Will be doing an oil change soon and would like to hear thoughts on wether to use an engine flush or not.
Thanks
Paul
Just my opinion but when I get a new car (new to me) always use it on the first change as you can’t be sure what type of oil has been used before and it’s not a good idea to mix mineral and synthetic as it can sludge up and blow the engine.
Hi Black Magic,
My opinion is not to use flushing oil, in the past I have found that while trying to rectify what was thought to be gummed up oil control rings on the pistons, it did a good job of removing the carbon from the pistons head which does build up after time and helps to seal the pistons, especially if the bores are worn. A strip down of the engine later confirmed this. I would recommend just use ordinary engine oil, leave it in for say, a week, then replace with fresh.
the other Mozza
Thanks for the replies guy’s, like your idea Mozza, use a cheap bog standard cheap oil then get the good stuff in.
while I’m here in the back of STHT magazine I see that Andrew Page offer a 10% discount but not sure if it applies to oil’s, any idea?
Cheers
Paul
Hi Paul
No don’t use cheap oil; you can’t mix mineral and synthetic oils in an engine. Use the good stuff both times, more expensive but far safer for the car.
Andy
I used a can of Wynns engie flush in my MK1 before an oil change on Sunday. No noticable improvement in hla clatter or anything else particularly so not sure its really worth the effort. And I have been using a good (expensive!) oil, took out Castrol Edge and put in Mobil 1.
[:^)] Hate to contradict, but yes, you can.
Well yes you can but then you run the risk of your engine blowing up because of a reaction between the mineral oil and the synthetic oil turning it all in to sludge. Maybe I should have said “you shouldn’t mix mineral and synthetic oil”[:D]
Really … smacks of fishing ladies tales. Never seen an offical warning on this. Never experianced it. Post evidence.
The risk used to be that the better detergent pack of a good synthetic oil will wash away varnish and deposits. This may cause an oil leak to start but I’ve not seen or heard of that for a long while (Duckhams used to do this nearly 20 years ago). Today I can only think of the risk of thinner synthetic grades perhaps causing HLA ticking (and you can get thin grade dino oil too so that is not really a synthetic issue)… apart from that they are all good…
A minute’s Googling suggests it’s an old wive’s tale:
For example, Valvoline say: “One urban myth surrounding synthetic oil is its compatibility with conventional oil. At one time, those who switched from conventional to synthetics had to stick with synthetics—there was no going back. Synthetics expanded the seals in the engine; then, when conventional motor oil was used, that engine sprang multiple leaks. Now, while the companies don’t recommend mixing or switching back and forth, one company’s synthetics are fully compatible with others and compatible with conventional oils.”
My, we do get some funny answers, does any body know what semi-synthetic oil is. Will it blow my engine up?
the other Mozza
Just to add more fuel to the fire (hope you like the pun)[:)], anyone got any comments on this, seems really cheap or is it as they say, “you pays for what you gets”.
Paul
It’s very cheap. It’s out of stock, though. I wonder who makes it for them.
Assuming it’s got the right API specification, then it’s “good enough” to be used for Mazda’s specified oil change intervals and your engine should last “long enough”. (I don’t know how long Mazda think is long enough.)
In case you think the above is intended sarcastically, it isn’t. I simply don’t have any way to judge what are the consequences of using cheap some-brand-or-other oil, since they’ll only show up in the long term.
Personally I traded up in price until I found an oil that kept my HLAs quiet.
Your engine will not blow up if you mix mineral and synth.
Tesco oil is made by Castrol. Halfords is made by Comma.
I once topped up a car with 1 litre of fully synth oil, and it ran loads faster until it went bang on the motorway - there was nothing left of it, and I was lucky to escape alive.
(Ignore that because I’m a lying bastard!) [;)]
Ah forums, full of people who all think they know best!
I really wish people would caveat their statements with anecdotal evidence or avoid typing in such a way that makes it sound like they are the reincarnated expert on, in this instance, engine oil…
We all have our own, usually very isolated, experiences and can talk about these but it amazes me the level of sweeping statements people chose to make. Not just does this make you sound like a class A pr**k but it also scares anyone looking into a topic for the first time.
Forums are an excellent place for getting tips on a job you have never done before, but can easily turn into a worry for some drivers who find 101 people professing their way is the “right” way.
An engine is not made of jam and is not going to explode at the merest hint of the wrong grade of oil.
Mobil 1 0w/40 is a fully synthetic oil and I had heard it was better for getting into the bits of HLAs that other oils just can’t reach. That may be true, but I found that when my engine was hot (after a lap of the nurburgring) it had become too thin and the clatter was awful. Other people like it, but I didn’t. I recently had my cambelt done by Mark at Freelance Mazda (excellent garage) and he said 10w/40 was really the way to go. So I got some Mobil semi syn off mx5parts, runs great but will report on track performance after Monday.
With regular oil changes (3-5k miles) I think a flush might be a bit superfluous and have heard some bad experiences, but it all depends on the car. If it is really gunged up then your best bet might well be to take it to an specialist garage / or call one, like Mark’s, and get some advice or get them to do the work. That way you’ll have peace of mind and not just loads of forum plonkers spouting crap at you…
When we bought our MX5 in April 2008 it had a full service history by Mazda at Washington. Like yourself I have read stories on the internet about people who have done an engine flush and had problems later.
I think a normal oil change is the way I will go and leave the EF alone, like the old saying goes “If it ain’t broke don’t mess about with it”
Cheers
Paul
Gosh this got some replies, I have used oil with a high detergent content as a flush for used motors (ie diesel engine oil) and running it for a few miles before draining and putting the right stuff in, did no harm but the oil buffs will be up in arms on this I am sure but before I get hammered for this you must think your engine is in a state to warrant flushing in the first place? if unsure just do a short change. I think sometimes the glossy pictures on the front of the can of oil can distract from reading the api ratings on the back of the can.
Regards
Geoff…
I had my car in a local garage for a new clutch and asked him to do an oil & filter change while it was up on the ramp.
A couple of days later sprung a major oil leak, mechanic said he spoke to mazda dealer and they told him to use 5w30 semi synthetic oil.
This was obviously too thin an oil and acted like an engine flush cleaning all the residue that had built up over time.
I drained the oil and used 10w40 semi synthetic and after a couple of days the leak stopped!!!
Thats not the end to the story though!!!
A couple of weeks later started smoking on start up… Took some advice and replaced head gasket, valve stem oil seals and reground valves… smoked for a couple of days then stopped… Thought id better change oil again to clear out any old bits of gasket etc that may of been knocked down the oilways and suprise suprise its smoking again [8o|]
Dont know if this is related to wrong grade or type used or if its just bad luck on my part but never had a problem in 2 years until garage did oil change.
Spoke to previous owner and she was unsure what oil had previously been used as a friend did servicing for her and she never asked…
If it keeps on smoking will have to sell car as cant afford to replace engine[::(]