Engine misfire, ticking noise and hole in the valve cover

[gpjlytham]

Hi All

2001 Buick Regal LS 108,000 miles. Hole in the valve cover, misfire and ticking noise.

The car was running great, then it started to misfire and the check engine light came on, then the engine started to make a ticking noise. My scanner shows a misfire in cylinder 3.

I thought it might be a bad coil causing the misfire so I swapped the coils to see if the misfire moved to another cylinder. It didn’t. so I’m fairly certain the coils are ok and a bad coil wouldn’t explain the new ticking sound.

I pulled the spark plug and it looks very old but looks ok (no damage or excessive gap)

I changed the oil to see if it had any metal in it. No metal, so nothing too catastrophic.

I filled it with new oil and replaced the filter and added some miracle engine cure to quieten the noise. But it still has the misfire and the ticking.

I now suspect a collapsed lifter so I’m taking the intake off and removing the valve covers.

The rear valve cover (one near the firewall) has a hole drilled in it and it doesn’t look like a hole drilled at the factory.

Q’s

• Is the hole, a factory hole?
• Why is the hole there? (no blow by at the oil filler cap on the front cylinders)
• Any thoughts on the ticking?

Hopefully some of you have some idea’s.

Thanks

 

[LARRY70GS]

That hole looks like damage to me, not a drilled hole. If the engine is ticking, can you localize the noise? If you suspect a valve lifter, you should be able to notice one of the rocker arms not moving as it should. Are any rocker arms damaged? Bent push rod? Seems to me you should eliminate those possibilities before pulling the intake. I'd also do a compression check on all cylinders, especially #3.

 

[gpjlytham]

That hole looks like damage to me, not a drilled hole. If the engine is ticking, can you localize the noise? If you suspect a valve lifter, you should be able to notice one of the rocker arms not moving as it should. Are any rocker arms damaged? Bent push rod? Seems to me you should eliminate those possibilities before pulling the intake. I'd also do a compression check on all cylinders, especially #3.

Hi Larry70gs.

thanks for the response. I think the hole was drilled with a dull drill bit, as it is clean hole on the outside but the inside shows damage, as though a dull drill bit was pushed hard and not allowing a smooth drill through.

The rocker arms don't appear to be damaged and I should get the push rods out today. I also thought it could be a broken valve spring but they all appear to be ok.

I believe that cylinder 3 is the cylinder under the oil filler cap and the valves appeared to move fine when I ran the engine with the cap off and looking through the oil filler cap hole.

 

[Mad_Coachman]

How long have you had the car?

 

[LARRY70GS]

Misfires are most commonly caused by a wire or plug. The 3800 has 3 coils that each fire 2 companion cylinders. Those companion cylinders are 1-4, 2-5, and 3-6. When a coil goes out, it will affect the pair it fires, so if it was a coil, #6 would also misfire.

Mechanical issues can also cause a misfire. If you have a loss of compression due to a bent/burned valve, or push rod/rocker problem, it will show up in a compression check. A non functioning fuel injector can also be a problem. That can be checked with a noid light to see if the injector is getting a signal to fire.

 

[Mad_Coachman]

Misfires are most commonly caused by a wire or plug. The 3800 has 3 coils that each fire 2 companion cylinders. Those companion cylinders are 1-4, 2-5, and 3-6. When a coil goes out, it will affect the pair it fires, so if it was a coil, #6 would also misfire.

Then I guess I've had coils go "halfway" out as a P030X (singular) has often been solved by replacing the coil and the companion cylinder was still firing.

 

[LARRY70GS]

Then I guess I've had coils go "halfway" out as a P030X (singular) has often been solved by replacing the coil and the companion cylinder was still firing.

Sure it's possible, but not the most likely scenario. The 3800 uses a wasted spark system. The companion cylinders both are at TDC at the same time, one on compression, and one on exhaust. They are sparked at the same time.

Wasted spark system - Wikipedia

en.wikipedia.org

 

[Mad_Coachman]

I know it uses the waste spark system. I've been dealing with the 3800 since 2003. 😀

 

[LARRY70GS]

I know it uses the waste spark system. I've been dealing with the 3800 since 2003. 😀

Me too.🙂 There are exceptions to everything. I like to check the simple things first.

 

[gpjlytham]

How long have you had the car?

I have owned it approx. 3 weeks and I drove it probably 500-750 miles, I didn't notice the misfire until I was on the on-ramp getting onto the freeway. normally i'm fairly easy on a car but that morning I was getting past a slow car so I had my foot down and it started to miss. When i slowed down I heard the ticking.

 

[LARRY70GS]

I have owned it approx. 3 weeks and I drove it probably 500-750 miles, I didn't notice the misfire until I was on the on-ramp getting onto the freeway. normally i'm fairly easy on a car but that morning I was getting past a slow car so I had my foot down and it started to miss. When i slowed down I heard the ticking.

I'll tell you what I have seen at times with the 3800. Everything is fine until you place a large demand on the car by putting your foot in it. Then either a spark plug shorts out (carbon track), or the ignition wire breaks down, and that cylinder will short to ground anytime there is a big load put on the motor. Maybe the ticking you're hearing is the spark shorting somewhere. Have a look in the dark with the engine running. The other scenario is not that good. I have seen a few older 3800's detonate on one cylinder. Maybe the fuel injector is partially clogged and the cylinder runs lean. Again, when you put your foot in it, that one cylinder detonates and damages the piston. A piece of the piston flies around in the cylinder until it exits via a valve. It usually closes the gap on the spark plug, or otherwise damages it. Seen that on the supercharged engines, but it can happen to the normally aspirated engines as well. The PCM will retard the spark when it hears detonation via the knock sensor, but it can only protect the engine so much. Hopefully, it is the first scenario, not the second.

 

[gpjlytham]

I'll tell you what I have seen at times with the 3800. Everything is fine until you place a large demand on the car by putting your foot in it. Then either a spark plug shorts out (carbon track), or the ignition wire breaks down, and that cylinder will short to ground anytime there is a big load put on the motor. Maybe the ticking you're hearing is the spark shorting somewhere. Have a look in the dark with the engine running. The other scenario is not that good. I have seen a few older 3800's detonate on one cylinder. Maybe the fuel injector is partially clogged and the cylinder runs lean. Again, when you put your foot in it, that one cylinder detonates and damages the piston. A piece of the piston flies around in the cylinder until it exits via a valve. It usually closes the gap on the spark plug, or otherwise damages it. Seen that on the supercharged engines, but it can happen to the normally aspirated engines as well. The PCM will retard the spark when it hears detonation via the knock sensor, but it can only protect the engine so much. Hopefully, it is the first scenario, not the second.

Spark plug wire arcing: I did look for that, I had my kid rev the car at night and i couldn't see any sparks, but the car only misfires under load so it could be an issue and i just couldn't see it.

Ticking noise:- I don't think the noise is electrical and it got louder when i removed the oil filler cap.

Fuel injectors: I will attempt to clean them before reinstalling them and perhaps try to flow test them.

Damaged Piston/rings/metal bits: I didn't see any metal in the oil and tearing it down I haven't found any metal. The gap on the spark plug was approx. 060 and was not damaged.

I appreciate all the help from everyone.

 

[LARRY70GS]

That's good. This is the kind of damage that I am talking about.



That isn't going to end up in your oil, it will go right out the exhaust in bits.

How loud is the tick?

 

[Mad_Coachman]

I have owned it approx. 3 weeks and I drove it probably 500-750 miles, I didn't notice the misfire until I was on the on-ramp getting onto the freeway. normally i'm fairly easy on a car but that morning I was getting past a slow car so I had my foot down and it started to miss. When i slowed down I heard the ticking.

The reason that I asked is that it's possible that the previous owner may have replaced the alternator and used the wrong bolt (too long) on the alternator and went right down into the valve cover. I just took a look at my brother's 2004 Regal to verify and the bolt is directly above where your hole is.
However it got damaged you need to replace it.

More Information for DORMAN 264967

Amazon has it as well.

Amazon.com

 

[Mad_Coachman]

If you don't own a scanner/code reader then I suggest that you get one. 😳

 

[Mad_Coachman]

The reason that I asked is that it's possible that the previous owner may have replaced the alternator and used the wrong bolt (too long) on the alternator and went right down into the valve cover. I just took a look at my brother's 2004 Regal to verify and the bolt is directly above where your hole is.
However it got damaged you need to replace it.

More Information for DORMAN 264967

Amazon has it as well.

Amazon.com

Here is an example of what I'm talking about.

Black versus silver valve covers

I got the alternator bolts mixed up on my 2000 LeSabre not realizing they are different lengths and the longer one made a hole in the right valve cover. Looking for a new valve cover, but both the Dorman and GM ones are black, not silver like whats on the car. Do these come in silver, do people...

buickforums.com

 

[LARRY70GS]

That's got to be it.

 

[gpjlytham]

If you don't own a scanner/code reader then I suggest that you get one. 😳

I have a code reader and the only code it detected was the misfire on cylinder 3. I cleared the code, but it came back when I put my foot down.

 

[Mad_Coachman]

Change the spark plug.

More Information for ACDELCO 41101

 

[gpjlytham]

I pulled all the lifters and they look good (no visible damage) but one or two could be sticky or ? so I am going to replace them all. The rods and rocker arms all look to be in great condition. I'm waiting on a gasket that amazon or ups have misplaced, so I either spend more at my local o'reilys auto parts store or wait on Amazon/UPS.

It looks like the upper intake gasket (the gasket that goes between the plastic piece and the metal piece) was starting to fail as it had black across the entire mating face to cylinder 3. I don't know if that could cause my issues but a new gasket will be good.