Driving the kids to school about a week ago, oil pressure dropped, dash said stop engine. About a minute later I pulled into a gas station, and because of the known oil burning issue in these vehicles I purchased 2 quarts, popped them in, no more problems. Assumed that oil was low, popped in 2 more quarts when I got home. Didnt think to much more about it other than I was going to change the oil and filter the next paycheck. About 2 days later, I started getting a LOUD knocking noise from the engine. Decided to change the oil right away. Pull the dip stick, and it was overfull. Drained almost 8 quarts out. Replaced oil, still have the knocking. Took it on the highway when I parked the loud knocking is still there, just not as loud. The old oil did not have any metal in it at all. What are your thoughts on this? I ordered an engine rebuilt kit on ebay for $360. Am I going to have to replace crank shaft? Any chance its just a REALLY bad lifter? Should I replace the lifters and push rods?
2007 Envoy Denali Engine Knocking
- Thread starter tomw1314
- Start date
RedRocketZ28
Member
- May 16, 2014
- 114
Is the knocking from the bottom end or is it a top end noise? If you have the old oil filter still I would cut it open and see what's inside. Really surprised there wasn't any glitter in the oil if it's knocking though.
If you spun a rod bearing (would explain your knocking) then I bet it got into the crank and it will need replaced. If you're diving that deep into the engine then I would do the DOD delete and replace the lifters.
If you spun a rod bearing (would explain your knocking) then I bet it got into the crank and it will need replaced. If you're diving that deep into the engine then I would do the DOD delete and replace the lifters.
Sparky
Member
- Dec 4, 2011
- 12,927
What he said. Where the noise is coming from will determine what kind of repair you need.
Generally, a higher pitched 'tack tack tack tack' is upper end stuff, while a deeper, lower "thud thud thud thud" is bottom end.
Could also pull the belts off and start the engine, just to see if the noise is coming from an accessory somehow. Don't run it long that way as the water pump, alternator, etc won't be operational, but it will tell you quickly if this is the case or not.
Generally, a higher pitched 'tack tack tack tack' is upper end stuff, while a deeper, lower "thud thud thud thud" is bottom end.
Could also pull the belts off and start the engine, just to see if the noise is coming from an accessory somehow. Don't run it long that way as the water pump, alternator, etc won't be operational, but it will tell you quickly if this is the case or not.
northcreek
Member
My money is on a spun bearing, it would explain a lot of what you have experienced.
It's funny but, when this happens I have seen the oil look like a pan on Gold Rush, other times I didn't see the particles until I pulled the pan.
Unfortunately you can never really do a complete assessment outside of the engine.
The proper AFM delete by RR is a great suggestion.
You don't state the mileage but, had you not already bought the kit, a junkyard or crate motor might have been more in your favor.
It's funny but, when this happens I have seen the oil look like a pan on Gold Rush, other times I didn't see the particles until I pulled the pan.
Unfortunately you can never really do a complete assessment outside of the engine.
The proper AFM delete by RR is a great suggestion.
You don't state the mileage but, had you not already bought the kit, a junkyard or crate motor might have been more in your favor.
thanks for the advice. From the looks of things I can do the rebuild myself for less than $1000. Junk Yards and Crate motors seem to all be well more than $2000. From the looks of things the hard part is taking the motor out, after that it appears to be a normal engine rebuild. It has around 176,000 on it. I thought about just junking it, but everything else is perfect on it, new tires, new brakes, just replaced the rear air bags. That and I am in the middle of selling my house and buying another, and adding a car payment cant happen right now. Ill try to get a sound clip and post it.
Mooseman
Moderator
That there be the knock of death unfortunately. When you pointed the mic towards the bottom of the engine, was definitely louder. Expect rod and crank damage. Break open the oil filter and you're likely to find bearing material in there.
maybe Ill get lucky and win the lottery tomorrow... If not, I still have to drive it 20 mins to the garage. ugh.
Tom... Have a look at this multi-part series on "How to R&R the 5.3L Engine..." to get the look and feel of his Swap Motor while it is on the Engine Stand and what is entailed in the job. More than likely...whatever is "Accessory Specific" to your present Denali set up can be adjusted.
The only real issue would be where you can locate a decent "running" engine that is available out of a recently wrecked vehicle.... without major engine area damage that could compromise the motor. And of course.. The PCM and what would have to be re-programmed to satisfy your circumstances and on board equipment. These videos will be very encouraging to watch if you plan on doing this swap yourself, as more than likely the Engine Hardware will be very similar in appearance and location to what is in your SUV:
http://gmtnation.com/forums/threads/complete-r-r-videos-of-chevrolet-1500-4x4-5-3l-engine.16137/
The only real issue would be where you can locate a decent "running" engine that is available out of a recently wrecked vehicle.... without major engine area damage that could compromise the motor. And of course.. The PCM and what would have to be re-programmed to satisfy your circumstances and on board equipment. These videos will be very encouraging to watch if you plan on doing this swap yourself, as more than likely the Engine Hardware will be very similar in appearance and location to what is in your SUV:
http://gmtnation.com/forums/threads/complete-r-r-videos-of-chevrolet-1500-4x4-5-3l-engine.16137/
Mooseman
Moderator
If you get a same era iron block 5.3L (LY5) from a pickup or full size SUV, it would be a direct swap.
https://en.wikipedia.org/wiki/LS_ba...gine#Generation_IV_.282005.E2.80.93present.29
And the difference between iron and aluminum blocks is supposedly just 85 lbs.
https://en.wikipedia.org/wiki/LS_ba...gine#Generation_IV_.282005.E2.80.93present.29
And the difference between iron and aluminum blocks is supposedly just 85 lbs.
Well... I had a few people listen to it..pulled one of the valve covers off and ran it... the sound appears to be coming from one of the lifters banging on the cam... decided to do a motor flush. I'm gonna drive it for a week and see where it goes...
Mooseman
Moderator
I sure hope so but if it's a bad lifter and it's banging on the cam, you're looking at a pretty involved job. Been there.
It does look like the Bottom End has Bad Bearing and is the Bad Guy here..... But....As a Last Ditch Effort to eliminate Lifter Noise from the drama... you might view this video from "Briansmobile1" on "How to Flush the Lifters on 5.3L Chevrolet". His Dual Whammy of using a Good Motor Flush and the direct assault upon the clogged lifters with targeted sprays of Berryman's Solvent did the trick for what sounded at first like an absolute disaster and his approach saved the day.... I mean... What The Hell... What have you got to lose...Right?