Morning Guys & Girls
Without prejudice
Yesterday we had another Cayman 718 with a 100% oil ash level along with the usual DTC code P242F.
The garage wanted to carry out a regeneration of the filter to try and clear the ASH.
We all know that you cannot regenerate ASH if it's actually present in the filter, to confirm the ASH level a simple exhaust back pressure check should be carried out.
Remember in all our cases with GPF filters that where at 100%, the differential pressure sensor reading ways shows the opposite, no pressure at all ?.
This is what a dealer checked before a GPF filter was replaced last year on one of our cars, they where looking for signs of internal oil contamination which could accelerate SOOT and ASH loading.
NO MENTION OF AN EXHAUST BACK PRESSURE CHECK TO CONFIRM THE REPORTED MEASURED VALUE OF 100% OIL ASH WAS CORRECT.
Service history is complete and showing correct viscosity of oil used at each service.
(MOBIL 1 ESP 0w40).
Removed turbo intake pipe and inspected for excessive oil formation – none found, Turbo in good condition and oil seals within turbo not leaking.
Removed oil vent pipes from oil separator and checked oil misting. No defects found with oil separator.
Spark plugs removed and found no signs of excessive soot or oil contamination.
Compression test showing all cylinders over 9Bar. (All well within spec of 9.5:1 ).
This showing rings and compression correct and no defects.
No defects found on engine or ancillary components.
Cause of soot build up due to amount of short journeys and engine operations
Confirmed via VAL info;
Total engine starts = 003978
Operations at standstill = 00900
Operations between 0 and 3 miles = 01401
Engine runs between 0 and 10 min = 02196
Requires OPF filter replaced and advise driving car at operating temperature for longer periods in
This car went back in after covering only a 1,000 miles with the new filter, and the oil ash level was already at 45%.
THIS IS IMPOSSIBLE, BEARING IN MIND ALL THE ABOVE CHECKS THAT HAD BEEN CARRIED OUT WITH NO FAULTS FOUND PRIOR TO FITTING A NEW FILTER.
Surely we need to look at this measured oil ash value more closely, remember its part of a algorithm to run the emmision system on these cars.
We are now 100% confident that replacing these expensive GPF filters is not fixing these cars.
And the dealers need to stop upsetting our owners with a potential bill of 8K for an exhaust system that's not required.
And why after all this time are the dealers not checking for exhaust back pressure before they ring the customer.
We hear so many times from owners that they have been told by the dealers that their driving style is causing this issue, and it's not covered under warranty.
So bearing in mind we have never seen the soot regeneration warning light and message coming on our dashboards which should leave a DTC code P2463, and the difficulties the dealers are finding to try and fix these cars, this definitely puts these cars into a not fit for purpose category.
We hopefully will have some news soon regarding some tests we are carrying out regarding the relationship between the differential pressure sensor readings and the engine ECU.
Regards
Dave