TheSamba.com :: View topic

Wed Jul 16, 2008 5:55 am

hey all

i hate bringing up oil topics cos they start so many shit fights but i just put my old spare 1600 back in while i make some changes to my 1776
its running well and is 10 years old with 30,000ish miles on it and the oil is still pretty clean but has been sitting for 12 months so im gonna change it.

currently its got 20/50 just cos the engine is getting abit old
pressure when cold is 60-70psi but once its up and hot it can get down to 20-25psi at 3000rpm and about 5-7 at idle, idiot light never flickers
was gonna swap to 10/30 but just worried my pressure might drop even further due to thinner oil
but then also thinking thinner oil would flow and cool better??

any thoughts??

Wed Jul 16, 2008 6:08 am

20/50 is like tar. thinner oil will flow and cool better. an engine with 30k on the clock hasnt even reached middle age yet. if all is well with the bottom end you shouldnt have oil pressure issues.

Wed Jul 16, 2008 6:10 am

I'd switch and 30k is not old.

Wed Jul 16, 2008 8:02 am

get a mechanical oil pressure guage and test the oil pressure when hot. Test at 3000rpms.

If 5w30 or 10w30 provides similar prressures use it. If it drops alot try a 10w40 or 5w40.

Wed Jul 16, 2008 9:26 am

I switched from, 20/50 to 10/30 and picked up a couple of mpg from my engine not having to stir mud.
Remember when warm its acting like a 30w which is a stock single grade for the vw engine.

Wed Jul 16, 2008 11:25 am

Buggin_74 wrote:

... but once its up and hot it can get down to 20-25psi at 3000rpm and about 5-7 at idle, idiot light never flickers
was gonna swap to 10/30 but just worried my pressure might drop even further due to thinner oil
but then also thinking thinner oil would flow and cool better??

any thoughts??

Since your hot pressures are borderline, Id take baby steps here. How about 15W-40 as a first step? Once I get my pressure and temperature senders hooked up, Im going to experiment to see if 30 actually cools better and holds the same hot pressure as the 15W-40 Im currently running. VW did change to a 40 recommendation from 30 for hot climates in later owners manuals. The general consensus today is that 50 is too thick.

Thu Jul 17, 2008 12:10 am

thanks for the help everyone
im running my 1776 on pennzoil 10/30 so will try this one on it too

i first ran the 1776 on GTX2 20/50 and it was getting abit warm (210) and the pressure cold was hitting nearly 100 and sittiing at 50 when hot and cruisng.
swaped to 10/30 and its much happier now, never over 195 and more stable pressures
my owners manual for my 74 super says in australia during summer run 30w so im hoping 10/30 will do the trick

Sat Jul 26, 2008 5:21 pm

just as a follow up to this
i dropped the 20/50 GTX on friday and put some 10/30 penzzoil in same as im running in my new 1776
it was alot happier cold pressure wise but by the time the oil got to 90c the oil light was just starting to flicker at 750rpm

like i said the engine is healthy and only done 30k but i drove it hard in the earlier days when i first got my lisence and its always run 20/50 since it was 600miles old
go figure...

Sun Jul 27, 2008 1:06 pm

Buggin_74 wrote: ... the oil light was just starting to flicker at 750rpm...
That is your problem, not the oil. Idle speed is supposed to be 850-950 rpm.