Well I think a lifter left the chat

[Chris2144]

2007 Yukon Denali awd 6.2
Well boys I thought I had the Yukon done maintenance wise then out of the blue cold morning start I get a nasty tap. Engine on on with a cylinder 4 misfire and feels like a dead miss.
Now I’m not at home to see it in person but to me this is sounding like a bad lifter.

Cold start first thing in the morning load tapping misfire and check engine light.
Give it a few mins misfire goes away and tapping get quieter.

At this point I’m pretty sure I’ve had a lifter give up but I know I could also have a trunion bearing going out but this doesn’t really sound like that

What does everyone think. I’m going to order a set of lifters trays head gaskets head bolts.

Anyone have any suggestions on parts I was looking on Michigan Motorsport and looking at ls7 lifters and and ls9 head gaskets.

 

[buckwild27]

Well boys I thought I had the Yukon done maintenance wise then out of the blue cold morning start I get a nasty tap. Engine on on with a cylinder 4 misfire and feels like a dead miss.
Now I’m not at home to see it in person but to me this is sounding like a bad lifter.

Cold start first thing in the morning load tapping misfire and check engine light.
Give it a few mins misfire goes away and tapping get quieter.

At this point I’m pretty sure I’ve had a lifter give up but I know I could also have a trunion bearing going out but this doesn’t really sound like that

What does everyone think. I’m going to order a set of lifters trays head gaskets head bolts.

Anyone have any suggestions on parts I was looking on Michigan Motorsport and looking at ls7 lifters and and ls9 head gaskets.

If you have the L83 I have a set of rebuilt heads. Shipping from Ohio to wherever you are might be costly but I have them if you want need them.

 

[Chris2144]

Oh I didn’t put the specific info in my bad no it’s not l83

It’s the 6.2
Thank you though

 

[Joseph Garcia]

Oh I didn’t put the specific info in my bad no it’s not l83

It’s the 6.2
Thank you though

Is the motor the L92?

 

[Chris2144]

Yes l92

 

[buckwild27]

Oh I didn’t put the specific info in my bad no it’s not l83

It’s the 6.2
Thank you though

For a small fee I can fix you up there too no stupid lifter issues with this beast.

 

[Chris2144]

lol yea I don’t think the wife needs that much horsepower.

I was on btr and they have a whole kit. Right about 500.
Ls7 lifters, lifter trays, head gaskets, and head bolts.
I think I’m gonna go ahead and order that.
I’ll try and get a video uploaded of the noise later this evening my signal suck where I’m at right now.

I figure after fluids and whatnot I’ll have about 700 in it.

I’m way to far in it to turn it loose now and it seems to run pretty good and gets 19mpg so I guess I’ll just keep fixing it.

Anyone have any experience with btr ls7 lifters I have heard they are good quality

 

[West 1]

I have used Melling, Top Line and Sealed Power lifters with no failures but I heard Sealed Power has moved its product to a Chinese made lifter. Top Line makes USA roller lifters but finding them can be tough. They usually sell in other brands boxes.
It was 3 years ago that I bought Melling lifters and they were Top Line at that time.

 

[rdezs]

Just make sure the lifters are the real thing. Gold clips in the end are genuine Delphi LS7 lifters. Michigan Motorsports sells them, even shows you an image so you know what you're getting with the gold clips. Not exactly sure what BTR is selling, haven't personally seen their lifters yet.

Don't forget exhaust manifold gaskets and the manifold to the pipe. One side is the donut and the other side is the flat metal one. Great time to do the oil pressure sending unit with an AC Delco genuine GM. Also an excellent time to have the heads gone through and checked, and properly surfaced for the reinstall.

 

[buckwild27]

lol yea I don’t think the wife needs that much horsepower.

I was on btr and they have a whole kit. Right about 500.
Ls7 lifters, lifter trays, head gaskets, and head bolts.
I think I’m gonna go ahead and order that.
I’ll try and get a video uploaded of the noise later this evening my signal suck where I’m at right now.

I figure after fluids and whatnot I’ll have about 700 in it.

I’m way to far in it to turn it loose now and it seems to run pretty good and gets 19mpg so I guess I’ll just keep fixing it.

Anyone have any experience with btr ls7 lifters I have heard they are good quality

You don't think she would enjoy 800hp?

 

[tom3]

I wonder if it could be a sticking valve? Give it the SeaFoam treatment and a couple full throttle tuneups when it gets up to full temperature for a while.

 

[Chris2144]

You don't think she would enjoy 800hp?

Now I never said she wouldn’t enjoy it I’m sure she would, but does she need it no. Lol

The goal with this is to be reliable for her. Honestly didn’t think I would be doing lifters on it so soon

 

[buckwild27]

Now I never said she wouldn’t enjoy it I’m sure she would, but does she need it no. Lol

The goal with this is to be reliable for her. Honestly didn’t think I would be doing lifters on it so soon

I feel ya. I came home for the night from being gone since December. 25 miles from home the torque converter finally gave it up in my daily driver work truck. 307,635ish miles on the original transmission. Now I'm driving the dirty max. At $4.99 a gallon for fuel.

 

[Chris2144]

Here is a cold start video what does it sound like.
Sounds like a cranky lifter to me

 

[rdezs]

Check closely for an exhaust leak between the manifold and the head. Make sure all your exhaust manifold bolts are there. Pretty common issue, and every one I've heard does in fact sound mechanical in nature... Just like a collapsed lifter.
On the last one I fixed, you could carefully slide your hand behind the manifold and feel the hot air blowing between the flange and the cylinder head. And that one had all the bolts intact.

 

[Chris2144]

Check closely for an exhaust leak between the manifold and the head. Make sure all your exhaust manifold bolts are there. Pretty common issue, and every one I've heard does in fact sound mechanical in nature... Just like a collapsed lifter.
On the last one I fixed, you could carefully slide your hand behind the manifold and feel the hot air blowing between the flange and the cylinder head. And that one had all the bolts intact.

Yea I have already done this. The driver side was the culprit it had a broken bolt.

I put a new manifold and gasket on and put the bracket on and that stopped the leak.

The sound it’s making in that video is much worse. I wish it was the gasket but unfortunately no

 

[mikez71]

Sounds like rod knock to me..

I haven't had either issue, but I expected lifters to sound more clacky.

But that probably doesn't explain the misfire?

Stethoscope it yet?

 

[Chris2144]

No im not home. But based on what I know im thinking real good chance its lifters.

Cold start tapping noise once engine warms up noise subsides to a faint lifter tick.

Code for cylinder 4 misfire.

Engine does have noticeable miss until warmed up then goes back to normal.

Oil pressure is 17psi hot idle and 38-42psi on the highway.

 

[mikez71]

Good! I was probably hearing the exhaust noise, amplified thru my phone speaker..

Why does lifter noise reduce when engine warms up? And why no miss when warm? Collapsed lifter pumps up better warm?

 

[Charlie207]

SMC Performance sells lifters for a good price. I've been running them in my 6.0 for over a year and a half, and 20k miles, with no kaboooms.