motor oil advice for stock 2.4T

[rockreid]

Hi. It's time as per Wayne's book for the 100 mile oil change.

I currently am running Castrol GTX 20W-50 but this morning have been reading through a lot of threads and now I am worried I have the wrong oil blend and lack of zinc in my current oil.

I rebuilt the 2.4T engine in my 73.5 CIS Targa and the engine runs very well with no unusual running or valve noise. I do have a bit of blue smoke on start up that last a bit until the engine warms a little. I did overfill the oil on its first oil change but corrected it to the middle of the dipstick with a hot engine.

I seem to be running too high oil pressure at the moment with my current 20W-50 oil. Ambient temps at 80F, cold start I see 60-70psi on my dash at idle and 80psi when revved to 3500rpm (I have yet to run past 4000rpm during this break-in). With the engine hot I am still seeing about 50psi at idle and 60psi at 2000rpm. The psi does creep down as the engine warms but I am seeing way above what others are saying is normal for proper pressures. Would 10W-30 bring my PSI down to a normal level, especially as we head into summer here in Connecticut? I currently have no oil leaks except for a bit of weeping through a few of the lower valve cover bolts. Nothing major.

[PCA7GGR]

Brad Penn 20W-50

Welcome!

[RedCoupe]

There is much written on this forum and elsewhere about engine oil for the 911. LN Engineering has some extensive writing about the subject on their website. If you remember that the viscosity number without the W after it is measured at 200 degrees F, you want something with more viscosity than SAE30. Particularly as we head into the summer months.

[grizzfan]

+1 Brad-Penn 20W50

Tom

[Jose_JGC]

Castrol GTX 15W50 + Mahle oil filter once a year and my 2.2T seems happier than ever (good oil pressure and temp, no noises, no smoke).
Jose

[Trackrash]

I used to run Rotella 15-40. It was (is) intended for diesel motors. For street use it was perfect. Problem is Shell has, apparently, reformulated this oil.

Maybe some expert can find Rotella's current formulation including the zinc levels?

OP there is some good info in this thread about oil pressure. Cracked oil cooler

[gamin]

Valvoline VR-1 racing 20W-50 NON synthetic.

[Sunroof]

I have a 1973.5T with the 2.4 and I have been running Valvoline 20-50 racing for 15 years now on this car. I also used Valvoline 20-50 racing in my 1985.5 944 I owned for 12 years, also in my 1979 911SC and my 1974 911. So I have been using this stuff for quite along time and the cars ran/run great.

Works just fine

Bob
73.5T

[pors1968]

Castrol GTX 15w40 diesel oïl heavy duty .Best for the price.