spark knock on my 05 GT
11-15-2006, 01:38 PM
#1
Thread Starter
Join Date: Nov 2006
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Posts: 8
spark knock on my 05 GT
Any sugestions on how to fix this? I have a 2005 Mustang GT stick shift with only 10,000 - problem started at around 7,000 - slight valve clattering/knocking on acceleration going from 3rd to 4th, sometimes in lower gears, but usually in 4th. I've taken it to the dealership a total of 5 times, starting back in August with the last visit two weeks ago (mid-October). They first tried to tell me it was gear noise, then they said it had to do with the fuel system- they changed out (or said they did) the fuel pump and fuel filter, even though the car only had about 8.000 miles. They've finally acknowledged that it's spark knock and has to do with the timing (what I had thought all along), but said that the 05 GT has a self-adjusting timing and they didn't know how to adjust it otherwise - i.e. they couldn't fix it. Then, the guy went on to tell me that the noise "wasn't hurting a thing" but that they would work on finding a solution - that was during my fifth visit to the dealership (each time, leaving my car for no less than 3-4 days). I've called back twice since mid-October and have gotten "still know nothing, but working on it" - even though they have not once called me. I feel as though I've just been screwed around and that they have no intentions on fixing the problem, especially since the service manager told me he felt that "it wasn't hurting a thing." I mean, if you bought a brand new car and it had a crack in the windshield, even thought it "wasn't hurting a thing" you would still expect it to be fixed, right! I told the guy, I didn't care what he had to do, even if he had to replace the engine, as long as it was fixed - of course, he commented that they wouldn't do that and he didn't know if they would be able to fix it or not. Wondered if anyone could tell me how to adjust the timing manually or what steps I should take (going over the service manager at the dealership) to get this taken care of
11-15-2006, 01:50 PM
#2
5th Gear Member
Join Date: Oct 2006
Location: Baytown, TX
Posts: 3,115
RE: spark knock on my 05 GT
have you tried a higher octane fuel
is this in a hot climate
or the knock sensor could be damaged
as for adjusting the timing from what I've read that would have to be done in the computer they might try replacing the computer as it could be defective or check the plugs for carbon build-up
maybe shanes90lxhatch can chime in
is this in a hot climate
or the knock sensor could be damaged
as for adjusting the timing from what I've read that would have to be done in the computer they might try replacing the computer as it could be defective or check the plugs for carbon build-up
maybe shanes90lxhatch can chime in
11-15-2006, 01:57 PM
#3
RE: spark knock on my 05 GT
Have they flashed the computer yet, that is where the timing is controlled. Seing as they dont know how the timing works, id be a little scared. If you were driving it gently the first few thousand miles the car has adopted a milder tune and will spark knock if you drive it harder now. You may want to try disconnecting the negative cable of the battery and forcing the computer to do a re-learn. leave it disconeccted while you are eating dinner or something, that way you get a full capacitive drain. (full memory wipe) If that doesnt help you could always invest in a tuner, that's an exp fix for a simple spark knock, but well worth it for the other benefits.
11-15-2006, 02:56 PM
#4
4th Gear Member
Join Date: Aug 2006
Location: Los Angeles, California
Posts: 1,277
RE: spark knock on my 05 GT
I've noticed the same thing on my 5-speed, but only going from 1 to 2 under load. If it's the same sound, I hear about 2 or 3 light knocks (like "pinging"), but that's all. The problem is intermittent, and seemed to start after I put my K&N CAI on. I solved the problem by going with an SCT xCal 2 with a Brenspeed tune. That's one reason to consider a tuner... in addition to the recurved timing and fuel maps.
11-15-2006, 03:15 PM
#5
3rd Gear Member
Join Date: Sep 2006
Location:
Posts: 760
RE: spark knock on my 05 GT
Archion's idea is a good one, but likely they have already tried this, or if they ever updated the pcm it would automatically reset the adaptive. Don't bother with premium fuel, this thing should run well with 87. It really may be the quality of the fuel you put in it. I am sure you have run several tanks through it but the entire nation has crap gas at a high price. The US is getting oil from Venezuala (or however you spell it) and it does not refine as good with the same process as that eastern oil that we have been refining since 1900. We have the eastern stuff down pat but I get bad gas cases on my phone daily. Try getting gas from a newer Mobil or BP station that is out of your area. There are fuel blends and if you get high-volatility winter fuel and it is warmer than like 40f deg outside, you will get some pinging. How often do you drive it? Carbon buildup will make it ping as well. If you drive like grandma and don't drive it often, or don't allow adequate warm up times carbon will build up on your intake valves and on top of the pistons and create detonation.
Spark knock is either pre-ignition or detonation. You will not get pre-ignition in an engine with a compression ratio this low (especially without turbo) unless the gas is total crap. Likely you have detonation due to a lean contributor (like an aftermarket air filter/CAI). Unless your trims are less than 5% in the positive, she is running a little lean. The dealer may be able to do what we call an octane adjust. This must be done with a scan tool and the navigation to it is rather confusing. It basically takes 2 deg of spark advance away and should reduce pinging, but also reduces power somewhat. Be careful how much you tell your dealer , specifically about the octane adjust. I really don't want to get in trouble for "trumping" a dealer when it comes to diagnosis and repair methods. Granted, I give dealers advice like this for a living, but I am typing this at work and don't want to overstep my bounds. Just say that a friend of yours used to be a tech and he mentioned the octane adjust. If they can't figure out how to do it, they can call me. Look in your owner's manual as well. "...Some spark knock may be normal..." It is a battle between driveability, power and the EPA. We just can't run it rich and powerful but at the same time keep HC emissions at a minimum. Bottom line, spark knock is due to crap fuel, lean condition, carbon or timing issues in most cases, so .......... I say it's gas, carbon, or normal. BTW, unless your plugs are white and pitted - you have nothing to worry about. Hope this helps!
Spark knock is either pre-ignition or detonation. You will not get pre-ignition in an engine with a compression ratio this low (especially without turbo) unless the gas is total crap. Likely you have detonation due to a lean contributor (like an aftermarket air filter/CAI). Unless your trims are less than 5% in the positive, she is running a little lean. The dealer may be able to do what we call an octane adjust. This must be done with a scan tool and the navigation to it is rather confusing. It basically takes 2 deg of spark advance away and should reduce pinging, but also reduces power somewhat. Be careful how much you tell your dealer , specifically about the octane adjust. I really don't want to get in trouble for "trumping" a dealer when it comes to diagnosis and repair methods. Granted, I give dealers advice like this for a living, but I am typing this at work and don't want to overstep my bounds. Just say that a friend of yours used to be a tech and he mentioned the octane adjust. If they can't figure out how to do it, they can call me. Look in your owner's manual as well. "...Some spark knock may be normal..." It is a battle between driveability, power and the EPA. We just can't run it rich and powerful but at the same time keep HC emissions at a minimum. Bottom line, spark knock is due to crap fuel, lean condition, carbon or timing issues in most cases, so .......... I say it's gas, carbon, or normal. BTW, unless your plugs are white and pitted - you have nothing to worry about. Hope this helps!
11-15-2006, 03:55 PM
#6
2nd Gear Member
Join Date: Mar 2005
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Posts: 219
RE: spark knock on my 05 GT
(same post from general thread - copied/pasted)
I've had a 2005 GT, and now have a 2006 GT. They both have/had this ticking noise under heavy load/acceleration. It doesn't seem to matter much what rpm I'm at as long as I'm cruising in gear then suddenly floor it. It can be heard better at mid-high rpms, but it's still there down low.
I've been searching for a cure for a long time. Here's what I've heard so far... (from Ford techs)
1. spark knock:
"The design of the engine along with it's position in the engine bay close to the firewall causes one of the cylinders to run at a higher temperature than the rest. All plugs are gapped the same, which does not compensate for this temperature difference. Changing out that plug or regapping to adjust for this temperature difference may fix the problem."..."my old turbo VW did the same thing"
2. valve lash:
"It's the design of the 3-valve heads. They're noisy, but will not harm the engine. There's nothing we can do to fix the problem."
3. injectors
"It's these darn modern cars. This Ford engine is just noisy" (me: "If it's the injectors, why only under load instead of at idle? I hear the injectors at idle, and it's not only quieter, but a different sound than what I'm describing.) **blank stare** "I dunno. There's nothing wrong, so we can't fix it."
I think #1 is worth paying attention to, but I don't know how to go about evaluating this (infrared thermometer?). As far as it "will not harm the engine", sure, until I run boost and blow the thing!
Oh, and I've also tried multiple fueling stations and higher grades of fuel without success.
I've had a 2005 GT, and now have a 2006 GT. They both have/had this ticking noise under heavy load/acceleration. It doesn't seem to matter much what rpm I'm at as long as I'm cruising in gear then suddenly floor it. It can be heard better at mid-high rpms, but it's still there down low.
I've been searching for a cure for a long time. Here's what I've heard so far... (from Ford techs)
1. spark knock:
"The design of the engine along with it's position in the engine bay close to the firewall causes one of the cylinders to run at a higher temperature than the rest. All plugs are gapped the same, which does not compensate for this temperature difference. Changing out that plug or regapping to adjust for this temperature difference may fix the problem."..."my old turbo VW did the same thing"
2. valve lash:
"It's the design of the 3-valve heads. They're noisy, but will not harm the engine. There's nothing we can do to fix the problem."
3. injectors
"It's these darn modern cars. This Ford engine is just noisy" (me: "If it's the injectors, why only under load instead of at idle? I hear the injectors at idle, and it's not only quieter, but a different sound than what I'm describing.) **blank stare** "I dunno. There's nothing wrong, so we can't fix it."
I think #1 is worth paying attention to, but I don't know how to go about evaluating this (infrared thermometer?). As far as it "will not harm the engine", sure, until I run boost and blow the thing!
Oh, and I've also tried multiple fueling stations and higher grades of fuel without success.
11-15-2006, 04:39 PM
#7
3rd Gear Member
Join Date: Sep 2006
Location:
Posts: 760
RE: spark knock on my 05 GT
LOL, you can't regap your plugs. They have a "U" shaped ground electrode that connects on both sides. They have a preset gap that cannot be adjusted.
Yes the rear cylinders run a bit hotter than the rest and this is the very reason there is an updated cylinder head for 4 valve engines (cooling passages a bit too small making valve guides wear out typically only on #7,8) Either way, there is nothing you can do about it and it should not matter that much
His turbo vdub could not be more different than this engine. Way to compare apples and oranges! Turbo, inline, german, wow!
Don't take the injector thing personally. You may be suprised, but we complaints on injector ticking all the time. You are correct though, you are not hearing the injectors.
If it pings with premium fuel, it has to be a spark advance thing. You may be able to perform an octane adjust, ask the dealer to give it a whirl. It will reduce your throttle response (even more) and slightly reduce the power. Give and take.......its all relative.
The 3 valve is noisy. What can I say, it has 24 hydraulically adjusted valves with roller rockers........ it will be noisy naturally. forget a few oil changes and put 100k miles on it and see how much worse it gets. Nature of the beast. I personally prefer the cup & bucket design that the germans and japs use because it needs virtually no oil pressure and is much much less complicated and much much more dependable but whatever. The cup and buckets used to be the noisy ones, now they are the most quiet. But again, you should only hear that stuff at idle. If you get a really tin-like rattle on light accel in high gear - its spark knock.
Worst comes to worst, just look in your owners manual. Spark knock can be normal and will not necessarily be harmful. Everything in moderation. Hell, vitamin C is good for you unitl you take too much... Then you go blind!
Nobody likes to accept things like this as normal. And rightfully so. I personally couldn't care less if I leased it or if I bought it used. But your concern is completely understandable if you bought it new. Believe it or not, people have had vehicles bought back over stupid stupid crap that is normal. Supercharger whine........ Cobras and Lightnings have been taken in for the supercharger whine. To each his own I suppose......
Yes the rear cylinders run a bit hotter than the rest and this is the very reason there is an updated cylinder head for 4 valve engines (cooling passages a bit too small making valve guides wear out typically only on #7,8) Either way, there is nothing you can do about it and it should not matter that much
His turbo vdub could not be more different than this engine. Way to compare apples and oranges! Turbo, inline, german, wow!
Don't take the injector thing personally. You may be suprised, but we complaints on injector ticking all the time. You are correct though, you are not hearing the injectors.
If it pings with premium fuel, it has to be a spark advance thing. You may be able to perform an octane adjust, ask the dealer to give it a whirl. It will reduce your throttle response (even more) and slightly reduce the power. Give and take.......its all relative.
The 3 valve is noisy. What can I say, it has 24 hydraulically adjusted valves with roller rockers........ it will be noisy naturally. forget a few oil changes and put 100k miles on it and see how much worse it gets. Nature of the beast. I personally prefer the cup & bucket design that the germans and japs use because it needs virtually no oil pressure and is much much less complicated and much much more dependable but whatever. The cup and buckets used to be the noisy ones, now they are the most quiet. But again, you should only hear that stuff at idle. If you get a really tin-like rattle on light accel in high gear - its spark knock.
Worst comes to worst, just look in your owners manual. Spark knock can be normal and will not necessarily be harmful. Everything in moderation. Hell, vitamin C is good for you unitl you take too much... Then you go blind!
Nobody likes to accept things like this as normal. And rightfully so. I personally couldn't care less if I leased it or if I bought it used. But your concern is completely understandable if you bought it new. Believe it or not, people have had vehicles bought back over stupid stupid crap that is normal. Supercharger whine........ Cobras and Lightnings have been taken in for the supercharger whine. To each his own I suppose......
11-16-2006, 03:30 AM
#8
3rd Gear Member
Join Date: Jul 2006
Location: British Columbia
Posts: 638
RE: spark knock on my 05 GT
shaners,
as always your posts are super informative
Thanks for all that info. I bought my car used with 8k so i dont know whats "normal" and whats not.
The whole knocking in 4th gear has always been in the back of my mind everytime i boot it. I was super paranoid and thought it was engine knock / tranny or the bottom end of the engine about to give, but after reading what you said, i guess its normal.
Can't wait till i get a tuner and tunes
as always your posts are super informative
Thanks for all that info. I bought my car used with 8k so i dont know whats "normal" and whats not.
The whole knocking in 4th gear has always been in the back of my mind everytime i boot it. I was super paranoid and thought it was engine knock / tranny or the bottom end of the engine about to give, but after reading what you said, i guess its normal.
Can't wait till i get a tuner and tunes
11-16-2006, 04:27 AM
#9
5th Gear Member
Join Date: Oct 2006
Location: Baytown, TX
Posts: 3,115
RE: spark knock on my 05 GT
ORIGINAL: shaners90lxhatch
Believe it or not, people have had vehicles bought back over stupid stupid crap that is normal. Supercharger whine........ Cobras and Lightnings have been taken in for the supercharger whine. To each his own I suppose......
Believe it or not, people have had vehicles bought back over stupid stupid crap that is normal. Supercharger whine........ Cobras and Lightnings have been taken in for the supercharger whine. To each his own I suppose......
11-16-2006, 11:01 AM
#10
3rd Gear Member
Join Date: Sep 2006
Location:
Posts: 760
RE: spark knock on my 05 GT
Yeah. I agree. I always told them... "no problem, I can get rid of that noise in about 1 minute but I guarentee you won't like how it runs afterward...." But they are the same people that will turn around and mod the hell out of it and then complain to the dealer when it blows up. Great example - Got a lightning that was leaned to the point of stretching the intake valves. NO obvious signs of modification. In the glovebox the tech found a dyno sheet that showed like 475rwhp and two reciepts from a performance shop. One for installation of a chip and underdrive pulleys and the other for the reinstallation of the stock stuff the day before he took it to the dealer. Needless to say, he declined further repairs and bought his own engine.
Another Marauder at a Cadillac dealer (trade in) that showed a history of having holes in the side of the block from going 32,000 miles on the original oil (Who says Fords arent tough?) and no repair history. the engine in the vehicle now is totally fine but it bucks at certain loads. The tech said " this thing says intech on the valve covers.......is that standard?" I said "uhh. no. that would be a 4.6 4v out of a mark viii. Dude put a mark viii engine in a marauder and traded it at book value to an unsuspecting caddy dealer. People can be pretty shady but not all of them have good poker faces! Too bad the new owner thought it still had a warranty. One shady customer screwed two dealers and the next guy to buy the car........
Another Marauder at a Cadillac dealer (trade in) that showed a history of having holes in the side of the block from going 32,000 miles on the original oil (Who says Fords arent tough?) and no repair history. the engine in the vehicle now is totally fine but it bucks at certain loads. The tech said " this thing says intech on the valve covers.......is that standard?" I said "uhh. no. that would be a 4.6 4v out of a mark viii. Dude put a mark viii engine in a marauder and traded it at book value to an unsuspecting caddy dealer. People can be pretty shady but not all of them have good poker faces! Too bad the new owner thought it still had a warranty. One shady customer screwed two dealers and the next guy to buy the car........