Synthetic to regular to synthetic oil - any problem?

[babyduke]

Posting for a buddy...he took his '05 X5 to a local shop for an oil change. Mechanic inadvertently put regular oil. My buddy complained and it was drained and refilled with synthetic. Is there any harm in this?

[upallnight]

If it was drained right away probably not. On the Porsche forum going from regular oil to synthetic oil sometime result in leaks, but that was for owners of the aircooled Porsche.

[JCL]

No issue. It won't last as long, or protect as well, but a short amount of time on regular oil (assuming the correct 5w-30) would have no long-term effects IMO.

[nebilex]

I have a friend that switched from Synthetic to regular because his car was leaking about a quart a week... after finally getting it fixed (i think he changed CCV, valve cover and something else) he went back to synthetic he didn't have any problem. But here is what he did: He used to change synthetic every 8-10k miles, when he switched to regular he changed every 4-5k miles. He drove about 12k miles on regular 5w30 before he got it fixed and switched back.

[sktn77a]

No problem at all. There are reports of leaks occurring after the switch from regular oil to synthetic for any length of time (on older engines) but it's difficult to corroborate them. A little regular oil left in the engine after draining and then filling with synthetic won't be a problem (a low content "blended synthetic"!)

[bigwave2255]

as for leaks, i had the opposite experience, some years ago i went from regular oil to synthetic, mobil one oil in my 1994 jeep cherokee, a vehicle renowned for oil leaks, especially the rear main seal. and the synthetic oil stopped the oil leak, apparently as i understand it the syn oil has the ability to soften the seals a little thereby making them more effective.

at least that was my experience

[TiAgX5]

Originally Posted by babyduke

Posting for a buddy...he took his '05 X5 to a local shop for an oil change. Mechanic inadvertently put regular oil. My buddy complained and it was drained and refilled with synthetic. Is there any harm in this?

With the shops inability to refill with the correct oil, I would be more concerned that the filter was not replaced ("Iffy Lube shops do not stock BMW filters, they drain, refill and roll it out the door). Some BMW owners who use these shops for years then decide to DIY find the filter has rotted away and the oil running thru the canister unfiltered. Anyone who thinks a shop charging around $30 for an oil change and fluid check is using the correct materals is kidding themselves, the correct fluid/filter ALONE (no labor cost) runs over $50!

Don't use the word "inadvertently" to describe the mechanics actions or lack thereof, better words would be incompetently (as in he has no right to be under the hood/vehicle), or profitmaximizingly (he puts profits/minimum effort before any concern of vehicle longevity!

[TerminatorX5]

[TiAgX5]

As a DIYer who shops for the best deal on oil/filters an oil change costs over $70.