- My model of MX-5 is: NC
- I’m based near: Macclesfield
- I’m looking for technical help or recommendations on: Do members advise putting Wynns
engine flush in the engine with the old oil before renewing it. The garage mechanic suggests
it may cause engine damage, NC 2010 reg 58000 mls Thank you.
The problem with ‘engine flush’ type products (in reality just paraffin/solvent) is that you’ll never get it all out when you drain it, there’s always a residue left.
If you think the oil strainer may be getting blocked, usually due to poor maintenance especially on Diesel engines, whip the sump off and clean the strainer or replace it.
It used to be the case that lube oil became contaminated with carbon deposits, but modern production methods have all but eliminated this in petrol engines.
So no don’t bother imho, just ensure at 10k or annual synthetic oil changes.
2 Likes
Personally, no I wouldn’t use it.
As above if you have a sludge problem.
Regular oil/filter changes with modern fully synthetic oils takes care of the cleaning.
The longer you leave it to drain the more comes out (obviously).
I just change mine annually no matter how many miles I have done, currently not a lot!
Enjoy your motoring. 
2 Likes
As an engineer who has been involved in lubricant testing I would never advise using a flushing oil. Provided the oil has been changed regularly and the engine has not suffered excessive wear there is no benefit to be gained from flushing the engine oilways, in fact it may even disturb any wear debris and redistribute it into the oilways. The danger with using a flushing oil is that it will strip the old lubricant anti-wear additives that clings to the engine surfaces and you will then have metal to metal contact until the fresh oil forms a new boundary layer. Once drained any flushing oil remaining in the engine could well adversely affect the properties of the new engine oil. Stick with a good quality oil that is changed regularly.
6 Likes
Put some in and follow the instructions, it won’t do any harm. In order to get it out however you’ll have to perform an extra flushing oil change to flush out the flushing oil, so factor that in too. For that you can just put in the cheapest oil you can find.
Given the MZRs penchant for destroying itself anything which does no harm, but has a possibility of doing some good is not a bad idea.
Each to their own of course.
Likewise, if you want to go through the expense and time of going through the “flush procedure” that is your choice.
Keeping on with the original question.
By using a modern fully synthetic engine oil you don’t need to flush it like you used to do decades ago.
Quality of oil has move on significantly.
Quite simply with relatively modern petrol engines and oils you simply don’t get the build up as the deposits are kept within the oil itself and go when you drain it.
From my experience (and indeed many others on this site) the MZR engine is very reliable if it is maintained properly with regular oil/filter changes and kept to the correct level.
(Same as ANY engine to be honest).
To quote what the vast majority of oil manufacturers state in various forms or another.
“Excellent washing and dispersing properties and the highest thermal-oxidative stability effectively prevent all types of deposits and keep engine parts clean throughout the service life”.
PR-Yorkshire above gives a sound professional and logical point of view and advice.
None of the other replies are of much use. I’ve stripped and rebuilt enough to know what goes on inside.
You don’t know the history of your second hand car, but one thing we do know for a fact is that Mazda recommend semi-synthetic, an oil change at 12,000 miles and that they are dropping like flies due to the oil control rings being stuck together with black sticky oil deposits.
So it’s pointless saying ‘Shoulda woulda coulda’.
If you can find a proper laboratory controlled test or a white paper on engine flush then post it up.
Until then you’re just an uniformed opinion on the internet and there is no shortage of those.
1 Like
And he’ll do for me even tho the last thing I’ll be doing is flushing my 2 litre. I’ll rely on 3k oil and filter changes on fully synthetic
2 Likes
You don’t change oil based on mileage alone, that would be silly.
Is that comment for my benefit Martin ?
Does anyone know the rebuild oil fill capacity vs the oil change fill capacity?
On my Suzuki bike, draining the oil only gets about 70% of it out. When I got it, I did three oil changes before it looked clean, and now I will change it frequently to keep it clean.
Using an engine flush chemical would mean that a proportion of that chemical would likely be in there for the rest of the life of the engine. I don’t like the sound of that, but presumably the stuff is made with that in mind and diluted with fresh oil would be harmless. Presumably…
So short answer, if I was unsure of the service history, I would give it a couple of oil changes in quick succession using a grade of oil I was happy to leave in there.
By the way, Lidl have some expensive Petronas oils for £5 a litre they have been trying to shift for months. If I wasn’t moving house in a few weeks I would be stocking up.
1 Like
Yes. You change oil based on a combination of:
Type of oil.
Mileage
Time
Type of usage.
No you’re incorrect - again. I don’t think you’ve read and/or understood what i’ve written even though it’s simple enough.
And you wonder why the threads get closed!!
For some strange reason you just like to be rude and wind people up.
You have an opinion, but please give it politely.
This Forum used to be fun until all this nonsense started.
PPF
Professional Polite and Friendly.
Keeping to the thread.
Incidentally according to Green Flag research (Professional company) FORD do not recommend the use of flushing agents which the MZR engine is as you know.
1 Like
The MZR is a Mazda designed engine, not Ford.
I’m quoting factual information, i’ve never been rude nor am I the one dishing out threats.
You need to read my posts quite carefully, they are precisely written. E.G. I never called anyone silly.
I’m bound over by a duty to be professional and factual, I can’t really be seen in public to be dishing out garbage.
I’m not going to sit here and agree with misinformation, is that what you really want?
Because ignorance is bliss.
1 Like
Thank you.
Gordon
Thank you
Gordon
1 Like
Thank you for your technical advice.
Gordon
Thank you for you advice
Gordon
Thank you for the overview
Gordon
1 Like