Notices
991 2012-2019
Sponsored by:
Sponsored by:

Thoughts on a high mileage but Porsche cert 991.1?

Thread Tools
 
Search this Thread
 
Old 06-28-2024, 04:49 PM
  #1  
DC911S
Drifting
Thread Starter
 
DC911S's Avatar
 
Join Date: Oct 2014
Posts: 2,674
Received 242 Likes on 151 Posts
Default Thoughts on a high mileage but Porsche cert 991.1?

I was not really looking for it, but a casual scan and I found a nice 911 C4S with PDK and lots of options that’s Porsche certified with full two year warranty. But it’s got 80k miles on it. I was out on my Ducati and stopped by to take a look. It’s super clean. You’d never know it had that many miles. All service records too. So it’s all up to date with belt, oil and filter, pdk service, spark plugs and more. Had my bike gear on so didn’t drive it. But will tomorrow. Sooo anyone in here got a high mileage 991.1? Thoughts?
Old 06-29-2024, 01:49 AM
  #2  
na4life
Instructor
 
na4life's Avatar
 
Join Date: Feb 2021
Posts: 141
Received 121 Likes on 52 Posts
Default

It’s my experience that cars that actually get driven end up being far more reliable. These cars will happily live very long lives. I personally wouldn’t hesitate for the right price.
The following 2 users liked this post by na4life:
sletcher (06-29-2024), Watson (06-29-2024)
Old 06-29-2024, 09:48 AM
  #3  
JeepJLU2020
Instructor
 
JeepJLU2020's Avatar
 
Join Date: Aug 2021
Posts: 105
Received 25 Likes on 17 Posts
Default

I just got a 2015 911 GTS with 69k. Same as your car can’t tell has 69k miles on her. But would definitely get a PPii done, even though CPO car.
Old 06-29-2024, 10:50 AM
  #4  
Sledge911
Track Day
 
Sledge911's Avatar
 
Join Date: Jul 2023
Location: Atlanta
Posts: 18
Received 21 Likes on 11 Posts
Default

Originally Posted by DC911S
I was not really looking for it, but a casual scan and I found a nice 911 C4S with PDK and lots of options that’s Porsche certified with full two year warranty. But it’s got 80k miles on it. I was out on my Ducati and stopped by to take a look. It’s super clean. You’d never know it had that many miles. All service records too. So it’s all up to date with belt, oil and filter, pdk service, spark plugs and more. Had my bike gear on so didn’t drive it. But will tomorrow. Sooo anyone in here got a high mileage 991.1? Thoughts?
It’s certified for two years so not too much to worry about. If serviced, not a lemon based on service record and no accidents I wouldn’t worry. After the 2 years you will know if keeper or not.
Old 06-29-2024, 11:50 AM
  #5  
Watson
Burning Brakes
 
Watson's Avatar
 
Join Date: Dec 2018
Posts: 1,086
Received 326 Likes on 236 Posts
Default

go for it, do the usual PPI stuff and enjoy! if the car was maintained properly, should be no issue
Old 06-29-2024, 01:01 PM
  #6  
wootloops
Advanced
 
wootloops's Avatar
 
Join Date: Mar 2023
Location: S. Florida
Posts: 54
Received 35 Likes on 20 Posts
Default

I have a 105k mile 981 Cayman S and it has been very reliable, even standing up to repeated track days. So I would have no concerns with an 80k mile CPO car in terms of reliability, plus you have the warranty to back it up.

Only issue I had was a maintenance issue related to the intake valves and carbon deposits as a result of the direct fuel injection. It caused a mid-range rpm hesitation (especially at part throttle) and loss of power. I had to walnut blast the valves, which was a pain on the Cayman due to the mid-engine layout, but I think to do it in a 911 it would be even harder without dropping the motor down.

People will say this isn't an issue on these engines but I guarantee those people have never looked inside a high mileage Porsche DFI engine. It happens to all DFI engines eventually due to the lack of gasoline (with detergents) washing the valves. May or may not be an issue at 80k but I would bet by 100k it starts to run rougher until it's cleaned out.
Old 06-29-2024, 02:57 PM
  #7  
MingusDew
Three Wheelin'
 
MingusDew's Avatar
 
Join Date: Jan 2015
Location: Pasadena, CA
Posts: 1,379
Received 1,243 Likes on 626 Posts
Default

Originally Posted by wootloops
People will say this isn't an issue on these engines but I guarantee those people have never looked inside a high mileage Porsche DFI engine. It happens to all DFI engines eventually due to the lack of gasoline (with detergents) washing the valves. May or may not be an issue at 80k but I would bet by 100k it starts to run rougher until it's cleaned out.
Well not all DFI engines. Some use port injectors on the manifold in addition to the high pressure direct injectors, and this configuration is specifically used to address the carbon build up on intake valves. My Tacoma had 12 injectors for its V6, and plenty of those running around with 200k+ miles and never needing walnut blasted valves.
Old 06-29-2024, 03:12 PM
  #8  
wootloops
Advanced
 
wootloops's Avatar
 
Join Date: Mar 2023
Location: S. Florida
Posts: 54
Received 35 Likes on 20 Posts
Default

Originally Posted by MingusDew
Well not all DFI engines. Some use port injectors on the manifold in addition to the high pressure direct injectors, and this configuration is specifically used to address the carbon build up on intake valves. My Tacoma had 12 injectors for its V6, and plenty of those running around with 200k+ miles and never needing walnut blasted valves.
I should have been more specific, I meant all DFI-only engines. you're right that DFI + Port injection solves this but none of the Porsche engines use that type of setup.
Old 06-29-2024, 03:15 PM
  #9  
MingusDew
Three Wheelin'
 
MingusDew's Avatar
 
Join Date: Jan 2015
Location: Pasadena, CA
Posts: 1,379
Received 1,243 Likes on 626 Posts
Default

Originally Posted by wootloops
I should have been more specific, I meant all DFI-only engines. you're right that DFI + Port injection solves this but none of the Porsche engines use that type of setup.
I wonder if it’s a packaging issue, or some other performance related reason. These seem like otherwise fantastic engines, crazy strong internals and a stock fuel system that has LOTS of headroom for more power. I guess compared to older air cooled turbo 911 motors, that seem to be out every 30k or so miles having their top ends rebuilt with all new valve train, having to walnut blast the valves every 100k may seem not that a big of a deal to Porsche.
Old 06-29-2024, 03:24 PM
  #10  
wootloops
Advanced
 
wootloops's Avatar
 
Join Date: Mar 2023
Location: S. Florida
Posts: 54
Received 35 Likes on 20 Posts
Default

edit: im stupid disregard

Last edited by wootloops; 06-29-2024 at 03:29 PM.
Old 06-29-2024, 07:38 PM
  #11  
DC911S
Drifting
Thread Starter
 
DC911S's Avatar
 
Join Date: Oct 2014
Posts: 2,674
Received 242 Likes on 151 Posts
Default

It’s a nice car. At some point the sports front bumper was added. The 80K service was done, by the dealer. New tires all around. Brake pads and rotors done short time ago. No coolant or oil leaks after it warmed up. If it was manual I’d probably buy it, but it’s pdk so still thinking about it. Not much info about how pdk is at that mileage. Granted you get two years of warranty so it would be covered in those two years if it took a poop.
Old 06-29-2024, 08:02 PM
  #12  
rnl
Burning Brakes
 
rnl's Avatar
 
Join Date: May 2012
Location: Glenmoore, Pennsylvania
Posts: 1,214
Received 464 Likes on 206 Posts
Default

If you like it, then go for it. I have over 108000 on a 2012.5 C2 with PDK. Techs routinely comment that it's trouble free because it's driven.
Old 06-30-2024, 11:06 AM
  #13  
rwbern
Rennlist Member
 
rwbern's Avatar
 
Join Date: Mar 2022
Location: TX/LA
Posts: 927
Received 930 Likes on 416 Posts
Default

2015 Targa 4S - Sitting in Phoenix, 6,800 miles down the road on a summer road trip. 2,200 to get home. Odometer went through 86K yesterday.

It a leak, squeak or rattle. Health permitting, I will do it again next year.

Not a secret, timely maintenance will keep these cars running forever:-)

If u like the car, go for it!
Old 06-30-2024, 09:24 PM
  #14  
DC911S
Drifting
Thread Starter
 
DC911S's Avatar
 
Join Date: Oct 2014
Posts: 2,674
Received 242 Likes on 151 Posts
Default

It’s got a Insta 360 camera on the windshield with the connectors being routed to it under the headliner. No big deal. But it’s also got some weird looking OBD2 connector in it, via a cable that goes to the actual port on the lower dash. I have no idea what this is, perhaps some odd tuner thing. I’m quite surprised that Porsche certified this car with the weird connector just sort of laying there. These cars are too sensitive to hacked electronics being present, cause if I bought the car and problems happened, they might blame it on said parts and deny a claim. The dash cam is no big deal, but that other cable is sketchy.
The following users liked this post:
JeepJLU2020 (06-30-2024)



Quick Reply: Thoughts on a high mileage but Porsche cert 991.1?



All times are GMT -3. The time now is 04:49 AM.