Rattle coming from oil pan, loose nut or bolt? Should I pull the oil pan?

[Ollie88]

Hey guys,

Another question, my FJ40 1978 makes a strangle rattle. Usually only when engaged in gear and driving, but sometimes also does it in neutral. The sound varies with RPM.
Really think this could be a loose nut or built that fell in during repairs, the car had it since I bought it (6 months) and hasn't caused issues but I'd rather now fix it to avoid further trouble.

What's the best way to get a loose nut or bolt out? Do I have to pull the oil pan or are there alternative tricks?

Thanks again in advance!

 

[middlecalf]

Sure it’s not a loose driveshaft bolt?

 

[Pighead]

Or maybe a loose throwout bearing?

 

[3_puppies]

or the bellhousing cover is loose

 

[Ollie88]

Thanks for the replies guys, the weird thing is that sometimes it's rattling sometimes it's not.
For example, yesterday I took it out for a short spin and it was rattling continuously in all gears, then I stopped at a traffic light and in 1st gears with clutch in it rattled, when putting it into neutral with clutch out it still rattled (the road was at a slight incline). Then when I came home (rattling), I drove to my parking lot in my garage (in a decline) the rattle disappeared. I had idle for a while in neutral but couldn't get the rattle to appear again so I could listen underneath the oil pan...

Really seems to be a loose nut/bolt... but wondering what the quickest way is to diagnose that without taking the oil pan off altogether??

 

[pb4ugo]

Get a stethoscope or put a long screwdriver to your ear and start touching stuff while it's rattling. Get a length of hose, like heater hose, one end to the ear and move the other end around to isolate the location.

 

[mattressking]

If your motor is full of oil - the oil itself would dampen the sound of loose metal rattling in the oil pan so we can rule that out.

There’s a million options that we can’t help determine, like @pb4ugo said - figure out how to isolate it or pull off immediately when the sound occurs and start looking….So drive the truck a lot more until it happens again.

 

[sterling]

Long shot here. Does your truck have a catalytic converter for whatever reason?
My truck had one that was falling apart inside, making a metalic popping sound at random times.
Baffling inside converter came apart and was bouncing around.

 

[Ollie88]

Thanks again for your insights all, I just went for a drive in my garage to further diagnose it (I live in a building with a parking garage that has multiple stories with steep driveways). Here are my findings:

- Only rattles in an incline or decline (or by accelerating quickly or decelerating/braking); either in gear, clutch in or out and also in neutral
- Usually rattles most when in gear (e.g. 1st) and accelerating, especially when in an incline
- The rattle sounds irregular, i.e. it's not a constant rattle
- It looks like it's coming clearly from underneath the front of the engine, definitely not the transfer case and it's also less likely the gearbox

Here's a video of the sound:

IMG_1290.MOV

MOV File

1drv.ms

 

[B y r o n]

If you still have splash shields installed, I would double check that all the mounting bolts are in place and tight.

 

[Skreddy]

Was going to suggest splash shields as well. Maybe loose or a bolt is sitting on top of one or?

 

[Skreddy]

Thanks again for your insights all, I just went for a drive in my garage to further diagnose it (I live in a building with a parking garage that has multiple stories with steep driveways). Here are my findings:

- Only rattles in an incline or decline (or by accelerating quickly or decelerating/braking); either in gear, clutch in or out and also in neutral
- Usually rattles most when in gear (e.g. 1st) and accelerating, especially when in an incline
- The rattle sounds irregular, i.e. it's not a constant rattle
- It looks like it's coming clearly from underneath the front of the engine, definitely not the transfer case and it's also less likely the gearbox

Here's a video of the sound:

IMG_1290.MOV

MOV File

1drv.ms

I just watched the video: is your fan hitting the shroud or something else?

I would not drive that until I found the source of the noise.

 

[mattressking]

I just watched the video: is your fan hitting the shroud or something else?

I would not drive that until I found the source of the noise.

I agree on fan hitting shroud - sounds like that to me as well.

 

[Ollie88]

Hmm interesting, I'm going to check the fan/shroud, I would assume that if that's the case, the result is a damaged fan or shroud?

 

[mattressking]

Hmm interesting, I'm going to check the fan/shroud, I would assume that if that's the case, the result is a damaged fan or shroud?

That’s the result, the cause would be engine mount related or something related to fan/shroud combo. It’s a South American truck so who knows what questionable work someone has done.

 

[3_puppies]

Hmm interesting, I'm going to check the fan/shroud, I would assume that if that's the case, the result is a damaged fan or shroud?

you can place a jack under the oil pan with a block to spread the load and see if the engine raises up. if it does, usually it is the left front motor mount bad

 

[Ollie88]

Alright, another update: I just checked whether the fan was hitting the shroud...

- Realized piece of the shroud was broken and hanging loose, I taped it as a quick fix (see pics)
- Drove again through my garage but the rattle persists

See pics below. I have a plastic fan that seems to have quite a bit of space around it and no clear signs of damage (at least not from continuously hitting it).
Thoughts?

 

[mattressking]

Record a video of the engine running and slowly walk around engine bay. Fan has wear marks and doesn’t look great but a video walking around slowly will help.

Electrical tape isn’t going to last, lol. You need to actually bolt them together or a small weld.

 

[Ollie88]

Thanks Mattressking, my handbrake doesn't work backward so need help but yes will ask someone to sit in while in an incline to keep a foot on the brake so I can make a better video. In the meantime, just wanted to say you folks are all amazing by helping me troubleshoot this and pointing me in the (hopefully) right direction!

 

[Skreddy]

Well, while under there, give the parking brake adjuster a click turn and see if it starts holding in reverse.