MX-5 OC Forum

 I sometimes get a noisy rattle on my 1.8 2.5 for 1 to 2 seconds on start-up, particulary if the car has been parked on a slant (hill).  I saw this:

http://www.mx5oc.co.uk/forum/forums/t/225.aspx

However mine is a 2003 model and I assume already has the mods.  It's nice and smooth after the 2 seconds, I've changed the oil with a new Mazda filter but it still happens.  Wondered whether the mod made any difference and whether it's a real problem.  Anybosy else get this on a 2.5.  Is there any further info on this anywhere?

 No response on this so I'll ask a relevent question:

When I changed my Oil I used Mobil S, Semi Synthetic, 10w-40.  Would it improve the initial rattle if I used Fully Synthetic 0w-40 as I've read that this Oil gets round the engine quicker on start up.

G'day Phil

No response usually means nobody has any ideas. I'm afraid I don't either. Maybe the oil level is down and you are suffering because of the slope. Check the oil level and see what happens after you park on a bit of level ground.

I don't think that changing oils would effect the problem

 Thanks Geoff.

I'm sure I've seen somewhere that others have had this rattle on 2.5s and it is associated with the VT gear even after the new parts were fitted from Mazda, but it's not really a issue, just annoying.  I just can't find any other info other than the link above.

Wondered if others know any more and/or whether synthetic oil would help.

Occasionally I get a similar thing, and I'm 99% sure it's just a heat shield - could it be that, or is it definetly coming from the engine?

Hi Phil Just found your thread, I to have a Mk2.5 1.8 sport, and on start up it rattled for 2 sec's  or so but I did change the oil to fully synthetic Castrol Magantec and used the OE oil filter cannot hear any ratlle at present, but I have to say I have changed the oil and filter at 6000 mile intervals Once start up I don't rev the engine just let it tick over for 5 seconds or so before I move off.  

Cheers Alan

 yes it is oil, how often do you change your oil, the rattle is caused by thin oil draing from your hydrolic tappets when the engine is at rest, ie thin oil or well used oil will drip back to your sump faster than a fast thing good oil will stay in the tappet cause its thick, so when you start the engine a good oil will stay in the tappet giving you a noise free start. dont use fully synthenic, mine runs on coma 10/ 40 and its fine, however if you leave the car standing for a week or so you will get a rattle for a second till the oil pump fires it round, old school cars. happy days

jonnyenglishpants:

 yes it is oil, how often do you change your oil, the rattle is caused by thin oil draing from your hydrolic tappets when the engine is at rest, ie thin oil or well used oil will drip back to your sump faster than a fast thing good oil will stay in the tappet cause its thick, so when you start the engine a good oil will stay in the tappet giving you a noise free start. dont use fully synthenic, mine runs on coma 10/ 40 and its fine, however if you leave the car standing for a week or so you will get a rattle for a second till the oil pump fires it round, old school cars. happy days

jonnyenglishpants:

the rattle is caused by thin oil draing from your hydrolic tappets when the engine is at rest

On a Mk 2.5????????????????

01mx5:

it's just a heat shield

Mazda-mender:

01mx5:

it's just a heat shield

  at the front before the cat.

That's the one - and it's thin enough you can just re-shape/move it by hand.

If/when mine get's worse I'll sort it again - but so far it only happens when the date is a prime number and there's wind blowing north east at 24mph and at least 2 of the planets in our solar system are aligned...
Or, when I think "good, not had that rattle for a while...must have sorted itself"

01mx5:

That's the one - and it's thin enough you can just re-shape/move it by hand.

If/when mine get's worse I'll sort it again - but so far it only happens when the date is a prime number and there's wind blowing north east at 24mph and at least 2 of the planets in our solar system are aligned...
Or, when I think "good, not had that rattle for a while...must have sorted itself"

They are only tack welded on and with age and where it is ,it just becomes loose,a zorst bracket for your local car shop should fix it by just re- clamping it back down solid,but dont over tighten it and crush the zorst,couple of Pounds and fixed for good.

This will happen on the Mk 1's also, as well as the Mk 2's

Mazda-mender:

They are only tack welded on and with age and where it is ,it just becomes loose,a zorst bracket for your local car shop should fix it by just re- clamping it back down solid,but dont over tighten it and crush the zorst,couple of Pounds and fixed for good.

Good tip! Mine's held together with rusty baling wire at the moment. Maybe the kind of thing that plumbers use to fasten earth bonding straps to water pipes would work, or these?

niggle:

Mazda-mender:

They are only tack welded on and with age and where it is ,it just becomes loose,a zorst bracket for your local car shop should fix it by just re- clamping it back down solid,but dont over tighten it and crush the zorst,couple of Pounds and fixed for good.

Good tip! Mine's held together with rusty baling wire at the moment. Maybe the kind of thing that plumbers use to fasten earth bonding straps to water pipes would work, or these?

I like the look of those snap straps,going to order some and see if they work,nice one nigel.

I'll send an e-mail again with some pic's,the file was to big,so was knocked back

I have been in the transport industry all my life and in most cases Castrol oil was used up to 800 bhp engines down to 1.1 ford engines and always has been a good product.

Alan