L05 350tbi knock

[Andrew Barker]

I have already made a post on this, but I now have lots of video

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Take a seat this is gonna be a long one. Back in June I bought a 1992 Buick roadmaster wagon that needed it’s 700r4 rebuilt. I was told it has 200,000km on it and the cluster which reads 300,000 was swapped out of a different car. So I’m not really sure the mileage on it. Anyway, the oil was pretty black when I bought it so I changed the oil to 5w30 conventional with a fram filter. Oil pressure was good. 50 pounds on startup idle and about 25 when warm. It had been warm basically every day so I always had the windows down and music playing. One day it was raining maybe a month and a half after I bought it, and I had the windows up. I noticed that about 1500 to 1550 there was a knocking sound. Louder when the car was cold and more quiet as the car warmed up. Sometimes completely gone, sometimes barely there. NOTE THAT IT ONLY HAPPENS IN DRIVE, NOT IN PARK IF I REV IT. I am also ABLE to put my foot on the brake and gas and get it to make the noise while not moving. If I hold it there for a couple seconds the noise seems to slowly fade away and the be gone for the rest of the drive SOMETIMES. And if you get up to around 1600rpm the noise went away. I thought that it was probably timing related because my four cylinder mustang sounded the same until I reset the timing, so I just drove like that for another couple months because the hold down bolt wouldn’t move. Maybe two weeks ago I checked the timing and saw it was set to 0 degrees. That’s when I became a little concerned. I was able to get the hold down loose and adjusted the timing to 4 degrees atdc. That did not help or change anything. I was thinking piston slap but I’m not sure sure as it’s still there a bit when the car is warm. The car runs really well and seems strong. Burns no oil. My next thought is to see what temp thermostat is in the car because it has a new rad, so it is possible that they had an overheating issue and put in a 160f instead of a 195. I bought a 195, just haven’t installed yet, and now I might be waiting even longer to install it because now there is a giant oil leak from the top of the engine coming from either the intake manifold or distributor gasket. I am so fed up with this stupid car. I bought a tbi because they are supposed to be more reliable than the LT1. Not sure bout that one in my case.

Currently has 10w30, made no difference

 

[b454rat]

Hard to tell from the vid, but almost sounds like a bolt is loose, or bracket or something like that. It's not a rod or main, it would do more when warm, not cold.

 

[Andrew Barker]

Hard to tell from the vid, but almost sounds like a bolt is loose, or bracket or something like that. It's not a rod or main, it would do more when warm, not cold.

could it be something super weird like a partially spun cam bearing?

 

[Schurkey]

could it be something super weird like a partially spun cam bearing?

Sure. By definition, that's not likely.

I made it seven minutes into the video and all I could hear was you.

Knocking that comes and goes with load? Loose torque converter bolts, loose flywheel/flexplate bolts, CRACKED FLEXPLATE. For the record...cracked flexplates are common on the one-piece-seal engines like this one.

Maybe--not real likely--cracked/broken windage tray in the oil pan. Vibrates at certain RPM. Shouldn't really be load-dependent like yours seems to be.

I would scrap that Fram filter for a Wix-made unit--Wix, NAPA Gold, CarQuest/Advance Auto, etc. Baldwin is also a good company.

You do not need to waste ten minutes warming-up an engine. Get in, start it, drive it keeping the RPM down as practical. The extra warm-up time makes you more comfortable, not the car.

 

[thinger2]

Yep. Get rid of the Fram oil filters on anything you own.
A few years ago they had some pretty major QC problems and blew up quite a few engines.
The CEO made a big apology and claimed it was all fixed.
It aint.
I cut the filter open on anything I work on and I have seen way too many failures.
The fram filters use a glued in paper element that often times comes unglued.
Especially if you have real dirty oil.
Dirty oil is acidic and eats the glue.
Thats if they actually got it glued in to begin with.
This is bad enough on a "traditional" engine design.
If your engine has variable valve timing and hydraulic chain tensioners, it will kill it stone dead just from the crud that goes into the vvt solenoid.
They also dont have any anti drainback provision.
So if you start the engine in cold weather and then shut it off before it gets up to temp.
The next time you start it you have no pressure at the tensioner and the chains are loose as hell and can rip **** to pieces.
Ask anybody who ownes a nissan vq35de about this

 

[Andrew Barker]

Sure. By definition, that's not likely.

I made it seven minutes into the video and all I could hear was you.

Knocking that comes and goes with load? Loose torque converter bolts, loose flywheel/flexplate bolts, CRACKED FLEXPLATE. For the record...cracked flexplates are common on the one-piece-seal engines like this one.

Maybe--not real likely--cracked/broken windage tray in the oil pan. Vibrates at certain RPM. Shouldn't really be load-dependent like yours seems to be.

I would scrap that Fram filter for a Wix-made unit--Wix, NAPA Gold, CarQuest/Advance Auto, etc. Baldwin is also a good company.

You do not need to waste ten minutes warming-up an engine. Get in, start it, drive it keeping the RPM down as practical. The extra warm-up time makes you more comfortable, not the car.

Alright. Forgot to update, it’s got 10w30 synthetic with a delco filter. I’ll give you time stamps of the sound. 7:45 you can hear the noise, and 12:05 ish you can see the car is warmed up snd the noise is gone

 

[Andrew Barker]

Yep. Get rid of the Fram oil filters on anything you own.
A few years ago they had some pretty major QC problems and blew up quite a few engines.
The CEO made a big apology and claimed it was all fixed.
It aint.
I cut the filter open on anything I work on and I have seen way too many failures.
The fram filters use a glued in paper element that often times comes unglued.
Especially if you have real dirty oil.
Dirty oil is acidic and eats the glue.
Thats if they actually got it glued in to begin with.
This is bad enough on a "traditional" engine design.
If your engine has variable valve timing and hydraulic chain tensioners, it will kill it stone dead just from the crud that goes into the vvt solenoid.
They also dont have any anti drainback provision.
So if you start the engine in cold weather and then shut it off before it gets up to temp.
The next time you start it you have no pressure at the tensioner and the chains are loose as hell and can rip **** to pieces.
Ask anybody who ownes a nissan vq35de about this

Makes sense. I forgot to update saying that I had put changed oil twice since I originally posted this and used a/c delco filter both times

 

[thinger2]

Go get a mechanics stethotscope

Take a good long listen to your ac compressor and the ac clutch and bearings.
Gm ac compressors kick on when you run any heat/ cool cycle.
And it will load/unload as you take it out of gear.
Look at the belt tensioner and the whole assembly that bolts onto the front of the engine.
The entire housing that all of that bolts to.
Hard to tell, but to me that sounds like an intermittant external rotating failure that is temp related and load related.
I think you should search for an outer/accesory problem first

 

[Andrew Barker]

Go get a mechanics stethotscope

Take a good long listen to your ac compressor and the ac clutch and bearings.
Gm ac compressors kick on when you run any heat/ cool cycle.
And it will load/unload as you take it out of gear.
Look at the belt tensioner and the whole assembly that bolts onto the front of the engine.
The entire housing that all of that bolts to.
Hard to tell, but to me that sounds like an intermittant external rotating failure that is temp related and load related.
I think you should search for an outer/accesory problem first

I’ll pull the accessory belt off when it’s still cold, and take it for a short drive and listen.

 

[Andrew Barker]

Go get a mechanics stethotscope

Take a good long listen to your ac compressor and the ac clutch and bearings.
Gm ac compressors kick on when you run any heat/ cool cycle.
And it will load/unload as you take it out of gear.
Look at the belt tensioner and the whole assembly that bolts onto the front of the engine.
The entire housing that all of that bolts to.
Hard to tell, but to me that sounds like an intermittant external rotating failure that is temp related and load related.
I think you should search for an outer/accesory problem first

Not an accessory