What is a "reasonable" number of Type 2 Over revs to see on a PPI? Is anything over zero still OK?

I am looking at an 03TT with 8K miles from an independent dealer and waiting until Monday on a PPI result. The tech at Champion needed to get an explanation of the Type 2 OR's from the shop manager. I didn't get the raw number, and I'm concerned about where to place the decision point on whether the engine was abused. The car has 17 months of original factory warranty left which is a big plus which could evaporate if Porsche determines the number is too high and voids it.

I realize there is no absolute right number (other than zero) and I'll only be guessing how another dealer might interpret the T2 OR's down the road, if I buy the car. So, I am just looking for some opinions from the forum.

Thanks,
Carmen

 

Reasonable is in the eye of the beholder...Porsche can and has denied claims because of Type2's...I have a CPO car that had a few early on the engine clock and the car has had both major and minor warranty with no issues...Whatever you do, since the car looks like it may still have warranty, get it in writing..Kevin

 

I copied this awesome post from rennlist hope it helps.....

Type 1 and Type 2 Over-revs
I discovered some information on the Type 1 and Type 2 over-revs that I would like to share. I purchased the Durametric OBD-II software and cable set a week ago and have evaluated my error codes and Over-Rev Counts The count that is recorded, and cannot be erased to my knowledge, is a count of the ignition firings above the redline threshold. It is not the total of the times that the engine has breached the redline value, as I was led to believe. The count is broken down into the two categories and I'm not sure how it does this, but it just does.

A Type 1 is an over-rev condition that thru to engines own inertia or power stroke has exceeded redline and the DME has fired the ignition during above redline and the condition has recorded the individual firings. It also records the time (Total Hours) and is revised at each event.

A Type 2 is an over-rev condition when an external force has caused the engine to speed beyond the redline threshold such as down shifting to a lower gear and engine matches the rpm of the transmission input shaft.

The difference between the two may sound subtle, but is more involved.

In a Type 1 condition, such as when one misses and up-shift. The engine is in a free-wheeling state and the internal energy is acting on the rotating and reciprocating mass. The crankshaft is unloaded for a brief moment and there is still some force on the top of the piston during most of the 4 stroke cycle.

Type 2 conditions are not healthy for the rod and rod bolts, although there must be some design reserve before yield. When one down shifts to a gear which leads to an over-rev condition, there is little energy pushing down on the head of the piston to keep the rod in a compression mode. The crankshaft is pushing violently on the rod and then jerking the piston and rod assembly back towards the crank centerline. The rods are primarily designed for a compression mode, meaning forces enacted on the top of the piston and imparting energy into the crankshaft via the connecting rod. The connecting rods and bolts really don’t like the dynamics in a stretching mode and this condition leads to material yielding. This is the condition that causes the rod bolts to fail. They yield during the stretch. The connecting rod can also yield due to stretch, but that is seen more with Aluminum Connecting Rods.

When I saw the number of type 1 and type 2 over-revs, my heart started to race. I was thinking that the engine was going to explode at any time because of the previous driver was thrashing the engine. Well when I came to my senses, I realized that the counts were ignition firings, and that at 6,700 rpm’s there are 55.8 firings in a given second, I felt a little better. Consider the actual time the engine is in an over-rev’ed mode. The DME caught the condition, responded with the appropriate shut down to protect the engine. This would be the dwell time of what, may a second or two. So at 2 seconds there were 112 firings. So if your count was 1435 over-rev firings, then it would have been 13 times that the engine over shot the redline. The type 2 over-revs were 91 and means that maybe someone jammed it into a lower gear just once.

After reviewing the number, I concluded that my numbers were not that bad and although it was not lily white clean, my engine was not thrashed because what I saw as a high count.

 

Agree...my car had 28 ignitions of Type II. Freaked me out at first but when I realized that it was less than 1 second I quickly got over it.

Type I are not that big of deal since the computer can protect the engine.

 

Would increasing the redline (ECU mod) cause type 2 over revs?

 

No, type 2 is a forced mechanical over rev.

 

Thanks Tom for the post. I'll use it when I get the call tomorrow. Hopefully it will be a LOW number!

Carmen

 

You are welcome Carmen, good luck!!

 

Got the number from the Service Manager at Champion. Type 2's were 96 which looks like one time event of less than 2 seconds. They felt this would not be a warranty issue and reported the car drove fine.

Carmen

 

I have a couple print outs of these. If I remember Ill scan them in soon and post them for you guys to check out.

 

Carmen that sounds good but remember the dealer has the option of voiding a warranty with type two over revs if there is a valve train or mechanical problem, buyer be ware, just looking out for you, but sounds like all is well!

 

Porsche voids the warranty for type REV2 violations of any sort. PERIOD. Once this has happened, you are now in a dealer-relationship-thing and have to hope your guy is nice. If you get the car from a third party and go to your local dealer whining about popping out of second, you stand a nearly certain chance of paying top dollar for the repair if you have a REV2.

My dreadful experience about this very issue on my PPI USED X50 with PAG leads me to say that you should not get a used 996TT with REV2 overruns. PAG is using this as an excuse to avoid warranty repair. And these things do have reliability issues.

 

Ah, Carmen that's what I meant!!!

 

but I'm a little puzzled.
I've had my TT from new and can honestly say I've never had a mechanical over rev by changing to a lower gear too early. What's more apart from when its been in for service I've always been in it when someone else was driving - again no mechanical over rev which might have been logged as a type II.

I have however hit the rev limiter in 1st a couple of times (who hasn't?) - but yet when it was recently in the dealer for a service they commented on a type II over rev !!

I denied it was me and asked when it was logged - they couldn't tell me.

Makes me wonder......

 

Well, I was going to buy the 03TT anyway since the number is low, but now I'm not sure. Sounds like a potential recipe for disaster. One of main selling points was 17 months of original factory warranty. TIPS are looking better all the time...ah well. Thanks for all the info.

fore warned...
Carmen