07TorchStang

I just turned 31,000 on my '07 and I took it in an oil change. The service manager convinced me to also change the fuel filter and do an entire fuel system flush. I have never had a fuel system flush in any vehicle I've owned but I will be putting the Mustang away in the the next month or so for the winter so I thought it would be a good idea. Long story short I have noticed and pronounced knock coming from the top right side of the engine. I hear it at idle when the motor is warm. Even my wife noticed it so I got to believe its is new. It is not the injectors as I know then tend to be noisy, this sound is new. Talked to the service manager and they start in how it is probably piston slap since the motor is broken in now. Pointed out that new GM engines have this noise right off the showroom floor. Bottom line is that I have not heard piston slap being a problem on the 4.0. Any ideas of what might be going on? I thought possibly a chunk of carbon may be stuck somewhere causing the noise. Got a bad feeling I will be getting the run around.

Kona6Stang10

I seriously doubt you are getting piston slap....not with an engine that is stock and never taken apart.

tx_zstang

You wont have piston slap now as a new sound. Make sure you have plenty of oil!!! You may be low even though it was "just changed". Check underneath for oil leaks as well. Sometimes they'll leave the filter or oil pan bolt loose and you oil will mostly leak out. the "oil gauge" on the dash is just a dummy and does not show real pressure, just shows that you have SOME pressure. If you're low on oil, the engine will indeed get noisy.

Sadly, it sounds like you are at the mercy of what any service manager will tell you. You'll likely get talked into a new engine or engine overhaul "to fix piston slap". That's not your problem, though.

sailing220

If you don't change the oil yourself make DAMN sure they put enough (of the RIGHT KIND) in when they do it.

Story time:

You wouldn't believe how stupid some shops can be. Somehow I ended up at the Ford dealership near me for a "free Full Interval Service" for my 50,000 mile service (no idea where it came from, but I figured "hey, why not?"). I had them do everything that is supposed to be done at 50,000, except for the oil change.

I had JUST changed the oil the day before and put in Mobil 1 Full Synthetic. Talked to the service manager, told him to skip the oil change. He wrote that in big black sharpie on the checksheet to give to the technician.

When I picked the car up, I was looking through the $0.00 bill just to see what they had done, and (yep, you guessed it) they changed the brand new motherfvcking oil and put sh/tty Motorcraft Synthetic Blend in. I immediately drove to the auto parts store and bought new Mobil 1 oil, then dropped the reciept off at the dealership and demanded a reimbursement.

This is why I drive 40 minutes to a different dealership (with a Ford Racing shop attached) instead of using the one 5 minutes from my house.

Ric

07TorchStang

Just got back from the dealership. The technician initially thought it might be a lifter from where the noise was coming. As it turns out they believe that an injector is making the noise. Without saying it, I think he believes that they didn't flush the fuel system as fully as they should have when I had the flush done 2 weeks ago. He added some heavy duty fuel system cleaner to the gas tank and suspects that will take care of it. Interesting that 2 technicians in addition to the one working on my car and the service advisor were all there when he was describing what was going on. Bottom line is I think the Quick Lane guys didn't do the job they were supposed to. From now on I'm going to the service department, not the Quick Lane for things beyond oil change or tire rotation.

tx_zstang

Injectors will make noise, they are inherently noisy at times. Cleaner isn't going to help much with that, at least not for long.
And, if the tech told you a "lifter", then he has no f'ing idea what's inside these motors!!! There ARE no lifters!!! The overhead cams push down on "rockers" to open a valve, and the spring pulls the valve back to closed position.
Now, the valve train can be a little noisy as well, but the passenger side chain is at the back of the motor, and the driver side chain at the front.
Enough said.