Oh no not again: what oil in Mk.1?
Discussion
I've always used the recommended oil in my 1.8 Mk.1 (5w40 is it? or 5w30...)
Originally had semi-synthetic in there on the recommendation of my specialist, but trying to quieten down the HLAs I tried fully synth Halfords which seemed to help.
Eventually had HLAs replaced with known good ones which cured the rattling (obviously still 30 secs from cold and when the oil was dirty as with all Mk.1s).
However, since the last change (Halfords again) it is fine until I sit idling in traffic for more than a few mins or the engine gets really hot, where it will rattle for Britain. Usually, some hard revving quietens it down again (even just in neutral holding the revs at 5k for 10-15 secs!).
What's the best brand/type of oil to use? Fully/semi synthetic? Anybody had similar experiences?
Originally had semi-synthetic in there on the recommendation of my specialist, but trying to quieten down the HLAs I tried fully synth Halfords which seemed to help.
Eventually had HLAs replaced with known good ones which cured the rattling (obviously still 30 secs from cold and when the oil was dirty as with all Mk.1s).
However, since the last change (Halfords again) it is fine until I sit idling in traffic for more than a few mins or the engine gets really hot, where it will rattle for Britain. Usually, some hard revving quietens it down again (even just in neutral holding the revs at 5k for 10-15 secs!).
What's the best brand/type of oil to use? Fully/semi synthetic? Anybody had similar experiences?
Speculating here, but that doesn't sound like an issue with the viscosity or brand of oil you're using.
Since it's heating up and rattling when idle in traffic, could it be that the oil pump is only being driven when the engines being revved? Do you have any electrical issues when idling, i.e. lights dimming, radio dropping off?
I think you might have something more serious here, and oil starvation could very well lunch your engine. Hopefully an expert will be along shortly to advise better than I can.
Oh, and to answer the original question, I use Castrol Magnatec 0W-40 Fully Synthetic.
Since it's heating up and rattling when idle in traffic, could it be that the oil pump is only being driven when the engines being revved? Do you have any electrical issues when idling, i.e. lights dimming, radio dropping off?
I think you might have something more serious here, and oil starvation could very well lunch your engine. Hopefully an expert will be along shortly to advise better than I can.
Oh, and to answer the original question, I use Castrol Magnatec 0W-40 Fully Synthetic.
No issues that I or my mechanic (MX-5 specialist) have picked up on. I would have thought if it was going to kill the engine it would have done it by now! 99% sure it's just one of the HLAs sticking, I know the sound very well 
Magnatec worth it or is it all smoke and mirrors about the oil "sticking" to the top end when off?
Magnatec worth it or is it all smoke and mirrors about the oil "sticking" to the top end when off?
MX-5 Lazza said:
Mobil1 0W-40 is the best to use to keep the HLAs from rattling.
As a short-term cleaner try using some full synth diesel engine oil for 1000 miles. Diesel oil has stronger detergents so works like an engine flush but shouldn't be used long-term.
Back in 2006 I asked the Opie Oils man (see sticky in General Gassing) if there is actually any difference between oils marked as being for diesels and those for petrol engines. Indeed, some oils say they're fine for either. he replied: As a short-term cleaner try using some full synth diesel engine oil for 1000 miles. Diesel oil has stronger detergents so works like an engine flush but shouldn't be used long-term.
"Most are market research if you like, The way to tell if it is suitable for both is by the ACEA spec, A is for petrol and B is for diesel, most oils will carry both.
The only real call for Diesel specific oils now are for heavey commercials, trucks/generators etc."
So in esssence, unless an oil spec is specifically marked as A or B, but not both, then it will be equally suitable for petrol or diesel.
From what I've read, yes most petrol oils can be used in diesels and most diesel oils can be used in petrol engines (I used Mobil1 TD 0W-40 in my car for 5k miles with no problem - certainly made the VVT valve quieter). However, the detergents in each are different, diesel oils have anti-foaming agents for example which petrol oils don't have or need. Conversely, using a petrol oil in a diesel won't damage anything but with the weaker detergents it won't last as long (I have no idea what the lack of anti-foaming agents will do). They also have stronger detergents to cope with the diesel soot it will encounter. So while both can be used in either they aren't made for it and aren't the ideal choice either way.
Skinny - can you shed any more light?
Skinny - can you shed any more light?
all but the heavy duty diesel oils are the same as petrol oils these days, the detergent packs that go into the oils are the same. basically as long as there's a customer perception that their diesel cars need diesel oil, we'll always have the two types.
as above, basically all oils in europe carry both ACEA A and B specs as a minimum which relate to petrol and diesel tests, and some of these tests cost tens or hundreds of thousands of pounds to run, so you wouldn't get a two different oils for petrol and diesel when both meet the same specs.
as for magnatec it's ok but it's still a fairly basic part-synthetic oil.
for the OP's problem it maybe due to insufficient oil quality / excessive age. oils thin down with high temp so if you're getting a rattle sitting in traffic after a good run then you need to replace it. if it started doing it quite quickly after you changed the oil then you might want to upgrade it or use a higher grade.
as above, basically all oils in europe carry both ACEA A and B specs as a minimum which relate to petrol and diesel tests, and some of these tests cost tens or hundreds of thousands of pounds to run, so you wouldn't get a two different oils for petrol and diesel when both meet the same specs.
as for magnatec it's ok but it's still a fairly basic part-synthetic oil.
for the OP's problem it maybe due to insufficient oil quality / excessive age. oils thin down with high temp so if you're getting a rattle sitting in traffic after a good run then you need to replace it. if it started doing it quite quickly after you changed the oil then you might want to upgrade it or use a higher grade.
and that was on halfords fully synthetic!?
if you look at the specs on teh halfords oil, there are barely any OEM specs which are the really hard ones to get so might indicate quite a basic oil but to be honest, if it's a fully synth it should be ok, i'm surprised it's rattling unless you got a thin grade?
if you look at the specs on teh halfords oil, there are barely any OEM specs which are the really hard ones to get so might indicate quite a basic oil but to be honest, if it's a fully synth it should be ok, i'm surprised it's rattling unless you got a thin grade?
Sorry to bump, couple of questions:
Mobil 1 0w40 comes up as "new life" - is this the right stuff? Halfords have it on offer at less than £40 which seems pretty good for 5L.
Also been reading up and it sounds like the filter can be a pig to get off. Some seem to recommend a claw type filter remover, some a cup type, but there are 2 sizes of filter that can be fitted!? (Mk.1 1.8)
Mobil 1 0w40 comes up as "new life" - is this the right stuff? Halfords have it on offer at less than £40 which seems pretty good for 5L.
Also been reading up and it sounds like the filter can be a pig to get off. Some seem to recommend a claw type filter remover, some a cup type, but there are 2 sizes of filter that can be fitted!? (Mk.1 1.8)
Mobil have just rebranded their oils, so "new life" could well be the right one. A tip if you have one nearby is to find a costco member for your mobil 1 - it's around £25 for 5L - in fact, there's a sticky somewhere on Nutz with people offering to use their membership to get oil for other Nutz members.
browno said:
Mobil have just rebranded their oils, so "new life" could well be the right one. A tip if you have one nearby is to find a costco member for your mobil 1 - it's around £25 for 5L - in fact, there's a sticky somewhere on Nutz with people offering to use their membership to get oil for other Nutz members.
Nutz 
Are you sure that's motor oil they're offering to buy?
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