Please help me my motor is knocking

hayhauler59

hayhauler59

THA TURTLE
Joined
Aug 29, 2009
Messages
76
OK, i was racing my roommate I hit the speedlimiter and let out then i heard a knockin noise from the engine bay. The knock progresses with acceleration. i pulled the valve cover and i know its not a valve or rocker or bridge i have not pulled the pushrods yet please send me a direction. i have a comp jamer 5s and airdog. Please let me know what you think
 
Probably need to buy a stethoscope and pinpoint where the sound is coming from. If you posted a video from under the hood, some of the "trained ears" on here might be able to tell you what it sounds like.
 
valve seat or thrust bearing would be my guess but with your weak clutch i lean toward the vavle seat.
 
with the engine running crack each injector line loose one at a time. if and when the knok goes away or gets quiet . you will know witch cylinder to look at. rod , wrist pin , scored piston. i do not think it is a vavle seat. usely when they come out you will have valve to piston contact.
 
we just switched pumps on an 01' that dropped a seat to rule out the pump. knocked like hell, but still ran. couldn't see any problems with valves, push rods, rockers or bridges. pulled the head and found a dropped seat. what year is the truck? 01' right? let me know if you need anything Ethan I got a few parts laying around.
 
Ok guys just an update, the head is off and i pulled the valves everything looked fine to me but I'm not sure what exactly I'm looking for I will add though that when i was loosening the head bolts it was like there was pressure built up inside of them and I saw some coolant on a few, one of them was actually rusted. I pulled the coolant line that runs into the head and whenever I pulled the bolt closest to it it shot coolant out of the fitting. I inspected the head gasket and I did not see anything wrong with it. the valves all look fine as well as the push rods although there is some buildup on the valves I can take some pictures if yall believe it will help. I am still in need of direction I don't have any clue what I'm lookin for guys
Thanks
Ethan
 
Every engine I've ever made "knock" had a spun rod bearing. If I were you my next step would be to drop the oil pan and check the crank and rods.
 
Damn........ you wanna come take a gander at my rod?!?!?!?!?!?!!?:D


But on a serious note thanks for the advise I really don't wanna go in that direction but it keeps appearing like I'm gonna have to.
 
If it goes with rpm and load I would check rod and cam bearings. I had the same thing in a gasser, sounds like bottom end to me.
 
The time I had a melted piston and my HG was blown, I got the hissing noise too when loosening the head bolts...You sure the HG was totally ok?
 
hayhauler59 said:
Damn........ you wanna come take a gander at my rod?!?!?!?!?!?!!?:D


But on a serious note thanks for the advise I really don't wanna go in that direction but it keeps appearing like I'm gonna have to.
Click to expand...

No thanks I don't like the crooked ones.

BigErk77 said:
If it goes with rpm and load I would check rod and cam bearings. I had the same thing in a gasser, sounds like bottom end to me.
Click to expand...

In a 2 year period I went thru approximately 8 enigne rebuilds for spun rod bearings or twisted rods..... I know that sound, it fills me with dread.
 
i had a cr do this the other day.take the piston and see if it moves around in the bore. if it moves alot and knocks on the wall. broke piston rings. how do the bores look?
 
Generally with a broken piston ring you're going to see white smoke, he hasn't mentioned that.
 
if the knock keeps speed with engine speed its in the bottom end... a cam or other valve train noise will be at 1/2 engine speed.
 
Broken piston squirters...cylinder wall scored or oil pressure dropped at main or rod bearings and spun a bearing. $.02
 
I would guess scored piston or spun rod bearing, If piston you should be able to see something on cylinder wall with piston down. Compression test would have been good before pulling head. As to the hissing noise when removing head bolts that is somewhat normal, some compression has got past gasket and was stored in bolt cavity. If you don't see anything by rolling each piston to the bottom on the cylinder walls, I would pull pan and shake rods on crank journal. If one seems looser than the others- pull that cap. Also look at edges of rod caps to see if there is any bearing material rolled over edge. I would think if it is a bearing your gonna see some metal in the bottom of the pan.
 
after pan is off rock try moving the rods while they are bolted to crank.. the one that is knocking will be apparent. it will move the rest wont
 
Dang guys I really don't wanna pull the pan but it looks like thats where im headed. The walls and pistons are fine the only thing left is the crank I guess.
 
You've heard it before I'm sure, "You have to pay to play". Sorry bout your luck, but, if you had left it stock and not been racing, there's a good chance this wouldn't happen. Knowing that doesn't make it suck any less though.
I say, go over to CF and post in the College Station Area Roll Call that you gotta drop your oil pan, and I bet you get plenty of offers to help.
 
You must log in or register to reply here.
Back
Top