Yummybud924

I've noticed after hard driving my temperature gauge never goes above the middle mark but when I come down to an idle the oil pressure can drop below the two mark to like 1.8-1.9 at 850-900 rpms and when I rev it it will only go to 4 bar or just a hair above 4 bar (even when cold it goes just tiny bit above 4 bar). The car has 245,000 kms on it.

one of my concerns is huge oil leaks starting from going ot synthetic... I have replaced the oil pan gasket, resealed the oil pump, all front engine seals.

what I have not done is replace the rear main seal or the balance shaft housing or rear balance shaft seal.

I think my rear balance shaft seal was leaking a tiny bit when I got it so I cleaned it up with brake clean and applied the right stuff rtf gasket all over the rear balance shaft seals and it hasn't leaking a drop since.

also haven't replaced the cam housing gasket but it doesn't leak at all right now. so right now my engine is bone dry and clean.


anyways I want to try synthetic like mobil one, royal purple, or castrol synthec which is what I see in the stores here.

think is I'm using 20w50 now and I only see 5w50 synthetic her no 15w50 or 20w50. there is mobil one 20w50 motorcycle oil but I don't think you can use that.

would 5w50 be too thin when cold? also if I can find 15w50 or 20w50 synthetic I guess it would be less likely to leak because the 5 viscocity when cold is too thin.

what do you guys think?

dv8nxs944

ive seen a high mileage synthetic at walmart before, but i dont remember who makes it.
but i wouldnt go with a full synthetic

Yummybud924

went to a bunch of places, thickest synthetic I cand find anywhere is

10w40 castrol or 5w50 mobil

I'm guesing 5w50 would be better in my cas? (to help with oil pressure when hot) but would the 5 weight be a problem when cold (leaks or oil pressure when cold).

Yummybud924

why not?

dv8nxs944

cause if the motor has that many miles on it, it might not be a good idea for full synthetic (too thin) since no rear seals have been replaced

Yummybud924

wouldn't 5w50 be just as thick as 20w50 at operating temperature?

I know mobil one makes 15w50 also but I can't find it anywhere here. I have only ound 5w50 and 10w40 (castrol).

SD Porsche Fan

Valvoline MaxLife (synthetic blend) is sold at Walmart. I believe Castrol has a high mileage version as well.

Yummybud924

no walmarts around me lol.

one question I'ld like answered, would synthetic even help with oil keeping oil pressure up when hot or would it not do anything.

I"m using castrol gtx 20w50 right now wich is thickest you can get but would 5w50 mobil one (also 50 weight when hot) help keep the oil pressure a bith higher?

CO951

My 951 is around 115,000 miles and haven't replaced any seals. I've run the Valvaline maxlife full synthetic, but they only had 5w-30 which is no good for the summer. I've run Mobil 1 0w-40 and currently have Castrol Synthetic 5w-50. The Castrol is my favorite, I haven't had any leaks with any of them. If you currently have any signs of leaking, switching might make it worse. If you don't have any leaks, it is unlikely the will suddenly appear.
BTW, I think they may have stopped making the Maxlife full synthetic, I can't find it. It's all synthetic blend. I will be putting the Maxlife back in for the winter months.

UncleMaz

I use either Valvoline or Royal Purple 20-50w full synthetic in the summer and the Mobil 1 15w-50 (5000 mi) in the other three seasons. Mostly, because it is readily available at all auto parts stores out here.

Yummybud924

yeah around here I can only find 5w50 mobil or 10w40 castrol synthetc nothing else that is thick enough.


my main reason for switching to synthetic is to help with oil pressure when the car is hot after hard driving but I wonder if synthetic would even make a difference or possibly make my oil pressure worse if I use say 5w50 synthetic vs the 20w50 gtx i use now.

anyone know?

Yummybud924

oh and there's also 5w50 quaker state full synthetic which is cheaper than mobil 1

UncleMaz

I am sure they have 5000 mi. Mobil 1 in 15w-50 somewhere out there. I would get as close to spec as possible. More importantly, just change it a lot. For dyno-based oil, I like Kendall GT1. I would sooner put something like that in than go too thin.

tk's944

Royal Purple 20w-50 best stuff you can buy if you ask me

Yummybud924

they have royal purple here at the lordcos but only in 5w50.

In canada mobil one 15w50 was replaced with 5w50 and I can't find synthetic anywhere thicker than 5w50 or 10w40.

i'm worried 5w50 will be way too thin when I start it up and 10w40 won't be thick enough when hot.