97GT still pings like a bastard

[bhuff30]

I have a 97 GT that pings at WOT. It will ping badly at mid to upper rpms, say 3000+. Running 90 octane instead of 87 will ussually help the problem, but it will still ping some even then. It has no modifcations, so no wet filters or anything like that to oil up the MAF.

So far, I've tried:
Cleaning the MAF
Replacing the fuel filter
Changing the plug and wires

It has come across my mind, that maybe a previous owner installed a chip. Is the computer in the passanger kick panel, and where in/on the computer would I find said chip? I doubt I'll find a chip though... because my dad bought the car when it had just 60k miles and it never needed anything but 87 before.

 

[Mike97gt]

heads might be loaded with carbon buildup. try cleaning the carbon out with seaform or somthing similar.

if it's not that check and see if your getting good fuel presure at WOT

 

[Aggie 08]

Damn, that sounds alot like what mine was doing! I would get it checked out quickly! When mine started pinging it would only do it until I reached 3500 rpms then stop, then 3 days later, it did it from idle to red line. We took it to 3 shops, one of which was a ford dealership, and all 3 said I needed a new engine! They couldnt tell me exactly what the probablem was without tearing the engine apart, but that was gonna cost nearly as much as a new engine. The guy that had it before me did alot of suspension work, and, though he wont admit it, I think he probably raced it, and messed it up. I dont know too much about cars, so take what I'm saying with a grain of salt, but knowing what I know now, I would get it checked immediately!

 

[sgarlic]

I'd try Seafoam as well. That stuff works wonders. In "the thread," some people actually claim it fixed their detonation issues.

 

[bhuff30]

I looked at some Sea Foam today, but didn't buy any yet. How is everyone using it? We've run injector cleaner a couple times, with no change. It looked as if you could pull off a vacume line, and let the engine suck some of the sea foam up at idle. Wouldn't that do the best job of cleaning carbon out, or is it a bad idea?


I'm not really that worried about it. It's been pinging for probably the last 2 or maybe 3 years, but only when you use base 87 and you load it hard (higher rpms, in higher gears). Like I said, it basically goes away on 90 octane, and never causes a problem unless you are reving it.

Damn, that sounds alot like what mine was doing! I would get it checked out quickly! When mine started pinging it would only do it until I reached 3500 rpms then stop, then 3 days later, it did it from idle to red line. We took it to 3 shops, one of which was a ford dealership, and all 3 said I needed a new engine! They couldnt tell me exactly what the probablem was without tearing the engine apart, but that was gonna cost nearly as much as a new engine. The guy that had it before me did alot of suspension work, and, though he wont admit it, I think he probably raced it, and messed it up. I dont know too much about cars, so take what I'm saying with a grain of salt, but knowing what I know now, I would get it checked immediately!

 

[sgarlic]

I prefer to start the engine, then remove the brake booster hose (haven't done my '04, but used this hose on every other vehicle I've done) to allow it to suck about half the bottle down. When it gets near the halfway point, I plunge the hose in the bottle so it kills the car. Then, I pour the remainder in to the oil fill tube. I let it sit for 15-20 mins, then start it, and rev it continuously until the smoke clears.. usually 10 minutes or more.

Edit: The reason for plunging the hose and killing it, is to allow the wet seafoam to sit on top of the pistons to eat away the carbon.

 

[Aggie 08]

Well thats good to hear, mine did it even with a new oil change with full syn, and 90 octane.

 

[Mike97gt]

seafoam is worth a shot before you look into more expensive stuff.

another cheap thing to try is plugs one range colder than stock.

speaking of plugs make sure you got the right heat range plug in there. parts guys do screw up like everybody.. double check your part number to make sure it's right.

 

[bhuff30]

Update:

I ran some seafoam through it. I noticed it is less likely to ping, but still pings quite noticibly under heavy loads in higher gears.

I highly doubt it is the plugs. Putting new plugs in had little effect on the pinging problem, but it ran a lot smoother with the proper plug gap again haha.

I'm still at a loss for what the problem is. It is possible I have a bad tank of gas now, and that the fixes I've done helped enough to keep it from pinging when I fill up again.

Either way, the car is runs smoother and seems to be getting better milage. I attribute a lot of that to cleaning the MAF. I can just continue running 90 octane since I can get 90 with 10% ethanol for the price of 87 here.

 

[Mike97gt]

Update:

I ran some seafoam through it. I noticed it is less likely to ping, but still pings quite noticibly under heavy loads in higher gears.

I highly doubt it is the plugs. Putting new plugs in had little effect on the pinging problem, but it ran a lot smoother with the proper plug gap again haha.

I'm still at a loss for what the problem is. It is possible I have a bad tank of gas now, and that the fixes I've done helped enough to keep it from pinging when I fill up again.

Either way, the car is runs smoother and seems to be getting better milage. I attribute a lot of that to cleaning the MAF. I can just continue running 90 octane since I can get 90 with 10% ethanol for the price of 87 here.

Ok let me try to explain this better. I don't know if it's your problem or not. But it's quite common that you get the wrong plug sold to you.

if you use a plug thats too hot you will have a problem like this.

 

[bhuff30]

Ok, let me explain it this way.. It isn't the plugs.

The plugs were purchased from the ford parts counter rather than sum monkey at autozoo who grabbed the wrong ones. I know how to cross reference plugs, and these are the correct heat range. Again... there was no change in the pinging problem after going from worn out factory plugs to new motorcrafts. Also, I'm not going to throw colder plugs in just for the hell of it. It would be a waste of time, money and could create problems next winter if they run too cold and start fouling.

I am not new to cars by any means. I've got a 4cyl stang which I've taken from mid 19s in the quarter, to a 14.2 @98mph with a slipping automatic, way too high of compression, ****ty pump gas and nearly all factory parts. I know about plug ranges.

I have a wide band O2 sensor and controller which I built to monitor the 4cyl. I'll probably stick that into each side to see whats really going on with the AFs.

Ok let me try to explain this better. I don't know if it's your problem or not. But it's quite common that you get the wrong plug sold to you.

if you use a plug thats too hot you will have a problem like this.

 

[46gtsblown]

clean your maf and change the air filter.
Failing that get your codes read and go from there.
Dwayne

 

[bhuff30]

clean your maf and change the air filter.
Failing that get your codes read and go from there.
Dwayne

Cleaned the MAF several days ago, and a new filter today.
Will there still be codes if the CEL is on?

 

[CanadaStang]

Cleaned the MAF several days ago, and a new filter today.
Will there still be codes if the CEL is on?

It's possible to have a code without tripping the cel light, but first off, I'm thinking you should check to see if you have a timing adjuster or a chip [like you say, probably not, but it wouldn't hurt to check] The EEC is behind the passanger kick panel, if there is a chip it would be plugged in through the back of the EEC. If not, then start checking for problems. Airleaks after the Maf, vacuum leak, clogged EGR, excessive carbon buildup.....

 

[Mike97gt]

Ok, let me explain it this way.. It isn't the plugs.

The plugs were purchased from the ford parts counter rather than sum monkey at autozoo who grabbed the wrong ones. I know how to cross reference plugs, and these are the correct heat range. Again... there was no change in the pinging problem after going from worn out factory plugs to new motorcrafts. Also, I'm not going to throw colder plugs in just for the hell of it. It would be a waste of time, money and could create problems next winter if they run too cold and start fouling.

I am not new to cars by any means. I've got a 4cyl stang which I've taken from mid 19s in the quarter, to a 14.2 @98mph with a slipping automatic, way too high of compression, ****ty pump gas and nearly all factory parts. I know about plug ranges.

I have a wide band O2 sensor and controller which I built to monitor the 4cyl. I'll probably stick that into each side to see whats really going on with the AFs.

LOL don't roll your eyes at me.. If you knew what was wrong with the car you would not be on here bouncing ideas off of us.

I understand the way I wrote that might have been a little insulting, but I had no way of knowing that you can tell one plug from another. BTW a plug one step colder should not foul out on you in the cold. I have run 1 step colder on nitrous cars and never had a problem in the winter, and I live in the northeast.

Many people on here don't have the experience you have, and I had no way of knowing if your knowledgeable or not. and many will just assume that because they bought new plugs that they got the right plugs. So I was not trying to insult you, I have to assume you know very little untill I see a reason to think other wise. I hate trying to help fix a problem and I overlook the simple stuff becuase I assumed the person asking for help knew it already.


I am tring to help you diag a car sight unseen, if I had the car here with me it would be fixed by now ( not trying to be a jerk but I have access to every peice of ford diag tool out there including special tools) without being able to test stuff in person I can only relay to you stuff I have run into in the past.

several things can cause your problem anything from incorrect plugs to a bad maf to hot spots in the chamber.

I thought maybe you were sold plugs that were the incorrect heat range, and you were not so move on to somthing else.

I think you should use your wideband 02 setup to check the A/F ratio thats a good idea.

BTW did you check your fuel presure at WOT? many times I have had cars come in that run ok at part throttle but if you get on it you will get pinging like you have.

Oh one last thing, if you have a CEL on scan the codes and post it, that might help.

 

[bhuff30]

don't use the rolling eyes with me. Many people on here don't have the experience you have, and I had no way of knowing if your knowledgeable or not. and many will just assume that because they bought new plugs that they got the right plugs.

Sorry, I was in a bad mood from work. Something about everyone asking me questions, only to ignore what I have to say even though I am ussually right. Kinda gets on my nerves to tell someone something, and watch them prove me right, or ask someone else.

I guess tommorrow, I'll check for a chip...

 

[Mike97gt]

Sorry, I was in a bad mood from work. Something about everyone asking me questions, only to ignore what I have to say even though I am ussually right. Kinda gets on my nerves to tell someone something, and watch them prove me right, or ask someone else.

I guess tommorrow, I'll check for a chip...

It's ok, sorry if i came off insulting. Just trying to help. check for a chip like the other guy said and check your fuel presure at idle and at WOT and scan the codes, hopefully we will find out whats wrong.

 

[MoatesGarage]

So what are the best plugs to get? I'm assuming Mike has the part numbers? Mine is pinging a little too, but I assumed it was because we're getting crappy gas here. Mine is an 01 GT auto.

 

[Digger]

Just a shot in the dark, but is your 90 octane an ethanol blend? I have had similar trouble in the past, to the point of destroying injectors (long time ago though), and it went away when I quit using ethanol blend gas.
Just a guess

 

[Mike97gt]

So what are the best plugs to get? I'm assuming Mike has the part numbers? Mine is pinging a little too, but I assumed it was because we're getting crappy gas here. Mine is an 01 GT auto.

if you have the stock plugs then they are probally fine, many other things can cause a concern like this.

his problem is probally related to a hot spot in the chamber.