I just bought a 95 Cherokee sport. I didn't notice a engine knock because it needed a new muffler, so i dropped 200 and had a muffler and tail pipe put into it.
I now hear the horrible knocking in the engine. I am not a mechanic so i am not sure what it is but its horrible a friend of mine thinks its a piston.

what do you guys think?
I really hope its nothing major because i just bought the thing for 1300.
Do you think its the pistion? how much would a pistion job cost?
do you think i could sell the vehicile for at least 1000?

Thanks guys.

JPXJ

 

There is only 4 things it can be,1. bad main bearing,bad rod bearing,bad thrust bearing,all require new bearings and at least the crank polished,if there is no damage to it,or it could be a cracked flexplate,which requires pulling trany. and 5,I doubt it from what you are describing but it could be a bad lifter.

 

Does the knock go away when you put it in gear and give it light throttle? It's not uncommon for a cracked flexplate to knock and sound just like a rod bearing. What is the oil pressure like? What does the oil look like? Fine sparkle like metal particles?

 

fast easy check. take your oil filter off and cut it open. pull the filter media open and see if there is any thing in it. if you are loosing a bearing it will leave metal in the filter

 

does it sound like this?
http://www.youtube.com/watch?v=http:...?v=LePW9seBwVs

got my 89 for 1200, were still diagnosing the knock...

 

that sounds like an exhaust leak to me.

 

It could also be the camshaft when I got mine I drove it home planning to change the engine annyway. When I got it close to home I punched it to see if the engine was worth selling and the sound it made sounded alot like a broken connecting rod(AND I HAVE DEFFINITLEY HEARD PLENTY OF THOSE) but when I scrapped the engine I noticed the cam gear moved in and out about an inch, decided to check out the rest of the engine and it turned out that was the problem.this will also leave matal in the oil filter as it is also a bearing problem

 

very true, i overlooked the cam. from my experience, there aren't too many cam related failures. not saying it isn't that. if you plan on keeping that engine, it's not all that hard to diagnose. pull the valve cover, oil pan and front cover. check all the rockers for same travel. check to see if any rods are loose on the crank. check the cam for end play.

 

wasnt trying to hijack a post, just giving the OP and everyone else an example of engine knock. To see if thats what his sounds like...

we think its a lifter..

 

i think most would agree a piston is unlikely. a knock typically reflects a rod bearing. i would start by pulling the pan and checking for a loose rod.

 

I am not sure if it stops when lightly throttled. Where is the oil filter located at in the engine( i told y'all i wasn't a mechanic), so i can cut it open and find out,but then i will have to replace it correct?
It would be worth buying a new oil filter to find out the answer.
If its the lifter how do you find out? and how much would that be to replace I am hoping its something minor but i doubt it .
How hard do you think it would be to sell it for 1000-1200 with the engine knock.

 

The filter is located on the passengers side,I think it would be inpossible to sell it for $1000 with a bad motor.

 

Yeah i didn't think so. I was tricked into buying it bc they took hte muffler off to hide the piston noise. F***** stealer ships.
How much would another 4.0 engine cost and how hard would it be to sawp em?

JPXJ

 

You can get a longblock for $1,500 and up,you can rebuild yourself for arounf $800,or $400 for a used one from the jy or craigslist,maybe less,swapping them is easy if you stay within the years that will work,but you can use almost any longblock.

 

Defiance665 no that's not the same sound mine makes. mine is def a pinging noise.