen make noise in an LS valvetrain is hard surface coming off the nose of the cam lobe and roller, or the lifter turning sideways, but that doesn't ever shut up.
In reply to dean1484 :
fresh oil seems to make very little difference
In reply to Knurled. :
Should I put a high volume pump on it?
In reply to Streetwiseguy :
Cam and lifters will probably be the next thing if the oil pump doesn't cure it?
At 348,000 miles, I'd be pretty nervous about taking things apart. Odds are, you are going to see stuff that makes you go "Hmmm". Heads have to come off to get the lifters out, and that could expose all sorts of wear.
Lifter noise is the result of low oil pressure. With that mileage it could be anything. Worn bearings are a likely possibility that hasn't been mentioned.
So if you are going to do the pump you might as well do the bearings while you a in there.
TRoglodyte said:In reply to Knurled. :
Should I put a high volume pump on it?
No.
In reply to TRoglodyte :
Are you absolutely sure it’s lifters? Very common on that engine for wrist pin to clatter. If that’s the case your best action is to ignore it. We use those engines in the short school buses and once in a while they clatter from the wrist pin.
The bus company has over 100 of those and never lost an engine.
Thanks for all the input, it clatters on Startup and when it gets up to operating temperature. I may just ignore it until it gets too obnoxious. I can buy a rebuilt long block for $2200
Are you sure it's the same clatter hot and cold? I'm pretty sure they all have piston slap when cold. Is it constant or does it vary in volume/tone with load/rpm?
What does the oil pressure look like? Hot idle, cold idle, hot cruising, etc. Note that it takes the oil a bit longer to heat up than the coolant.
High volume pumps are mostly for race applications with loose bearing clearances, lots of oil squirters, etc. On a stock engine it will just be in bypass (too much pressure) most of the time, wasting power and heating up the oil doing it.
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