AZCobaltss

So, here we go. I'll make this as short and sweet as possible. Driving down the road last night, did a no-lift-shift to 3rd and missed the gear. It made a small grind noise and I immediately let of the throttle and coasted for a bit since I was already at about 60. Put it into 5th and the car just would go anywhere. Misfiring like crazy couldn't accelerate at all. Thought I shot a rod or something at first. Upon pulling of to the side of the road and limping it back to my mechanic buddy's house. We localized the issue to the 4th cylinder. Or first. Now here's the crazy part. The car makes a very loud and mostly random ticking noise at idle. A series of loud ticks almost knocks every second or so. The ticking gets consistent if I rev the car. But it also gets quieter. IF I remove the coil pack on cylinder 4 the noise completely goes away and it runs better then if it is sparking. Why and how is that even possible? The car will actually run in a steady state with this coil pack removed. Obviously it's misfiring but it runs. The crazy part is. Also I did not/have not thrown any codes at all. Not a single pending code or anything. Help me. 😢

tuned08ss

Wheres the thread?

AZCobaltss

Oh and I did check compression and it was even across all 4

tuned08ss

I dont see an opening post. Try a new thread

Terminator2

Pull plug number 4 and post pics of it. Also check the high pressure fuel pump wiring for damage from the charge pipe possibly hitting it. Plug could be screwed more than likely replacing all the plugs will help unless number 4 is covered in oil and if it is oily you cracked your piston at the ring lands. If none of the above pull the valve cover you broke a lash adjuster/rocker.

AZCobaltss

No oil on the spark plugs that I saw. I do know the fuel rail pressure was going nuts last night. Ranging from about 150-375. At idle normally it's about a constant 450. Is that a symptom?

AZCobaltss

I'm currently at work until 6pm so I'm not able to post pics right at the moment. I can tell you just about anything you have questions on cause we looked over just about everything. But we didn't pull the valve cover yet. It was late and I had to be at work at 7...

AZCobaltss

Can you guys see the thread now that he replied?

Terminator2

How did #4 plug look? Never mind. Pull the valve cover and check the hpfp. Change plugs to be safe only use ACDelco plugs.

AZCobaltss

I just changed the plugs about a week ago with acdelco. Gapped to .30. It's definitely not just a plug problem. There's definitely a loud ticking. We thought it sounded like a valve hitting the piston. We thought dropped valve. But we ruled that out since it only makes noise when cyl 4 is firing

AZCobaltss

I'm having my buddy take a video for you guys. Maybe that will help

Terminator2

Broken lash adjuster most likely.

AZCobaltss

And how hard is it to replace and is it very expensive to replace a lash adjuster?

Dyn0mitemat

iTrader: (3)

Sounds like broken lash adjuster to me. They don't like over revving on the stock springs

You can pull the cover, rotate the engine until the cam lobe on the valve your working with is facing up. You can either get a plastic dowell and push the valve spring down (careful so you don't have the keepers pop out, you could drop a valve if so), or loosen a few of the cam caps and pull the rocker out. Lash adjuster just lifts out with a magnet and drop the new one in.

Only other option is to pull the cam completely and you'll have to also pull the front cover and retime it.

Itd suggest at least a set of springs (zzps 82#ers are good) and ti retainers if youre gonna pull it apart

09CobaltSS1

My initial thought was a busted lash adjuster as well.

AZCobaltss

Just bought two lash adjusters from my dealer. 10$ a piece. Going to pull the valve cover tonight and see if that's the problem. My car sounds exactly like this and his problem was lash adj. so I'm hoping that's the issue and I'll have it up and running for ifo tomorrow! Thanks for all your guys help. If it's not the lash adj. I'll be back haha http://youtu.be/mPGD8gQiK4c

SSlobalt

Ah, the old "my car sounds like a Subaru" thread.

AZCobaltss

You know what's funny is those were literally the first words out of my mouth when I got out to see what was wrong.

kzak104

iTrader: (1)

probably bojangled something in the head

AZCobaltss

Do I need a new valve cover gasket? Or can I reuse the old one. Even if temporary

09CobaltSS1

The valve cover gasket is reusable, unless it tears or rips during removal. Just don't over torque it when reinstalling and you'll be fine.

AZCobaltss

Just got the lash adj. installed and car was running good but in my way home it started misfiring and all the sudden I heard a loud pop. Pulled over and my upper charge pipe was blown apart at the clamp. Would having a boost leak cause a misfire?

Dyn0mitemat

iTrader: (3)

Yes, spray the charge pipe lightly with some hairspray before you put it back on and you'll be fine.

AZCobaltss

So I fixed to lash adjusters. Two were sheared off. Ran okay but now I'm getting a very aggressive misfire on cyl 4. The same cyl with the broken lashes. I threw a code for misfire on 4. What could cause this? Edit: the misfire is only when I'm boosting 8psi or more. If I stay under 8. It's won't misfire at all. Idk what to do.

SSlobalt

Oh, man. I'm not an the guy to talk to about the inner working of an engine, but it's starting to sound like you broke a piston 4 ring land. Hopefully some of the engine builders will chime in. Check with cmiller or monograt.