Topic: 2008 Mazda5 GT Engine Knocking/Pinging

[serenaray]

Picked up a Mazda5 GT Auto in April and currently have just over 5000km on it.

Since day 1, I've heard engine knocking at around 4000rpm+, especially on load like on a grade. Initially, I was told by the dealership that the engine needs a few thousand km's to break in and the sound will go away.

Well, I brought it into the dealership yesterday and of course, the technician couldn't hear anything. So, I took the technician on a ride and sure enough, we both heard it. He asked whether I use good gas... I've put in Sunoco/Pioneer gas and 2 tanks of PetroCanada 87 octane.

So his immediate suggestion was to put a tank of higher octane fuel in and then it should go away.
In the meantime, the technician's going to look at any Mazda bulletins...

Does anybody have any thoughts about this?

[tpl]

i would have put a tank of 89 in the moment I heard the first ping and if that had cured it thought no more about it.

Secondly.... why are you driving around at 4000+ rpm?      This is an automatic right?   So it must be in 2nd or third with a heavy foot to rev that high.  I guess thats what Mazda 5 automatics do, I am not used to automatics yet but my car in drive has to be accelerating flat out to get to 4000 rpm ( or doing 145+ km/h)

[dr_spock]

Is the anti-knock sensor working?   Is 4000+ rpm too fast for it to retard detonation?

[vdk]

the 2.3 should be working fine on regular... shouldn't it? I know some 3s with the 2.3 had problems with valves being bent by the cylinder head or something like that... ask your technician about it...

check some mazda3 forums... also wing had a 3 maybe he knows more about that..

[Leviathan]

I've read that the valves on a 2.3 being bent is due to having low oil/low oil pressure and simultaneously rev'n the crap out of the engine. Something to do with how the variable valve timing works with oil pressure and if there isn't enough the timing chain will slip and then there goes the valves. Not an everyday occurrence. Low oil condition seems to be caused by home changing or fast-lube places that somehow bugger up the cartridge oil filter portion of the oil change and a leak develops.

[serenaray]

If I'm going uphill in 3rd gear, and the engine is just under 3000rpm, I hear the engine knocking.

This also happens on the highway around 105km/h in 5th gear and I try to mildly accelerate (and also if I'm going up a mild grade).

I'm going to try the higher octane gas but I highly doubt it'll resolve the problem. I have a long trip coming up so I should be able to put in a couple tanks. When I get back, I'll try to take it to another Mazda dealership.

I haven't had an oil change because I've only got 5365 km on it. I'm not sure what else to do!?!?

[rrocket]

You'd be surprised at what better gas can do.....

[serenaray]

You'd be surprised at what better gas can do.....

Do you mean better gas or higher octane gas?

I'm guessing higher octane doesn't mean better/cleaner gas?!?!

[rrocket]

Higher octane...and/or better gas.


But higher octane even a point or two can make a world of difference.  I'd be extremely surprised if you had any ping with Sunoco 94.  If you do, then you can be sure something is not right with the knock sensors.

[Thinking Out Loud]

I've had my 2007 GT for just over 17,000 kms and had no pinging noise - I've done some trips under 'full load' conditions heading out to Ottawa and Muskoka with the family and 4 days worth of luggage.

Esso regular grade petrol.  I don't hang out much at 4,000 RPM tho, unless on-ramping or up-hilling.

Still, nothing audible to note.

[serenaray]

I've had my 2007 GT for just over 17,000 kms and had no pinging noise - I've done some trips under 'full load' conditions heading out to Ottawa and Muskoka with the family and 4 days worth of luggage.

Esso regular grade petrol.  I don't hang out much at 4,000 RPM tho, unless on-ramping or up-hilling.

Still, nothing audible to note.

I honestly don't know what to do... might need to go to a few Mazda dealerships to get somewhere... doubt Mazda Canada would do anything

[Thinking Out Loud]

Always get a second (or third) opinion  .

Even go to a Midas or similar for a test drive if another Mazda isn't near by.

Try the higher octane gas first.  I think (could be marketing tho) that you need to get a couple of tankfuls in for it to work.

WORTHY OF NOTE - mine does have the 4 speed auto, and I believe your is the new 5 speed, so your engine could be experiencing things differently than mine.

Good luck, and (otherwise) enjoy the ride!

[rrocket]

Do this first.  Fill it qith top-notch gas.  94 Sunoco or whatever.  See if that cures it.  If not...then you know for sure that a) It wasn't the quality of the gas b) it's something that NEEDS the dealer to look at.

Of course if you are very worried you can just skip running the good gas...but I thought that would be easiest since it would rule out a thing or two...

[ArticSteve]

The problem with going the 91 or 94 octane route is that this engine is rated to run WELL under all conditions on 87.  I'd just leave it as it is and hope it gets worse and that will force Mazda to repair it.  Don't try and fix this yourself when you SHOULD have a full warranty supporting this car. 

Of course if we had a lemon law you would know the outcome would be good.

[perfecto]

I'm coming up to 100,000km on my 5, and I've had no problems with knocking or pinging in the engine.   

[Car_nut]

I have a 2007 Mazda 5 GS automatic, bought new in 2008, currently with 7500km. I have been using Petro-Canada regular gas, no ping. I rev it up to 4-5k rpm from time to time , no ping neither.

Since you bought yours with 5000km, do you know the history of the car? May be it was a demo or daily rental and got beat up pretty bad during the first 5000km?

I can vouch that premium gas is not needed in the Mazda 5, but if the problem goes away with 89 octane gas, then it may be the easy solution.