compression pressure

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Mar 12, 2018 | 03:26 PM

6.0 and 7.3 United

Thread Starter

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Joined: May 2016

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From: Frederick, MD

compression pressure

I am looking for the compression pressure for a 2001 ford f250, 7.3 diesel.

Is there a service manual that would have this information in it?

Let me know your thoughts.

thanks,

Mar 12, 2018 | 04:39 PM

DogRidesInBack

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Joined: Jul 2017

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General understanding is I would expect to see around 400 pounds. Not documented or tested, just my gut feel for this engine.

This is with good batteries and starter, excellent cables, all glow plugs removed, and at least 6 "puffs."

But I'm not hung on a number. Personally, I like to see no more than 15% between the low and high cylinders, but have read the spec for the 7.3 is 25%, I have not found an actual document, I've just got the anecdotal 25% spec with no specific pressure.

I do not get hung on the actual numbers with compression, I look at the relative values.

Now, if your engine shows excessive blow by (quick oil cap test), and all numbers are low, then I would squirt a little oil in each cylinder and see it the numbers bump up a lot. That would mean rings are bad. If the oil does not bump the numbers, then I would look at valve guides. If it is valve guides, you will also be able to see that when running the engine without valve covers.

Mar 15, 2018 | 12:35 AM

retiredsparky

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Joined: Sep 2011

Posts: 979

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From: Vancouver

Dog is right, both the 7.3 and 6.0 are around 400 psi cranking with glow plugs removed. I have tested multiple engines over the years and gotten that reading.