I got me a Tahoe!

[Nutro]

I did it! I got her home. My first Tahoe, a PPV. She's a 2014 with 150K on it. Ice cold AC BUUUT it has a Cyl #4 misfire. I swapped coils, new spark plug and wire on that cyl and no change.
When it was idling today, I can smell raw fuel and it had a little white smoke, but smelled no coolant or oil. I looked and noticed the air filter was FILTHY and the MAF wire inside was black. I pulled it and cleaned it, put a new air filter in. Still smells a little like raw fuel but not really smoking now. I'm wondering if the MAF sensor is bad. I'm guessing the #4 lifter is bad and thats why the code is there. I'm debating just putting in an LH9 6.2L non AFM and having it tuned instead of doing the AFM delete etc.

This thing was stationed in West Texas its whole life so it was disgusting dirty. I got the rear cop box removed, started cleaning everything real well.

 

[petethepug]

Nice 14. Welcome from SoCal. The 07-13 L86 6.0L from the 2500 / 3500 gassers are a bolt for bolt drop in. Iron block, aluminum heads. It’s a tough engine. No AFM and 10+ versions run e85 too.

The all aluminum 6.0L from the 08-13 hybrid is also a drop in but it has AFM. 08-09 (LFA) 10-13 (LZ1 run e85). The hybrid Tahoe, Yukon & Escalade can often be found in scrap yards due to electrical issues. They have nice interiors (hint hint)

 

[Miami-Dade]

Welcome from Miami&NYC!
Nice PPV Tahoe!

 

[OR VietVet]

Time for a proper compression test.

 

[j91z28d1]

pull the valve cover and see if the rockers move on #4. if not, I'd personally try to release the afm lifter just out of curiosity since I'm guessing this isn't you're daily right now.

 

[B-train]

I agree with @j91z28d1 A quick inspection will tell you what you are dealing with. If the lifter seems stuck, you could do the seafoam, MMO, or ATF addition to the oil and see if it helps unstick it. This is assuming it's gunked up from dirty oil. If it's a mechanical failure, you only option is repair or replace

 

[Fless]

Welcome from Colorful Colorado!

Test that MAF with a good scanner. At hot idle the MAF reading in g/sec should be very close to the engine displacement in liters.

 

[BlackBearPerf]

Welcome from Idaho! Congrats on the Tahoe!

 

[Bigburb3500]

Do the swap! 6.0 aluminum with a 6L90. Then supercharge it. Make it into what the police always wish they had.

I’ll be here for that build

 

[Nutro]

Changed the oil filter and added a quart of Marvel Mystery Oil, started it and let it idle for a few minutes with no change. The exhaust has a smell to it, that I can't describe. Like a concentrated combustion smell. I can hear a faint odd noise coming from that valve cover. I'm HOPING its a broken valve spring but I'm sure its a lifter. I will pull the pass valve cover next and run it and watch the rocker arm for movement and inspect the valve spring.

I did replace the interior lights with LED and put a new battery in it so now it starts without a jump box. Woohoo!

 

[Fubar0715]

I love the LED light upgrades in my SSV - getting older and poor lightening makes this a worthwhile update.

 

[j91z28d1]

a valve spring is definitely worth checking for.

you can also try mechanically release the stuck lifter. it seems to work if it hasn't been driving long enough with a stuck lifter that it damaged the cam or the lifter holders

 

[OR VietVet]

So.....no compression test?

 

[Nutro]

So, I was going to ask. Should I check compression first you think or pull valve cover and check/watch valve spring/rocker? Not being a smart alec, genuinely asking.

 

[OR VietVet]

When you are cranking the engine over for a compression, you will get a little oil squirting if valve cover is off but if the valve cover is off, you may be able to see right away what is wrong. It's a choice because if you have low compression, you are gonna pull the valve cover asap anyway.

 

[Grady_Wilson]

I would start with a compression test and go from there.
If you have low to none on that cylinder then you'll be pulling the valve cover to check the valve train, anyway.

 

[Nutro]

Ok so dumb question. I'm going to attempt the compression test today and remove valve cover. Question: When I do the compression test, do I disconnect both sides of the coil packs and just crank it up. Same question applies to removing valve cover to watch rocker arm. Do I disconnect both coil packs and just crank or can I disconnect the pass side only?

 

[OR VietVet]

Leave the valve cover on when doing the compression test. Remove the fuel pump relay at the relay box. You do not want it to start while doing the test. Just remove the plug wire and remove plug. You said cylinder #4 is the problem hole. Remove #2 and #6 plugs too. If you do not know the cranking process for the testing, look at, at least 3-4 you tube videos for help. The first one you see may be wrong. Note the reading and then do the cylinders on each side for comparison sake. If the reading is low er than the other two cylinders, then you can dig deeper and remove valve cover and watch while doing the test again. If you can take a video or pics and post here, so much the better. IIRC a good compression reading is about 170 psi. If you get close to that, great, but you want the other two to read close to the good reading, too. If you have never done a compression test, make sure you also know what line to thread in the hole for the test.

 

[Nutro]

Thank you! I'll watch a few videos. The last time I did a compression test was on an old SBC like 20 years ago and I just don't remember much about it

 

[Nutro]

I've already hit my first head scratcher. How am I missing the fuel pump relay but the vehicle fires up fine?