Pre-ignition or pinking? 2007 MX5 coupe.

But you should not be accelerating up steep hills at less than 3,000 rpm. It would be lugging the engine. That is why there are gears.

Leon

Probably a combination of:

1. Bad fuel. Octane ratings may not be what they should at some outlets, try a differant fuel supply
2. Carbon build up in the combustion chambers. Run a car of fuel additive designed to flush it out.

You've answered your own question. Keep the revs up.

So the 2007 engine is really that much worse than the 2005?

My mistake. The old MX5 was in fact a 2002 model.

Our 2007 is difficult to drive in town centre traffic. It almost needs putting into 1st gear every time you turn at a green light at an intersection. I have driven a lot of cars over nearly 40 years but never had one this sensitive.

Still people seem to be saying that the 2007 engine is just plain un-drivable compared to a 2002. I find that a little hard to believe.

I haven't driven a 2007, but I'd be surprised if the NC engine is that much worse than the NB.

Which is why I posted here. I suspect ours has a problem

If it was a couple years older I'd guess plug wires, but it seems a bit soon for them to be shot.

Since it's still "new", take it back to the dealership and demand that one of the service guys drive it. While you're there, test drive some other 2007s and see if they're better. If they are, then demand that they make yours right.

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Now THERE'S someone talking some sense! Thanks Grant. Once the invisible man does this I believe the problem will be clearly 'visible!

Keep us posted please, Chris

99BBB

We have a 2006 w/ the 170 hp 2.0l, same as yours though the derated the '07's to 166. No white in the exhaust at all, in fact black and slightly sooty, is much closer. It will ping (a light rattling sound) if you put much of a load on the engine at under 2000 rpm. I've never heard anything I'd describe as a knock out of ours.

Due to the high compression of the 2.0l engines (10.8:1), Mazda does recommend 91 octane or higher for the 2006 and newer models and some reports of pinging and knocking from those running regular gas have been reported.

I live in the boonies and often run regular as most stations around here don't carry premium and have never noticed much of a difference.

I suspect something is wrong. Our 2.0l simply screams, 0-60 6.5 secs., low

15 secs. quarter mile times, 7000 rpm redline. With a six speed stick, it simply hauls ass.

Compared to the earlier Miata's the 06 and later MX-5's are quite capable when it comes to stoplight action.

Jim

They did away with the plug wires on the 2006 and newer MX-5's

Jim

Not sure whether it is 2 tanks of non-Texaco petrol or 800 miles of often fairly quick motoring over the long weekend but the rattle/light knocking has now disappeared unless provoked and the car is picking up much better from lower revs.

At least in the UK you can cruise at 80mph on dual carriageways without much risk and floor it in 3rd to overtake up hill at 85 mph+ if you keep your eyes open. Not sure how well some of the low speed limits are enforced in the USA.

If the problem noise returns I'll try mixing a couple of gallons of super unleaded into the tank to see what happens. Our local petrol station (about 100 yards away) not only sells super but also sells genuine leaded 4 star petrol (GBP1.50 per UK gallon, approximately USD2.50 per US gallon) - No we won't be trying it in the MX-5.

Now we just have to wait for a new CD player for the MX5 (on order under warranty) because unlike the radio it only plays out of the left speakers. We also have a Mazda 3 Sport where the rear windows only work from the driver's controls occasionally. Again still under warranty so we'll get it sorted at the next service. Still love Mazdas and Mazda dealers after numerous problems with Fords and Vauxhalls (GM) in the past. Just keep hoping Ford don't intervene too much in Mazda and bring Mazda down to Ford's level.

$2.50 US per Gal. ?????? We have not seen gas that low in Washington State USA in oner 4 years ! We are still in the $3.16 to $3.50 US per Gal. (That is for 97 Oct. 91 Oct is $ 3.60 + !!!

What is the regular price in the UK ?

Bruce Bing '03 LS

We can get 97 octane for a little less than $3.00 a gallon today.

The premium was $3.09 at my last fill-up, but it has been as high as $3.25 recently.

Pat

Of course Bruce meant 87 octane (lowest grade normally available).

Here in Houston, prices are finally beginning to fall although we've been one of the cheapest areas of the country. We're seeing as low as $2.67. I never thought I'd be happy about that (and I'm not really).

Chris

99BBB

One arm and one leg. Here in the U.S. it is only one leg, for now....

This list shows gas purchased in London as being $5.79 USD a gallon. I'm not sure how up to date it is.

It's only 12 cents a gallon in Venezuela.

Pat

Errr, that's what I meant too, 87 octane, not 97. Our premium is 93.

Pat

Sorry - brain fade. Price is in fact per litre. I think there are about

4.5 litres to the UK gallon which would be something like 3.75 to the US gallon I think. In the UK regular unleaded is just under 1 British pound per litre.