Boxster 987 3.2 Engine Problems

[ale86]

Hello everibody, I own a Boxster 987 3.2 280 hp my05 since 2009 with 59k miles; my car has always had unstable performance and a little poor hot start, but i didn't mind it beacuse Piwis checks were allright.
I've always used Mobil 1 5w50 changed every 6000 miles....oil consumption is normal about 0.6-0.7 liter every 6000 miles;
No track and a very nice use.
Last year I decided to restore this engine in a Porsche workshop changing many parts including:

-Spark plugs
-Ignition coils
-Mass air Flow sensor
-Fuel pump
-Fuel pressure regulator
-Relays Fuel pump and Dme
-Vos
-Water temp sensor
-Engine compartment temp sensor
-Ultrasonic injectors cleaning
-Tank cleaning
-All oil vapors tubes
-Coolant
-Water/Oil exchanger
-Air filter
-Crankshaft pulley belt
-Throttle body



After the injector cleaning hot starts are worse; essentially after 20 -30 min i stop the car, when i try to restart engine employs 4-5 seconds to start and sometimes I see white/light blue smoke that smells of oil burned. Then if i stop it and try to restart, there isn't any problem.
The same day after the injector cleaning i broke a secondary lambda sensor after cat (right bank code P0159), so i changed this sensor too.
All parts i've changed are genuine Porsche.

However performances are unstable and engine is rough too.
We have done many Piwis tests inclunding lambda sensors and variocam tests but it's always allright wiothout any fault code.
Compression cylinder test is ok and there isn't any air aspiration; starter engine is ok, Evap canister allright too.

Porsche workshop has no words.
Now i've bought 6 new injectors from Pelican Parts and I'll try to replace them. I've spent so much money and i don't know what to do!!!

If you can give me some advices, I'll be very grateful. I love my car too much and i want absolutely solve this problem !!!

Best regards

Alessandro

[Sapientoni]

No engine will run properly if it has uneven compression in the cylinders. No amount of top tuning will correct that. A basic check of leakdown is currently the gold standard test. After that valve timing, intake air leaks, air oil separators, deteriorating cats. The list could go on and on. Best of luck. this is based upon the expectation that assembly is properly done and components properly coordinated.

[ale86]

Hello, thank you for your reply. Compression test has just been done in Porsche workshop and they told me that all cylinders are equal and well compressed.
If you know a particular way to remake this test, please tell me.

Many thanks

[tonythetarga]

Leak down is different than compression and when used together, give a better picture of engine health. Where are you located? I'm sure you can get a rx for a good shop from members here. You need a fresh set of eyes looking at it.

[ale86]

Hello Tony, i'm from Italy land of mafia and corruption !!!
Now i tell my Porsche mechanic to check leak down too; I think that
it would be in its interests if my engine is really to rebuild.

Thank you