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Your car does not have hydraulic lash adjusters which are the cause of the common NA \"ticking\" noise.

I think you have a valve clearance adjustment problem or a piston pin/conrod bearing problem. If it has a warranty, take it back.

I have a late 2001 model and my engine rattles like a diesel at cold start up but goes away after about a minute. It has done so since around 10000km. Mazda have tried everything. I've had a steady stream of people out from Mazda Australia technical area to listen to it and faxes to and from Japan. Mazda have replaced the entire head assembly including the cams/valves/SVT controller etc. They even changed the recomended valve clearances for the SP and SE to help after playing around with my car. After they do something the noise usually goes away but after a few thousand km it always comes back. It's been about 16000km since they last played with the valve clearances and it's as noisey now as it was just before they replaced the head. Apparently it's not supposed to make the noise but no one knows what's causing it but they are always keen to point out that it's not doing any harm. I'm not sure how they know this when they dont know whats causing the noise, but anyway.....

If it makes you feel any better, the last Mazda3 loan car I had with about 3000km on it did the same thing. I think it might just be a Mazda thing.

It's almost due for it's 100000km service. I'm going to mention it to them again as the rattle is still under warranty but I'm not sure what else they can do.

Garry wrote:I have a late 2001 model and my engine rattles like a diesel at cold start up but goes away after about a minute.

Same with mine. It goes away so I don't really care. I know how I maintain my car and I use good oil so I know there's nothing much more I can really do.

I'm due for an oil change actually and i'm going to dump some lifter free into the engine before draining. I'll let you know how that goes.

I'm due for an oil change actually and i'm going to dump some lifter free into the engine before draining.

Save your money, it doesn't work. That was one of the first things Mazda tried.

I didn't think a 10000km car should do it. Thats why I complained to Mazda about it 3 years ago and the main reason my car has been off the road for so many months since then.

It would be really nice if someone would determine the cause of it so that I know it's not doing any harm like Mazda claim.

It sounds like a diesel

Yes, people have actually asked me if it was a diesel

AMR I know them well. I'm sure they were thrilled to end up with another \"diesel\" MX5 after their experiences with my car.

I started off at AMR but moved my business to John Newells.

JBT wrote:Your car does not have hydraulic lash adjusters which are the cause of the common NA "ticking" noise.

I have this problem with my NA6. The noise dosn't go away until the engine gets quite warm! What's the solution to fix this problem?

fleery wrote:So there could be some truth to what they say, that the SVT gear is noisy and that it is a common problem and wont cause damage??

What I don't understand is how the S-VT system, which is just using some oil to advance the intake(?) cam timing slightly, could cause tappet rattle.

What I don't understand is how the S-VT system, which is just using some oil to advance the intake(?) cam timing slightly, could cause tappet rattle.

Neither does Mazda, of if they do then they're not letting on to me.

The noise appears to be valve or head related, in my car at least, because every time they check or adjust the valve clearances and when they replaced the head the noise went away for a while. They even tried moving the buckets and shims around in the head, and the noise stopped for a while. but it always comes back. After they replaced the head 18 months ago when the noise did come back it started off being quieter and of shorter duration, but gradually it is now as loud as ever and takes a bit longer to go away.

It sounds like it's much easier to tell customers with this issue in their cars that \"they all do that dont worry about it\" when in fact only some cars do it and Mazda dont have a fix for it.

mr_rotary wrote:I have this problem with my NA6. The noise dosn't go away until the engine gets quite warm! What's the solution to fix this problem?

Try a good oil flush, Lifter Free or replace the (expensive)HLAs. Sometimes a change of oil grade will work. Do a search for HLA here and put aside a few hours to read all the stuff.

just a thought...
My rodeo had similar problem of diesel envy...
After numerous mechanic's inspections an tune ups (one even said that the noisy tappets were a factory added option )
I finally got sick of it and adjusted them myself with a drop of loctite on the locking nut, it never happened agai

Use at your own risk though

No adjusting nuts ampz, Mazda use shim over bucket.

Yeah, I tried Lifter Free for the last 3000km Daz but it didn't work. I've just jettisoned it with the 3000km old oil today......oil change before tomorrow's track day.

Oddly, with my car if it rattles after start, I just switch off and then re-start. 99% of the time it fixes it. Very rarely might have to do it a second time. I change the oil (Magnatec) and filter every 5000km/6 months. I'm thinking about trying a different grade of oil to see what happens.

The noise from the head goes away after about a minute. There is another ticking noise coming from further down in the block that tends to start up once the car is warmed up a bit. It's always made that noise and my NA used to make the same noise so I've never worried about it.

The fuel injectors will make a soft ticking noise as well. This is normal.

they suspected there was some gunk in the lifters

Your car (NB) doesn't have hydraulic lifters.