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Purchased this truck on Oct 4th. Records that I have would indicate that the original motor was rebuilt in March 1993, 71k ago. Oil was unknown brand/weight/time in use. It was unfortunately 3qt low out of 6. I put in 2qt of 5w30 and drove it about 75 miles home.
Changed the oil 2 days later and sent a sample off to Blackstone.....
Ignore mi on unit (that is 158,701 on chassis, engine has a little over 71k).
Analysis looks pretty decent.Put some miles on it and watch oil consumption. PO probably drove it a million miles without checking oil level.
thanks- it was running too rich when I got it, so I was concerned with fuel in oil (which doesn't seem too bad) or water (none--good).
The truck only saw about 3000 miles in the last 10 years, so consumption is indeed what I'll be watching for.
I did a dry cold compression (148-153, with most cyls at 151), and also a leakdown test (all cyls were very even). One thing of note is a rapid vacuum fluctuation at idle, which I'm led to believe could be worn valve guides (and maybe seals too). If so, that may also correlate to oil consumption. No blue smoke that i can discern, but we will see.
The iron did catch my eye. perhaps from 'dry' startups following low/non-usage?
You might check for an intake manifold leak.They can cause oil consumption with little to no exhaust smoke and depending on where the test port is in relation to a leak,might cause vacuum fluctuations.Just throwing this out there....Lots of gasket failures in that area with certain gaskets...
You might check for an intake manifold leak.They can cause oil consumption with little to no exhaust smoke and depending on where the test port is in relation to a leak,might cause vacuum fluctuations.Just throwing this out there....Lots of gasket failures in that area with certain gaskets...
My 460 consumes more oil than I would expect, based on the general engine condition, and lack of smoke. I'm interested - how does an intake manifold leak cause oil consumption with little to no exhaust smoke?
Coincidentally,a friend has a recent stock 460 rebuild.Compression and leak down were good.It had excessive oil consumption along with a very slight miss at idle...no visible smoke.The vacuum needle bounced more than expected and we assumed there was a vacuum leak.We couldn't find one at first so we pulled the intake and found a gasket failure on one port in the valley.This turned out to be both the vacuum leak and oil problem.The block and heads had been resurfaced and there was a slight mismatch on the intake.New gaskets and a small bead of RTV on all the ports cured the problem.Worth a shot if you can't find any other problems.
You might check for an intake manifold leak.They can cause oil consumption with little to no exhaust smoke and depending on where the test port is in relation to a leak,might cause vacuum fluctuations.Just throwing this out there....Lots of gasket failures in that area with certain gaskets...
I did spend some time with the carb cleaner spray today. I'll start a new thread.
As for the vacuum flux, if i use a small 'sensitive' gauge salvaged from my mityvac that the potmetal housing broke the needle is quite jumpy between say high17/low 18 and 20-21.
If I use 2 different large vacuum gauges, the reading is very steady around 18-19 (I suppose those have "damped" mechanisms....)
