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YOUR RESEARCHWhat are normal compression numbers for a 3.6 motor?
Leading reported evidence
Run engine as opposed
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Suggestion
This is just giving the valve stem a tap with a hammer (valve stem protected with something), letting the valve snap back into the seat as opposed to being let gently down as with turning the engine by hand.The fit of things can vary a bit from a hot running engine as opposed to a cold static engine.
What are normal compression numbers for a 3.6 motor?
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Leading evidence: 'Run engine as opposed' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Run engine as opposed' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
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Suggestion
If the car is yours, and the engine runs fine otherwise, I'd not worry about it and not bother to do a leak down test unless you plan on pulling the engine to address the cause of the compression test difference based on whatever the leakdown test indicates is the possible source of the problem.
What are normal compression numbers for a 3.6 motor?
Test indicates is the possible source of the problem
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Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
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Suggestion
If the car is yours, and the engine runs fine otherwise, I'd not worry about it and not bother to do a leak down test unless you plan on pulling the engine to address the cause of the compression test difference based on whatever the leakdown test indicates is the possible source of the problem.
What are normal compression numbers for a 3.6 motor?
Test measured
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Suggestion
The annual inspection requires a compression test measured with 80 lbs input through a calibrated orfice.
What are normal compression numbers for a 3.6 motor?
Test returned 3.5-7.4% difference between cyclinders
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Suggestion
My most recent compression test returned 3.5-7.4% difference between cyclinders.
What are normal compression numbers for a 3.6 motor?
Frequently discussed actions (6)
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Run engine as opposed
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Suggestion
This is just giving the valve stem a tap with a hammer (valve stem protected with something), letting the valve snap back into the seat as opposed to being let gently down as with turning the engine by hand.The fit of things can vary a bit from a hot running engine as opposed to a cold static engine.
What are normal compression numbers for a 3.6 motor?
Test difference based
No successful repair reported for this finding.
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Suggestion
If the car is yours, and the engine runs fine otherwise, I'd not worry about it and not bother to do a leak down test unless you plan on pulling the engine to address the cause of the compression test difference based on whatever the leakdown test indicates is the possible source of the problem.
What are normal compression numbers for a 3.6 motor?
Test indicates is the possible source of the problem
No successful repair reported for this finding.
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Discussions that contain suggestions
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Suggestion
If the car is yours, and the engine runs fine otherwise, I'd not worry about it and not bother to do a leak down test unless you plan on pulling the engine to address the cause of the compression test difference based on whatever the leakdown test indicates is the possible source of the problem.
What are normal compression numbers for a 3.6 motor?
Test unless you plan
No successful repair reported for this finding.
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Reported fixes
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Unsuccessful attempts
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Discussions
Read evidence and context
Discussions that contain suggestions
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0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
If the car is yours, and the engine runs fine otherwise, I'd not worry about it and not bother to do a leak down test unless you plan on pulling the engine to address the cause of the compression test difference based on whatever the leakdown test indicates is the possible source of the problem.
What are normal compression numbers for a 3.6 motor?
Coverage and how to read this overview
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
5 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
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Generation: 20261026T152433Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
Also, what would be typical for the leak down figures? Finally, how much differential between cylinders would be considered OK? For example, if all cylinders had one compression reading and one was 10-15% lower than the other 5. Same thing on the leak down numbers. I am just trying to determine if the PPI leak down and compression numbers are good or not. Thanks for the feedback.
Pat
is not real good. They want to be closer than that.
If the car is not yours, then I'd not worry about doing a leak down test. Let the owner sort the engine out and you move on to looking at another car.
If the car is yours, and the engine runs fine otherwise, I'd not worry about it and not bother to do a leak down test unless you plan on pulling the engine to address the cause of the compression test difference based on whatever the leakdown test indicates is the possible source of the problem.
Sincerely,
Macster.
My most recent compression test returned 3.5-7.4% difference between cyclinders.
The first one done a year ago was at 3.7-5.5%.
It's a 2002 C4S @ 86k miles, original engine.
I have owned an aircraft for twenty years. The annual inspection requires a compression test measured with 80 lbs input through a calibrated orfice. It is well known that the compression on good cylinders will "wander" from year to year. One source is the engine temperature at the time of the test, with hot engines usually scoring a bit better. The other factor is the position of the ring gap on the piston, if the gaps "line up" there will be a somewhat lower reading.
If one jug is low without other symtoms, a retest after running the engine a bit will sometimes find the compression back up. Although probably not possibel with a Porsche engine, "staking the valves" can be tried. This is just giving the valve stem a tap with a hammer (valve stem protected with something), letting the valve snap back into the seat as opposed to being let gently down as with turning the engine by hand.The fit of things can vary a bit from a hot running engine as opposed to a cold static engine. Of course if the difference is dramatic further investigation is warranted.
This is a source reference. Confirm exact model applicability in the original material.
