leak down test ???

[i c e b l u e]

     We think we're burning to much oil.  It's a fresh   440   with 2000 miles on it .  How does one perform a leak down test?           ken and marcus 

[Plumcrazy]

You would need a leak down tester and an air compressor.  The tester will come with detailed directions.
But I don't think a leak down test will tell you the whole story.  It mainly checks the compression rings and valves.

How many miles can you drive before you need to add a quart of oil?

[John_Kunkel]

I've done leakdown tests on engines that used a quart of oil per hour and had only 1-2% leakdown. Almost useless for checking the source of oil consumption.

What do the plugs look like?

[firefighter3931]

I agree with Plum And JK....it's too early to tell if there's really a problem. A compression test might shed some light into the problem. A wet and dry compression test will give you some clue as to the condition of the rings. You could be sucking oil into the chamber by way of a leaking intake manifold gasket or defective pcv valve.

Like the others said....how much oil is it consuming and how do the plugs look ?

What type of rings were used during the rebuild ?


Ron

[i c e b l u e]

I plan on checking and changing the plugs tomorrow. However last time i checked the plugs two of them had oil corrosion i believe cylinders #3 and #6. I will check the pvc valve because it is original but i think that would result in oil on all cylinders. We used toal seal rings with the gapless top ring. I intstalled each piston and precisely set all of the gap locations, as for the fitting was done by the machine shop. it seems to consume about a half a quart a week or so with very little mile a week. However, I never see blue smoke.? I will let you know on the plug situation tomorrow

[is_it_EVER_done?]

I agree that you need to pull the plugs to see if any show more oil than others, as you could have a intake leak, but I'm guessing that the gapless top rings are the problem.

They are notorious for causing oil consumption problems, as the second ring does not get compression/combustion pressure to force it against the cylinder wall, so instead of scraping the excess oil off, it hydroplanes over it, leaving the top ring to do all the work.

I hope you find another problem, but even with a really good crankcase ventilation system, the applications I have seen use oil. On the plus side, many people don't mind adding a quart or so more frequently, and the excess oil doesn't seem to cause any real problem.

[firefighter3931]

I agree that you need to pull the plugs to see if any show more oil than others, as you could have a intake leak, but I'm guessing that the gapless top rings are the problem.

They are notorious for causing oil consumption problems, as the second ring does not get compression/combustion pressure to force it against the cylinder wall, so instead of scraping the excess oil off, it hydroplanes over it, leaving the top ring to do all the work.

I hope you find another problem, but even with a really good crankcase ventilation system, the applications I have seen use oil. On the plus side, many people don't mind adding a quart or so more frequently, and the excess oil doesn't seem to cause any real problem.

I haven't used the gapless style rings personally but have read of similar issues with oil consumption. I'd still swap out the pcv valve to eliminate it as a potential problem and run a compression test to make sure all is good.

The fact that you're not seeing any blue smoke and a few plugs are oil covered leads me to believe that there might be some oil seepage into those intake ports via the manifold gasket.


Ron