csorrows

Saw a thread here that said it's important to have a DME check done to see if a car has had any overrevs, and in what RPM ranges, to know if there might be potential "denied warranty" items later.

Does anybody know when you get a Porsche CPO warranty on a car, if they already do that check and verify overrevs aren't an issue? I suspect I should specifically ask for a DME printout of my own?

cpbmd

I have been looking at a number of CPO'd 997's this week all over the Northeast. The DME scan is not part of the CPO process. I have asked that question at a number of places. All of the dealerships had to have the DME report printed for me as they had never looked at it during the CPO process. I looked at a few 997's from independent dealerships that had the DME's ready to show. I think from the dealership prospective a DME scan can only hurt them so they don't bother to show it to the customer the scan. Most customer have no idea about it so why introduce data that may sour a deal.

Now if there are range 5 and 6 over revs on the scan unknown to the customer and there is engine work that needs to be done under warranty, the warranty may be voided and the customer may have to pick up the tab. Buyer beware!

utkinpol

depens of what you mean by 'CPO process'. it will be done for sure when you blow your engine, so, usual advice is to do PPI when you buy used car and have existing overrevs documented.

on a blown motor if overrevs in sections 4+ are discovered it means no warranty. don`t money shift.

slider

I looked at a CPO C2S with bad over rev issues. The dealer was aware, and claimed they'd honor the CPO if there was an engine issue, but I could never get a iron clad "yes, we will fix it". I could have gotten it in writing, but at the end of the day, I went with a never-abused C2S without a CPO. Why buy a car you know has been abused at the track?

alexb76

Quick question, how does the engine even over-rev? doesn't the ECU kick-in to stop over-revving? Is it mostly due to Mis-shifts?

cpbmd

Were the over revs in the range 5 and 6. I understand that range 1-3 is normal. Would you agree with that? I had one mechanic from Porsche tell me that they have received new cars from Germany with range 1-3 over revs!

ADias

Yes money shifts (mis-shifts). Engage a second when it should have been a 4th, for example. Many hot-heads do that.

csorrows

Dealer printed out DME report, and I'll be looking it over this weekend.

I think he said there were some "1" ignitions in the higher ranges, but from what I've read here, those "1" entries might be a fluke. He said one of the service guys said it happened either 40 hours into the engine, or more than 40 hours ago, or something like that...it had something to do with engine hours, and that it wouldn't affect the CPO warranty.

Anyway, I need to collect more details this weekend when I go back up there.

Is there anything else in a DME printout that I need to look for? Or is the overrevs/ignitions the main thing?

GSIRM3

I think the DME over rev report is something that Porsche would rather not know the answer to, until you have an engine problem. If they do a DME scan as part of the CPO process and find over revs, especially in the higher ranges, they are stuck with either issuing the CPO, or denying it. If they issue it knowing about the over revs, they are basically removing a future option to deny a engine warranty claim as a result of the over revs. If they deny the CPO coverage, then that sends a signal to a buyer that the car will not be covered for future engine claims. That would make it very difficult for the dealer to sell the car if the customer asks why no CPO and the dealer has to say Porsche would not cover the car.

This is Porsche's version of "don't ask, don't tell".

utkinpol

during PPI request to do DME scan. They will not do it by default.
problem with all those overrevs is that dealer sells you CPO but it is not a dealer who decides to cover or not your engine by warranty when it blows so it you had any pre-history of abuse on the car you will need a concrete proof it was done before your purchased it. even with a proof it is an additional pain and question is - why do you need it if there is plenty of non-abused used cars out there.

Ranger911

Alexb76, the short answer is that an "over-rev" is a missed downshift. The "rev-limiter" function only applies on upshifts. One can bang their car off of the rev-limiter all day long without an "over-rev", because of the ecu retarding throttle, etc.

The dreaded "money-shift" is the slang term for the "over-rev." As ADias notes, this happens when one goes to downshift from a higher gear and misselects the lower gear. (Most extreme example, driver intends to go from 6th to 3rd, but selects 1st, lets out the clutch and BOOOOOM--"over-rev" occurs as RPM spikes and no ECU intervention occurs(rev limiter does not intervene). Anyone with a better technical definition feel free to chime in...

Hope that helps.

csorrows

Thanks for the replies.

I'm going to tell them that as part of the purchase, I'm going to insist on some verbiage on dealer letterhead stating that the overrevs on that DME printout (and I'm also going to include the actual numbers in the verbiage) occurred prior to my purchase and the CPO being issued, and then have it signed by their service manager.

I used to be a real estate agent, so I'm well aware of "if it's not in writing, it's worthless."

As far as other cars out there, unfortunately my selection is very very limited. I'm only willing to look at Guards Red and Speed Yellow, I don't want a black interior unless it's got some of the interior trim items painted in the exterior color, I don't want a 2005, and my budget only permits me to look at model years 2006/07, and maybe some 08's. None of the 09's I've seen out there I can afford.

Also, I really only want to find one in California. It's too much of a hassle, and too expensive, for me to fly (especially cross-country) looking at candidate cars and then have to pay shipping, or drive them, back.

Lastly, it has to be CPO-able, which means buying from a Porsche dealer only (no non-Porsche dealers), or private parties that already have a CPO on the car.

The one thing that's affecting the number of choices the most is my color preferences. There just aren't that many red or yellow ones out there, especially ones with interior trim in exterior colors. In the six months I've been looking, I've only seen two cars I liked. It's that second one I'm looking at now.

EDIT: I wasn't planning on doing a separate PPI check, since the dealer has to do the CPO inspection and service, and I'm requesting my own DME printout. Do I need a separate PPI check and if so, would I pay that dealer to do it, or would I need to take it to an independent mechanic?

Thanks!

gota911

That ^ is not true. While you are correct that the ECU will cut off the fuel supply when you hit the rev-limiter, the momentum of the engine can still continue to increase the RPMs above red line limit. You can get over revs in ranges 1, 2, and possibly range 3, by bouncing off the rev-limiter.

User 4621

I bought my car knowing about an overrev. It was the typical 2 instead of 4 downshift and hit range 5 for 1/10 of a sec somewhere around 8600 rpm if I did the math right. It ran great with a perfect PPI so I didn't care.

I had it in for service and a few minor warranty fixes after the overrev and it was never an issue or warranty problem (2 different dealers). Yes they noticed because they mentioned it in passing.

The overrev happened at around 10k miles and now at 30k miles and a few years later the car runs perfectly in every way, I would argue better than other 997's I've driven.

IMO, an overrev will either hurt your engine or it won't. If it hurts it will be pretty obvious. Maybe I'm just used to buying older 911's where there was no way to tell, and we didn't care as long as it ran properly.

I'd rather have a "lugging engine all day in 6th gear and 1K rpm and riding the clutch in traffic" readout.

bbrc76

For what its worth, someone once described the "money-shift" to me as a "mechanical" over-rev. Think about the rear wheels turning at a given speed, then a missed down-shift, such as selecting 2nd when looking for 4th, then let out the clutch... the electronics that manage the engine cannot over compensate for the mechanical push coming from the rear wheels, thru the transmission, into the engine.