Real Engine Question - Sputtering

[itstheDRE4M]

For all you engine buffs, I need help diagnosing my little engine problem.

200k+ miles.
V6 Engine.

Looking at the engine.. on the left side around the valve cover/cylinderhead there is what I call sputtering. Especially when you stab the throttle (reaching 3500rpm). Then when the rpms decrease there is... 'gurgling/popping'. Can be heard from the exhaust as well, but it's more of a gurgling back there.. very 'muffled' haha.

Spark Plugs.. Gasket.. Valves.. MissFires.. etc..

Sorry about Quality.

 

[W3H5]

Blown a gasket? Exhaust blowing?
Take off the rocker cover and have a look, it's a simple thing to do. You'll only need a few sockets.

 

[itstheDRE4M]

Blown a gasket? Exhaust blowing?
Take off the rocker cover and have a look, it's a simple thing to do. You'll only need a few sockets.

I figured it's a blown gasket... other "older/not necessarily wiser" people have told me other things..

 

[Keef]

Usually the term "sputtering" comes up when people are describing an intermittent misfire while driving, not a sound while under the hood. But I'll work with you...

Often times a cracked exhaust manifold will make a ticking sound that obviously gets louder under power. A blown head gasket can make an odd poofing sound, like air leaking, because air is leaking. I'd imagine blown gaskets on the intake manifold would sound the same.

In this video you can vaguely hear the sound of a blown head gasket poofing air:

 

[Rotary Junkie]

I figured it's a blown gasket... other "older/not necessarily wiser" people have told me other things..

Head gasket is a maybe, although you'd certainly have a milkshake somewhere due to it.

Would help to know what the actual vehicle is though.

 

[itstheDRE4M]

I appreciate the help! I'm staying with.. a blown head gasket.

I've videoed it as of five minutes ago and currently uploading it. Will post as soon as it's finished.

Head gasket is a maybe, although you'd certainly have a milkshake somewhere due to it.

Would help to know what the actual vehicle is though.

02 Frontier N/A

 

[itstheDRE4M]

 

[cenk]

I appreciate the help! I'm staying with.. a blown head gasket.

I've videoed it as of five minutes ago and currently uploading it. Will post as soon as it's finished.

02 Frontier N/A

If you are not losing coolant or overheating, its not the h/g.

this sounds like an exhaust leak, but if you cannot find the leak at the exhaust manifolds, then check you spark plugs, you might have shot one out

i also heard something almost like a valve tick..if there is any ticking audible and getting louder as the RPMs go up, then you got some valvetrain issue as well.

good luck..

 

[Keef]

That The backfiring sounds like like an exhaust leak.

Cenk's spark plug idea is an interesting one - because the piston is moving up and down you would hear a clearly audible poofing/farting sound of air being shot out and sucked in - but that wouldn't cause a backfire and would be accompanied by an obvious loss of power and very rough idling.

I'm voting exhaust manifold gasket leak.

 

[itstheDRE4M]

Upon further investigation I've found that the Exhaust Manifold doesnt' seem to match up to the block. Both the block and the gasket have an extra bolt hole, but the exhaust just doesn't match up.

This is a hand-me-down basically, I've been driving the truck for 30,000mi and there is no record of having any exhaust work "to my knowledge".

 

[Keef]

That's quite the problem you have there.

Obviously it has the wrong exhaust manifold. I'm not even sure how you can do that and be that far off, but obviously somebody managed it. How you have driven this thing for 30k miles and not noticed the noise from one cylinder exhausting straight into the engine bay?

That explains the backfire!

 

[itstheDRE4M]

That's quite the problem you have there.

Obviously it has the wrong exhaust manifold. I'm not even sure how you can do that and be that far off, but obviously somebody managed it. How you have driven this thing for 30k miles and not noticed the noise from one cylinder exhausting straight into the engine bay?

That explains the backfire!

It hasn't always been acting this way until say.. November of last year. like 10-15k mi ago.

 

[Keef]

Then maybe it's not bolted on at all. Maybe the bolts broke or fell out and the manifold has shifted position. Is that the only exhaust port that isn't lined up?

 

[BrutherSuperior]

It hasn't always been acting this way until say.. November of last year. like 10-15k mi ago.

Remove the spark plugs on that bank and take a look at the tips. You should be able to find info on the 'net to see if you're having a problem. Exhaust manifold gaskets usually do not just go bad and its probably a symptom of something else gone awry.

A lean condition or a heat extractor bold backing out are 2 things that spring to mind that can cause an exhaust leak.

At 200k miles, you may also have a plugged up catalytic converter or one that fell apart and is now clogging the exhaust system. Lots of possibilities...but start with taking a look at a few plugs.

 

[Keef]

Sorry, I'm a dummy.

I was looking at that picture all wrong so ignore what I said about the exhaust manifold not fitting. I thought that sounded ridiclous...

Now I can see that the empty bolt hole is nothing to worry about. At each port the manifold probably only has two bolts, one on the top left and the other on the bottom right. Because that engine may have seen use in other cars the manufacturer probably just put the same holes in them all even though their manifolds may have been different.

That leads me back to the manifold gasket idea. Listen to Bruther.

 

[itstheDRE4M]

Yeah the VG33E is used in 7 other cars.. it does use two bolts for each port, but still doesn't seem to be right. Surely the gasket wouldn't extend as well.

I'll rip out the plugs tomorrow.. I've got one between the firewall that's a real **** to get to.

Appreciate the help guys.