Best oil for my 325i ?!

[satvir]

Jus recently brought an e30, so quite new to all this! It's an '89 325i and it has covered 152,000 miles. Has been off the road since 30/9/11. The previous owner had it for 18 months and nothing was carried out while in his ownership, apart from a fan belt change. He rarely drove the car as it was garaged and only driven on sunny weekends!

The car is a "project" as i'm only 23 and insurance is 6k plus for me! So my plan was to sort the leak on the engine (oil pressure switch), Give it a full service, oil, sparks, fuel/oil filter, coolant myself. Then get my mechanic to do the timing belt on it (waterpump, tensioner etc) and valve clearance as it sounds a bit tappety on cold start. Once that has all been done the car is going to be stored away!

Basically i don't know what oils have been used in the past etc. And i'm looking for some advice on what oil to service the engine with! As after the full service, timing belt kit and tappets are done, the car won't really be driven....maybe the odd cheeky test drive here n ther,e but no daily driver business.

Cheers!

[Das_BMW_E30]

10w 40 You might want to get your mechanic to remove and replace the oil spray bar, with a new one, when he removes the rocker cover.

[satvir]

Hey thanks for the quick response!

Sorry to sound like an idiot...but what is the oil spray bar and why would i need to change it ?

[Das_BMW_E30]

The oil spray bar, is a metal pipe that provides lubrication to the camshaft, if the previous owner has skipped oil changes, the oil may have become thick and gunky, this clogs the small holes in the oil spray bar, which starves the camshaft from essential oil lubrication...

Part 1 here....

http://www.realoem.com/bmw/showparts.do ... g=11&fg=15

[satvir]

Dont think the previous owner had the car long enough to skip anything lol but i get ya!

The part doesn't seem readily available and with the 10w 40 oil....is there any particular brand, part synthetic/fully that is recommended?

[Das_BMW_E30]

Failing that, get you mechanic to drop it into a bath of thinners or other solvent, to loosen the gunk, then blow through with an airline.

I have used a standard 10W 40 mineral oil, on these engines changed every 5000 miles, these oils were around long before semi and fully synthetic oils, and recommended for the E30 325i.

There's a saying, "halve the distance to oil changes, an double the life of your engine".....

[satvir]

ive heard about people talkin about synthetic oils in these forums, but you suggestion is that mineral oil should be fine? Are there any particular advantages it has over synthetics?

[Brianmoooore]

Mineral oil is absolutely fine, but synthetic will be a lot better.

[Das_BMW_E30]

Satvir

I'm no oil specialist, 25 years ago, these engines were designed to be lubricated with the correct viscosity mineral oil.

Change it regularly, and it will be as good as gold, problems arise when people skip oil changes.

Semi, and fully synthetic oils, to my knowledge, are deisigned for later engines, with multi valves (four+ per cylinder), hydraulic tappets, and higher revs....

So don't go running your S54 M3 engine on 10w 40 mineral oil.....

[Brianmoooore]

Satvir

I'm no oil specialist, 25 years ago, these engines were designed to be lubricated with the correct viscosity mineral oil.

Which was 15W-50 for UK temps., but oils, both mineral and synthetic, have moved on.
10W-40 would have been outside of its operating range on a summer's day (a normal summer, that is!)

[Das_BMW_E30]

Hence the reason my 1998 Auto Data book (published in the colder UK) states 10W 40....

However, having just checked the oil specs for the E36 3.2M3, it also states 10w 40...and I know BMW recommend a thinner oil, for this 315bhp high revving, rod throwing engine...

[satvir]

So for UK temps 15W-50 or 10W-40? And im think semi-synthetic...

[Brianmoooore]

Back in the 1980s, BMW specified a 15W-50 oil for E30s, but with the advances in oils in the meantime, the current recommendation is 10W-40.
A straight mineral will be adequate, a semi synthetic better, and a full synthetic better still.

[driftwood]

Hmm. Isn't synthetic oil a bit "thin"? I put synthetic oil in a vw scirocco and had constant problems with oil pressure. I went back to mineral oil and the pressure problems went away. Maybe clearance tolerances in oil pumps and bearings are tighter in modern engines. Same with gearboxes. Synthetic oil is much more slippery and can cause issues with shifting gear.

[maggspower]

Hmm. Isn't synthetic oil a bit "thin"? I put synthetic oil in a vw scirocco and had constant problems with oil pressure. I went back to mineral oil and the pressure problems went away. Maybe clearance tolerances in oil pumps and bearings are tighter in modern engines. Same with gearboxes. Synthetic oil is much more slippery and can cause issues with shifting gear.

The viscosity of oil is determined by its grade e.g; 10w40. Not what its base is. first number is its viscosity when cold the second when hot. Fully synthetic oils cope better with extremes of temperatures, and will hold its grade through many more heat cycles, potentially lengthening service intervals.

To me the only disadvantage to fully synthetic is the price. I have always used fully synthetic in my e30s.