Oil service decontamination - is it snakeoil?

matsmith749

Active member
Site Supporter
Hmm.

Whilst in at the BMW dealer for the 'big service', as part of the oil change they undertook a decontamination service.

I wasn't asked if I wanted it, but they sent a video to show me their nice new machine :) & thanked me at the end for the extra money.

Apparently after draining the old oil, it spurts around some soya oil / pumps & cycles it a few times through a filter. Then they refill will new oil. The filter did look filthy afterwards, which they say is evidence of how clean the insides now are.

I see only dealer side reviews of this kind of engine decontamination, but the supposed benefits are lower emissions, better power, better fuel economy, quieter smoother running etc etc.

Does it make any difference really? Anyone done it a while ago & seen a benefit?
 
No idea... but it has always puzzled me that we make such a fuss about changing the oil to get rid of contamination, yet (presumably) leaving a fair bit of contamination present in whatever oil doesn't drain out, and I guess with residue contamination that sticks to the insides and doesn;t drain out with the oil.

Obviously if 99% of the oil is draining out, and taking 98% of the contamination with it (figures guessed) then that is brilliant comapred to not changing the oil... but surely a proper clean is best.
 
Maybe driving it will reveal all? If the difference is similar in feel to using normal unleaded to a v-power type fuel maybe there is something in it? End of the day it won’t do it any harm, although I have heard many times not to do engine flush on high milers just change oil and any filters but who knows….i do think a lot of people are showing extreme care for their cars but future owners are the ones that benefit.
 
I will keep an eye on fuel use I guess over the coming weeks & see if I notice a change, otherwise I think it feels much the same as before :(
 
Stick a magnet to the sump, for improved MPG :D

I would imagine such machines are sold to clean sumps before removal, so to reduce exposure to staff contaminated oil.

So some clever clog said let's get our money back flogging idea to customers we can clean the sump and provide benefits.
 
The.Analyst said:
If it’s FOC no harm

Changing your oil more frequently would probably be a better idea if you’re paying for it

I tend to agree - but they kindly added the £100 to my service bill without discussion.

I only discovered as I came to pick the car up :(
 
From my own opinion

Your oil has worked hard and needs to be changed the oil was up to or above the BMW spec of oil there are loads of people who bang on about the need to have the exact oil needed for the engine etc.

You oil is drained out taking with it most of the contaminants with it.

Now add a cleaning oil that is not the same as your hi spec engine oil then drain that which takes some more contamination with it which is a good thing

But you now have an engine with some fluid which is not the same as the BMW spec oil that was in the car

You then add the correct spec of oil but it is lets say 98% oil to spec and 2% cleaner

Personally not keen on the idea

Was on an oil and lubricants course run by Castrol for a power station and the man running it claimed that even a teaspoon full of cleaner (from the parts washer) in the oil tank would show up in his oil tests, and could lead to bearing failure's bear in mine the oil tank was 30,000 ltrs so he did not convince me but I did not before or after add any cleaning fluid to oil as it just seams wrong
 
Sounds like a load of old Codswallop to me. Why risk the dregs of the Soya muck contaminating your shiny new oil. And as The Analyst says ,use the money you save to do more frequent oil changes.
 
Nick W said:
Sounds like a load of old Codswallop to me. Why risk the dregs of the Soya muck contaminating your shiny new oil. And as The Analyst says ,use the money you save to do more frequent oil changes.

Presumably the theory is that the dregs of soya muck are better for the engine than the dregs of the dirty old contaminated oil?

I had a thought recently... after changing the oil run the car for a few minutes, drain the new oil, allow it to settle, syphon off the top 95% of the new oil and put it back in the engine with 5% brand new oil.

Cost - time and an extra 500 ml of oil.

Potential benefit - that 5% of the new oil that has been discarded has hopefully taken with it a lot of the contaminants which would have otherwise gone round the engine for another 10k miles until the next service.

Worst case - you've not removed much in the way of contaminants and wasted a small amount of time and money.
 
Yet 2 of us posted pics of our engines with cam cover off on another thread..
My car was 95k when picture taken.
How much cleaner do we want engines.
20221010_154731.jpg
 
Yeh I kindof agree with everyone & feel the same.

I do quite like the idea of it (with no evidence or basis in fact whatsoever) - so I guess this is a warning for others that take their car to the main dealer (I have my reasons for that).

Watch out for them bumping up your service charges without asking - this doesn't feel like a process worth an extra £100 of your hard earned.
 
I wouldn’t be surprised if the same soya oil was used over and over again and just run through a filter in their machine, how on earth is it permissible to change a customer for something they didn’t ask for and had no idea it was going to be performed. It’s like asking for a £3.50 coffee and being charged £10 becomes they had to sterilise the cup for you.
 
I have a Ford Kuga grocery getter with the 1.5 3 pot motor in, had it serviced for the first time last November and there was an item on the invoice for “ Engine oil flush “ sounds like it could be the same sort of thing. Luckily it didn’t cost £100 though !!
Car was collected and delivered back so didn’t ask at time and assumed it was a process to try and preserve the wet cam belt these engines have 😮.

Will ask next time I am dealers.
 
If you are doing it yourself ir a friendly Indy then tipping a full load of cheap 5w30 in and running it for 10 mins then draining it would work as well as maybe..some of the oil like the DEXOS versions have a lot of detergent in them..

It’s very very unlikely…but in aviation…we had engines that ran on highly leaded fuel..accumulated deposits, when flushed they clogged up the oil ways..don’t think that applies to car ICE running unleaded..
 
matsmith749 said:
The.Analyst said:
If it’s FOC no harm

Changing your oil more frequently would probably be a better idea if you’re paying for it

I tend to agree - but they kindly added the £100 to my service bill without discussion.

I only discovered as I came to pick the car up :(

That is not on. They can't just carry out additional work that wasn't agreed and bill you for it.
 
Beerman said:
matsmith749 said:
The.Analyst said:
If it’s FOC no harm

Changing your oil more frequently would probably be a better idea if you’re paying for it

I tend to agree - but they kindly added the £100 to my service bill without discussion.

I only discovered as I came to pick the car up :(

That is not on. They can't just carry out additional work that wasn't agreed and bill you for it.
I did write the same thing but my post never made it on, it’s wrong….i think it’s fair to name the dealers in this case
 
matsmith749 said:
I tend to agree - but they kindly added the £100 to my service bill without discussion.

I only discovered as I came to pick the car up
Then dispute the charge, if you've not authorised it you are not obliged to pay. If you signed any paperwork with a general authorisation when dropping off I'd still argue the point.

Too many people let this sort of behaviour slide.
 
Not a fan of these flushing machines garages are tending to use, just a money making exercise from what I can see. I do my own oil changes and have used a can of flush before the old stuff is drained, that seems to do the job they claim it to do. When I have taken cam covers off I always expect to see evidence of a varnish like coating on the metal, not seen any that would cause me concern, frequent oil changes is the thing to aim for in my opinion. Same for cans of oil additive as long as the new oil meets the required specification there shouldn't be a need for an additive.
 
Back
Top Bottom