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Occasional Hesitation at WOT

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Old 02-08-2008, 03:30 PM
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Occasional Hesitation at WOT

This is something that I've recently seen. Sometimes, when accellerating at WOT, around 4K-5K I'll get power loss, hesitation, and I'm hearing some a slight clicking noise coming from the car.

I usually can't always redo it, but today, I was able to do it a couple of times. Scared the heck out of me as I'm assuming now that it's pre-detonation (knock) which is no good. This time though, it was after just filling up with gas. It makes me think "crappy gas", but it has happened across several tanks of gas since it's not a 1 time thing.

Is that really knock. I'm not getting a CEL or anything, just the hesitation and clicking/pinging noise. Only at WOT.

Thanks in advance.

Last edited by legokcen; 02-08-2008 at 03:39 PM.
Old 02-08-2008, 03:41 PM
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using 87?
Old 02-08-2008, 03:45 PM
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Originally Posted by heyarnold69
using 87?
No usually, 92/3 sometimes mid grade. This time it wasn't the midgrade.
Old 02-09-2008, 08:28 PM
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Could be one three things,
One; Spark Plugs are bad
Two; Compression check = might need a new Engine. When mine went it was having probs doing WOT.
Three; Coils are bad
Hope that helps.
-Gil
Old 02-09-2008, 09:58 PM
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how many miles on motor??

first check plugs and leads.

depending on miles replace coils..

also depending on miles it might be time for a bit of 44k..

beers
Old 02-09-2008, 10:31 PM
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it's seems like a lot of people have this problem with the winter blend of gas.even if you think you are putting 93 oct. in your tank won't mean that the gas station you get your gas from has the correct octane coming from that pump.there are some facts to this.meaning that if a certain gas stations ordered 20,000 gallons of regalar gas (87)and only needed 8,000 gallons when the truck showed up where do you think they put that extra 2,000 gallons they can't really return the gas?you guessed it right in the mix of 93 or 89 since only select few cars like the rx8 who really knows and or shows the change of octane differances.a lot of cars shows the octane fuel output and a lot do not even if they are the same model engine size and all.every gas station out there do not have anyone full time checking out there octane rates even if it's posted that they do.remember your car knows the 87 from 93!it just deals with it the best it can even in the form of short term power loss.nuff said do you own test and get back with me!!i can't be the only one with this crap as proof!
Old 02-10-2008, 11:41 AM
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Originally Posted by swoope
how many miles on motor??

first check plugs and leads.

depending on miles replace coils..

also depending on miles it might be time for a bit of 44k..

beers
Motor has 58K on it. Have plugs at home to put in, so they'll go in next weekend I hope. It's been about 20K since new plugs were installed.

Coils are old, they haven't been changed yet. I'll do those too just for good measure. I haven't had the coil problems that other have had, so I haven't changed those. I'll order them through Mazdaspeed and change them at the next opportunity.

I haven't done any fuel injector cleaner yet. It may be time for that as well.

Last edited by legokcen; 02-10-2008 at 11:44 AM.
Old 02-10-2008, 12:18 PM
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Originally Posted by legokcen
Motor has 58K on it. Have plugs at home to put in, so they'll go in next weekend I hope. It's been about 20K since new plugs were installed.

Coils are old, they haven't been changed yet. I'll do those too just for good measure. I haven't had the coil problems that other have had, so I haven't changed those. I'll order them through Mazdaspeed and change them at the next opportunity.

I haven't done any fuel injector cleaner yet. It may be time for that as well.
Yes. Yes. and yes. Recently replaced coils/plugs (second set of each) and put 44K in my car at last oil change. Didnt have WOT troubles but my stuff was getting old so WTH. I have around the same mileage as you.

IIRC, last time on the dyno bad coils caused a signal breakup (weak spark) at WOT.
Old 02-10-2008, 12:46 PM
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How much gas did you have in the car at the time?

If it was at 1/4 a tank or less I'm betting its fuel starvation.
Old 02-10-2008, 01:24 PM
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Originally Posted by heyarnold69
using 87?
I ran 87 most of the time I had my car and NEVER had a power loss problem
Old 02-10-2008, 02:52 PM
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do some 44k,

if you like i have a set of known good coils i can send you to test with...

but they are not expensive now and have been updated. so just good investement... also look at the plugs, at 20k miles they are usually starting to fade..

send me a pm if you need anything..

beers



Originally Posted by legokcen
Motor has 58K on it. Have plugs at home to put in, so they'll go in next weekend I hope. It's been about 20K since new plugs were installed.

Coils are old, they haven't been changed yet. I'll do those too just for good measure. I haven't had the coil problems that other have had, so I haven't changed those. I'll order them through Mazdaspeed and change them at the next opportunity.

I haven't done any fuel injector cleaner yet. It may be time for that as well.
Old 02-10-2008, 09:18 PM
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Thanks for the help everyone. Should I get the coils from anywhere in particular? I've heard of several suggestions.
Old 02-10-2008, 09:55 PM
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pm

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Old 02-11-2008, 08:30 AM
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i hear mazport has a nice set ... Or one of those... do a forum search for coils...

Im upgradeing the next tie a coil fails.
Old 02-11-2008, 09:23 AM
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Just saw that they are $20.65 each through Mazdaspeed.
Old 02-11-2008, 09:36 AM
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Since you track it.... Mazsport is a good investment.
Old 02-11-2008, 06:20 PM
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I've recently had a very similar problem to the OP... car is an '04, 6MT with 68K miles on original engine, spark plugs most recently changed at 60K miles,... typically driven to redline in at least 1st gear daily w/no issues so far.

Anyway, took a 200+ mile road trip this weekend that included a 45+ minute stop & go section (@$%#$% LA freeways) ambient temp was ~80 degrees. After this heat soak, the car accelerated sluggishly.

Even once it had cooled a bit at highway speeds, when I tried to run to redline in 1st and 2nd, I experienced a flat spot between about 4700-5700 RPM, then heard a click click, then acceleration picked up. No CEL was thrown. Again on my way home, after about 2 or so hours of highway driving, I had intermittant sluggishness, combined with the flat spot in mid-range acceleration at WOT. A couple of times, traffic conditions allowed me to run in second between 30 and 55 or so to see how repeatable this was-- the hesitation followed by clicking sound would happen on the first couple of acceleration runs, then the car would pull strong all the way to 8000+ RPM on the later ones.

Drove the car to work this morning (40 minute drive on fwy... some stop and go, mostly at 70 or so... outside temps in the mid 60's), and the car pulled fine in all gears.

My two theories so far have been 1) the engine is beginning its gradual decline... or 2) one or more valves in the intake are getting stuck when the engine compartment gets heat soaked... I recall seeing a few folks had their S-DAIS intakes replaced. Based on the above, I should also consider replacing the coils.

I've got an extended warranty to 100K miles, so I'll try to get the dealer to diagnose/fix whatever it is, but at this point, the symptoms are so intermittant, I'm sure I'll get a 'could not replicate customer concern/ car checks out OK' I guess I'll try to get a tech to ride with me on a hot day and see if I can replicate the problem.
Old 02-11-2008, 06:42 PM
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just went through the excact same thing.. repaced the fuel pump and coils.. this was at 82k miles....

not sure which it was, but was getting ready to go on a 2.5k mile trip and did not want to roll the dice..

i did get a 171 system to lean once...

beers



Originally Posted by nbthing
I've recently had a very similar problem to the OP... car is an '04, 6MT with 68K miles on original engine, spark plugs most recently changed at 60K miles,... typically driven to redline in at least 1st gear daily w/no issues so far.

Anyway, took a 200+ mile road trip this weekend that included a 45+ minute stop & go section (@$%#$% LA freeways) ambient temp was ~80 degrees. After this heat soak, the car accelerated sluggishly.

Even once it had cooled a bit at highway speeds, when I tried to run to redline in 1st and 2nd, I experienced a flat spot between about 4700-5700 RPM, then heard a click click, then acceleration picked up. No CEL was thrown. Again on my way home, after about 2 or so hours of highway driving, I had intermittant sluggishness, combined with the flat spot in mid-range acceleration at WOT. A couple of times, traffic conditions allowed me to run in second between 30 and 55 or so to see how repeatable this was-- the hesitation followed by clicking sound would happen on the first couple of acceleration runs, then the car would pull strong all the way to 8000+ RPM on the later ones.

Drove the car to work this morning (40 minute drive on fwy... some stop and go, mostly at 70 or so... outside temps in the mid 60's), and the car pulled fine in all gears.

My two theories so far have been 1) the engine is beginning its gradual decline... or 2) one or more valves in the intake are getting stuck when the engine compartment gets heat soaked... I recall seeing a few folks had their S-DAIS intakes replaced. Based on the above, I should also consider replacing the coils.

I've got an extended warranty to 100K miles, so I'll try to get the dealer to diagnose/fix whatever it is, but at this point, the symptoms are so intermittant, I'm sure I'll get a 'could not replicate customer concern/ car checks out OK' I guess I'll try to get a tech to ride with me on a hot day and see if I can replicate the problem.
Old 02-11-2008, 08:21 PM
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Swoope-- did the problem totally go away after the new fuel pump/coils?
Old 02-11-2008, 08:45 PM
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Originally Posted by nbthing
Swoope-- did the problem totally go away after the new fuel pump/coils?
yep,

and gas mileage went back up and all is well again.. i would do the coils first... that is the most likely issue..


beers
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