(30 sec video) '99 GMC Yukon Sounds Crazy-Advice Sought

Here's the bullet list to get oriented:

-Truck has 170,000 miles on it
-It's currently at a professional service center here in San Diego (AJ USA) who I have never been ripped off by before and has a good reputation
-Last week I brought it in for a "once over" and had them correct all the normal maintenance issues for a truck of this mileage
-Picked it up in the am when service was done, drove it for work about 50 mi that day, and knocking sound started from inside the engine
-Knocking sound got WAY worse near the end of the day all at once, but had been getting progressively worse, slowly, throughout the day. I parked immediately.
-Had it towed back to the shop
-Shop did put a higher viscosity oil into the engine during the oil change

Here's the 30 sec video of the noise, sorry it's just the link, I hosted it in google docs so it's not embeddable at this point:

https://drive.google.com/file/d/0B5gTGb70wDagVjJsWHFWQ1V1dFU/edit?usp=sharing

Here's the short story:

And before you guys destroy me in the comments for continuing to drive this throughout the day, I have an occupation where stuff has to be done in a time sensitive manner with many people waiting on me so you can't just stop, I had just invested $2,000 into a complete maintenance overhaul and when I picked up the truck that morning from the service center there was barely any sound at all. The service center said it was fine and didn't seem to be bothering anything, so go ahead and drive it and come back if it's worse.

Well yeah, it got worse all right :eek1!!! Luckily it dramatically increased right when I got home and I just parked right away and shut it down.

Which brings me to the actual question:

Any of you inmates know what the hell this sound is and how expensive/what to do about a repair and or how realistic is it to have to replace the entire engine?

AJ USA is telling me it may need an entire engine replacement, but they will open up the head and try to see what's going on inside which could result in a less drastic expense.

My issue is that the truck is worth maybe on a good day $4,000 on the used market. I just invested half of that into getting another year or two of use out of it and now I'm slapped with even more expenses.

My options at this point are:

1) Replace the engine which will be pretty expensive for a low value vehicle and possibly a bad financial decision
2) Somehow figure out how to repair it
3) Bail out now after putting $2K into it and dump the car for $1,000-$2,000 or whatever it shakes out at in current condition and get something else.
4) Leave it in Tijuana somehow (just kidding guys)

Thank you in advance for all your advice.

stoke

Have you checked all of the belts and made sure the noise is coming from the engine block?

I'd be some kinda pissed. What oil DID they put in it? Sounds like failed rod bearing as best I can tell from the audio. Wow. Did they do a transmission service? Maybe drain the torque converter? The cadence seems slow, like ONCE per revolution, so, a single rod bearing, or... the audio has a metallic clang to my old deaf ear, rather than a "rap", but it's hard to say what the recording/playback equipment does to the actual sound. The fact that it got worse as you drove it, is consistent with "oops! I forgot to fill it with oil!!!" and they pooched a bearing, filled it and sent it out.

What the hell kind of routine maintenance costs $2000, that's ridiculous. Please tell what was done to the truck.

I think you're screwed, sounds like a rod knock but IDK. Did it overheat when it started banging?


Before handing it over you should have checked it out yourself. Specifically checked the oil. Maybe they forgot to refill it or overfilled it, but you won't know now.
It is after all a chevy and it likely WOULD run for quite a while with only what remained after draining it.

I would have checked that all the spark plugs are installed. Kind of sounds like one of them is missing.

I truly hope that's what it is or something simple like that. Good luck.

I say cut your losses. Your transmission is next in line to fail because they probably sold you a transmission flush.

$2000 to make it knock?? :huh

Jeez, I'd be pissed.

"It is after all a chevy and it likely WOULD run for quite a while with only what remained after draining it."

Nah, plain bearings don't last long without oil pressure. No matter what shape the logo on the grill is.

Did you lift the hood with it running? use a stethoscope ($5 at Harbor Freight) to look around.

Maybe "they put thicker oil in it" was a clue... meaning : "we accidentally ran it without oil, wrecked the bearings, so we're trying an old shithouse used car salesman trick and hoping it'll run for a little while, then we'll knick you for the repairs"

Jiffy Lube paid for a complete new engine in my company car (leased) after they left the oil plug loose, the next day it spit it off, ran out of oil at 75mph during rush hour on I-495. Walking 2 miles in -5F weather really scorched my ass.

this. some ass cranked your truck up and ran it with out oil and smoked a crank bearing. there is no way of coarse to prove this. was it making any form of a knocking sound when you dropped it off. if not then they fucked your truck up and should pay for a reman motor.

it is possible that the flywheel is cracked, it can make a knock that sounds just like a crank bearing. but my money is on they screwed up, and them telling you to drive it and see if it gets worse means they knew it was damaged and should have never let you drive it. you could get lucky and have new main and connecting rod bearing rolled in a fix it if you haven't egg shaped a connecting rod.

honestly fix it. A rebuilt motor will be good for another 200k, and that's still cheaper then a new car note every month. a reman 350 should run you around 15 to 1700 but if it wasn't making any noise when you dropped it off it's their fault and i would make them pay for it. and DO NOT DRIVE IT ANYMORE.

-Shop did put a higher viscosity oil into the engine during the oil change

This is as close to an admission of guilt an oil shop can say.
They fucked up.
Most shops will refuse to put in anything but factory spec oil due to the liability. For them to tell you they did, something is fishy. (or did you ask them to put in heavy oil?)

I have seen more than one Vortex engine with a loose of oil pressure due to the o-ring on the pick up tube splitting......

Fantastic advice and knowledge guys-I just read everyone's comments once, thought about it and read them again. Thank you. I had good experiences with them before and tend to be too trusting in business relationships once it's gone well.

I had a shitload of work done to the vehicle and it was way overdue for some bigger stuff, I'll post the list as soon as I can get it out of the truck, dammit should of scanned it before I dropped it off again. I'll get it tomorrow and post it up.

The truck did not make this sound at all before I brought it in. The repair place is claiming it did but it was quiet until you had the hood up...and then he made a point to mention he put higher viscosity oil in it. I did not ask for non-spec oil, just asked for work according the maintenance schedule. The sound is coming directly from the engine itself, not any of the belts. Checked that.

Well, I will be stopping by there tomorrow and slipping some of the terminology I just learned from you guys into the conversation with the service guy and watching his face very closely. I will be posting up results!

The gist that I get is that its probable that someone fucked up and now they're trying to juice me for more cash. Dammit man.

Drive it MORE. The sound will stop on its own.

Here is some advice. You say very little and let them talk. An awkward silence can prompt them to say more than they otherwise might.

Keep to your facts. You brought it in, didn't make the noise. They replaced the oil with something other than the recommended viscosity, type, etc. you have grounds to think they are at fault.

:huh

Wow. I had a intake gasket go on my drive to work in -10 degree weather. Made it about 1/2 mile before I got a ride.

Hmmmm... Did the shop put a woodpecker in the engine with the "thick"oil!?

Sounds like a rod bearing... Hammering that hard I would guess the crankshaft is pooched.

My last gas GM I had a little more miles when it spit up a bearing. Rebuilt the engine with some go fast parts, and drive it for another 200,000 miles.

To me, the video sounds more like a sparkplug missing. Did you check that they are all in place?

could be the harmonic balancer, which is cheap

but I doubt it since one of the monkeys forgot to put oil in it... then lied

this doesn't need a new engine, it needs work, yes, but not a replacement

slap bearings in it and drive it another 50000 miles

As dieselpete mentioned, crank journal is ruined. Shop should install a reman engine. On their nickel.