Knocking at IDLE

[TalonspoolAWD]

My car has a fresh rebuilt motor, it ran great and never knocked in its life. It would tick a little when it was REALLY COLD but then go away as it warmed up. now at idle it KNOCKS REALLY LOUD LIKE A ROD IS KNOCKING. It is especially load in the back of the engine down near the intake, but it could be just resonating. Any ideas. The car runs good and maybe misses a beat at idle every once and a while. If its lifter tick then i have never heard lifts TICK so loud to sound like a rod is knocking. Should i just pull one plug at a time at idle and see if it goes away, will that tell me if its rod knock. It seems to go away so i cant hear it at high RPM's, but that could be cause the exhaust is so loud. Will the pull the plug wire method tell me if its the rods.
Thanks
Tom

 

[TalonspoolAWD]

Weird thing is that its gone at IDLE, now it only does it ONCE and a while at idle and you can hear it when you rev the engine, the knock increases with rpm steadily, and its DEF knock cause it sounds HORRIBLE. Will lifters do this, ANYONE??
Thanks
Tom

 

[Maglin]

NO.... Lifter tick is just that... They sould like tick tick tick... LoL like you can hear my thoughts... I just got my DSM which is a March 92 TSi AWD for $1250 cause of what I thought was a rod knocking.. Turns out that it was the Valves hitting the Pistons... It was really horiable sounding... I would pull timing covers and see if your timeing has slipped... you chould have a weak belt tensioner if you didn't have it replaced with the rebuild... A rod knock is usually very lound and at idle it's very fast... Valves on the other hand are very fast at idle and get crazy past idle... If it's a Rod the reason it's missing at idle could be the knock sensor is picking up the knock and severly retarding your timing to try and compensate...

 

[TalonspoolAWD]

well i doubt its the rods hitting the pistons. i think its either a stuck lifter or rod knock. Only taking the valve cover off will prove me wrong or right.
Tom

 

[Maglin]

Rod knock isn't the Rod hitting the Pistons... It's the Big end of the Rod moving on the Crank.. Usually caused by a severly worn out Rod bearing or a Spun Rod bearing which is almost the same thing... Wrist Pin knock is usually a tick tick pause tick pause tick tick kind of noise and Rod know is usually a stead ticking noise... I have spun rod bearing in high output V8's and If not attended to usually results in throwing the rod out the side of the Block... Not to sure about these little 2.0's but I'm sure the same princibles apply and if you kept running on it as it is you will end up with a costly repair bill...

 

[TalonspoolAWD]

UPDATE: I have changed the oil and cut the filter open. No metal at all was found. And since i changed the oil the knocking comes and goes at idle, but when you rev it you can hear it more, i can barely hear it sometimes when accelerating as other times it is louder, and when it idles it gets lound, and then it goes away, then comes back. I tried pulling each plug, and when i pull each wire off it stops and then comes back. It does the same for each wire. BUT WHY DOES IT GO AWAY THEN COME BACK. Could this be lifters cause it sounds like top end. I listened under the car and it sounds loudest in the intake manifold cause i think its resonating from the top end (somewhere in the intake cam near the middle). WILL LIFTERS SOUND LIKE THIS, ITS NOT A SLIGHT TICK, ITS A KNOCK THAT COMES AND GOES.
Thanks
Tom

 

[TalonspoolAWD]

Anyone had this problem??

 

[iNdo]

yes, try seeing if it is related to ur AC comming on and off. My car makes an odd, loud ticking noise but only when the AC kicks in, i think its a weird belt thing. That explained the on and off at idle. also got faster when i rev'ed it! hope its not somthing worse

 

[TalonspoolAWD]

Well today i took a few lifters out of the back of my engine and tried cleaning them, MAN WERE THEY DIRTY, when removing the plugs SPARK PLUG #2 was LIKE MELTED, THE ARM OVER THE ELECTRODE WAS MELTED AND THE PLUG WAS LIKE A COPPER COLOR. ALL THE PLUGS LOOKED GOOD BUT THAT ONE WAS MELTED AND MY CAR KNOCKS, BUT ONLY FROM THE TOP END. After cleaning and swapping lifters i got the same results, and it took about half hr for almost all the noise to quite down but it still makes that knocking sound like one is not pumped up or its something else, its like a TICK and KNOCK TOGETHER. it is definatly comiing from up top but i dont know what it could be, i swapped out a few lifters with some other ones that i had and it still does it, amybe the rocker arm is worn or something. I am gonna switch out some more lifters and see what happens. I did 4 on the intake cam in the middle where the knocking sounds the worst, and its weird it only does it sometimes at idle but you can hear it as you rev it.

 

[ViperKilrZ06]

you could have a lifter that has collapsed altogether......same thing happened to me. LOUD tick/knock. didnt drive it for a week. turned out that one of my lifters collapsed. not stuck or anything. i thought for sure it was rod knock.

pull all your lifters and squeeze each one long-ways. they should compress a little under pressure. if it doesn't then its stuck if it just slides back and forth with no effort at all, it has collapsed. good luck!

-chris

 

[TalonspoolAWD]

Ya, I am gonna take them out again an take a look. I swapped 4 of them out with different ones that i had and it didnt really change a thing. I guess that i will have to spend some time and take every one out and clean it and see if it pumps up.
Thanks
Tom

 

[Wing0tj]

I am having the same sort of diesel sounding noise and I think it is the same problem, have you been driving the car, and if so how performance, I have only driven it once since the noise and it ran 0 boost...

 

[TalonspoolAWD]

it runs great. The noise is not always there, but most of the time it is, I dont like my cars to sound like there gonna break but i can deal with the lifter noise for right now, my boosting problem i have is with my turbo cause it wont spool till 5500 somethimes and others it will spool low but not really make the car faster, plus it smokes. The turbo is shot and its time to put the t3t4 on.
Tom