Bad squeaky sound, probably bent crank (3.0L)

[jangell]

About a month ago I took a break from my working on getting my 3.0L swap running to replace the entire A/C system with the help of a friend of mine (who is an actual mechanic, mostly working on classic cars). When it was time to fill the system, we tried cranking the engine and got this horrible squeaking sound. Our assumption was that the flex plate bolts or torque converter bolts were scraping against something. We confirmed the sounds related with every revolution of the engine by looking at the missing tooth gear on the crank pulley.

~10 second video of the noise: https://youtu.be/vvou5ZHh1tc

At one point, we looked up through the inspection hole in the automatic transmission and noticed that the flex plate is moving in and out, implying that it isn't seated correctly.

~6 second video of the wobble: https://youtu.be/9UqkfG25lPA

So we pulled the motor, leaving the transmission in the car (my friend is confident that it won't be that hard to reattach; I'd have pulled the engine and trans together, but hey). We checked the flex plate with calipers against a flat surface and found it to be pretty much perfectly flat. When we remounted the flex plate (which sat flush against the crank), we noticed it seemed slightly tilted, like the top was closer to the engine than the bottom.

IMG_0752.jpg

We tried turning the engine with a wrench, and got the same horrible squeaking sound, even without the flex plate attached. Measuring with calipers after rotation the engine in 60 degree increments seemed to find a deflection of about 0.26mm (not that I'd necessarily trust the measurements, but it fits with the very slight tilt of the flex plate).

At this point, we're assuming the crank is bent. How this happened is unclear.

This engine has never been running, not completely. I have turned it over by hand before putting it in the car (it was tough at spots, but that was just the engine compression -- our attempts today seemed much tougher than that). I had also cranked it with no issues. I had gotten the car to run very poorly with MegaSquirt for some initial testing (forgot to connect MAP, only two plugs were firing, timing way off, etc), but never heard this noise.

In fact, the noise only started after we replaced the A/C system. We did not turn the engine at all during that process. We raised and lowered the nose of the car, but that's all we did. It seems unlikely that we knocked something loose or out of alignment in the engine simply from that.

My friend assumes me that the untuned engine didn't bend the crank, as it is more likely that I'd have destroyed something else before the crank bent. He thinks the engine was overheated by the previous owner (it had 35k miles, according to the junkyard, and was working), and that this softened the metal enough to warp it slightly. But I can't explain why this noise suddenly started happening. I didn't think to look for flex plate deflection when I put everything together in the first place, so I don't know if this was present before.

Next weekend we'll likely tear down the engine, and I'll be hunting for a new 3.0L to install in its place. Luckily the amount of work here is only a small part of a 3.0L conversion, although obviously not a trivial amount of work. Hopefully it'll go fairly quickly.

Mostly I was wondering if anyone had seen this sort of thing before. It's very odd.

Thanks!

-- Joe

[DMC5180]

Remove the belt and turn the engine over. This should eliminate many items that could produce the sound you heard. The squeal screeching sure sounded like the belt was dragging across a frozen pulley. In the video i could not see the A/C pulley rotate due to the dark black paint.


Sent from my iPhone using Tapatalk

[jangell]

Remove the belt and turn the engine over. This should eliminate many items that could produce the sound you heard. The squeal screeching sure sounded like the belt was dragging across a frozen pulley. In the video i could not see the A/C pulley rotate due to the dark black paint.

The first video does have the belt still attached, but I removed it soon after to rule out the accessories (I was really, really hoping it was the belt). There’s a slight squeak from the alternator, so I got a new one, but the other very loud squeak is still present.

At this point, the engine is no longer in the car, has no accessories or the transmission hooked up, and it still makes the loud squeak when turned by hand.

My mechanic friend showed the second video to his boss, and they theorize that “it might likely have spun a bearing towards the rear of the engine and that's why that it's so hard to turn over by hand and that it has a slight wobble”. Possibly repairable, unless it damaged the crank or the block, in which case it’ll be cheaper just to get another 3.0L engine. We’ll be tearing it down this weekend, and then we’ll know how bad it is and how we’re moving forward.

Thanks

— Joe

[Josh]

I can confirm the alternator and crank pulley are good (parts I supplied). No such noises on the accessory drive with my 3.0

This is a really strange problem, best diagnosed through isolating and eliminating components as mentioned by Dennis.

[jangell]

Since we're down to "the engine is out of the car and is really hard to crank by hand with no accessories and still makes the squeaking sound", the next step will be tearing down the engine.

My current theory is that maybe I didn't properly tighten the main bearing nuts properly when I swapped out the lower crankcase (although I swear I did it to the specs in the manual -- I even got an angle torquer for the required extra 75 degrees), that one or more of these came loose and it's letting the crank shift. I'll know if there's permanent damage (and if that's even what happened) once I get it apart. I'll report back when I know more.

I was hoping to have it on the road in time for Ready Player One (no particular reason; just seemed like a good arbitrarily deadline), but that's pretty unlikely at the moment.

Thanks again

-- Joe

[sdg3205]

Did you reassemble everything with assembly lube?

[DMC5180]

So you swapped the girdle section from the 2.8L to the 3.0L. Did you also use the 2.8L oil pan? If yes, did you transfer the oil pickup tube and extension spacer from the 2.8 to the 3.0? This sets the oil pickup tube deeper in the oil pan. If you didn’t do this, your pickup may have been positioned above the Oil level.


Sent from my iPhone using Tapatalk

[David T]

So you swapped the girdle section from the 2.8L to the 3.0L. Did you also use the 2.8L oil pan? If yes, did you transfer the oil pickup tube and extension spacer from the 2.8 to the 3.0? This sets the oil pickup tube deeper in the oil pan. If you didn’t do this, your pickup may have been positioned above the Oil level.


Sent from my iPhone using Tapatalk

If the motor has not actually run you may only have damaged the bearings. Examine the crank and cylinders and you should be OK with new main and con rod bearings. Of course you must figure out why the oil pump isn't pumping oil. When you removed the oil did you measure how much came out?

[jangell]

If the motor has not actually run you may only have damaged the bearings. Examine the crank and cylinders and you should be OK with new main and con rod bearings. Of course you must figure out why the oil pump isn't pumping oil. When you removed the oil did you measure how much came out?

I admit I assumed that I wasn't going to be able to find bearings for this engine and would just have to replace the whole thing (gaskets are easy to find, though), but a quick check of NAPA's site showed that they are indeed available (~$90 for the set of main bearings, and ~$8 for each con rod bearing), so that's good news. That will save a lot of trouble over having to get a new motor. I want to get this deflection issue sorted before I replace the bearings, though. And as you said, this is all moot if the oil pump doesn't work, so I'll be taking that out once the deflection is solved.

I didn't measure the amount of oil, but I still have it all in the pan that I drained it into. I'm betting it's all the oil in the system. There's a picture of that oil in another post, which is mostly filling an 8 qt pan. I can empty it into bottles to test it (or maybe I can measure it with a scale...).

Thanks!

-- Joe

[jangell]

So you swapped the girdle section from the 2.8L to the 3.0L. Did you also use the 2.8L oil pan? If yes, did you transfer the oil pickup tube and extension spacer from the 2.8 to the 3.0? This sets the oil pickup tube deeper in the oil pan. If you didn’t do this, your pickup may have been positioned above the Oil level.

That's an excellent question. I did indeed use the 2.8L oil pan, mostly because it seemed way nicer than the 3.0L one. When we disassembled the engine yesterday, we did take out a spacer, but I had to check the manuals to see if there was a spacer in the 3.0L and if I'd installed that instead (I don't actually remember if there was a spacer or not). As best I can tell, the 3.0L engine did not use a spacer, so I definitely installed the 2.8L spacer. I made sure to put in new O-rings, too. I also used the 2.8L oil baffle and inlet tube (the tube has one vs two mounting points, which made it obvious). Finally, all the lower crankcase parts that were removed were clearly submerged in oil, so they were definitely below the oil level.

-- Joe