Bruce In Philly

2009 C2S manual Transmission 182K miles

So... took another big-miles trip. Tracked MPG. I still love the car but it is showing its age. I was a bit worried about taking such a high mileage car on a trip as the last 12 months saw an HPFP, A/C pressure valve, and Ingition Paks let go. Good news as I experienced no problems at all. As for oil temps, they tracked at just over 220 F for most of the trip with ambient temps up and above 90 degrees a few days. However, I did hit just under 250 F when ambient temps were 90 F, and I was holding in 4th gear doing 80-90 for a while... crazy traffic... holding the horse power and hitting the throttle on and off. If I tracked my car, I definitely would do the 3rd radiator or replace the flattened AC condensers.

For reading about cleaning my radiators and oil temps: https://rennlist.com/forums/997-foru...-clean-it.html

So for miles per gallon... pretty darn consistent ... even as the car aged. Trip was all highway with .5 tank or less local driving. I used maybe... hard to tell... .5 to .75 quarts of oil... maybe.

Questions:
1 - If injectors age/deteriorate, what would be the symptoms?
2 - If power goes down as engines age, does MPG track to the deterioration?

You get at what I am looking for.... what the heck has happened to my engine after 182K miles? I just can't tell.

Peace
Bruce in Philly (now Atlanta)

Floyd540

Here is what has happened to your 997.2 engine after 182K miles----- almost nothing. The negative part of a mid-milage car (182 K is mid milage for a German car) is that piston ring wear will reduce compression level , but I would say the compression lose is minimal to almost nothing. The next item is valve and valve seat /valve guide wear and accumulated crud and carbon will also lower compression due to leakage. A leakdown test will show the numbers and they will be minimal as well. The injectors , whether DFI or ole timey port injection ones do change over time but generally do not wear but do suffer from burnt fuel additive deposits on the tip and nozzle. This makes them leak and have poor flow and spray patterns. Think of a shower head that has suffered from calcium/ lime deposits. These should be cleaned and tested for spray pattern. I bet they are not spraying to the correct pattern as they were designed for. Cam chains have stretched but the rails and tensioners are still doing their job. The improvement that has occurred is that the bearings for all the rotating parts has "run in" and internal friction of all these parts has reduced significantly ( a very good thing).
Why is it running so good and delivering consistent fuel milage? Oxygen sensors are the hero here. They are the feedback loop to the computer to adjust everything. Variable valve timing and ignition timing are also heroes as they adjust the engine parameters over time and wear. Modern oils have made the world a better place. Expect 300,000 miles
What would I do to prepare for the next 100,000 miles?
Besides repairing the condenser fins, I would pull the injectors out and have them tested. There is some controversy over cleaning ability of the DFI injectors, but have your injectors tested and have them cleaned or replaced. Injector spray test data after 150,000 miles will show crazy patterns, flow rates and some will be leaking.
Second I would do a compression test and a leakdown test for fun and information. Post them here. (Fun with tools)
A third possibility may be doing a walnut shell combustion chamber cleaning, but I have no data or experience on the need for this in the 9A1 engine.
That is all besides the normal maintenance. At 300,000 miles you may consider doing a top end valve /valve guide/seal job and check for any leaks.
Go for a 6,000 trip!

ManoTexas

Bruce. Do what you’ve done. Just drive it. Fix what breaks. You’re the golden child!

groovzilla

I don't get it??

Fuel economy is steady at 182K miles and it all seems fine. These cars will go to 300K miles if lovingly cared for as Bruce in Philly has been doing for years.
I'd never track the car nor would I ever buy a car that's been tracked. Too hard on engine/tranny/brakes/suspension.


GO BRUCE ----->

Chris M.

Agreed. Looks like it’s still performing very well.

What would you replace it with?