Heather <3 Mudd

I have had rod knock for about 2 years now.
Recently when moving, the knock when from not good to worse.
It got much louder and sounded like it was banging a lot harder.
Previously it was bad but after it got all warmed up the knock would quiet.
not the case anymore. When I accelerate it gets much louder and faster especially around 2000-3000 rpms.
I plan to tear apart the engine and try to fix this knock.
Is there any ways to diagnose the knock to find out exacly whats causing it from bearings to pistions or wrist pins?

we did try disconnecting the spark plug wires one at a time but the noise didnt appear to change.


Thanks
<3

razor02097

I've never known any engine with bottom end problems last more than a month.... let alone 2 years! There are several things that would make it sound like rod knock. Just curious what convinced you that it was rod knock?

TheJerm

Do you drive an automatic? If so i bet that the torque converter bolts came loose. You can google it to find out how to check them and tighten them.

Hows your oil pressure? A bad rod knock will have very low oil pressure and kill a motor very quickly by sending the rod thru the side of the engine block.

Heather <3 Mudd

I've had several people listen to it and they all said rod knock, and ive put a new torque converter on it and it remained. Ive herd of jeeps running on rod knocks for years till they throw the rod through the block. like a ticking time bomb ready to blow at any time. engine pressure is lower then normal but not dramatically low. It burns synthetic oil like no other. we also took sethascope to it, its for sure the engine not the lifters or anything else. it got worse after putting a lot of extra weight and stress on it.

razor02097

Well it is pretty difficult to narrow the problem down without actually tearing into it. Have you looked at re-manufactured short blocks? Most if not all come with a warranty and would be a LOT LOT LOT less work than rebuilding it yourself.

Heather <3 Mudd

I have, but im on a tight college kid budget and a lot of them are out of range for me at the moment. I just found an engine on craigslist that doesn't have a knock or anything but the compression is low in 4 cylinders i thought about rebuilding that (it was only $75) but idk yet

razor02097

Tight budgets and engine rebuilding do not go together. If you pull the engine apart without any idea of how much it will really cost in time and money to do it right it will never go back together.

TheJerm

1) synthetic oil is not the best for old worn out motors. Run thick dino oil

2) rebuilding the craigslist motor would be about the same as your motor. New bearings, piston rings and gaskets. plus machine work if you want.

3) The simplest and cheapest way i would recommend if your in a pinch, since Ive done it before, is to pull the oil pan and find which bearings are bad. hopefully its just rod bearings and not main bearings. Then pull the head and pull out the pistons, you dont have to pull the motor from the jeep. Carefully clean the crank and oil galleries of bearing material, then mic out the journals and install new bearings. This will get you by until you have money to get a good motor. Mine lasted for quite a while with me beating on it, I was trying to kill the motor but wouldnt die before i got a replacement

waltermitty

If you had the torque converter replaced did the mechanic even look at the flex plate? According to sources on the list, sometimes the crack is so small it's not apparent.

Also, if it is a bad rod assembly there will be bearing shards in the oil filter and pan. Cut your filter open and check it out. I would filter the oil drained from the pan through a cloth that will catch the solids and let the oil pass. One other option might be to replace the rod bearings with the engine still in the Jeep. The crank condition would determine if that is a viable option. It might get you by for a while if your compression is still good.

Heather <3 Mudd

I am thinking about doing that i am hoping that it is a bearing that i could change. hoping for the best.

Heather <3 Mudd

My father and I do all the work. I didn't even think to look at that when I put in the torque converter.

waltermitty

There are those on the list that stated a cracked flex plate sounded like a rod bearing going south. I don't have the first hand experience on this issue just repeating the statement. it may be something to look into.

How many miles on the engine? Compression still good?

waltermitty

Bump? How did you fare with the rod knock problem?

Heather <3 Mudd

well we got the engine appart and I had shattered the piston skirt on cylender two.
I am in the process of finding a new engine. But dads getting tired of it being in the yard and wants to take my jeep to scrap
nooooooo

Slick761

Tell him that's unacceptable! Hey you couldn't just replace the pistons and replace the bearings?