Loud ticking or popping noise coming from I think behind intake plenum

[baller760]

Hello,

Recently I went to the track and was unable to get any clean runs in because my car wasn't running right most likely due to a bad MAF (car doesn't idle at consistent rpm's). Anyway, on my second run I detonated 19.9 degrees of knock near the top of 2nd gear before I let out running 21 psi on a stock car. Since then when the car is idling I hear a loud ticking or popping noise coming from somewhere near the intake plenum or right below it. I checked and it's not coming from a specific valve cover and the noise is not consistent but it is always there. Sometimes it's once every second sometimes it's every 1.5 or 2 seconds etc.

What could this be? And could my fuel problems be due to a fuel system issue? Does Fuel Pressure rise with RPM or with boost?

 

[baller760]

I took it to my mechanic and he just did a brief inspection because his shop was closing at the time but he said the ticking/popping noise sounded like it was external and that he might possibly hear an exhaust leak. I think the exhaust leak he as referring to is my adj fpr which never re-seated properly and now makes a loud air leaking noise even when you only turn the key, but no fuel leaks at all

 

[DailyDrifter]

Could be the flexplate bolts. Make sure there tight and go from there. Whats wrong with your Fuel reg????

Edit: I just read your post. 19 degrees of knock! You might have hammered the bottom end apart. Also Fuel psi should raise 1:1 with BOOST.

 

[baller760]

Where is the flexplate located? I was thinking something in the bottom end but there is no noise down there. The car still holds 25 psi of oil pressure at idle and is around 65 during cruise or acceleration. The car has seen knock before above 20 degrees but it's always been at low boost and around 20-30 mph. This 19.9 degrees of knock was at 65 mph in 2nd gear but I think everything on the inside is ok since the car drives fine. Or could I be wrong? I'm just wondering what that noise is.

 

[DailyDrifter]

The flexplate is connected to the crankshaft at the back of the engine. The torque converter is bolted to the flex plate, make sure those bolts are tight.

In any situation knock is not good! You have to have some other problem that is giving you the knock in the first place. Do you have a scan master? Something is definatly not right.

 

[86george]

It sounds like you may have worn cam lobes and or trashed bearings.Noise sounds like it's from under intake,not valve cover on either side.Makes it hard to locate.Engine not runing up to par is a sign of a worn cam shaft.Get somebody to check it out before you do anymore damage.You might get lucky and find it's external but the odds are't good.Good luck.

 

[baller760]

Well I found out the reason it detonated was my MAF went bad. I just tested my idle without the MAF plugged in and it runs perfect and purs like it used to. So this was causing some kind of lean condition which caused the detonation. As far as the internals, I'm not sure if it's not running well or not because the car drives like it always has. I haven't tested it since the detonation but the engine always pulls to 5200 rpm just like it's supposed to and never feels sluggish in any gear.

I'll check the flexplate screws tomorrow but it's probably something internal. Maybe it's just a bent rod

I really hope it's not the cam, crank or bearings because isn't that a very very expensive job?

 

[meanmachine]

Did you find the cause of your noise yet?

 

[baller760]

No, unfortunately I haven't been able to figure it out yet. Haven't had the chance to take it into a shop. I do know my MAF is bad now though, as I unplugged it and the car idled much better.

 

[Turbo1dr]

No, unfortunately I haven't been able to figure it out yet. Haven't had the chance to take it into a shop. I do know my MAF is bad now though, as I unplugged it and the car idled much better.

Does the engine still run smooth at an idle even though it's making a clicking sound?

 

[meanmachine]

For the record that is what mine is doing. Runs smooth at idle but with a fast tapping noise off idle, that you would bet that it was a broken spring or bad lifter. I have checked roller rockers,springs,adjusted valve lash several times, double and triple checked. My noise is coming from the drivers side ,and sounds like it is coming from under the valve cover /intake area. it drives fine ,but the knock detector goes off like a rader detector .

There is no noise at idle, but as soon as you bring the r's up her it comes. You know how sound travels sometimes, so i pulled the pan and checked the rod bearing . They looked fine so i buttoned it back up started it up and retarded the timing to see if it was piston slap and there was no change in the the sound. Then i moved the rockers from one side to another to see if my noise would follow,the tapping stayed on the drivers side. also removed the convertor and the engine belt with no change. and the cam sensor isnt to old ,and has no slop.
Tried a compression test to see it would show anything all the reading were between 125-135. now im debating if i should do a leakdown. i'm running out of things to check before i have to start tearing it apart.

 

[Turbo1dr]

Sound like one of the lifters doesn't want to stay pumped up and causing your tapping. I'd replace that lifter since you've isolated where the noise is coming from. The noise can also be cause by an excessively worn valve guide or broken inner valve spring.

 

[meanmachine]

well about the lifters, i didnt tell you that before the noise started that i had bought some morel lifters from t/a performance (thru kip aspen) to replace the noisy comps . so when the noise started and the knock detector going off i was thinking that i broke a spring and it would be a good time to change these comp lifters and also drill a hole in my intake for my iat sensor .

so with new lifters and a good inspection when i started it to hear the same noise still.
could it be a headgasket ,from a lifted head . i dont mind pulling the head if i have to. just dont like fishing in the dark

 

[XLR8]

Both posters could have a headgasket issue. I would run a compression and leak-down test.

 

[meanmachine]

Well monday after work i couldnt wait any longer,so i pulled the driver side head and didnt see anything wrong w/the head or gasket . then on tuesday i pulled #1,3,5 pistons to measure the skirts (the old slugs might be worn out). ill find out thursday.

 

[baller760]

I really hope it is just a blown head gasket. Shortly after the 19.9 degrees of detonation I found out that my MAF had gone bad and was making the car run extremely lean. I don't know why I didn't figure that out before the run that hit 19.9 degrees. Anyway, how would I go about doing a compression and leakdown test? I've never done one before but I know I have the compression gauge to use. I think this would be a great idea to see what is wrong but I still hear a clicking-like sound at idle which appears to come from behind the intake plenum/manifold somewhere.

If it's something internal, how much do rebuilds of GN motors go for or should I just go for the 4.1? Basically, what is cheaper?

 

[meanmachine]

i found some wear on the cam gear that drives the cam sensor(it will get the lee thompson oiling treatment when it goes back together)

But by listening you would swear it wasnt comming from there. still digging ,illbe back latter . got to work 2nd and 3rd shift(damn) danny

 

[tbkustomz]

same problemo

wasup guys im having the same exact issue...my car spools up quick and drives normal but when i floor it knock guage and scanmaster goes off like a xmas tree....at idle and more when i floor it i can hear a little tick...it will only get louder as i floor it..when im on the freeway i can hear but not like if i would floor it...today i discovered that my valve covers were a little loose so i tightend them and the noise seems to get a little deeper seems like it could come from the lifters or in back by the intake...any help would be a aprreciated its my daily driver and i dont have another car incase this one breaks down...

 

[meanmachine]

1. remove the engine belt ,and start it for a sec. to make sure it isnt in the accesories

2. remove torque covertor bolts and push the stall back toward the trans. then start to make sure it isnt in the trans.

3. use a automotive stethoscope to pin point the noise , and dont forget to check around the cam sensor.

thats just a good starting point that might help pinpoint the problem ,or narrow it down to one area.

, danny

 

[GW2]

i'm having a loud ticking noise aswell and i think its coming from around the cam sensor. ill be taking it in tomorrow though. it seems to go away once the car is warmed up, but i have no clue what it is. sounds like it might be coming from the distributor aswell. but honestly i have no clue.