Bottom End Knocking - Any Ideas?

[BarryCarey]

Hey All,

Today I picked up an 03 EB with the 4.6 V8. It has 130k miles on it. I got it for half of book value but there's a knocking coming from the bottom end.

I was on the fence as to if it sounds like bearings so I took the chance on it.

The knocking is audible at idle and during acceleration. However, at times it seems to go away. Besides the noise the engine runs very smooth.

Oil pressure is good.

Anyone have any input?

Here's a video of it from the interior and underneath.

 

[2000StreetRod]

spun bearing?

I purchased an out-of-the-vehicle DOHC 4.6L engine from an Aviator that had a reported lower end knock. When I tore it down I found that two rod bearings had been spinning for a long time.

The crankshaft and two rods are unusable. I hope you have better luck.

 

[Onuma]

Could it be something as simple as a dented-in oil pan? Not sure if that's possible with this particular engine configuration, but I've seen noises come from there on other Ford engines. It's worth a look, and should be easily noticeable if that's the case.

 

[BarryCarey]

I'm starting to lean in the direction of rod bearings. The noise happens when the engine is loaded. When accelerating it's very loud. It stops as it shifts and then picks back up again. When letting off the gas it goes away.

I'll be draining the oil tomorrow to have a look at it. May drop the pan to have a closer look.

Here's a video of it driving. It's a but difficult to hear the knocking but if you turn the volume up it can be heard.

 

[shucker1]

When you drain the oil into a clean pan let it sit a while and run a small magnet thorough it to see how much metal you get back.

You can also cut the filter open to see how much you trap there.

It might give you an idea of the extent of the damage.

 

[BarryCarey]

Just wanted to update this.

I haven't changed the oil yet.

I jacked it up good and high today and spent some time under it. I don't think the knock is coming from the engine. Using the screwdriver to ear trick on the oil pan everything sounds perfect.

However, this time I crawled further back and it seems the sound is coming from the bell housing. More specifically right where it joins the block.

I spoke with the local Ford dealer and they said it could be a cracked flex plate. However, they also said it would be difficult to tell without pulling the tranny.

I do have an appointment with them tomorrow to give it a look over.

The noise can be heard lightly when parked, as in the first video. However, when accelerating it gets rather loud. Occasionally if I speed up just right I can keep it from making any noise. Sometimes it happens up to 2k RPM, sometimes higher.

Does anyone have any suggestions as to what this could be?

 

[BobRob]

Haven't run into it myself but I have read about rattling torque converters on this forum. Some say it's no issue... I suggest searching and checking out some posts

 

[2Trux]

Another thing to look at is if the nuts/bolts that attach the torque converter to the flex plate. If they get loose they can cause a knocking sound.

 

[BarryCarey]

Just got it back from the shop. They confirmed it's coming from the transmission.

All the torque converter nuts were tight.

They did say the tranny had been removed recently (I've only owned it for a week). So someone has been in there poking around.

The tech said he suspected a damaged front pump, torque converter, or flex plate.

Looks like I'll be pulling the tranny soon.

I very much appreciate the input everyone has provided.

 

[Number4]

There is a special tool for aligning the torque converter to the flex plate (I assume?) or some sort of plate that mounts to the converter. Could be an issue there if it wasn't used, believe it would be out of balance.

 

[DIYoh]

Wow, this is exactly what I was looking for. I have other issues going on also, but before I tackled those I knew this noise had to be addressed. I did not see this video before making mine, but check out the similarities. My name is even Barry Ca*%&$@@. Too weird, man. But thank goodness I found this. BTW, other Barry C, any more info on your final prognosis/outcome? I know its been couple years...