I would say to do every man's worst nightmare...

Compression Check

 

if your compression check goes okay make sure you aren't confusing typical KA lifter noise, timing chain/chain guard, or noisy injector sounds. I know they can sound kind of similar but if it's a steady pinging kind of like a diesel truck then sorry but there's 99% chance it's detonation. good luck hope its not serious

 

If you can hear/feel it from the front of the engine...it doesn't sound like it is knock, but timing chain noise. Maybe you busted the upper tensioner. Pull the valve cover and remove it. It is probably timing chain noise. There isn't any reason for a KA to have detonation type knock at idle. The only other thing it could be is rod knock...does the engine still run like it has power?

 

The engine runs fine. I havent noticed no power loss.

 

One of my friends 240 had a noise that sounded like the one you are describing and it turned out to be his timing chian. Check that out first.

 

my friend has almost the same problem, but his sounds like a lawn mower. The timing adjustment was adjusted to give him " Really good milage" but when we put it back to stock, he got the lawn mower sound. does anyone know what this is?

 

the timing chain guide is a very common problem....happened to me youll have to pull off the front cover.... pain in the ass

 

If it all of a sudden made a noise, you probably broke the upper tensioner, which is part of the timing chain system. That part is obsolete. Pull the valve cover and remove it. If it isn't broken, you'll probably want to pull the front cover and replace the timing chain altogether. If it is broken...that was probably your only problem, I'd remove it and quit worrying.

If the car still runs like it has power, then it isn't detonation knock, and you don't need a compression test, nor is it rod knock.

If your car sounds like a lawnmower, it probably is an exhaust leak.

 

So just pull the valve cover and replace the tensioner? You think it would be able to hold out till the middle or may? Thats when the SR goes in and I dont really wanna waste any more money on my KA right now.

 

If that upper guide (not tensioner, sorry for the confusion) has broken, like I suspect it may have, remove it. The upper and lower guides are not needed (they aren't in 97-98 motors, and Nissan does not recommend reinstalling them in a timing chain job). If it is fine...and you just have regular timing chain noise...replace it when you get a chance, but you'll need to do the full chain job.

Dennis

 

I got the same noise on my 91 Coupe. Its loud and comes from the front of the engine. The Noise Comes only when my car is idled at around 750-1000. Around 1200-1500 or above the noise is not there. Could this be another sign that this is the timing chain ?

 

Sure you just don't hear it because of road noise, exhaust, or windows rolled up? Because my chain's fucked and I can hear it slightly at idle but it's very annoying at high RPM on freeway. Otherwise it might be something loose that happens to resonate around at the frequecy caused by the vibration of your engine idling. Personally, I think it's probably loud as hell at high RPM and you just haven't been listening hard enough j/k dude like I said, it could be something which rattles at idle (check heatshields etc...)

 

Actually the car is not it motion. I popped the hood and had a friend rev the engine while i listened to it. The knocking seems to be coming right under the valve cover where the Oil cap is.

 

same problem

I have the same problem! The car runs fine and has power but there is still that small little knocking sound on top by the front of the engine. It stay the same same and doesnt get loud when I rev! Waht could it possibly be?

 

well it obviosly isnt knock. Knock causes extreme heat and wear in your engine, trust me you would be able to tell if its knock. plus knock happens alot of the time when your foot is on the gas and the car is moving. you yourself said it coming from right under the valve cover so rip it off already and fix the tensioner/chain. Its better to be safe and change it now so that you have a car to drive that doesnt sound like a pos.

 

If the car still runs like it has power, then it isn't detonation knock, and you don't need a compression test, nor is it rod knock.

I wouldn't discount rod knock. I had rod knock for a week and a half on my old motor and it pulled great up untill I lost #4 completely.

Might be valve lash. I had a bad case of that with the new motor after a couple weeks, but repeated flushing of oil got rid of it. (Was using Mobil 1 with it up to that point, then decided maybe I should go back to my trusty VR1 oil).

Still.... pop the valve cover off since it's easy to do, just to check the easy stuff first. Although, timing chain often isn't described as "knock"....

 

How old is this thread...oh 7 months. Maybe the person with the problem can tell us what it ended up being...but from his description, I'll bet you 20 bux, Ace, that it is timing chain related.

Dennis

 

How old is this thread...oh 7 months. Maybe the person with the problem can tell us what it ended up being...but from his description, I'll bet you 20 bux, Ace, that it is timing chain related.

Dennis

:werd

 

If that upper guide (not tensioner, sorry for the confusion) has broken, like I suspect it may have, remove it. The upper and lower guides are not needed (they aren't in 97-98 motors, and Nissan does not recommend reinstalling them in a timing chain job). If it is fine...and you just have regular timing chain noise...replace it when you get a chance, but you'll need to do the full chain job.

Dennis



THIS GUY KNOWS WHAT HE IS TALKING ABOUT! I read through everything before i was gonna write it .. lol i known people that have messed there motors up from that top guide! EVERYONE SHOULD TAKE THEM OUT!! like dennis said nissan dont even use them in the newer motors.

WOOT KA POWER

 

Most of the knocks I have experienced came from bad rod bearings. Does the car knock after it is warmed up or always? either way, rod bearings can be the cause too

 

sorry to bring this up but is this the top chain guide you are talking about?

 

sorry to bring this up but is this the top chain guide you are talking about?

yup. there's also another guide on the side which i've heard is also unnecessary.

 

my car makes a clicking noise. It clicks faster when i rev but doesnt get any louder. I have no clue what it is

 

Most likley lifters.

 

my car makes a clicking noise. It clicks faster when i rev but doesnt get any louder. I have no clue what it is

lifters or sticky valve... 85% of cars have this at some point or another. don't worry about it.