Mc.Queen 964

But, 10w50 is as thick as 20w50, the only difference is the temp range no? What do you think about 10w60?

Unkle

You currently use a 10w40

so 10w50 is the same as 20w50 when hot and a little thicker than 10w40, but it will be thinner than 20w50 when cold and so will lubricate the same as you 10w40 when cold. It will also be closer to the spec you have had suggested by the Porsche mechanic and will be in between your current oil and the 20w50 users. Its not set in stone but an option for you if you don't wish to go as far as 20w50.

Remember the 20w will have no affect on your hot pressure issue it will only make the cold oil thick.

Glad you are getting it sorted tomorrow, hope it goes well

Mc.Queen 964

I now have 5w40, no 10w40, but they are the same at hot i think.

So, I understand with your explanation that If I put 10w50 will be a little bit thicker at hot (that's what I need). So.. another thing is 5w50, that will be the same at cold as my 5w40, and as thick as 10w50/20w50 when hot, so is another alternative. I will tell him 5w50 or 10w50. But we will try to solve the problem mechanicaly..

I will tell!

Unkle

Yeah thats correct, sorry i thought you were using 10w40, 5w50 would be an good choice, 1 is on the approval list (if you are keen to follow Porsche approval).

rarebear

check also the oilcooler and coolerfin, are you sure the fin comes on when the oil temp gauge is at 9 o'clock ?

Olcha911

I would suggest the following:

1) First switch to either 10w50 or 20w50 motor oil
2) Replace both oil pressure relief springs

As long as you gain 1 bar of oil pressure for each 1000 RPMs, and you can max-out the oil pressure gauge at 5000rpm or more, you are okay.

Just drive it- the rebuild will come anyway and be very expensive...so put it off...

-Keith

Mc.Queen 964

I leave the car in the mechanic some minutes ago, They will change valve and springs relief. If it doesn't work, I will change to 10w50 (That have to do something)

Regards,

Mc.Queen 964

Guys, I can't find 10w50

I only can buy:

5w50 Mobil 1
10w60 Castrol Edge Sport
15w50 Motul V300

What would you chose? I live in Canary Islands, I think Mobil is the best option.. and w60 castrol? is it so much? It says is specialy designer for ///M engines.

Laker

I would choose the Mobil1 5W50 if you have no leaks from the current 5w40. w60 is a bit thick. Personally I would use Mobil1 15w50 if available.

Quadcammer

The motul is the best oil of the three, but it has a very short engine shelf life in that it should only be run 3k miles.

Unkle

Same as Laker

But i would stick with the cold viscosity of 5w and either have 5w40 or 5w50

Mc.Queen 964

but... 15w50 is as thick as 5w50 hot no?

Quadcammer

yes...but a lot of people tend to feel that the 5w is not thick enough on start up. search for posts by Kevin.

Mc.Queen 964

But I've got a question... The first number I mean.. 5w 10w 15w doesn't afect the second? I mean.. 5w50 is exactly as thick as 20w50?

Quadcammer

each viscosity has a range. So a 40wt, regardless of the number before the W will be in the same small range.

Will they be IDENTICAL? No...that varies between brands/formulations.

That said, a 5w-50 from one brand might be thicker than a 10w-50 in another, but only very very minorly so.