Synthetic oil destroying E30 engines? Nonsense or not?

[Dr Firefly]

Was chatting with an ex-mechanic today who scared the hell out of me by telling me that synthetic oil wasn't designed with engines like the M20 in mind and that there is no way I should be using it in my car - said that the engine didn't run hot enough for it and it was too thin to lubricate it properly. He was keen on Fords, so I don't think he knew that much about BMWs, but I was just wanting to check he was tallking a load of nonsense? I've been running mine on fully synthetic for about 6 months now, and I don't want to be doing it if it's damaging the internals as he said...

Cheers, Ian

[beardymat]

not sure if ive got this right as im a little

but doesnt oil get thinner (lower viscosity) as it gets hotter, therefore a cooler running engine would make it thicker than it was designed for not thinner.

[handpaper]

He was keen on Fords

For some people here, 'nuff said

Realistically though, you're not likely to harm your engine by using modern oil. The worst that can happen is that two decades of carbon deposits are washed away letting oil seep out through knackered seals.
The M20 is not an engine that puts a lot of stress on its oil; bearing surfaces are large, there's no turbo (unless you've fitted one ), it's well-balanced and it doesn't rev ridiculously high.
Simply put, it was designed to last several hundred thousand miles running on the oils available 20+ years ago when it was designed; the only real argument for not using the latest and greatest is that it isn't really necessary.

[316eyes]

Just checked the owners handbook and the ETK and neither mention anything other than the grade of oil recommended by BMW. The only mention of synthetic oil is on the TIS service information where it states that one characteristic of an engine oil is that it should be intermixable with other types.
eg. mineral oil with synthetic.

So you can safely assume that your motor will run happily with a good grade oil within the SAE range set by BMW.

Who listens to Ford mechanics anyway?

[GDBN]

As long as the viscosity is the same as BMW recommend then does it make a big difference?
A fully synthetic or semi with the same viscosity ... still have the viscosity ??

G

[DanThe]

Who listens to Ford mechanics anyway?

Bodge artists

[Demlotcrew]

Never heard so much bull

[Brianmoooore]

He was keen on Fords

For some people here, 'nuff said

Exactly!

[Globulator]

Was chatting with an ex-mechanic today who scared the hell out of me by telling me that synthetic oil wasn't designed with engines like the M20 in mind and that there is no way I should be using it in my car - said that the engine didn't run hot enough for it and it was too thin to lubricate it properly.

Perhaps I can guess why he is an ex-mechanic then!

Total bollox.

First point - synthetic oil is designed for car engines, especially ones with plain bearings, tappets, camshafts, piston rings, alloy and iron bits.

Second point - Thickness. sae 40 is sae40 and is the same thickness as sae40. FFS what don't people understand about this?! Regardless of the fact the M20 runs at the same temperature as any other petrol car on the planet, the sae rating tells you what thickness it is.

Ignorant tw4t mechanics who think synthetic is 'too thin' should a) go back to school, and b) watch some old Dino 10w40 draining out of an engine at sae10 (the base thin-ness) and then contemplate where all the plastic polymer thickeners end up, as they don't all come out with the oil, but varnish and sludge up the inside of the engine.

The 0w40 rating of your typical PAO synthetic gives you miles better cold start protection (because it is not too thick to flow properly) and performance is enhanced because the stuff is more slippery and does not require coiled polymers to get up to sae40 - it IS sae40 and as it ages will only get very slightly thicker. Synthetic will help the plain bearings on start up (higher shear strength), less bore wear (higher mobility when cold), less oil pump strain, less camshaft strain and more power (less friction).

My 160,000 miler has been running sweet as a nut on Mobil1 for ages now, and all through the winter cranking speeds were nice and fast too.

[Dr Firefly]

Was chatting with an ex-mechanic today who scared the hell out of me by telling me that synthetic oil wasn't designed with engines like the M20 in mind and that there is no way I should be using it in my car - said that the engine didn't run hot enough for it and it was too thin to lubricate it properly.

Perhaps I can guess why he is an ex-mechanic then!

Total bollox.

First point - synthetic oil is designed for car engines, especially ones with plain bearings, tappets, camshafts, piston rings, alloy and iron bits.

Second point - Thickness. sae 40 is sae40 and is the same thickness as sae40. FFS what don't people understand about this?! Regardless of the fact the M20 runs at the same temperature as any other petrol car on the planet, the sae rating tells you what thickness it is.

Ignorant tw4t mechanics who think synthetic is 'too thin' should a) go back to school, and b) watch some old Dino 10w40 draining out of an engine at sae10 (the base thin-ness) and then contemplate where all the plastic polymer thickeners end up, as they don't all come out with the oil, but varnish and sludge up the inside of the engine.

The 0w40 rating of your typical PAO synthetic gives you miles better cold start protection (because it is not too thick to flow properly) and performance is enhanced because the stuff is more slippery and does not require coiled polymers to get up to sae40 - it IS sae40 and as it ages will only get very slightly thicker. Synthetic will help the plain bearings on start up (higher shear strength), less bore wear (higher mobility when cold), less oil pump strain, less camshaft strain and more power (less friction).

My 160,000 miler has been running sweet as a nut on Mobil1 for ages now, and all through the winter cranking speeds were nice and fast too.

That was the kind of answer I was hoping for - thanks a lot!

I'll keep running it on the best synthetic stuff I can get then. Just checking I wasn't doing anything stupid - apart from listening to an ex-Ford mechanic that is...

[Globulator]

Not the best you can get - because the best you can get Ester based synthetic (for huge money) which has such cleaning powers you will need to change it regularly to remove all the dirt it digs out of your engine.

Stick to regular (PAO) synth like Mobil1 or equivalents

[ed325i]

I get my oil from here >> http://www.opieoils.co.uk/

[Morat]

I@m now losing so much oil through the valve stem seals (about 1 litre for 500 miles) that I'm effectively running as total loss oil system! I'm on my last green service light and the Semi Synth 10W40 on the dipstick looks brand new. err, because it is! When I get the head swapped over (next month, I promise!) I could probably use that ester based stuff and keep it clean as new.....

[slippo]

what oil should be used in a 325?

[Simon13]

if you have a pukka 2.5 use some proper fully sythetic oil. It will make a difference to the life of the engine, especially if you're a bit keen and take it on track

You're mate is off the mark on this one!

[pip]

you keep on using the synthetic oil and i suggest that you refrain from talking to that nut monkey because that sounds to me like an unqualified nut/monkey buster,he talks aload of crap.Iv'e used Castrol semi Synthetic in all my BMW's since it's inception and have nothing but praise for the oil,i think he has not caught up with time and still drives the Model T,regards Kiwi Pip,New Zealand and i'm of vintage age.