Your Oil Questions answered

Hello, I'm after advice regarding oil for a 1994 M3 engine.

The engine is in the back of a Metro 6r4 racing car we have built and is of unknown origin. We have only just finished building the car from scratch and last week got around to running the engine, and it runs great, which was a relief. We took it for an MOT on Wednesday which is passed but on the way home the oil light was flickering. The pressure gauge was jumping between next to nothing at idle up to about 45  - 60 psi at revs. We are using Valvoline VR-1 oil, I think it's 5w-40. What temperature should the oil be at when the engine is hot? I'm going to put a thermocouple in to the oil cooler to see whats happening, as it's not in free flowing air, might have to put a fan on it. 

Anyway, I spoke to a BMW dealer and they recommend Castrol TWS 10w/60 at about £19+vat / litre, which is er... expensive to say the least. Is Castrol RS 10w/60 the same or similar (I can get 25 litres for about £180) and would it be suitable? Would changing to this oil help the oil pressure issues, and / or what other than the viscosity might be causing our lack of pressure?

I've seen Shell Helix Ultra racing 10w/60 is cheaper than Castrol TWS and RS and has A3 specification like the TWS and RS, has anyone any experience of it?

TIA, Nicksmelly

Hello Oilman, The engine is an E36, from a 1994 Cabriolet that was involved in a crash. We got the engine from a breaker.

The oil that we originally put in was Valvoline synthetic VR-1 5w/50. Yesterday when we went for a short drive, the oil pressure with revs was about 50 - 60psi and at idle it was fluctuating between 0 - 20psi, with the oil light flickering. This was with water temp of just below 100 oC.

We drained the Valvoline out today and put in Castrol TWS 10/60 and went for the same drive and the pressure with revs was 60psi and at idle 20psi with no fluctuations... so it seems to have solved the pressure issues, but have we solved the problem or just masked it with thicker oil?

BTW, we got Castrol TWS from a BMW dealer on Saturday for £11/litre :(

We tried Valvoline VR-1 5w/50, which was sold to us as synthetic racing oil. We have always used Valvoline mineral racing oil 20/50 in our Rover V8 engines in the past with no bad experiences. Which other oils would you recommend.

If I understand you correctly, using thicker oil, will increase the oil pressure, but due to it being thicker it may not be able to get in to the tight spaces as easily?

If the engine is quite well worn, which would show symptoms of lower oil pressure, and we have put the thicker oil, the pressure is back to normal???

Why do BMW tell us that it needs to be run on Castrol tws 10/60? It very confusing.

Nick

Hello Simon,

Need your advice on the oil for the getrag manual box on my E36 318iS...my mechanic says it's ATF and recommends Dexron III. Is this correct and what's your recommendation?

Oh yes, also the differential I heard uses a life-time fill...the car is now on 150k miles so I guess it would be wise to drain it. Appreciate your advice too!  TIA...

Vince

Thanks Simon! Is there a difference between Dexron II and Dexron III? I mean are they interchangeable?

I guess mine's an open differential...will the 90LS do? Thanks again!

Ciao

Vince

Great...so it's the ATF4000 and LS90. What are the filling capacities for the box and diff? TIA

Vince

She's a '95 E36 318iS.....Cheers

Vince

hi Oilman

What u may recommend at a warmer part of the world Hong Kong winter time around 5 degree C for one or two weeks, then 10 to 15 degree C for 2 month, summer 30+ degree ...

my car is 2003 facelifted E46 330ci..

wondering to use 0w30 for the next change..

Never seem an active and infomation oil related talk...but here...

hi oilman what would you recomend

528i

1996 200000 miles

petrol

not used much one of four other vehicles but when is used only short trips but the odd long run driven pretty hard oil change every 12 months 10-12000 miles