Synthetic Oil to Conventional

[Tico Frank]

So I just bought a 1987 325i convertible and the valves are super loud. So I called the guy to ask when the last oil change was and what he used and he said it was in october 2010(car sat undriven since november 2010) and he used 5w30 synthetic.

I have read quite a few threads and the consensus is 20w50 and seems like lots of folks like Castrol (which is my brand of choice anyway).

Any thoughts on the best way to transition back to Dino oil?

Anything to look out for.

Really any advice is appreciated.

ADD The car has about 140k on it.

[SilentJon]

just change the damn oil
i dont get why people make such a big deal about it

[Tico Frank]

just change the damn oil
i dont get why people make such a big deal about it

Thanks,
Not trying to make a big deal about it just asking as I am not familiar with BMWs.

I've read that synthetic can release carbon deposits. But appreciate the response.

[deploytosave]

Thanks,
Not trying to make a big deal about it just asking as I am not familiar with BMWs.

I've read that synthetic can release carbon deposits. But appreciate the response.

dont concern yourself with it...

[jasonsnoddy]

i used royal purple for a couple oil changes then switched to shell rotella t once i figured out RP is a sham. nothing bad has happened.

[Tico Frank]

Thanks

[boom-monkey]

Gonna get flamed but...

Oil is oil, if you change it every 3000.

[AndrewBird]

Going from dino to synthetic is generally the concern, not the other way around. Synthetic oil is made from smaller particles and can leak on old engines that have been running dino.

Otherwise, you should be good to go.

One thing to consider is running Castrol VR1 racing oil. It has high levels of ZDDP in it which work much better at lubricating solid lifter engines. Keeps from wearing your cam lobes out. Newer oils have very little ZDDP due to environmental reasons.

[Cabriolet]

i use full synthetic and i still change it every 3000-3500 miles.

[mikeedler]

i use full synthetic and i still change it every 3000-3500 miles.

then you my good friend are just throwing money out the window.

[Blendercloud]

then you my good friend are just throwing money out the window.

+1, unless you've got a big, hot, nasty turbo somewhere under there.

[expressfish]

I bought my car back in september 2010, this is my first oil change (i know, i know) I filled her back up with rotella 15/40, smells just like my cummins now, lol. Drove her home thirty miles last night and checked the dipstick, to my surprise the engine must be pretty clean inside or it was a synthetic child >? Odometer stopped at 132,000.

[nando]

Going from dino to synthetic is generally the concern, not the other way around. Synthetic oil is made from smaller particles and can leak on old engines that have been running dino.

that is total nonsense! Synthetic does not cause leaks.

Otherwise, you should be good to go.

One thing to consider is running Castrol VR1 racing oil. It has high levels of ZDDP in it which work much better at lubricating solid lifter engines. Keeps from wearing your cam lobes out. Newer oils have very little ZDDP due to environmental reasons.

yes, but you meant valvoline VR1. Mobil 1 20w50 also has good amounts of ZDDP. There are others too but they cost a lot more. Most of the diesel oils don't have as much as you'd think.

[NeoMishMoo]

I really hope you're out changing your oil right now.

So the question is how to go about using conventional oil in a car that has previously had synthetic oil? As far as I know just use conventional oil when you change the oil. Doesn't really matter that it had synthetic oil in it before. If you want to "ween" your car off synthetic get castrol syntec blend. That way you'll have partially synthetic oil, then next time you change put in regular conventional oil. There probably is no point to do this but it might help you sleep at night if your worried about going from synthetic to conventional.

I gotta agree with boom-monkey for the most part oil is oil. If you buy more premium oils then you can usually get away with changing it less. Personally I like my LUBRO MOLY chocolate milk, and I change around 5k.

[SilentJon]

i just run rotella 15w40
synthetic doesnt cause leaks, won't make chunks of sludge break loose and f*ck your engine, or any of the other stupid shit people say it will, and it's pointless to "ween" an engine off of synthetic or dino oil. it's not going to go into shock. as far as an engine is concerned, oil is oil as long as it lubricates properly.
run 15w40 or 20w50, and adjust your valves if they are noisy after you get the 5w30 out of it. most likely they just need to be adjusted, and the thin oil probably wasnt helping the noise either