Noisy Hydraulic Tappets
Discussion
Here's a new one (for me, anyway). Bought my first MX5, a Eunos 1.8 VR-Special recently. Looks great but evidence of skimped maintenance perhaps. The oil was a black as yer hat and manky so I bought some cheap semi synthetic 10W40 as shown in the motor factor's book and a filter. The oil is made by Granville up North. The filter was difficult to reach and I got a scuffed and bruised forearm. Anyway all was well until I'd covered 80 miles on a mild night at 70-80mph up the M40 and M25 and I thought there was a top end rattle. There was. I stopped at Clacket Lane and there was a pronounced tappety tap. It was 2am so I just did the rest of my journey to Medway at 60 and hoped for the best after checking the oil level. Next day good as gold and quiet again. Five laps of Brands Hatch at Retro Cars track evening and noisy again. Going to try Mobil 1 fully synthetic as it seems that I need oil that doesn't go too thin once it is really hot. I hope it works! I have got 5 litres of Castrol semi synthetic in the boot perhaps I will try that, leaving the pesky filter alone!
There were a few MX5's, which was yours Sir? Actually..is it in this lot? I did a video for a friend..
Part 1
http://www.youtube.com/watch?v=QsaR39IgJV8
Part 2
http://www.youtube.com/watch?v=UqXDVrf-xeI&fea...
Part 1
http://www.youtube.com/watch?v=QsaR39IgJV8
Part 2
http://www.youtube.com/watch?v=UqXDVrf-xeI&fea...
I think you were watching the earlier track day. Bikes were out immediately before my session. Anyway I am getting a new cambelt fitted professionally tomorrow at an independent specialist in Chatham. There is a leak from the rocker cover which they will address. We discussed the tappets on Monday and the oil will be changed from 5w30 to 10w40 which I am convinced/confident/praying will do the trick. Will advise. A couple of recent gentle motorway trips have produced the symptom again. Sounded like death throws after trip from Silverstone to Rochester on Sunday. Monday morning running like a well oiled Swiss watch again!
Luckily I managed to sell my Mercedes 190 for £300 yesterday which will cover most of the forthcoming servicing. That car cost £411 on Ebay two summers ago.
Luckily I managed to sell my Mercedes 190 for £300 yesterday which will cover most of the forthcoming servicing. That car cost £411 on Ebay two summers ago.
10W-40 will be fine but if you're tracking it, it should really be a synthetic or you'll suffer from it shearing / thinning down at high temps leading to the taptap again. personally i'd never use 5W-30 in an engine that sees any track work.
pattern, stick the castrol part synth in there for now, it might do the job - but just bear in mind for the future that you might want to change to a decent oil and then do the filter then as well. mobil 1 0W-40 is as cheap in costco as a part synthetic bought elsewhere.
pattern, stick the castrol part synth in there for now, it might do the job - but just bear in mind for the future that you might want to change to a decent oil and then do the filter then as well. mobil 1 0W-40 is as cheap in costco as a part synthetic bought elsewhere.
MX-5 Lazza said:
Why would he want to change TO 5w30? 
Because that's the recommended oil for an MX5, perhaps? - as in, the one currently recommended for MkIs by Mazda.My HLAs sounded like they were making an escape bid after 5 laps of Llandow when I was running 10w40 - and I also had 30 secs of it when starting from cold.
Switching to 5w30 has silenced them, both on track and from a cold start.
the problem is that 5W-30 is typically a ford oil, as ford use this spec for all their cars. they also tend to recommend it for all their cars, even the old ones that weren't designed to run on that oil, and their engine partners too.
therefore, the majority of 5W-30 oils in teh UK are this ford spec, which is a fuel economy oil. aside from being pretty thin at high temps because of its basic viscosity grade, it means that the oil shears down even more than usual in the bearings, offering even less protection. that's fine in a modern engine designed for this but i certainly wouldn't use it in my car.
the 5W-30 you used could just have been better than your previous oil as it needs to be of a certain quality to meet the ford spec, and your previous could have just been the basic ACEA/API spec. there are literally no advantages in using a 5W-30 compared to a 5W-40, 0W-40 (unless you are specifically looking for fuel economy) and one that is of decent quality and meets decent OEM specs *will* be better for your engine.
therefore, the majority of 5W-30 oils in teh UK are this ford spec, which is a fuel economy oil. aside from being pretty thin at high temps because of its basic viscosity grade, it means that the oil shears down even more than usual in the bearings, offering even less protection. that's fine in a modern engine designed for this but i certainly wouldn't use it in my car.
the 5W-30 you used could just have been better than your previous oil as it needs to be of a certain quality to meet the ford spec, and your previous could have just been the basic ACEA/API spec. there are literally no advantages in using a 5W-30 compared to a 5W-40, 0W-40 (unless you are specifically looking for fuel economy) and one that is of decent quality and meets decent OEM specs *will* be better for your engine.
Edited by skinny on Wednesday 17th August 22:07
MX-5 Lazza said:
I would suggest that it was just changing the oil that cured the HLA rattle, not the grade of oil you changed to.
No, that wasn't it - as the oil in there was relatively fresh anyway, according to the last service record.I've just done some checking, and Mobil say 10w/30 for normal use, 5w/30 for winter use. Castrol say 5w/30 or 10w/40.
Mazda say 5w/30 "Ford Spec".
I'd probably suggest that you can chuck almost anything at them, as they're hardly the most exotic lump out there... but if you have HLA rattles, thinner oil seems to be a cure.
(And I'm generally of the school of thought that 10w/40 works for anything - so for me to switch to 5w/30 took a bit of a leap of faith!)
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