Yummybud924

I already have an oil leak right now, think it might be the oil pan gasket. I'm using regular oil right now and I have new front engine seals and I will probably have to get the oil pan gasket replaced sometime soon. Only other seal that mgith start leaking are teh rear balance shaft seals but I can probably replace those myself.

so if I have to replace my oil pan gasket seal anyways I might just go with synthetic oil but I'm not sure what grade oil. I was looking around at the store today and I saw 10w30, 5w50 and 5w40 synthetics. I don't see any 20w50 synthetic anywhere.

would 5w50 be okay? it doesn't get colder than -5 here, usually above freezing.

skene

5w50 will probably be too light. I had mobile 1 10w30 in my car for a while and think that was too light too since it burned a TON of oil. I'm running mobile's 15w50 "extended performance" synthetic now and have probably halved the oil consumption. I know it's leaking around my air oil seperator but I've not bothered to fix it yet.

If you do a search on oil on here I think there was a thread on what synthetic people ran and most were using 15w50.

lleroyb

I have used Mobil 1 15w-50 in four cars without increased oil leaking. I switched to Redline 20w-50 for the 951. I don't drive it when it gets below 25 deg F. anyway so the 20w rating was no sacrifice.
You should do some searches, you can read about synthetics and oil in general for hours.

I run Mobil 1 10w30 in my daughter's Toyota Carolla, 15w-50 in the wifes Volvo wagon and formerly in the 944 NA and 951 before switching the 951 to Redline. I even run M-1 in my lawn mower, it has an Onan opposed twin.

Lou

PS: Don't forget the rear main seal.

CO951

I run Castrol 5w-50 and it works great in the cold or at the track. I don't have any leaks.

Erzengal

I am using 0W40 Mobile 1 atm. Seems to be doing well so far. The common is a 0W50 to 20W50.

Yummybud924

thanks for the info, I"ll look for 15 w50 but I think it'll be tough to find. I couldn't even find 20w50 regular oil the other day in Canadian tire, probably because most people don't buy 20w50 in the winter.

Oh I forgot about the oil cooler seals, that's what may be causing my current engine leak, if I don't have to replace my oil pan seal I"m not sure if changing to synthetic is such a smart idea, I've heard that it will likely start leaking.

also are there any real benefits for using synthetic in a 944 na, it's just my daily driver and pretty high milliage, 246,000 kms.

KLR

I wouldn't bother to swap it over. There are many more seals that can leak (cam tower gasket for example). What problem are you really trying to solve, anyway? It seems like your car has done quite well for over 20 years on dino. How much are you going to extend the life of your motor at this point?

Dave951M

One leak that can look similar to an oil pan is the cheapo gasket on the back of the cam carrier.

Mike C.

An oil cooler seal leak (assuming you have an NA) will usually only show oil up in the coolant since the oil passages are suurounded by coolant within the cooler body. Generally though, if you change to any oil with a lower base viscosity (i.e. from a 10W - to a 5W), oil leaks will increase. The less viscosity the oil has, the more readily it will leak out. But in cold climates it's a bit of a balancing act - thicker oil makes it harder to start a cold engine, but it leaks less.... I agree with KLR - there doesn't seem much point in swapping now. As for the benefits of synthetic, there are many opinions (just do a search here) or you can read up on the subject here http://theoildrop.server101.com/forums/ubbthreads.php

Yummybud924

good point, but longer oil change intervals would be a benefit however if the motor turns into a big oily mess then that's not such a smart idea.

I still haven't had time to check my oil pan seal to see if that is what is leaking. I don't have a garage so I have to wait until the wheather gets a little better.

944CS

run 5w-50, the less viscious the better if you are starting it up in those low temps, skene prob. burned a lot of oil because the 30 refers to the hot viscosity, and your 5w-50 will be thicker than his 10w-30 was. Also, synthetic oils have additives that swell seals to help prevent leaks, where as not all dino oils have these additives (high mileage oils most likely do)

Catfood

when you change all your gaskets dont introduce synthetic to it immediately, put some cheapy stuff in and run it awhile to make sure all your gaskets are sealed and then go synthetic. sometime synthetic can be to aggresive on new gaskets.

Personally I thought my car ran better on synthetic than regular oil

Keithr726

Only use synthetic if you replace ALL the seals, it finds its way into every little crack/leak. Dino oil doesn't do it as much do to the fact it is more dense and hey it's cheaper.

cava

I've been using Mobil 1 10-40 for 3 years now and don't have any leaks problem, mine is an 87 944, I change oil every 2500 mi., so far so good, I didn't change anything when I swapped to synthetic and when I change oil it isn't so dirty, first time I did it I was living in Las Vegas, NV, now I'm living in Houston, TX...

odurandina

running synthetic with an engine at 120 k miles, there's zero oil loss whatsever.


the previous owner babied this engine just as much as i do. wonder how long it will go....