05GT4.6

Ok, so I've been trying to search every where and have been trying to find the answer to this so I'll just lay it all out.

So my car has been acting up lately and it kind of came out of no where. I have noticed that the idle is really rough and then I tend to hear a loud knocking or rattling noise in the engine that causes my whole car to shake and I can even see it on the gear shift(5 speed manual). Also when it starts doing that, when I try to take off like a normal person, it feels like the car has problems doing this. I feel I have to give it a lot of gas pedal for it to take off smoothly. The take off just feels so off and it is hard to describe fully. Been searching everywhere and wanted some input. 2005 mustang gt

lowblustang00

I would start by cleaning the throttle body and MAS. When these get dirty on our cars they tend to idle like crap, and will hesitate when you press the gas. It could be so bad that your engine is having a hard time staying cranked at idle and that may cause the noise your hearing.

Just my .02

05GT4.6

Thank you for the reply man! Will for sure do this first

lowblustang00

No problem, let us know how it goes.

BTW make sure you unplug the battery while you clean stuff. That way it resets the learned tables in the ecu for a dirty throttle body and such. It will take a few miles for the ecu to relearn everything.

ford4v429

I'd just unplug the battery first, see if that clears it- especially if battery has been dead or disconnected recently- I put one in mine at end of winter(was shot) car ran fine a month later when i took it out- till first time decelerating from highway speed on a very bumpy road:

these things 'learn' the misfire detection by measuring electrical timing between crank trigger 'teeth', after unplugging, it runs in default, misfire detection limited at best- due to slight production variations in the teeth... sooooo, first three times you decelerate in gear, brake off, in drive or clutch engaged, from 65 to under 45, the PCM 'measures' the backdriven, 'not torsionally distorted by power pulses' spacing between those teeth(must be fast as hell-sub microsecond stuff) and from then on, it looks for minute variations to indicate a misfire...after I lifted on a bumpy off ramp, my car wouldnt run at all without constantly hitting the gas, got my scanner, cleared codes, no change... guy said 'unhook it to clear it', in my all-knowing 'i just cleared it' thinking, thought nuts, but did it to humor him- and it worked... did a lot of reading, found the ford procedure/explanation for it- i put a thread in here somewhere... try it- its easy.

ford4v429

here it is- page 19- neat stuff
https://themustangsource.com/forums/...e-copy-501923/

05GT4.6

Tried doing what you did except I forgot to unplug the battery. Cleaned throttle body real good and you could tell the idle wasn't that bad, but it is right back where it was and seems even worse. Idle feels even more rough, and the feeling like the car is about to stall happened to me on the highway. Some how didn't get in a wreck

05YellowGT

If you didn't unplug the battery, or re-flash your tune, the computer will still be using the bad values in the adaptive memory.

05GT4.6

So, unplugged the battery and went ahead and took the throttle body off again and gave it a nice cleaning again just to do so buffing. Car seemed to run better, but then I finally had to stop. The rattle isn't there or just isn't loud, but that shake is there and you can tell the difference in the exhaust. It is like a beat of idling instead of a flow idle. Every now and then the feeling of stalling while accelerating was there.

A side note, I also switched my oil from 10W-30 back to 5W-20 on my last oil change, and I am curious if this could be a problem, because it was after the oil change that this problem started. Also, my car has been shooting the P0345 and P0349 codes. Curious if it is my cam sensor bank or if I should replace the alternator.

05YellowGT

The P0345 is Camshaft Position Sensor A Circuit (Bank 2) && Camshaft Position Sensor A Circuit Intermittent (Bank 2) both of which have CMP problems as a possible cause. I don't know if it's related or not, but Ford uses 5W-20 because of the close tolerances on the variable cam timing. How long did you run with the heavier weight oil, was it dirty when you changed it? I know you can also get the codes with a bad alternator as you mentioned, so I hope you get it figured out.

Glenn

I tend to hear a loud knocking or rattling noise in the engine = rod knock??

05GT4.6

It was awhile I know that I couldn't believe I went as long as I did. Got caught up with school and sports at the time, probably 6 months. I am sure it was dirty. I am just curious how to replace camshaft position sensor. I think I might go ahead and change the alternator

05GT4.6

I sure hope it isn't that!! I am still not perfect or super skilled with cars, but that sounds super expensive to fix and difficult. When I reset the battery, the noise went away. Now it just seems the car has trouble at idle

07 Boss

Have you done any data logging? Could be the timing chains slapping around in there.

05GT4.6

I honestly don't know what you mean by that or how to do it, so I am going to say no.

05GT4.6

Just to update you guys, things have just gone horrible for me. Drove the car to work and seemed to act a little better so was hoping that maybe I just needed to replace the alternator.

Well.....on the way home things got real bad. Wasn't really acting up at all, take off was smooth even though idle didn't sound right. Was in traffic and was in 4th at one point to where I was just cruising and had to go into neutral. After that, I was approaching my exit and shifted into 2nd and my car started making loud noises, it sounded like the fan was going nuts, the car would hardly move at all and the check engine light was flashing. Some how got into a parking lot before it just flat out died on me. I tried to start it back up and it just died as soon as it started. That rough idle sound is still there. Starting trying to get it started back up and it would crank and turn over and eventually turn on, but it would die right after that.

Had to leave my favorite thing I've ever owned in a parking lot and walk home. Thankfully it was only half a mile in Texas heat. Hopefully I can get it towed somewhere and see if it can get fixed.

Imatk

Sorry to hear that man.

I was hoping maybe it was just your fuel filter or something but sounds like it may be a bit more serious than that.

Good luck.

07 Boss

Do you still get the same codes or are they different?

Data logging is when you hook up your tuner and record engine/sensor parameters so you can diagnose issues.

Timing chains keep your cam timing in sync with your crankshaft. These are held under tension using oil pressure. If the tensioners are bad the chains can get loose and mess up cam timing and slap around under the front cover making a loud knocking or bad rattling noise.

And what else have you done to troubleshoot/diagnose this issue besides clean the TB and unplug the battery?

05GT4.6

Big news update. Actually, a hole some how got into one of my air tubes and living in west Texas finally got to my engine and shot it. There was a bunch of metal shavings in my engine and valves are burnt up. Had two different buddies look at it and came up with same conclusion.

LEXiiON

Oh wow. Sad news. Let me know if you want to get her back on the road, I might be able to help you out with an Engine (34k Miles).

LEXiiON