Fixed leaks - can I go to Mobil 1 now?

[Rick Lee]

I want to switch from Castrol 20/50 to Mobil 1.

Following my clutch R&R, during which we replaced all the seals we could think of, my car is done leaking. We replaced chain cover gaskets (both leaking), flywheel seal (not leaking), breather cover seal (not leaking), oil t-stat O-ring (not leaking) and main shaft seal (not leaking). I have since put about 600 miles on the car and the oil level has gone down about 1/2 qt. So I assume I'm still burning about 1 qt. per 1200 miles, as it was before the engine drop.

Saturday, while having my emissions inspection, I noticed it still smells of burning oil in the engine compartment. Car does not smoke at all and I have noticed no more drops of oil underneath even after spirited driving.

I want to go to Mobil 1, but am afraid of springing/finding more leaks. I've heard so many stories about Mobil 1 that it's tough to know what to believe. Some say it will actually plug leaks after a while, once it's soaked the seals. This is my best hope. What can I do?

I use 0W-40 Mobil 1 and have no traces on the garage floor. I worried too when changing to this type of oil, but luckily no leaks have ocurred.

[Targa Dude]

Hi Richard...

I'm curious as to why you want to change your Oil to Mobile 1?
Castro GTX is very good oil.. thats all I run in all my cars except my 911, which gets Kendall GT1.


Jorge (Targa Dude)

[carmad]

When I first got my car it had several oil leaks in the common places. Any seals I could get to with the engine in the car were replaced.
I still had a leak from the tranny seal which was in fact the worst of them all, but has gradually gotten to the point it has stopped leaking. I use Mobil 1 15/50, there maybe some truth in it conditioning the seals.

[Rick Lee]

I have no complaints about Castrol, I don't track my car and I'm sure it's a lot cheaper to just change my Castrol even more often than I need to than to go to M1. But if Mobil 1 really offers the best protection, then I want it. I was prevented from switching before because of leaks, which are now repaired. Does anyone know if Mobil 1 will make my car burn slightly less oil?

[GoodMojo]

I've experimented with both Mobil-1 0w-40 and 15w-50. I'm currently running 15w-50 due to the onset of summer around here and also because 0w-40 is not generally available in your run-of-the-mill auto parts store. My '88 turbo w/ 28K miles on the clock currently burns about 1/2 quart every 2000 miles or so with all original gaskets. PO #2 ran Mobil 1 as well according to the paperwork. PO #1 ran dino. I've read that if it's leaking now with dino (even just a little), it'll be somewhat worse with synth.


-Wade
'88 930 Slant Coupe

[rstoll]

Hey Carmad, better check the oil level in that tranny. Those seals don't heal.