Loud clicking noise

[2kdet]

I just aquired my buddy's old car.1993 NX2000 with a SR20DET swap.After a few days of figuring what kind of project I have to work with.I came with this problems

A loud clicking noise coming from the Intake Manifold area.While at idle and under a load.The clicking noise is random.I kinda felt it around the throttle body.

Number 3 spark plug fouled,while the other plugs are normal.

O2 sensor disconnected

Idles bad

Sometimes I can hear a popping noise coming out of the Air Intake.

Any help will be appriciated

Any help regarding the clicking noise will be appriciated.

[nametakennow]

The disconnected O2 and the bad idle are probably related. The clicking may be a function of problems related to the other stuff.

[2kdet]

Thank you for the reply,I spoke with my buddy about the 02 sensor.He said that it was disconnected before all of the problems started.I will order a new one and replace and see whats happens.Also I just notice that everytime that I hear the clicking nosie.I saw the boost gauge move everytime it clicked.Is there any type of electronic sensor that is connected to a vaccum line that I can not see.That may be bad.

[nametakennow]

No. Maybe the AIV is dirty. I'm not completely sure what to make of this one.

[2kdet]

Ok,I just finished installing the new O2 sensor,Dist cap and rotor,and I am still having the same problem.I my concern is the number three cyclinder.That is the only plug that is very sooty while the others are perfectly normal.I really need some help.

[RED_DET]

I'm beginning to think its a lifter, valve or at worse even rod knock. How loud of a sound are we talking about? Does it get louder as the RPM's rise? If you pull the number 3 plug wire does the sound continue or cease?

[2kdet]

Thanks for the reply.Well,the clicking noise does not get louder with the increase of RPMS.What I did notice,is when I took off the piping to the throttle body.The random clicking noise sounded like it was coming from inside the Intake Manifold.Is there any kind of electronic sensor that maybe going out that I should look into.The items that I have changed are the following,Dist and cap,rotor,O2,wires,spark plugs.And the #3 spark plug is still very sooty/dry fouled.I even interchange injectors to see maybe that was the problem.It seems that that cylinder is not working.I have pulled off the wire while car is running.If the clicking noise goes away ,what do you think?

[RED_DET]

Well we need to make sure you are getting spark to that cylinder. Pull the plug out, connect the plug wire and lay it on the valve cover. Have someone turn the engive over and see if there is any spark. Now if you are getting spark, then the problem lies within the injector or even the ecu. Put the plug back in the car, start it up and while its running, unplug the #3 injector. Is there any noticeable change in the way the engine idles? If so, then the injector is working at least. Now if you are getting fuel and spark, then either the ECU has taken a crap on you, which has happened to me effecting the same cylinder or the valve(s) on that cylinder are messed up.

[2kdet]

Ok,I did what you told me to do.I am getting spark from the wire.I am also getting fuel.What I did notice, is when I took off the #3 plug wire the clicking noise went away even when I raised the RPMS.But as soon as I put the wire back on.The clicking nosie came back.Please tell me what is going on.Is this engine done with?

[RED_DET]

The injectors will making a clicking noise, this indicates they are working. It sounds like you are getting fuel, obviously getting spark. I say something is going on internally on that cylinder. Wheter its valves or piston ring issues. Last thing you can do is a compression check on that cylinder and hope for the best, at this point I'm not to hopeful though. Friend of mine had the exact same thing happen to him. He thought the injector was not firing, but it was. Was also getting spark. Car ran like **** and plug was fouled out. Compression checked was way off.

[2kdet]

Hello,again.I did a compression test all the cylinders are at 120 psi across the board.Well,I believe I a head problem.I notice that when I took off my piping to the intake.Instead of just having air being suck in,I also had air being pushed out.I think this were the #3 cylinder comes to play.I do not think that the exhaust valves are working.So instead of the exhaust leaving the exhaust ports.They are exiting the intake ports and coming back out the throttle body.What do you think?How hard is it to remove the head?All I have is a Haynes manual and it sucks.

[RED_DET]

The worse part is removing all the other things in the way so you can pull the head off. 120 on the compression check across the board is way low. I think your exhaust valves are messed up as well.