2005 LM7 and Sea Foam

[Marky Dissod]

So, the TSB doesn't address a 2005 or an LM7.

https://static.nhtsa.gov/odi/tsbs/2014/MC-10114272-9999.pdf

And the updates apparently are in their 3rd revision.
So, if anyone here has the latest information, I'm all eyes.
The search continues ...
And another thread started too.

@donjetman's answer would be to upgrade to the Gen4 valvecovers, I think?

 

[Alberta Tahoe]

@donjetman's answer would be to upgrade to the Gen4 valvecovers, I think?

I read his reply although i didn't appear to me to clearly identify what needs doing. The TSB didn't list a 2005 LM7. That's nothing on donjetman though. In all fairness, I didn't dissect it as I will going forward but that's mostly because I've kind of zeroed in on that the PVC system is gunked up in it's entirety (the symptoms of oil consumption and leaks fit the cause to a tee) and the simplest route will be to restore the original equipment to as new and see where that takes me. I don't expect that to last but I'm sure that there will be some easily observable results.
Or as I like to say, "cause and effect".

 

[Marky Dissod]

Bet his answers are so brief because the details are covered elsewhere.
By 2005 GM was likely equipping their engines with the updated valvecovers already,
and it'd never occur to GM to suggest updating Gen3 V8s with Gen4 valvecovers even though this is very doable (as is using 2010 front brakes on a 2002).

 

[Alberta Tahoe]

You want to remove carbon off your piston crowns in a hurry? Just pop the intake off and spray mist cold water into it with engine running around 1000-1200 RPM. Use about a 1/2 quart of water. Clear all codes when done.

DO NOT POUR LIQUID WATER INTO INTAKE STREAM.

An old school trick that we employed decades back. Seems too that water injection, again back in the day, was an effective means of keeping combustion chambers and piston tops clean.
That said, I'll take the carbon buildup. Maybe it'll add a bit to the compression ratio and give a little bump in torque!

 

[Alberta Tahoe]

Bet his answers are so brief because the details are covered elsewhere.
By 2005 GM was likely equipping their engines with the updated valvecovers already,
and it'd never occur to GM to suggest updating Gen3 V8s with Gen4 valvecovers even though this is very doable (as is using 2010 front brakes on a 2002).

The devil is in the details and there's a knock on effect with the Gen IV valve covers. Not having digested all of that information (from here and elsewhere) there are other component changes that need to be addressed. The boss cast into the cover I believe is different between years as is the method as to how the orifice is arranged. IIRC, Gen III has a fixed orifice cast directly into the valve cover and the Gen IV is a separate component pressed into the cover. Hoses would logically follow any change there. I could all turned around on that but it matters little at the moment.
Seems to me that's been covered (all of the extra bits and pieces) but as I said, once I saw a way forward without any expense other than elbow grease, some solvent and new valve cover gaskets, I can forgo the TSB update, restore the original valve covers and see where I end up. My bet is that the oil cloud on start up and the leaks will stop. Science says it won't last as it's failed before but if there's an improvement, then on to stage 2 and updated covers.

 

[Fless]

Here's what GM shows for the '05 LM7. The DS cover is an updated version, with the rectangular PCV (not PVC) opening. The 2008 on up valve covers are a different part number.

 

[Alberta Tahoe]

Here's what GM shows for the '05 LM7. The DS cover is an updated version, with the rectangular PCV (not PVC) opening. The 2008 on up valve covers are a different part number.

View attachment 480093
View attachment 480094

GREAT info! And thanks. Pricing is far better than what I had seen with an initial, but admittedly light, look through too.
What vendor is that?

 

[Fless]

GREAT info! And thanks. Pricing is far better than what I had seen with an initial, but admittedly light, look through too.
What vendor is that?

Not one any of us would recommend. (GMPartsGiant - we typically use it only to look up part numbers.)

If you provide @915_Tahoe with the last 8#s of your VIN (can be done here or in a "conversation") he can look up part numbers. But I can't imagine they would be any different from the online vendors that appear to be dealers.

 

[Alberta Tahoe]

A part number is all I need. I can figure out a source. I've the same sort of search M.O. (find it one place and buy it from another) and can take what you've provided and run with it.
Thanks again.