BMW Werkz banner

1 - 11 of 11 Posts

·
Registered
Joined
·
16 Posts
Discussion Starter #1
I've had my 1991 325i for about 2 weeks now and am getting the car ready for winter and was wondering which synthetic motor oil to use in it and what weight is best for the 2.5 L engine. It's between the Mobil synthetic and the Castrol synthetic. The winters here in the midwest range on average between 0 F and 40 F.
Any opinions on this would be greatly appreciated.
 

·
Registered
Joined
·
2,053 Posts
I use 10w-40 as do some other E30ers and that seems to work well, although i use castrol gtx high mileage (non-synthetic)
 

·
Registered
Joined
·
16 Posts
Discussion Starter #3
So would the non-synthetic Castrol be better for a high mileage engine? I've got 182,000 miles on it with a slight tapping sound coming from under the valve cover and was thinking a synthetic oil might stop it from tapping (or maybe a valve adjustment?) im not sure.

Thanks for the opinion :rock
 

·
Registered
Joined
·
2,053 Posts
Originally posted by quickmike@Oct 5 2003, 10:47 PM
So would the non-synthetic Castrol be better for a high mileage engine? I've got 182,000 miles on it with a slight tapping sound coming from under the valve cover and was thinking a synthetic oil might stop it from tapping (or maybe a valve adjustment?) im not sure.

Thanks for the opinion :rock
i dont know, i guess its worth a shot. non-syn oil is generally better for a higher mileage engine. i would also do a valve adjustment too.
 

·
Registered
Joined
·
16 Posts
Discussion Starter #5
Cool thanks for the info!! As I learn more about this car I hope to help answer other peoples questions as well. :thumbs
 

·
Registered
Joined
·
90 Posts
Originally posted by MrM3@Oct 5 2003, 10:42 PM
I use 10w-40 as do some other E30ers and that seems to work well, although i use castrol gtx high mileage (non-synthetic)
I use castrol gtx too!!! :cheers

kali*
 

·
Registered
Joined
·
178 Posts
Non-synthetic oil isn't necessarily better for higher mileage motors. I run Mobil 1 synthetic in my car with 160k miles and I have no problems whatsoever. Just make sure that your engine seals are in reasonable condition.

Synthetic oil isn't going to solve your tapping noise though. Your M20 has mechanical lifters, so valve lash is only adjustable manually. Adjust your valves.

Pretty much just a matter of weather or not you want to spend the extra money for synthetic oil. :dunno
 

·
Registered
Joined
·
1,637 Posts
synthetic oils eat through old seals. Its incredibly thin and youll most likely have lots of leaks
 

·
Registered
Joined
·
178 Posts
Originally posted by Fox@Oct 7 2003, 09:49 AM
synthetic oils eat through old seals. Its incredibly thin and youll most likely have lots of leaks
Show me how this is true.
 

·
Registered
Joined
·
1,637 Posts
Go put some in an old chevelle see what happens.
 

·
Registered
Joined
·
178 Posts
Originally posted by m42technic@Oct 7 2003, 03:29 AM
Just make sure that your engine seals are in reasonable condition.
Weeeeeeeeee!!! :rolleyes:
 
1 - 11 of 11 Posts
Top