PPI good news/bad news
06-25-2012, 08:35 AM
#1
Rennlist Member
Thread Starter
PPI good news/bad news
Excerpt from a PPI on an S3 with approx 90k on the odometer below. Good news - crank endplay well within spec. Bad news - compression, oil fouled plugs.
Compression test done on cold engine. Shop doing the PPI found on a recommended installer list from one of the suppliers well known and often used by members of this community.
Thoughts?
check comp one at 125PSI, 3 at 145 rest 150,2 have oil build up on plugs and piston, intake had lots of oil in it (blow by?) messure crank endplay 6 thousandths
Thoughts?
06-25-2012, 10:07 AM
#2
Rennlist Member
It sounds suspiciously like a ring problem (125 cylinder) ... but a leakdown would really be called for to nail the cause (ring/bore, gasket, valves). A leakdown will give a dramatic leak difference with a failed ring, with massive blow-by out the oil filler. Also .... If it is a ring issue, squirting about 10ml of oil into the low cylinder and repeating the compression test will give a dramatic rise ... 50 or so lbs versus 20+ on a cylinder in the normal range. A borescope can also give a few more clues.
06-25-2012, 11:57 AM
#3
Rennlist Member
Thread Starter
I am running away from this one. Very disappointed, but life goes on.
Lesson learned - If you get a compression test in a PPI, tell the shop to do a leakdown if they come up with anything funky.
Lesson learned - If you get a compression test in a PPI, tell the shop to do a leakdown if they come up with anything funky.
06-25-2012, 12:01 PM
#4
Race Car
06-26-2012, 05:59 AM
#6
Rennlist Member
Looking forward to seeing the pics when you find it.
06-26-2012, 07:16 AM
#7
Craic Head
Lifetime Rennlist
Member
Lifetime Rennlist
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This was really good news-good news. I wish that PPI could somehow stay with the car though. The next person to come along may not know this info and buy it anyway...
For you, information is never a bad thing, it's what you do with it that makes it either good or bad news. You made an informed choice and passed on this one.
I'm not sure if you're going to be able to ask someone doing their 'standard' PPI to follow up on the results of one test with another, but who knows. What you call 'funky' may not be so odd to someone else so you should probably give detailed instructions like: 'if the compression is more than 10% different on any cylinder, please follow-up with a leak-down to determine the cause.' Or something like this. (I forget if 10% is the rule or what, just an example).
These cars are getting harder and harder to find and the division between the real hard-luck stories and the garage queens is getting wider. I think very soon the survivors will show themselves and the rest will just be parts cars.
For you, information is never a bad thing, it's what you do with it that makes it either good or bad news. You made an informed choice and passed on this one.
I'm not sure if you're going to be able to ask someone doing their 'standard' PPI to follow up on the results of one test with another, but who knows. What you call 'funky' may not be so odd to someone else so you should probably give detailed instructions like: 'if the compression is more than 10% different on any cylinder, please follow-up with a leak-down to determine the cause.' Or something like this. (I forget if 10% is the rule or what, just an example).
These cars are getting harder and harder to find and the division between the real hard-luck stories and the garage queens is getting wider. I think very soon the survivors will show themselves and the rest will just be parts cars.