The only thing I can think of is the gasket caught an edge and crumpled back when the manifold was going back in. The Amazon smoke tester works great!

It's all put back together now. Did the entire thing w/ cleanup and then salvage of the jacked gasket in 3 hours flat. Smoke tested after torquing the manifold bolts without the TB housing installed. No leaks. Then put the TB housing back on and the hoses and smoke tested again. No leaks. Then finished putting it all back together and smoked it again - no leaks! I've got a new set of lower gaskets coming from a local shop that'll be here Monday as insurance. I don't want to pull it apart again and if it's holding and happy then won't and will just hold onto them for future CYA.

Smoke does come from the top of the EGR (as noted before in a way earlier post) and it only happened after pressure built up in the system from the smoke. I spoke with an LR master tech on another group and he said that always happens with a smoke test and it's designed to do that so not to worry. Dunno if that is accurate but it's a thing.

I finally fired it up and the rough idle is GONE. Idles smooth as silk. It help's there's not a giant self made air leak or original worn gaskets with 238,000+ miles on them.

So I took off for a short lap around the block and it ran well. No rough idle. Ran an IID log (below). Parked and had dinner. Reset adaptations which I though I did but maybe didn't.

After dinner I reset adaptations again just to be sure then took it to get gas and back. No rough idle, smooth acceleration - way smoother than before this entire odyssey started. No engine light.

Now for some logs:

• Ran a log with the jacked up gasket in there. The numbers are WACK. LTFT in the 25% range and rough idle all over the place. This one is titled Crack is Wack.
• Then there's the log from my short drive around the block right after salvaging the lower gasket. It's called Fixed Lower Gasket.
• The following two logs are the drive to the gas station then home titled First Drive After Fix and Second Drive After Fix.

It's too soon to tell if it worked but its better than it was and I'll update everyone after romping on it all weekend.

 

OMG! That gasket was mangled. Honestly, I know this is ****ty, but I’d recommend replacing that gasket. That metal is brittle and because it’s been folded over on itself, tightened down and has heated up and cooled. It’s only a matter of time before it develops another leak.

Here’s a big but, you had lean codes before you messed with the intake manifold. Has the original leak been fixed? After looking at your LTFT’s. I’d say you’re in the clear.

 

I think the original leaks are fixed. Looking back at the thread and my pics from the first smoke test make me think it was the worn out upper gaskets, all 8 of them. I’ve learned a LOT.

There are no longer smoke leaks in those palaces, or anywhere.

I agree, putting it back the way it is with the mangled gasket isn’t ideal. At all.

I used a vice to flatten and make it flush after gently unfolding it. Then cleaned the crap outta both sides of the gasket and the mating surface on the intake manifold. I placed a very small bead of gasket sealant on both sides of the crinkled part of the metal gasket that’s wasn’t totally flat and reinstalled. These were genuine gaskets too.

I’m going to run it this weekend and see what happens. Then maybe next week install the new gaskets. Or not. I dunno. If it’s happy, I don’t want to break something else either trying to finalize it.

Gotta weigh out the pros and cons.

 

Add me to the EGR club!

 

So maybe they are supposed to do this?

 

Hmmmm.....I think they do, but I don't think they should...

I've been digging into my EGR pretty deep. I have some thoughts I'm trying to test. I'll try to update in the next couple of days.

 

I’ve put around 140 miles on the truck since it all went back together. A mix of city/highway and the idle is smooth, the engine light is still off and the LTFT are within limits, about 3.5% with the highest I’ve seen of 6% which was instant and hasn’t come back.

I’m hopeful it’s there but don’t want to say it aloud. 🤣

 

So all in all you think its the upper manifold intake gasket??

 

Smoking a 165k mile EGR vs a brand new EGR:

 

Plunger play in the EGR is a direct source of unmetered intake air.