Exhaust Manifold - Rotted Heat Shield

psa55

Original poster
Member
Oct 29, 2014
116
New Brunwick, Canada
Swapped out my Power Steering Fluid tonight... found pieces of my exhaust manifold heat shield laying on the the manifold, and pieces elsewhere all broken apart. Should I be worried about it, replace the manifold, or am I safe to drive without the heatshield?

This is the third one... two OEM's barely lasted at all and were replaced under warranty... this one I had a shop put on and is a Dorman that has been on for 6+ years and 100K kms or so. I can see all the bolts now, just not sure I dare try turning them myself.
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
Personally, I would just rip it out and be done with it. Those bolts will probably break in the manifold. Maybe put some heat barrier tape like this to on anything close by that might need some protection.

 
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psa55

Original poster
Member
Oct 29, 2014
116
New Brunwick, Canada
Thank you! Exactly what I need to know! Gonna take the heatshield out and drive'r. Will look into the tape.
 
Dec 5, 2011
574
Central Pennsylvania
One observation from someone who ran for years without a heatshield... if you add transmission fluid after driving the vehicle - a very normal thing to do - the tube will be hot enough to make the fluid sizzle as it goes down the tube. Either wait for the tube to cool.... or don't worry about it. I'm also pretty sure removing the heatshield shortened the lifespan of my transmission cooler lines, but can't be sure... they weren't in the greatest shape to begin with and I didn't do anything to protect them.
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
That tape could be useful on the tube. For the tranny lines, I'd be afraid it would retain water and rust them further.
 

psa55

Original poster
Member
Oct 29, 2014
116
New Brunwick, Canada
Installed 4 new Moog Ball Joints yesterday and started poking around in the engine bay. With the heatsheild gone, its easy to get a good look at the manifold. I've noticed the exhaust being louder, especially on a cold start, but once it heats up and expands it is pretty good. It reminds me of the sounds before the first two exhaust manifolds split... I remember when they were replaced, how quiet the truck is. What I can clearly see now, is that a couple of the bolts have backed out of the block some and rusted in place on the manifold.

@Mooseman and a few others might remember that I still have slight miss on Cylinder #4 and #6 that I've have for around 50K kms and 2+ years, but has not gotten worse, but can be felt at idle and startup. Start up, on cold nights is quite rough for 15 seconds, but it all evens out. I'm wondering if a small gaps in the manifold mounting is allowing unmetered air issues on startup. Once it heats up, all seems good, unless idling in a drive thru for a long time (which I now avoid).

I've had good luck with this Dorman compared to the OEM manifold. RA has them for $130 CDN and I am thinking of just replacing it. My buddy that I borrowed his Ball Joint press kit works for an exhaust shop and says he'll do it for me in his garage.

Any other recommendations for Manifolds? Gonna pick up a Camshaft Position Sensor while I'm at it... They are just so damn cheap at RA and mine original.
 
Dec 5, 2011
574
Central Pennsylvania
Give this thread a read.... my experiences. There's some good info and good advice (from others).
https://gmtnation.com/forums/threads/exhaust-manifold-replacment-input-requested.21156/

As for what to do while you're there... Upstream O2 sensor, CPAS, ex man gasket (should come with manifold). You may be tempted to not install the new heatshield.... DO. Also, check your tranny dipstick grommet/seal... You're gonna jockey around the tranny dipstick tube which may finish off the grommet/seal. I had a real adventure with mine.
 
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psa55

Original poster
Member
Oct 29, 2014
116
New Brunwick, Canada
Thanks @TequilaWarrior

I'll give that thread a good going over! Appreciate the advice.

Did the CPAS last year, after the TB got laid up for a week waiting for a new CKP sensor. CPS is the next in line as I slowly knock the sensors out.
 

psa55

Original poster
Member
Oct 29, 2014
116
New Brunwick, Canada
Thanks everyone who commented and helped out! @TequilaWarrior that video and thread was fantastic.. Thank you! Manifold, etc. arrived yesterday afternoon... I was really hesitant to give this a try and talked to a couple buddies of mine to see if they had some time coming up. My biggest fear was trying to deal with broken bolts, which I have no experience with.

Two coffee's into the morning and I figured hell, lets see what happens.... I'll just spray some penetrating oil on the bolts... At lunchtime, I was pulling out the manifold!

My old girl is all back together and purring like a kitten. It hasn't been that quiet in what seems like for forever. Four ball joints (lifetime warranty replacements), new power steering fluid, tensioner pulley and now the manifold. Pretty solid past 10 days. New tires arrive tomorrow.
 

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