pulling the exhaust manifolds out a 1/4inch

[duramax-rob]

hey everyone, been quite a while since on here. still got truck which has been fine till now. love the truck and gonna keep it. its a 2001 lb7 with 150,000 miles only mods were 4" exhaust and PPE programmer run on lowest tune sometimes. otherwise stock truck.

the injectors were replaced about 35,000 miles ago with factory remanufactured bosch from dealer. now it has started a slight miss at just off idle (just move the foot feed throttle) just enough to like moving the throttle off the stop, and no rpm increase, and engine starts running and idling ruffer. the fuel milage has also dropped. it also begins to smokes when started below 40 degrees and really rough idle and gets worse the colder it gets. no smoke after warms up or during summer, just the rough idle and low fuel milage.

what I'm asking is how hard is it to loosen each manifold and move or gently pry away from the head to see which cylinder or cylinders are smoking when cold? i think i have a cracked injector body or bad injector. anyone have an idea how to do this the easiest way either one side at a time or both if easier. I'm hoping this would save some money on only replacing the one bad injector since all have low milage.

if done in summer, i would have to ice the engine compartment down with bags if iced down overnight to see smoke coming from bad cylinder.

any help would be appreciated! thanks rob

 

[DAVe3283]

Mj me

Edit: phone pocket posted lol

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[2004LB7]

What are your balance rates?

Do you have a V2 or access to a tech2?

 

[duramax-rob]

last time i check the balance rates, they were 2.3 +or minus 2. this is what i don't understand. i don't have access to a tech 2 or v2. that was why loosening exhaust manifold might be easiest and cheapest way to find injector. for sure way which one. has anyone ever done it?

 

[Ne-max]

Pulling them out 1/4 inch means you risk it sealing up again. Would need to pull them off. Clean surface and install new gasket. If in doubt pull them all and have them tested. Could have multiple with issues

 

[TheBac]

Why cant you find someone near you with either of those scan tools to help you out? Or bite the bullet and take the truck to a shop and have it properly diagnosed?

Personally, I find the way you want to do this to be sketchy at best. Sorry, but my opinion.

 

[DAVe3283]

Sorry, pocket posted earlier.

As stated, you would want to take the manifolds all the way off so you can put a new gasket on. The passenger manifold isn't bad at all, but the driver's side sucks. It can be done, I installed a LML manifold on my LB7. Just sucks to do.

With the potential for breaking bolts/studs, it might actually be cheaper to pay a shop to diagnose. Or if you really want to go to the effort, I'd strongly consider putting a LML manifold on the driver's side while you're at it.

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