Crazy Knocking Noise

[WDRacing]

Got the 240 running again yesterday. Fixed the oil return problem and whatnot. FIxed the idle problem, stalling problem ans all the other minor ailments...but now I have this really ugly knocking. Starts at about 2200 rpm in neutral or while driving. Definitly in the motor. So I took off the valve cover, checked the chain, still tight, removed the upper chain guide, no help there. Any idea's for me to check on today? I'll do a comp check after work. I don't see how the motor goes from smooth to crazy knocking while sitting still in the garage!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

ANy idea's/help will be appreciated. I thought I might drive her awhile since I'm waiting on my internals to be ordered etc.

WD

[S14tat]

your car a auto or 5 speed? if its a auto, maybe the flex plate came loose.

[TheOne]

like this noise http://media.putfile.com/engine_noise ?, if its that then its most likely 1 of the rods.

[nismofly]

does it sound like its coming from the head?

could be a valve tick, this is what i have

[Structure240sx]

sure its not something like the fan hitting the shroud or something else external?

[fiznat]

Rut ro. So the knocking JUST started?

Honestly the first thing that comes to mind is busted bearings and a knocking rod, but that doesnt really make sense if the car was just sitting in the garage - unless it was put together improperly. I would drain the oil and check for metal fragments/shavings. That should get you started on a bearing diagnosis.

Other than that, there is lots of potential for noise in the head and timing components. Can you narrow down what area of the engine you're getting the noise from?

Meh, I dont know. Try and narrow it down and let us know whatcha find. I'm hoping its something like Anthony mentioned.

[DammitBobby]

That is why I pulled my motor out a few weeks ago. Should finish tearing it down this weekend. Mine started knocking really loud after I started to data log with the wideband. My AFR`s looked good so I am thinking old tired motor. Didn`t really get to play with the JWT and SAFCII to much. I will post pics when I get finished. When I did my compression test 140140110100

[Dragon_284]

I remember when I let my 240 sit for a couple of months and then tried starting her up she made a horrible knock/ticking noise. As it turns out it was just one of the lifters. So I changed the oil and let the car idle for a while and sure enough it went away. Never had a problem since. I dont know if your problem is the same as mine but I thought I would post this just to see if helps at all.

[Import_Ant]

does it sound like its coming from the head?

could be a valve tick, this is what i have

AgreedESPECIALLY if the car has been sitting for a while. my car sat for 2 weeks and I had a horrid lifter tick going on. toss a half a can of seafoam in the valve cover and drive it for a few miles (def no more than 20-30) then change the oil. it should clear it right up if this is in fact the problem.

[wild_maxx]

you prob. shouldnt drive with seafoam in your oil. it thins the oil out and may cause bearing damage. just like running really rich will cause bearing failure. just pour in seafoam and let it idle for about 10-15 min. then change the oil out.

[Craving4Boost]

could it be the tensioner thats broken

[240sxs1377]

i have the same problem i think it is the valve lash that is off. Im going to be adjusting all of my valves to fix the problem. But mine startes to rattle when i am driving at 2200 rpms. and then dies its really anoying and the cams make a rattleing noise when its idleing.

[Import_Ant]

you prob. shouldnt drive with seafoam in your oil. it thins the oil out and may cause bearing damage. just like running really rich will cause bearing failure. just pour in seafoam and let it idle for about 10-15 min. then change the oil out.

I just drove it home from the shop. no crazy driving, just 'limp-mode' while it was still NA. I was planning on changing my oil when I got there so I didnt see it as being a big deal. thanks for the info though I'll definitely take that into consideration in the future and for offering advice.

[paemt6220]

ROD KNOCK!!!!

That is the exact sound mine makes. Startes around 2400rpm to redline!

[WDRacing]

I'm going with rod knock as well....motor comes apart today.

[DammitBobby]

Take some pics when you finish. Dam signature is funny.

[Luderacer14]

My car made that sound and started getting worst. Last week it lost all power and the rod went through the block!!

[DammitBobby]

Well If I would have kept driving mine I would have done the same. One of the rod bearings was completely wiped out and had a lot of shavings in the oil pan. Sorry to hear it. How many miles did you have. By the way I have a spare set of rods with pistons and rebuildable block with crank. Wont be needing any of it since the KA I have now is running.

[Nismo_Freak]

Pull the injector harness clips one by one, the knock will either go quiet or be alot more muffled. If it doesn't then you either have a completely failed rod bearing, or you have a piston to valve problem.

You have worse luck than I do.

[Mustangs_Suck]

nice 2 month old thread revival

[Luderacer14]

57,000 miles. I plan on getting a sr20, lol. I'm going on deployment and won't be back for 8 months in a couple days. So i pretty much have 8 months to plan.