mkess

I just joined the ranks about 6 weeks ago with my '97 C2S, 14K on the clock (have posted pics already!). Going through the papers that came with the car I noticed that the last oil change, which was just before I received the car, was done with Castrol 10W-30. Anyone have any idea why someone would have done this? I've put about 700 mles on the car including 1 track day. Besides the obvious - changing it - do you guys think I've run any risks? Would you drive it prior to changing the oil?

Thanks - and Happy 4th!

amfp

I would change to 0x40 Mobil 1 with both filters ASAP. If do a lot of track change to 15x50. Why they used 10x30 is because shop did not know any better. If only drove 700 miles would not worry too much, what is done is done. BTW, great looking car and wheels!

Marv

Pew, uhg, yuk!

Actualy, it shouldn't make any difference. Just change it to Mobil 1.

texas911

Engine is ruined. Sell it fast!

mkess

Really?!?!?!?

How much should I ask for it?

long_beach_968

my guess as to why this was done is he po wanted to sell the car and wanted to hide some oil leaks. that sucks as it seems the po may be a little dishonest. I remember on my 968 if I ran dino oil, my leaky oil pan would seal up.

95 C4 993

I dont think I have ever heard of a car being destroyed for having oil in it. However, I would stick with consistancy of what has been used in the past.

c993k

Depending on the temperature in your area, here in Florida where it's 90'+ most of the time
I find running 15-50 Mobil 1 is the best down here. If I lived a bit north then 0-40 would be my choice.
I ran Mobil 1 on almost every vehicle I have owned
and never had a failure related to oil. Get rid of that Castrol quick! Chris

Marv

There is something to be said when a car has been run on standard cabonacious punch (non-synthetic) and changed to synthetic. Seals that are old tend to leak more once synthetic is used. I think that synthetics do a better job of scrubbing imurities from the seals than standard oil.

Incidentally, both types of oils, synthetic and non-synthetic come from the same place. Synthetic simply is engineered oil with longer molecular chains.

I would convert to synthetic and see what happens. Keep the engine undertray off the car. This will improve air circulation and keep the cylinder heads a little cooler. More importantly, it will allow you to see oil leaks quickly since the oil can not accumulate on the tray.

993inNC

I've read that more times, yet I had the complete opposite happened. I had a 944 that was leaking and making a little lifter noise......put synth in it and almost overnight the leak went away. Better yet the lifter tick disappeared
I put synth blend in the tranny that was shifting hard and a hint noisy. The shifting got better and the noise almost went completely away. Was going to switch to full synth but never got to it......sold the car shortly after getting the 993.

Bull

The "your car will leak if you switch from dino to synthetic" story started when the first synthetics started to sell many years ago. I have switched cars as old as 130k mile 356s to sythetic and NEVER had a leak begin. I suppose that a car that is already leaking a bit..."seeping", could continue to leak, maybe even more, when the owner is "on alert for the problem" and finds his/her baby has leaks.

amfp

My experiences, decades ago, synthetic had reputation to cause leaks, but the blends in last several years with my experiences do not find leaks. Actually one of my cars did leak dino oil, switched to synthetic, the leak stopped, and that was 5 years ago and about 30K miles ago. Guess it swelled the seals just enough.

I would think the 10x30 oil used was probably synthetic, not dino oil. I know it all varies as we have some different benchmarks, but my 993 used to tap slightly when it sat for a few weeks and then started up using 15x50. Since I switched to 0x40, no more tapping. Seems logically as the lower weight oil will provide quicker lubrication.

mkess

The 10W-30W is synthetic, not dino. That said, still feel as if I should swap it out. Now I need to determine if I should go 0W-40 or 15W-50, but that's another thread entirely.........................

Ms Kita

I use 0W-40 in most of my cars here in the mid-east. My mechanic switched my 1991 to 15W-50, and I have had real hard time finding it and the price I paid was premium around $6.99 quart at Pep Boys. I am keeping my eye open for the female turn-on word.. "SALE"!

sidned

That's interesting. I had my car serviced on Friday, and they put Castrol Magnatec in it instead of fully synthetic which was in there before. Since getting the car back I have noticed a distinct tappetty noise, especially when driving past a high wall. Could this be resolved by going back to fully synthetic? Do you think I am doing any harm running on semi-synthetic?