Possible Concern

[TheKid]

Im getting a higher rpm, metallic sounding rattle that is bothering me, seems likes its only 4200+ rpm definately engine related, its an unusual sound that i cant really figure out. Im worrying that its detonation from what ive read/looked around but Ive never heard this in person before or at least i dont think so ...

2005 GT Manual w/90K
Car is pretty basic as for mods:
JLT Intake (smaller one)
SCT3 Tuner - A.M./Chris Rose Tunes (87S,93P,93R)
Axle Back

Ive tried all three different tunes all seem to do it even with 87 tune and a full tank of 93 - Also tried a dozen different gas stations no difference

Trying to problem shoot this Im taking the car back to the stock intake/tune tomorrow to go for a spin and see what that does to it, as well as ordered 3 new tunes from AM for 91 octane thinking my original tunes may have had some randon issue/too aggressive/or that fuel around here isnt truely 93 and the 91 tune will fix this (any of these three would probably be luck if they fixed it)

Even considered going and buying 5 gal. of 110 octane and adding it to the tank to see if that would clear it up?

Am I chasing the right problem or could this be something else? Any suggestions/help would be appreciated.

TheKid

 

[G.T]

i think that sounds like pinging/detonation
i'd start with checking the sparkplugs and injectors, since you already tried a lower octane tune

 

[Scott_0]

definitely sounds like detonation/pinging, may going back to the stock map will get rid of it.....

 

[WTBTraction]

check all heat shields, etc underneath the car, maybe get a buddy to stick his head under to listen closer?

 

[Fullboogie]

Have you checked the separator plate for the well-known rattling issue?

 

[TheKid]

Have you checked the separator plate for the well-known rattling issue?

Havent heard of this before could someone give me a quick bit of info on this ?

I got called into work today so i wont be able to try anything today until later this evening

Im going to go through the car pretty well tonight ill check all the heat shields/underneath the car and someone to listen closer ...

Also im not sure if the rattle occurs when simply revving it up, every time ive noticed it the car is under a load ill check this out as well tonight

TheKid

 

[S197gt07]

Havent heard of this before could someone give me a quick bit of info on this ?

It was a TSB for the plate that sits above the transmission to be replaced. I had a rattle, only when cold, and it sounded like somebody was shaking a can of nails.

Had the TSB performed to replace it and it's never come back

Mine only happened around 2-2200rpm's though

 

[Fullboogie]

Its the plate between the tranny and the engine. Mine rattled a lot, cold or hot. Not sure it this is your problem, but it's a free, easy fix.

I find it hard to believe you are having pinging issues on such a mild engine, unless your tune is really screwed up.

 

[TheKid]

Its the plate between the tranny and the engine. Mine rattled a lot, cold or hot. Not sure it this is your problem, but it's a free, easy fix.

I find it hard to believe you are having pinging issues on such a mild engine, unless your tune is really screwed up.

Whats the problem/TSB called and ill look around for a write up on how to fix this if thats what this is

Thats what i thought, its the most basic bolt-on car .... i possibly thought it was just an overly aggressive tune but this is all new to me so im guessing

The car seems to pull/run good but as soon it starts the rattle i always backed out of it, dont want to destroy anything ... I got the intake/tuner last august i think but where i dont beat on the car hardly ever it took until now to notice it

I even thought timing chains might be slapping something in the higher rpms but that just a guess too never heard that before

 

[AMChrisRose]

Well, let's start with the easiest. Shoot me over your name/order number and let me look at the tunes first. Let's see if it was just human error when creating your tunes. Let's also make sure that the tune info you submitted matches your mods. Once we get that out of the way, we can start to check other things.

Typically, pinging is brought on by crappy fuel, but if you're running a name brand (Sunoco, Shell), that might not be the case. Try running an 87 tune with 93 octane in the tank, does the problem go away?

Check for vacuum leaks after the MAF, unmetered air will always cause issues! Typically, you'll find a leak at the coupler to the throttle body. Also, make sure that the line from the passenger side valve cover to the intake isn't leaking.

At 90k miles, you might want to change your fuel filter (cheap and easy - could be your problem) and clean your throttle body. Take the throttle body off, and use some CRC (they have stuff that doesn't hurt the coating on the throttle body) and clean both sides of the blades, and anywhere you see build-up. Even a 100,000 mile TB can look brand new. This typically isn't the cause of a lean condition, usually idle quality, but it's worth getting out of the way.

Let's start there!

 

[TheKid]

Well, let's start with the easiest. Shoot me over your name/order number and let me look at the tunes first. Let's see if it was just human error when creating your tunes. Let's also make sure that the tune info you submitted matches your mods. Once we get that out of the way, we can start to check other things.

Typically, pinging is brought on by crappy fuel, but if you're running a name brand (Sunoco, Shell), that might not be the case. Try running an 87 tune with 93 octane in the tank, does the problem go away?

Check for vacuum leaks after the MAF, unmetered air will always cause issues! Typically, you'll find a leak at the coupler to the throttle body. Also, make sure that the line from the passenger side valve cover to the intake isn't leaking.

At 90k miles, you might want to change your fuel filter (cheap and easy - could be your problem) and clean your throttle body. Take the throttle body off, and use some CRC (they have stuff that doesn't hurt the coating on the throttle body) and clean both sides of the blades, and anywhere you see build-up. Even a 100,000 mile TB can look brand new. This typically isn't the cause of a lean condition, usually idle quality, but it's worth getting out of the way.

Let's start there!

Ill get into checking all of that out ... Yes i always run name brand gasoline like Shell/BP/Exxon ... I tried out the 87 tune with 93 the rattle was still there

Ill check all of the connections for leaks of unmetered air/vacuum
Never thought of the fuel filter ... ill get on that tommorrow about year ago i ran into the idle issue and cleaned both the throttle body and MAF sensor but will hit it again cant hurt ... Working on finding the order number but shouldnt be too long ...

Thanks AM/Chris Rose
This is some amazing Customer Service

 

[TheKid]

Update:
So far today i have put in a new fuel filter, pulled the throttle body off and cleaned it really well with crc re-installed everything and made sure all the connections were nice and snug to stop any vacuum leaks....

Problem it still has the rattle: extra info on the rattle ... it only seems to do it at WOT starting at 4500+rpms, also it seems load dependant just a touch of the rattle in first, a little more in second, and third its a pretty good amount. WOT uphill vs downhill also seems to make a difference downhill having slightly less rattle ....

I also noticed a small puddle (a little larger than a quarter) of oil pooled in the valley of the intake ... could enough oil be blowing by to cause detonation?

Chris Rose I tried to send you a PM last night but something happened and im not quiet sure if it sent or not ?

 

[G.T]

oil pooling up in the intake is coming from the passenger side PCV
excessive oil blow-by could be what's causing your issue as oil in the air fuel mixture will effectively lower your octane rating and cause detonation.

i'd clean it up and monitor closely to see how much and how often this oil is building up.. and consider a separator, or looking further to see why you're getting excess blow-by from the passenger side PCV

 

[TheKid]

oil pooling up in the intake is coming from the passenger side PCV
excessive oil blow-by could be what's causing your issue as oil in the air fuel mixture will effectively lower your octane rating and cause detonation.

i'd clean it up and monitor closely to see how much and how often this oil is building up.. and consider a separator, or looking further to see why you're getting excess blow-by from the passenger side PCV

Ill look into the oil seperator, i dont think its anything beyond what these cars normally have (i.e. never seen any blue smoke from a start even after sitting for 3-4 weeks, i looked inside my jlt intake tube today after i saw the oil puddle there was only a spot about 1 inch in diamter around the fitting and its been on since last aug. with about 6k miles) but maybe its enough to cause it to ping in my case Thanks ill be checking into this

 

[Scott_0]

Problem it still has the rattle: extra info on the rattle ... it only seems to do it at WOT starting at 4500+rpms, also it seems load dependant just a touch of the rattle in first, a little more in second, and third its a pretty good amount. WOT uphill vs downhill also seems to make a difference downhill having slightly less rattle ....

thats definitely detonation, what you described is when detonation is the most likely to be an issue, under a load and in the 2nd 3rd and 4th gears. something is awry for sure. get with AMchrisrose and dont beat on the car until its cleared up

 

[TheKid]

thats definitely detonation, what you described is when detonation is the most likely to be an issue, under a load and in the 2nd 3rd and 4th gears. something is awry for sure. get with AMchrisrose and dont beat on the car until its cleared up

Definately not beating on it ... just needed to give a better description of whats going to get help is the only reason it saw the rpm it did today ... unless im remembering incorrectly today was the first time its been over 3500rpm since jan. every time ive heard it ive instantly backed out

 

[Scott_0]

good luck with it, keep us updated

 

[Full_Tilt]

Did you try uploading the 87 octane tune like Chris said? If it goes away you can pretty definitively say that it is detonation. From youre description it sound exactly like detonation to me, but its hard to be sure without hearing it in person.

 

[char259]

+1 detonation, not to beat a deadhorse, but thats what you described

 

[G.T]

guys he's already tried the low octane tune with high octane fuel, it's mentioned on the first thread: "Ive tried all three different tunes all seem to do it even with 87 tune and a full tank of 93 - Also tried a dozen different gas stations no difference"