engine knock on a 2.4

[justin0717]

Ive got a new problem that just started today, its a knock type noise, comming from what seems to be the timing chain area. Has anyone seen this type of noise from the 2.4? I am looking for a place to start. Thanks

[Forkliftguy]

Oh, Oh, Oh!!!!!! Mr. Cotter, I have! lol At first we suspected a valve on #1, but then being that my tensioner was shot and using a stethescope all signs pointed to the tensioner. Since I changed the tensioner yesterday the noise is very faint but still there sometimes especially when the engine is cold (so it seems). And since the engine runs really smoothe I think it safe to eliminate my valves, but I suspect my timing chain and ass'y are worn. Sounds kinda like what you may be having, what's your mileage like?

[justin0717]

120k...i wasnt suspecting any valves, it doesnt sound like a valve problem. Ive heard 3.4 where people have put a push rod in the wrong spot, and it doesnt sound like that. So you say a bad tensioner caused a knock type noise?

[Forkliftguy]

Yeah, it was more like a quick raping noise for a quick second (like an exagerated ticking sound in quick succesion) when I would get on the throttle hard from idle or whenever I would have the a/c on and would be idleing. Now that the belt tensioner has been changed it has quieted down dramatically. Oh yeah I have 111K on my engine, not far off from yours.

[Ridenour]

Before you go tearing into anything, I would suggest simply doing the following - run 1/2 a can of seafoam carbon remover in your crankcase oil (change your oil like 60 miles later), 1/2 a case direct-fed into your manifold through your PCV valve, and 1 can in a full gas tank. It might just be a carbon build up issue, and seafoam could solve it. I'm just saying remember to address the small things first.

[Forkliftguy]

Good point Ridenour, on my end though the tensioner was shot (the bearing was wasn't too bad on the pulley but the spring had pretty much "walked into the light", damn tensioner, I'm gonna miss the little fella, oh well got a new one for CDN$78 ) plus I think my engine sees 6grand more often than idle rpms. Lol

[justin0717]

im 99% sure its my timing chain. Im going out right now to take it apart it and see. Im pretty sure a tensioner broke or guide or something.

[eaglegtx]

I hear a slight ticking/tapping noise in my 2.4 as well. I had a mechanic look at it...but he said it was noisey fuel injectors, and that the 2.4 engine is well known for it.I have no idea if he was being truthful....or brushing me off.
BTW. There is no PCV valve on a 2.4 liter engine. At least not mine...which is an 01.

[Ridenour]

Yeh actually, I have heard of noisy fuel injectors on the 2.4 too - it's another possibility. An injector purge could solve that problem. And Oopsy - I knew they didn't have a PCV valve I don't know what I was thinking. LoL

[justin0717]

well i seem to have found the problem. Two collapsed lifters. i pulled everything apart, and found two lifters that i could press in. So im gunna replace them and hope everything runs good. Ill let ya'll know what happens.

[Forkliftguy]

I hope that solves it, I ran my car without the serpentine belt and my noise went away completely. It looks like the clutch or bearings on my A/C pump are shot. It's a tricky noise to hunt down.

[justin0717]

yea i first ran my car without the serpentine belt, noise was still there. I went in and replaced the tensioner on the timing chain, noise still there. So i went deeper and found two collapsed lifters. So now i gotta wait a few days b/c no place around here stocks them. Its wierd though, b/c the noise my car was making, didnt sound like a lifter problem, like the clicking of a lifter. I dont know, im hoping this fixes it.

[Forkliftguy]

Good luck with it. Noises can be a pain in the @ss, especially on that side of the engine where there's so much potential for problems.

[justin0717]

yea...both the collapsed lifters were on the intake side on cylinder number 3. Which would kind of explain why it sounded near the timing area. Im really hoping this solves the problem.