Knock in gears 3-6th, a common problem?

[Meder]

Hi.

I drive a ms3 with about 7300 miles. Mods are cobb intake and su motor mount. Based off of data logs with the dashhawk, my car seems to be knocking in gears 3-6. The knock seems to get about 2.5 to 3.5 but I have seen 4's and 5 once or twice. Some pulls are ok with little to no knock at all. It seems to happen nearly everytime I simply floor it. Rolling onto the throttle may help somewhat, but its almost the same results. The knock always seems to happen around 4800-5k+ rpms.

I have read quite a few diffrent threads in the last few days. Some people claimed they had bad gas, some claim the sensor is too sensitive. I would really like to continue on with my mods, but do not want to because of this issue.

I have switched from shell and tried exxon and chevron all with similar results. Are these readings normal? Anyone else seeing knock of this caliber on a nearly stock ms3? What can I do to track down this problem?



I am not sure how to post pictures. Here is the log. Knock stays around 2.5 and spikes to 3.2 in this log.

http://img87.imageshack.us/my.php?image=66258132xk6.png

 

[smakdown61]

Hi.

I drive a ms3 with about 7300 miles. Mods are cobb intake and su motor mount. Based off of data logs with the dashhawk, my car seems to be knocking in gears 3-6. The knock seems to get about 2.5 to 3.5 but I have seen 4's and 5 once or twice. Some pulls are ok with little to no knock at all. It seems to happen nearly everytime I simply floor it. Rolling onto the throttle may help somewhat, but its almost the same results. The knock always seems to happen around 4800-5k+ rpms.

I have read quite a few diffrent threads in the last few days. Some people claimed they had bad gas, some claim the sensor is too sensitive. I would really like to continue on with my mods, but do not want to because of this issue.

I have switched from shell and tried exxon and chevron all with similar results. Are these readings normal? Anyone else seeing knock of this caliber on a nearly stock ms3? What can I do to track down this problem?



I am not sure how to post pictures. Here is the log. Knock stays around 2.5 and spikes to 3.2 in this log.

http://img87.imageshack.us/my.php?image=66258132xk6.png

Its completely normal, mine and many others with the dashhawk have noticed this too. I'm beginning to think its not exactly "spark knock" that its measuring, but just the difference between the timing the ecu wants and what its getting. If the knock was really bad you would be able to hear it. I think its more interesting to see how lean the car runs at full boost. It has to go to negative timing to compensate lol.

 

[SPEED3TYPE2]

completely NORMAL!!!! NOT!!! when you floor it in the upper gear with an intake you get "Boostspike" this should cuase fuelcut wich is the ecu sensing knock and cutting the fuel to protect. If youir knocking its cuase this saftey feature isnt working, an intake cuases boost spike- cuases this issue knocking is very dangerous if i where u i would not floor it in the upp gears... i alwasy experianced fuelcut when i was first discovering this, never knok, that means the ecu isn't doing its job... knock knock = zoom-boom!

 

[Meder]

Seems about right, anyone else seeing the same results as me? I pulled a 4.9 in 4th gear awhile ago, but that does not happen often. 3.5 ish seems to be common in 4th gear and over, is this ok? How did the dh log look? You guys know a lot more than me, but I am doing all I can to learn.

Speed3, many people seem to have knock of my caliber. Boost spikes on a stock car doesnt it? My boost in that log spiked a max of 16.3, knock was 3.2, rpms 5085, afr 10.10. and spark +9.00. These numbers do not seem off to me, but you guys probably know a lot more than I do about our cars. 3-5 knock does not destroy engines are far as I know. It seems that sometimes knock is simply not possible to avoid.

I figured a quick check for this would be to find some race fuel once my gas light comes on. If it is actual knock, it should go down a great deal due to the higher octane gas. If it is some sensitive false reading, it would roughly stay the same. Do you guys think this is possible, or do I have this all wrong? Another thing I have heard of are loose engine components causing false knock readings. My front bumper is a bit wacky and will be fixed soon. My battery box, the plastic covers, have broken clips that the dealership broek and are being replaced. Could these things cause false knock readings? Where is the knock sensor on our motor?


Another thing I noticed. Spark advance IS ignition timing, correct? If so, when I am knocking, why isnt the car pulling timing, only adding?

 

[Meder]

Can anyone else confirm they are seeing this kind of knock? Anyone not seeing knock based off of the dashhawk?



Does anyone even monitor knock but the handful of us?

 

[tru-boost]

you are fine especiall during these months when the gas stations use the bad winter blend of gas. i have seen my knock go over 6.0 with around
23psi in 5th

 

[Davidb]

I have ran between 17-19psi....with little to no knock(< 1.5). I went on a road trip (out of state). I was closer to sea level and using there gas and I was showing around 3.0ish...ran that fuel out and put different gas in and it was back to normal...

mods:intake, test pipe, boost controler, map clamp...

 

[subparpunk03]

Little tip when putting in gas:

Look for a station that has seperate hoses for the different octanes, otherwise you'll get a big ol' hose full of bad gas before the higher octane gas kicks in.

 

[mrlilguy157]

subbed.

 

[Davidb]

Little tip when putting in gas:

Look for a station that has seperate hoses for the different octanes, otherwise you'll get a big ol' hose full of bad gas before the higher octane gas kicks in.

Werd...I hate single pump gas stations....

 

[SxySpd3]

Seems about right, anyone else seeing the same results as me? I pulled a 4.9 in 4th gear awhile ago, but that does not happen often. 3.5 ish seems to be common in 4th gear and over, is this ok? How did the dh log look? You guys know a lot more than me, but I am doing all I can to learn.

Speed3, many people seem to have knock of my caliber. Boost spikes on a stock car doesnt it? My boost in that log spiked a max of 16.3, knock was 3.2, rpms 5085, afr 10.10. and spark +9.00. These numbers do not seem off to me, but you guys probably know a lot more than I do about our cars. 3-5 knock does not destroy engines are far as I know. It seems that sometimes knock is simply not possible to avoid.

I figured a quick check for this would be to find some race fuel once my gas light comes on. If it is actual knock, it should go down a great deal due to the higher octane gas. If it is some sensitive false reading, it would roughly stay the same. Do you guys think this is possible, or do I have this all wrong? Another thing I have heard of are loose engine components causing false knock readings. My front bumper is a bit wacky and will be fixed soon. My battery box, the plastic covers, have broken clips that the dealership broek and are being replaced. Could these things cause false knock readings? Where is the knock sensor on our motor?


Another thing I noticed. Spark advance IS ignition timing, correct? If so, when I am knocking, why isnt the car pulling timing, only adding?

with a/f like that you should not be knocking. its probably due to something else like a bad motor mount or sensor

 

[tru-boost]

his afr may look like that because the ecu is pulling timing due to the knock. if it didnt pull timing it would most likely be much leaner.

 

[SxySpd3]

did you log the run before it shows "knock"? if the a/f is consistent 10:1 then its not pulling timing and knocking

 

[SPEED3TYPE2]

ah yeah "no big deal" here is a quote from someone who just blew there engine

"Hey everyone. First post here. Wish it was under better circumstances.

I have a stock 2007 MS6 with 28,000 miles (primarily highway commuting to and from school). Only upgrade is the Mazda CAI that I had installed at the dealership. Since I bought it I have experienced an intermittent pinging (detonation?) from the engine whenever I lug (~2,500-3,000 rpm) the engine on the freeway (catching up to or passing traffic after we've slowed down to like 50 mph or so). I always put 91 in it since that's the highest octane we have in Cali.

This past week it did it to me again, but it was much louder than before. I lifted as usual and when I started to roll back into it the engine let go. I've always changed my oil every 3-5k miles and always used Mobil 1. However, without having every receipt and since I'm due for another oil change soon, Mazda is understandably refusing to honor the warranty.

The dealership wants $13k for a new engine. No remans are available yet, so I feel like I'm stuck. Do any of you guys have any ideas for how I can get my car running again? Have any of you heard of any other blown engines in the Speed 6? Know where I can find one from a junk yard or buy a block? Are there any non-Mazda/Ford engines (performance?) engines that might package? Anyone want to buy a non-roller (grin)?

Thanks.

-Brian"

 

[exxed]

On the main ms3 area, I posted this:


http://www.o-m-g-w-t-f.com/stuff/Mazdaspeed6/01-022-08-1919b[1].pdf

I have a feeling that it causing alot of our engines too blow, and mazda isn't going to fess up.

And they say it's only some cars, I get the feeling that is why some people on here can't relate to others of us that are having these insane problems with these engines. I am taking mine in tomorrow to get worked on, hopefully everything is okay.

 

[cosmic_spd3]

So type2 why is ur motor is not covered under warranty??At 28000 miles u should be cover unless u've done major mods..

Do u guys think this knocking is from bad gas..??a mean i've never heard any noise from my motor besides when i first start my car up in the morning or even after sitting all day..the noise comes on the first 2 seconds of staring the car.."YOU GUYS PAY VERY CLOSE ATTN TO THAT.."

The service guys say it's normal on these mazda motors..but i think our oil pump was poorly designed..You guys let me know if you all are hearing that noise..

 

[SPEED3TYPE2]

So type2 why is ur motor is not covered under warranty??At 28000 miles u should be cover unless u've done major mods..

Do u guys think this knocking is from bad gas..??a mean i've never heard any noise from my motor besides when i first start my car up in the morning or even after sitting all day..the noise comes on the first 2 seconds of staring the car.."YOU GUYS PAY VERY CLOSE ATTN TO THAT.."

The service guys say it's normal on these mazda motors..but i think our oil pump was poorly designed..You guys let me know if you all are hearing that noise..

I was quoteing someone else bro! he said they voided his warrent cuase he lost some of his oil change receipts....bs!! the knocking is cuase ny having the mazdaspeed cia "boost spike" if u don't get fuel cut u get ping-knock-boom

 

[cosmic_spd3]

That sure sounds like BS..I guess he do his own oil changes..because the dealers keep records of the work they do..
well am still stock and i use 93 octane..

 

[Davidb]

So type2 why is ur motor is not covered under warranty??At 28000 miles u should be cover unless u've done major mods..

Do u guys think this knocking is from bad gas..??a mean i've never heard any noise from my motor besides when i first start my car up in the morning or even after sitting all day..the noise comes on the first 2 seconds of staring the car.."YOU GUYS PAY VERY CLOSE ATTN TO THAT.."

The service guys say it's normal on these mazda motors..but i think our oil pump was poorly designed..You guys let me know if you all are hearing that noise..

That sounds like the cam actuator TSIB...is yours a 07? Go look at the tsb's. I'm a lexus tech and the is250 and is350 engines as well as the gs300 and gs350's have this same noise...

 

[tru-boost]

that should have nothing to do with the blown motors. if the fuel pump cant keep up the car will trigger fuel cut. my car is one of those affected with the weak pump. i always got cut when the pump ran out of steam. and as for the ms6 blowing the motor, i blame a bad knock sensor. these cars should never detonate to the point that you can hear it. the knock sensor is supposed to detect it long before that and pull timing to avoid a problem. my car pulls timing all the time because of knock. thats what it is supposed to do.