did leakdown on old engine

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Apr 24, 2007 | 06:42 PM

muscletruck7379

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Joined: Apr 2003

Posts: 2,703

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From: Harrisburg, NE

did leakdown on old engine

i got an engine out of a free 87 crown vic that had about 150,000 miles (tranny going south), it had also been sitting dormant for around 5 years. after i got it pulled out and somewhat cleaned up in the auto tech shop, i did a leakdown test on it.

now let me remind you,
150,000 miles
5 years
cold engine

what i got was 30% on the highest and 15% on the lowest with most around 22%

i don't think that this is too bad giving the circumstances. plus they were all mostly equal.

i intended the engine to be a quick drop it in and run it for my bronco that has been sitting for a while as well.

so what are your thoughts on my results?

Apr 25, 2007 | 07:26 PM

ReAX

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Joined: May 2006

Posts: 10,007

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From: Central Florida

You might just need new valve stem seals, but as long as it's not your daily it should be fine with it the way it is.

Apr 26, 2007 | 09:29 PM

Rusty_S

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Joined: Apr 2007

Posts: 5,958

Likes: 105

From: Houston

With 30% on one cylinder. I wouldnt push the engine too hard, 30% is what we have been told 5% more than the max allowable. If you have others that are around 15% and 22% then I would recomend you take and squirt 3 oz`s of oil into each cylinder, start with the one that had 30% and then quickly do another leak down test. If you then get the percentage to drop below 30% then dont drive the engine too hard cause your rings are worn actually worn bad enough that you wont have power. Most likely if you havent ran the engine yet, that 30% blow by cylinder will cause the engine to idle rough most likely.

If it was me I would do wet leak down test and if the engine still has the same leak down results i would pull the heads and have the valves and valve seats redone/replaced. Then you should be fine. If not then youll probably have to have the engine overbored, and new piston rings installed.