Pre-ignition or pinking? 2007 MX5 coupe.

On 2007-06-25, The Invisible Man > wrote:

>> 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

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.

--
Grant Edwards grante Yow! An air of FRENCH FRIES
at permeates my nostrils!!
visi.com

"The Invisible Man" > wrote in message
. co.uk...
>>
> White exhausts used to often mean that mixture was a bit lean.
>


The white deposit is causued by lead oxides. No lead, no white deposits.

">
> 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.
>
> --
> Grant Edwards

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

"The Invisible Man" > wrote in message
. co.uk...
> Hi
>
> Our 2007 MX-5 Coupé 2.0 (not sport) makes some knocking? noise when
> accelerating gently at fairly low revs. Not a lot of torque starting off
> on steep hills in Cornwall the last few days.
>
> Garage can find nothing wrong. Never had any similar problems with our
> 2005 1.8 but exhaust is quite white inside.
>
> Anyone come across anything similar? No problems over 2500 rpm. Goes best
> over 3500 rpm.
>
> TIA for any help.

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

"Grant Edwards" > wrote in message
...
> On 2007-06-25, The Invisible Man > wrote:
>
>>>>>> 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.
>>>
>>> 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.
>>>
>>>> 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.
>>>
>>> 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.
>

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

Jim

George Jetson wrote:
> "The Invisible Man" > wrote in message
> . co.uk...
>> Hi
>>
>> Our 2007 MX-5 Coupé 2.0 (not sport) makes some knocking? noise when
>> accelerating gently at fairly low revs. Not a lot of torque starting off
>> on steep hills in Cornwall the last few days.
>>
>> Garage can find nothing wrong. Never had any similar problems with our
>> 2005 1.8 but exhaust is quite white inside.
>>
>> Anyone come across anything similar? No problems over 2500 rpm. Goes best
>> over 3500 rpm.
>>
>> TIA for any help.
>
> 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
>
>
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

BRUCE HASKIN wrote:
> $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



"BRUCE HASKIN" > wrote in message
...
> $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
>

BRUCE HASKIN wrote:

> What is the regular price in the UK ?
>
>
> Bruce Bing '03 LS

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.

http://money.cnn.com/pf/features/lis...ces/index.html


It's only 12 cents a gallon in Venezuela.

Pat