I've got a 2003 Mazda Protege5 that has developed a huge pinging problem. Running on 93 octane, anytime the motor is spun above 3800RPM's it starts pinging badly. Lower the octane, the worse it is. Certainly seems like carbon build up - its got 165,000+ miles on it. From what I have read, this is sort of a common issue however, no one seems to be able to offer any remedy. I've tried a gas additive to clean up the carbon and screwed up the O2 sensor. Any help?
-Keith
seafoam it
http://www.youtube.com/watch?v=Ef3HNvxblxQ
Or squirt a fine mist of water into intake
both will de carbon it
check to see if you hear unusual noise coming from the timing belt area, it is not uncommon at all for the tensioner spring to break and or stretch and alter timing with these cars happens all the time at work.
If your 2003, has an EGR system, check the function. Make sure it's not all carboned up as well. A malfunctioning EGR causes combustion temperature to rise.
My first vote is EGR as well. Not only that, but is it using oil? If it's using a quart every thousand miles or so, the oil lowers the octane rating of the fuel and that leads to preignition. Also make sure there are no air bubbles in the cooling system, they'd be trapped in the head (the highest point of the engine) and cause localized overheating.
At this point it is not using oil. I will check the EGR.
The other thing is, as the ambient temperature rises, it gets worse (i.e. 45 degree day like today is not as bad as a 70 degree day)
The EGR thing will make your idle suck. I need to pull mine apart and clean it out. My car idles like a cammed big block right now lol suck
The EGR not opening will cause a detonation/ping but the idle won't be affected.
It getting worse with an ambient temp rise makes me think that it's more likely that it's got air pockets. Has it had a coolant flush recently? Might have some congealed coolant somewhere.
Another thing to check for is something sharp sticking out into a combustion chamber (edge of a plug thread, sharp chunk of carbon etc) which will get hot and act like a glow plug. It would be worth trying ignorant's water spray thing and see if that helps. Water definitely won't damage the O2's.
CamaroKeith wrote: The other thing is, as the ambient temperature rises, it gets worse (i.e. 45 degree day like today is not as bad as a 70 degree day)
Same thing happened to my 3.0 ranger. The internets generally said it was carboned up. I did some seafom treatments and want to think it helped. I also checked and cleaned my EGR, it was not the problem. The EGR was clean and nice. Plugs, wires, nothing. I think I needed new coil packs and the engine was badly carboned.
Ford released a proceedure and TSB for both the rangers and explorers. It sounds really similar to seafoaming an engine.. HA!.
http://www.explorerforum.com/forums/showthread.php?t=195979
Jensenman wrote: The EGR not opening will cause a detonation/ping but the idle won't be affected. It getting worse with an ambient temp rise makes me think that it's more likely that it's got air pockets. Has it had a coolant flush recently? Might have some congealed coolant somewhere.
Remember, the EGR system is there to lower combustion temp and pressure. Cooler ambient temps help in that regard so they make the engine less sensitive to whatever else is ailing it. With the heavy pinging he's describing, I'm thinking it's a problem affecting all cylinders instead of a localized problem like air pockets or carbon. Three possibilities to check first:
Coolant flush is on the list of things I need to do anyway, so I will certainly give that a whirl.
Um, even if the egr weren't opening it shouldn't have any effect on stuff that happens in the motor durring hard acceleration. The egr system is ony active on decel, correct? In the 2.0 the valve gets gummed up and unable to close copletely.
On the EGR?
The EGR will work under many different circumstances. The short version: if the engine is not idling it's very possible for the EGR to be at least partly open.
The exhaust gases fed back into the intake dilute the intake charge and keep combustion chamber temps down. The second part of that is what helps with pinging. So if the EGR is not opening (vacuum system problem) or the passages from the exhaust to the valve or from the valve to the opening in the manifold are clogged with carbon it's very possible for the engine to ping.
I don't recall off the top of my head exactly how the P5's passages are laid out; on the 98-up Isuzu V6 the tube ran down the center of the intake and the tip was visible if you opened the throttle all the way and looked below the flap. This made it run somewhat on the cool side and the tip could get clogged pretty good inside of 40-50K miles. The 2.2 Holden motor used in some of the Amigos etc had a passage cast in the intake and then into the head, the part cast in the head ran right next to a coolant passage and could rapidly build up carbon too. The first time I saw that, the tech showed me the shiny sticky ball of carbon that came out and said 'Looks just like black tar heroin'. 
I did not pursue that line of thought any further.
EGR problems are a common complaint on the 2.0, but I haven't seen it causing pinging...
http://www.msprotege.com/forum/showthread.php?t=94788
Just to verify there isn't someone with a fully automatic bb gun on your block that is pissed at you for running you damned import hot rod up and down the street at 7:00pm when everyone should be asleep (you damned kids with your rock and roll and your yellow hair).
Just throwing it out there.
Yeah Keith, Stop Ricing it up... LOL
davidjs wrote: EGR problems are a common complaint on the 2.0, but I haven't seen it causing pinging... http://www.msprotege.com/forum/showthread.php?t=94788
Don't know if this will help my problem but this is a good bit of info. Randomly the car stumbles at idle. Its been doing it for a long time now but never consistantly. May have to check this out. Thanks!
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