[R3dFyre02]

So this weekend I over revved my 02 GT and right after that it developed a really bad tick or knock under acceleration. I have been abusing the heck outta Google for a couple days now and last night on allfordmustangs.com I found a thread that described determining if it really is rod bearings by disconnecting the coil on each cylinder one at a time.

Well I went through all my coil packs just now, and once I disconnected the drivers side rear coil the noise was completely gone... does this mean that I spun my bearings on that rod?

If so, I don't know that I will be able to keep this car, unless I can find a killer deal on a used motor. My wife has been after me for a while to trade it for something more economical (I drive 98 miles from my door to my parking spot at work...) and I really fear that this is the death knell for my time with my Mustang.

Im thinking that maybe I can just jack the car up, drop the K member and oil pan and swap rod bearings that way? I know it is not a good solution as the crank is most likely fubar'd, but hoping that might get me a little more life left so maybe I can figure out something else...

Any thoughts? advise? offers of a donated or cheap motor?

 

[00vabchgt]

If you spun a rod bearing (and I know this because I did it back in '07), the noise would still be there regardless of whether or not the coil is connected. The crank is still moving, therefore, the entire rotating assembly is still moving. Disconnecting the coil just stops the sparkplug from firing. A spun rod bearing sounds like marbles rolling around in the block. When it happened to me, it started off very quiet and then increased in vloume and finally the engine stopped. This all happened in about 7 or 8 seconds...

 

[R3dFyre02]

oh... well crap... or maybe thats good... I dont know...

 

[01V8MUSTANG]

Sounds like a rebuild is in order.Or maybe a swap?

 

[R3dFyre02]

dont have money for either... probably going to be parking the mustang and getting a beater for a while. my wife is happy though.

 

[00vabchgt]

I just reread your initial post, and it makes no sense to me how disconnecting a coil is going to tell you whether your rod bearing is wiped. With the engine running, everything in the block is rotating; disconecting the coil just stops the sparkplug from firing. The cams and valves are still moving. Disconnecting the coil just makes no sense with regard to troubleshooting a mechanical problem like a bad bearing. Unless I'm having the mother of all brain farts, I'd disregard everything in that thread...

 

[R3dFyre02]

i went by that due to reading that on multiple posts... wasnt sure about it so I posted here as well...

 

[99GT35thLE]

It takes the load off that cylinder when the spark plug isn't firing, when they refer to the rod bearing they are talking about the bearing in the top of the rod where the wrist pin goes through that holds the piston to the rod.

I wouldn't want to pull a piston from the bottom of the engine, but I have seen it done before.

 

[R3dFyre02]

oh... so its not the lower bearing.... crap. this is rapidly getting out of my scope of what I can fix myself in my driveway. sadly I dont have the cash to get my motor rebuilt. any one wanna buy a 2002 GT with a knock?

 

[00vabchgt]

It takes the load off that cylinder when the spark plug isn't firing, when they refer to the rod bearing they are talking about the bearing in the top of the rod where the wrist pin goes through that holds the piston to the rod.

I wouldn't want to pull a piston from the bottom of the engine, but I have seen it done before.

Negative. The rod bearing is on the crank end of the rod:

rod bearing - Google Search

And like I mentioned previously, without the spark plug firing, you still have mechanical motion between the crank and the rod, so there's still a load on that rod bearing...

 

[R3dFyre02]

well I called three different shops with in about 150 miles of me, and described the symptoms. low oil, over revved, knocking. disconnect coil and noise goes away. reconnect coil, noise is back. they all said the same thing, wrist pin or piston skirt. the reason the coil affects it is with out it firing there is not as much pressure and force from the top slamming the piston down. yes there is a rotational force from the crank, but it isn't forcing the piston cockeyed in the bore.

So now I'm debating either trying to rebuild this, or get a replacement motor. kinda looking at a 5.4... I can get them for about a grand....

so whats your thought 00vabchgt? any clue?

 

[00vabchgt]

well I called three different shops with in about 150 miles of me, and described the symptoms. low oil, over revved, knocking. disconnect coil and noise goes away. reconnect coil, noise is back. they all said the same thing, wrist pin or piston skirt. the reason the coil affects it is with out it firing there is not as much pressure and force from the top slamming the piston down. yes there is a rotational force from the crank, but it isn't forcing the piston cockeyed in the bore.

So now I'm debating either trying to rebuild this, or get a replacement motor. kinda looking at a 5.4... I can get them for about a grand....

so whats your thought 00vabchgt? any clue?

Right, it's not the rod bearing. I was just pointing out that disconnecting the coil wouldn't affect the the rod bearing...

Your next move depends on your budget. I spent 3 grand on a forged rotating assembly, then about another 3 grand on labor including getting the block bored and honed. In the long run, it may have been cheaper to just get a new shortblock...

 

[KB99GT]

How far did you overrev? Im having a similar issue but the noise isn't constant....and sounds more like either a blown manifold or midpipe gasket...could also be bad gas because it didn't start until I filled up at a place that I usually don't. I did hit 6k while driving home and am concerned about it...

Edit: I should note that I was full on oil and I run valvoline maxlife synth blend 5w30....blew the doors off a 5.0 95 stang (why I hit 6k) but im beginning to wonder if it was worth it....

 

[Eagle2000GT]

Before you get too far, a 5.4 won't fit under your hood. A 4.6 3v won't fit under your hood either. To tell you the truth, whether its a wrist pin or a rod bearing, it really doesn't matter. The engine is shot. If your problem is either one, you've got a blown motor. There is no resale value. The less expensive fix is to find a salvage 2v and just put it in. By the way, it cost a lot more to rebuild a motor than to get one out of a salvage yard. (I know. I've had to do this several times.)

 

[R3dFyre02]

So your saying a 5.4 won't fit under my hood, I thought it would with the proper intake. Regardless I'm looking at either getting rid of the car or just getting a replacement motor. I can get a crown vic motor 70,000 miles on it for 100 dollars. Good running in s*** what was pulled bout 20 miles from my house. That motor should be fine correct? I don't know if it is pi or non pi but hey I already have pi heads and intake. That way I wouldn't have to tune my tcu or anything either. Or I also have my eye on a 4 cylinder fox body for 800 dollars. Kinda leaning toward the fox as I have always wanted 1 and later on I could swap a 5 liter into it. And just park my 02 for now.

Sent from my HTC Incredible via Autoguide app...

 

[hardhitter]

Right, it's not the rod bearing. I was just pointing out that disconnecting the coil wouldn't affect the the rod bearing...

Your next move depends on your budget. I spent 3 grand on a forged rotating assembly, then about another 3 grand on labor including getting the block bored and honed. In the long run, it may have been cheaper to just get a new shortblock...

Where does it cost 3k to get a block bored and honed? You can buy a brand new block for $600.

 

[00vabchgt]

Where does it cost 3k to get a block bored and honed? You can buy a brand new block for $600.

Reread my post. I said I spent another 3 grand on labor including the work on the block...