997 Engine Compression and Leakage Values
Discussion
Just had the ridiculous engine compression and cylinder leakage test completed for Rev Rang3 coming up in renewing my warranty for my 997 – bought from OPC 2 years prior, and RR3 recorded in 2008 according to their readouts..i.e before they placed the last warranty on it and before my ownership.
Anyway it was all clear and warranty was given but I was wandering what are good/expected Compression and Corresponding leakage values across all 6 cylinders for a 7 year old 997 C4S ?
Does anyone know? mine were around 18.3-18.5 bar and 4-5% leakage.
Thanks.
Anyway it was all clear and warranty was given but I was wandering what are good/expected Compression and Corresponding leakage values across all 6 cylinders for a 7 year old 997 C4S ?
Does anyone know? mine were around 18.3-18.5 bar and 4-5% leakage.
Thanks.
steing said:
Just had the ridiculous engine compression and cylinder leakage test completed for Rev Rang3 coming up in renewing my warranty for my 997 – bought from OPC 2 years prior, and RR3 recorded in 2008 according to their readouts..i.e before they placed the last warranty on it and before my ownership.
Anyway it was all clear and warranty was given but I was wandering what are good/expected Compression and Corresponding leakage values across all 6 cylinders for a 7 year old 997 C4S ?
Does anyone know? mine were around 18.3-18.5 bar and 4-5% leakage.
Thanks.
Pressure values from a compression test and leakage rates for various engines are like fuel or oil consumption. Otherwise equally fine engines will have different numbers.Anyway it was all clear and warranty was given but I was wandering what are good/expected Compression and Corresponding leakage values across all 6 cylinders for a 7 year old 997 C4S ?
Does anyone know? mine were around 18.3-18.5 bar and 4-5% leakage.
Thanks.
Without digging into the math the 18.3 bar to 18.5 bar is "about" right.
More importantly is the cylinders do not differ very much at all. A general rule of thumb is the difference between the highest reading and lowest reading cylinder wants to be 15% which is ok, but 10% or less is better.
You have to be careful. Compression test a hot engine which is preferred and by the time you get to the last cylinder the engine may have cooled some and enough the reading from the last cylinder will be lower than it would be otherwise.
As for leakage percentage? Same with the compression test results. No big variation cylinder to cylinder. Really though a leak down test is worthless in this context.
The main things are: 1) The engine appears to have been running just fine before the compression test with no misfires, the CEL was off, and with no other signs of distress; 2) The company underwriting the warranty was happy with the numbers because you got the warranty.
That the company relied on compression test/leak down test when the DME does a far better job of nonitoring the engine's performance *while it us running* suggest to me the company is a bit behind the times, like nearly 20 years...
Anyhow, the engine runs fine. You got the warranty for the car. Relax.
Except for one thing that bothers me. I do not like the fact the engine was compression tested and the plugs were reused.
The plugs should have been replaced. The plugs are meant to be installed as they come out of the box and with no thread lube or whatever and then if removed replaced. If the plugs were reused there's an increased risk the plugs could develop corrosion and if left in service too long seize in the threads in the head. The plug change interval is miles or time based. The change interval based on time is itself based on the assumption the plugs were installed new and as directed by the factory.
Like I said ...about 20 years behind the times.
Thanks for the Info, and just to be clear as I didn’t explicitly mention it in my 1st post is that the warranty was the official Porsche warranty not a 3rd party one etc.
I had to pay for the check I tried to negotiate but got no where, OPC said this was new rules from Porsche HQ and wouldn’t budge! However since then I have seen some reports on forums that some people have been able to get the OPC to absorb the cost but I was having no luck and I wanted the 2 year extended warranty put on so had no choice.
I had to pay for the check I tried to negotiate but got no where, OPC said this was new rules from Porsche HQ and wouldn’t budge! However since then I have seen some reports on forums that some people have been able to get the OPC to absorb the cost but I was having no luck and I wanted the 2 year extended warranty put on so had no choice.
steing said:
I had to pay for the check I tried to negotiate but got no where, OPC said this was new rules from Porsche HQ and wouldn’t budge! However since then I have seen some reports on forums that some people have been able to get the OPC to absorb the cost but I was having no luck and I wanted the 2 year extended warranty put on so had no choice.
That's pretty poor service if the rev range records were there when you bought the car from them and you have a record of this.steing said:
Thanks for the Info, and just to be clear as I didn’t explicitly mention it in my 1st post is that the warranty was the official Porsche warranty not a 3rd party one etc.
I had to pay for the check I tried to negotiate but got no where, OPC said this was new rules from Porsche HQ and wouldn’t budge! However since then I have seen some reports on forums that some people have been able to get the OPC to absorb the cost but I was having no luck and I wanted the 2 year extended warranty put on so had no choice.
Porsche requires compression/leak down tests? That is news and one I'll research Tuesday.I had to pay for the check I tried to negotiate but got no where, OPC said this was new rules from Porsche HQ and wouldn’t budge! However since then I have seen some reports on forums that some people have been able to get the OPC to absorb the cost but I was having no luck and I wanted the 2 year extended warranty put on so had no choice.
mollytherocker said:
Its like they know about some sort of inherent problem with them? We should be told.
Well, let's not get all carried away just yet.While I believe the person who posted the compression/leak down tests are now required by Porsche I may not believe his source. I am not saying the source lied, that maybe the source of the info the OP posted may have got the info twisted.
I've heard nothing about this from the various dealerships I visit and with the techs I spend time talking with, but maybe something on this has just come over the wire from PCNA or even the factory.
OPC said Porsche HQ changed the rules on this last year I can’t remember exactly when they said. Checking around the net and other forums a number of folk have mentioned this across I assume different OPC’s so I don’t have any reason to suspect my OPC being incorrect in this regard despite me personally thinking it is a money spinner from Porsche and ridiculous especially when in my case the issue happened 4 years previously and they’ve sold the car before on that basis….anyway here’s an example of somebody else mentioning it on here http://www.pistonheads.com/gassing/topic.asp?t=121...
Cheers
Cheers
No conspiracy - as of last year any car renewing warranty will have to undergo leakdown and compression test if significant over revs on ECU interrogation. If you pass (whatever the threshold is) then you get warranty, if you fail, tough. And it makes no difference how long ago the over rev ocurred. Level 3 is the cut off I think.
Gassing Station | Porsche General | Top of Page | What's New | My Stuff