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Leaking exhaust manifold?

BainMan

BainMan

Full Member
Joined
Mar 22, 2019
Messages
1,216
Does this look like a leaking exhaust manifold to you?

Gzd0KeN.jpg


I've got a slight tick, sometimes, from drivers side when engine is hot.. I'm guessing it's AFM related but noticed the drivers manifold has dark spots above the ports whereas the passenger side looks very clean with no signs of leak.. Please make my week and honestly tell me the hot ticking could be from the (what appears to be) small exhaust manifold leak shown in the picture..
 
check each bolt as one could be broken causing the leak.

Exahust leaks look whitish

the oil on manifold is from valve cover leaking.
 
Thanks, valve cover makes more sense with the color.. On the broken exhaust manifold bolts, would the head of the bolt be completely missing?
 
yes head of bolt could be missing... or it is cracked and about to break.

known issue
 
I'll look more closely at the manifold bolts, thanks for the info. But unfortunately I'm pretty sure mine is either oiling and/or lifter issue. I asked this question because I wanted to eliminate easy things first just in case. Hot idle is 20psi, hot under load is 40psi. I'm going to try Seafoam or MMO followed by an oil change to see if that makes a difference, but I'll likely end up replacing the oil pickup tube and since I'm that far anyway probably the oil pump too. The tick (only when engine is hot, and only sometimes) goes away as soon as RPM's go up a above idle (when oil pressure goes up)

Edit: or is 20-40psi hot normal?
 
With oil pressure that low, you might have the common oil pick up tube o-ring problem.

Adding stuff to the oil will most likely not change anything.

Been there, done that.

I finally changed out the entire oil pump, oil pick up tube and o-ring.

I now have full strength oil pressure across all temps and RPM ranges and a quiet and smooth running engine again.

(y)

Hint: Put your truck's information in your forum signature so everyone has an idea on how to respond to your questions.

Different truck models and engines behave differently and have their own set of issues.
 
BainMan said:
Edit: or is 20-40psi hot normal?
Click to expand...

Mine was like that before my oil pump replacement.

Now, I have 45 at cold oil idle.

40 at hot oil idle.

55+ at hot oil cruise RPM.

65+ and hot oil WOT.
 
EXT4ME said:
Mine was like that before my oil pump replacement.

Now, I have 45 at cold oil idle.

40 at hot oil idle.

55+ at hot oil cruise RPM.

65+ and hot oil WOT.
Click to expand...

Nice! Did you go with a high volume pump or original equipment to get those numbers? Signature info added, thanks.
 
I went with the high volume Mellling M295HV-324S oil pump kit with included oil pick up tube and o-ring.

Now seeing you have a 2010, the pressure readings I listed may not apply to your AFM engine.

Perhaps someone with one of those engines can post their pressures.

The pressures I listed are for my 2004 LQ9 6.0 engine.
 
Seeing 20-40 psi is absolutely normal. GM made a change to their V8 engines starting in 2010 which causes it to be lower than previous years. Something related to the variable valve timing if I recall correctly. 07-09 (and previous gen) you'll usually see 40-60 psi.
 
ca2kjet said:
Seeing 20-40 psi is absolutely normal. GM made a change to their V8 engines starting in 2010 which causes it to be lower than previous years. Something related to the variable valve timing if I recall correctly. 07-09 (and previous gen) you'll usually see 40-60 psi.
Click to expand...
Interesting! It just feels wrong to see the idle gauge at 20... I'll focus on other areas for now.
 
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