Cobra Engine Noise

[ra03svtcobra]

I need a little help with this one. My cobra seems to make a "ticking" sound coming from the engine. Seems to be coming from the middle and it doesn't seem to be more on one side than the other. It almost sounds like it is coming from under the supercharger, but it is hard to tell. I kinda don't want to know the answer, but I still need to find out. I am dreading it is in the valvetrain and will need to be torn apart. It doesn't do it all the time and sometimes it doesn't do it at all. It did it a few days ago. Drove it the last few days and it stopped. Now today it was doing it again. Any help is greatly appreciated. Thanks

Cobra noise - YouTube

Cobra engine noise - YouTube

Cobra engine noise 2 - YouTube

 

[X3FBrian]

Too loud to be injectors. Google "03 cobra head tick"

 

[SNK-BITE]

Sounds like the head tick to me. Hopefuly mine doesn't get as loud as that. I would have to take it apart.

 

[ra03svtcobra]

Yeah. I'm afraid that's what it might be.

 

[roy_1031]

Yup that whipple is bad, I'm gonna have to trade you my heaton for it...

 

[ra03svtcobra]

Yup that whipple is bad, I'm gonna have to trade you my heaton for it...

I'm keeping my options open lol

 

[03SonicVert]

Subliminally the camera keeps panning back to the bank 2 head......

How many miles on the engine?

 

[testorossa1989]

Sounds like the head tick to me. Hopefuly mine doesn't get as loud as that. I would have to take it apart.

Stop scaring him.


OP - When was the last time you checked the oil level or changed it. Does it get louder and more rapid as you accelerate or put load on. And is this only when the engines cold and stops when its warm?

 

[ra03svtcobra]

Subliminally the camera keeps panning back to the bank 2 head......

How many miles on the engine?

28k

 

[ra03svtcobra]

Stop scaring him.

I'm already scared lol. Not sure if I can do the repair myself if that's what it is and don't want to know how much it would cost for a shop to repair it.

 

[testorossa1989]

I'm already scared lol. Not sure if I can do the repair myself if that's what it is and don't want to know how much it would cost for a shop to repair it.

Im not sure if you saw my edit. When was the last time you checked your oil level or changed it. Does this only happen on cold start and stops when warm? and does the sound get louder and more rapid as you put load or accelerate?

Lets not jump to conclusions just yet

 

[SNK-BITE]

Stop scaring him.

Lol, That wasnt my intentions

 

[ra03svtcobra]

Im not sure if you saw my edit. When was the last time you checked your oil level or changed it. Does this only happen on cold start and stops when warm? and does the sound get louder and more rapid as you put load or accelerate?

Lets not jump to conclusions just yet

Change the oil every spring. I only put maybe 500 miles on it a year. The noise has been intermittent, but seems to be happening more frequently now. I drove it home from work this evening and it was making the noise from when I started it until I got home (which is 3 miles from work). I got home and borrowed my wife's stethoscope to listen. It sounds like it is coming from the drivers side head. Very pronounced sound and barely noticeable towards the front of the head, but VERY noticeable towards the back of the head. I don't hear anything on the passenger side but normal valvetrain noise. Checked the intake and could hear the air being sucked into the Whipple. Using the stethoscope was pretty neat. Never tried that before. I did notice on the drive home that there was a weird sound when I let off the accelerator. Kinda like an exhaust leak, but not as noticeable, like air being let out somewhere. Might be time to put it up until I can get it fixed :shrug:

 

[03SonicVert]

It really doesn't sound like the classic exhaust valve guide to exhaust valve stem excess clearance issue, aka head tick, but do agree some more diag is needed.

The head tick usually changes at varying operating temps and gets louder in time as the clearance opens up. The head tick is also very prominent audibly in the bank 2 exhaust. If you can listen from underneath with the s-scope on the exhaust manifold runners or above the upstream cat it should be the loudest there. Again... If this is the classic head tick.

If the noise originated out of no where then I would guess you have a lash adjuster that is not pumping up, dislodged roller follower due to a sticky valve from varnish/sitting and not being driven, etc.

Have you cancelled cyls by unplugging the bank 2 injectors one at a time? You could do a compression test too but I'm guessing the cam cover will need to come off in the not too distant future.

I wish the driver cam cover wasn't such a pain to get off or else you could pop it off for a quick view.

 

[ra03svtcobra]

How do I do this cancelling cyls by unplugging the bank 2 injectors one at a time?

 

[03SonicVert]

Unplug each injector one at a time and see if the noise changes. It will change slightly based on the rpm but a valve train noise will stay consistent. Also by eliminating the fuel you eliminate combustion. If it is a piston, wrist pin, rod bearing, etc the reduction in force from eliminating combustion will dramatically reduce the noise. My guess is that the noise will not change by canceling cyls but you want to do all of the easy tests first.

You then plug the inj back in and move down the line one cylinder at a time. You should only have one inj unplugged at any given time and only for a few seconds. Just long enough for you to evaluate the noise.

 

[ra03svtcobra]

Thanks. I'll try that and get back to you.

 

[ra03svtcobra]

Ok. Started the car this morning after it sat all night (so it was cold) and the ticking was still there. Sound seemed to get louder as it got warmer. Tried unplugging the injectors on the drivers side and nothing. Engine slows briefly when I unplug it, but no change in the ticking sound. Put the Cobra up on the lift and listened with the stethoscope from underneath. No ticking sound on the oil pan. On the x-pipe (after the manifiold flange) the sound is there. When I listen on the manifold just above the x-pipe connection, I don't seem to hear it. I listen on the bell housing and can hear it. I did replace the throw out bearing last winter so I hope this isn't it (although that would be easier to fix than replacing the heads).

Oh and the sound changes with the RPM's. RPM's go up, the sounds gets faster

 

[gnatsumarboc03]

Sound like valve train issue....

 

[testorossa1989]

OP, Dont giveup yet.

One last thing would be check your sparkplugs and see how loose they are. A sparkplug blow out would replicate that sound in your clips and increase the sound as the RPMs go up.