Awful noise with load/ part throttle only. cannot replicate in neutral

[LukesCougar]

So. my luck with this car keeps getting better. I am wanting to believe this is detonation, but im not very good at diagnostics and this sounds very metallic .. At first i thought it was related to my bad tensioner, but after fixing it the cold start noise is gone and all that remains is the warm/ part throttle noise

I cannot replicate this noise in neutral or high or really low loads, only part throttle cruising with load

i cleaned pcv, checked plugs and theyre all gapped to .054-0.55 but one hole was dirty and the plug felt loose.. cleaned it and it snugged down fine..

cleaned maf and reset pcm.. and i still have a noise.

on a similar note the egr almost looks brand new on the outside but im not sure if its dirty. it is probably what ill check next, but what in the hell would make this noise if its not something internal?

 

[LukesCougar]

 

[Grog6]

I don't hear anything.

 

[LukesCougar]

i have also checked egr and it looks fine.. barely any carbon build up. now im stooped. i havent tried higher octane gas yet though

I was reading a dodge forum that described the exact symptoms and ended up being a lash adjuster. Makes me curious but that isnt work id be doing myself.

 

[LukesCougar]

too much bass? i cant hear it either on my computer speakers. i can with my cell phone

 

[1997ThunderbirdLXV6]

I can hear two noises. One a crickets type noise (which may literally be crickets in the background), and the other a metallic rattle type noise which reminds me of the noise a flag makes in very strong wind.

I'm guessing we're talking about the second?

But the fact that I can hear them doesn't help us because I'm clueless as to what noises mean.

 

[LukesCougar]

I can hear two noises. One a crickets type noise (which may literally be crickets in the background), and the other a metallic rattle type noise which reminds me of the noise a flag makes in very strong wind.

I'm guessing we're talking about the second?

But the fact that I can hear them doesn't help us because I'm clueless as to what noises mean.

the metallic rattle noise is what is bugging me. i may try and take another video.

The current video definitely doesn't do it justice. In person it sounds like one of the pistons is doing a happy dance or a heat shield is violently rattling

i also dont know my noises so im lost. i might lift up the rear and see if it makes the noise just putting it in drive part throttle so i can actually point it out

 

[LukesCougar]

Im still thinking it is valvetrain related maybe? any search with my exact symptoms leads me to a forum of someone finding a bad lash, or valve.

I did read one described as a warped flex plate making noise when load was applied. I have no idea how likely that is for a stock car but i do drive pretty spirited

 

[Grog6]

I've never heard of a flex plate coming loose on one of these.
I've got a friend thats a hypocondriac, looks up lots of medical problems he doesn't have on google. You can find a lot on the net.
ALoose lash adjuster doesn't happen; it spit's out the follower, which makes some serious noise. And bends valves, which are obvious.

 

[XR7-4.6]

I’d drain the oil and check the drain pan for glitter, load dependent metallic knocking noise is indicative of rod bearing


Valvetrain noise isn’t that rapid, keeping in mind the cams operate at half the speed as the crank, and noisy sticky lash adjusters tend to quiet themselves down with engine/oil temp, where rod knock becomes louder

 

[Grog6]

I’d drain the oil and check the drain pan for glitter, load dependent metallic knocking noise is indicative of rod bearing
Rod knock id distinctive, and unmistakable; there should be plenty of examples on the web.

Rod knock gets louder, more insistant, "I'm gonna break now" kinda way.
Detonation sounds like wind rushing leaves around, not scary, like a rod or loose follower. Rod knock exactly follows engine rpm. Valves rattle, and sound kinda like a rod, but more tinny, when the piston smacks it.

Valvetrain noise isn’t that rapid, keeping in mind the cams operate at half the speed as the crank, and noisy sticky lash adjusters tend to quiet themselves down with engine/oil temp, where rod knock becomes louder

Rod knock gets louder untill it ends suddenly with a "TAP-TAPP-TAPsQUeeeaK POW!!! ...AS IT SNAPS OFF.
How do I know, you ask? (lol) My count is 4, so far; two dirt bike, a 2.8l v6 firebird, and now a 4.6.
The teardown on Lazarus will be impressive, I'm sure. 550k miles, hooned daily, at least 6 transmissions, soon to be a PI.

 

[LukesCougar]

I’d drain the oil and check the drain pan for glitter, load dependent metallic knocking noise is indicative of rod bearing


Valvetrain noise isn’t that rapid, keeping in mind the cams operate at half the speed as the crank, and noisy sticky lash adjusters tend to quiet themselves down with engine/oil temp, where rod knock becomes louder

That was kind of my first thought, but i just have been hoping not. If it is a rod bearing why would i not beable to replicate it though? i cannot hear it when the rpms are falling in neutral or revving, and when driving it does it specifically when im at part throttle and nowhere else...?

the only thing i can really compare it to is a massive exhaust leak on my grandpas continental, but still more prominent and this gets worse when hot instead of closing up.

It probably is a rod bearing or wrist pin or something along the lines of, i was just really hoping not. already drained the oil pan not even a month or 2 ago when i first heard the noise and everything looked fine. Used, but mostly clean oil? I even took a magnet through it and couldnt find anything out of the norm and there was barely any metal on the magnet after sloshing it around in the oil for a good minute or so

 

[LukesCougar]

I’d drain the oil and check the drain pan for glitter, load dependent metallic knocking noise is indicative of rod bearing


Valvetrain noise isn’t that rapid, keeping in mind the cams operate at half the speed as the crank, and noisy sticky lash adjusters tend to quiet themselves down with engine/oil temp, where rod knock becomes louder

Well i drained the oil, there is an almost non existant amount of metal, I really can't see anything. Even with a flashlight it didn't look like glittery oil just looked like regular Ole used oil.

Magnet barely picked anything up either.

I'm throwing some 10w 40 in for the summer. Just incase it is something just starting to go out

 

[XR7-4.6]

If there’s any in there it’s most noticeable after you drain the drain pan where the glitter clumps up in the corner. It won’t be magnetic material, the bearing surface is basically aluminum.

If there isn’t any that’s good. The reason rod knock is auditable under certain conditions is the load, free revving the engine doesn’t load up the crank so knocking isn’t auditable like when it has the weight of the vehicle attached to it for the rods to really hammer on. Likewise it’s usually not as loud at higher RPM(partly because the engine noise drowns it out but also there’s more oil pressure filling the gap…until it doesn’t

 

[LukesCougar]

Couldnt find anything in the edges of the pan either.

Im really just stooped until it decides to change or do something.

10w-40 did not improve the noise what so ever and i was running 5w-20.

If it is just a rod bearing in the very early stages of crapping itself could i diagnose it by pulling injectors one by one until the noise gets quiet/ goes away?

 

[XR7-4.6]

Couldnt find anything in the edges of the pan either.

Im really just stooped until it decides to change or do something.

10w-40 did not improve the noise what so ever and i was running 5w-20.

If it is just a rod bearing in the very early stages of crapping itself could i diagnose it by pulling injectors one by one until the noise gets quiet/ goes away?

If there’s no metal it’s not a bearing, so at this point I’d take that out of the equation. The beginning stage of a failing one IS glitter, next stages are loss of oil pressure followed by hole in block.

Honestly the next best bet would be exhaust leak, as it too is a load dependent noise.

 

[LukesCougar]

After a closer look, i may need a second opinion, but honestly still nothing crazy or sizeable grains of anything, but there is some level of shiny silt that i was unable to see in the daylight.

I havent used any additives either.

 

[Grog6]

Did you change the idler as well as the belt tensioner? Check the ac clutch/pulley?

 

[XR7-4.6]

After a closer look, i may need a second opinion, but honestly still nothing crazy or sizeable grains of anything, but there is some level of shiny silt that i was unable to see in the daylight.

I havent used any additives either.

I legit can’t see anything other than the close encounters of the third kind light show. But shiny silt is not necessarily indicative of a failed bearing, that may well be the oil composition, a failed bearing is very very obvious with irregular sized silver chunks. This isn’t from a drain pan but the actual oil pan of my original 2V that spun a rod bearing. This is the sort of thing worth concern



Beyond a cursory look at the drain pan you could also cut the filter open to get a look at the media caught for a more accurate idea of what’s going on (you want to use a shear type method to open it for assessment, not drills, saws or grinders).

 

[LukesCougar]

Did you change the idler as well as the belt tensioner? Check the ac clutch/pulley?

I just replaced the belt tensioner, the idler pulley didn't seem to have any play, but belt feels quite a bit tighter now.

Also out of curiosity i drove the car for not even half a minute with the belt off. Noise was still there. The cold start noise that the tensioner was doing in freezing temps is gone

 

[LukesCougar]

I legit can’t see anything other than the close encounters of the third kind light show. But shiny silt is not necessarily indicative of a failed bearing, that may well be the oil composition, a failed bearing is very very obvious with irregular sized silver chunks. This isn’t from a drain pan but the actual oil pan of my original 2V that spun a rod bearing. This is the sort of thing worth concern



Beyond a cursory look at the drain pan you could also cut the filter open to get a look at the media caught for a more accurate idea of what’s going on (you want to use a shear type method to open it for assessment, not drills, saws or grinders).

Yeah if we are talking about all the grey sediment looking bits of metal in your pan i didnt have any of that draining my oil aside from debris from the drain bolt itself and a dirty muddy oil pan- little bits of stuff that would crumble in my hands so just corrosion that had fell from me bumping into stuff or wiping the oil pan. If i slosh my oil around there isnt any actual sediment at the bottom.


Im still curious. Aside from a massive exhaust leak which i still have yet to investigate.. what ignition/ fuel wise could cause this? Ive had issues with maf before on another car but it wasnt a knock/ tap more like the marbles in a can description and erratic . Have cleaned egr, maf, pcv, checked for vac leaks ect. Nothing out of the norm is obvious but that is the diagnostic of someone with minimal experience.

When i first bought the car the #3? plug hole was full burnt coolant, and i had a bad miss which felt and sounded similar to the current noise which went away after new plugs until the more metallic noise came on. I pulled the now replaced plug and there wasnt anything on it this time around but it did look to be lean? it was the "whitest" plug but i didnt think much of it at first

running ngk iridium ix? I think i might pull that injector and take it on a drive if thats safe?

 

[LukesCougar]

Another update. Shop is saying spark knock/ or lash adjuster?

He pointed out that my wires were rubbing in some areas, and suggested i replace them with proper insulation. I did notice one was burnt

but thinks it is most likely top end related after listening to it what makes me doubt this is the noise seems to follow the speed of the crank

 

[Grog6]

Do you have an old school timing light? If you do, put it on #1, and see if the noise is in time with the flash.
You might borrow one at a parts store.
In time is valve noise; if it has a beat between flashes it's the crank.
Valves are 1/4 crank speed. but we use waste spark,so it's in time with the valves. Note: This DOES NOT APPLY if you have a distributor. This may only work on a v8, I can't do math anymore.

 

[LukesCougar]

Do you have an old school timing light? If you do, put it on #1, and see if the noise is in time with the flash.
You might borrow one at a parts store.
In time is valve noise; if it has a beat between flashes it's the crank.
Valves are 1/4 crank speed. but we use waste spark,so it's in time with the valves. Note: This DOES NOT APPLY if you have a distributor. This may only work on a v8, I can't do math anymore.

I do not have one, but if I buy one can I use it while driving..?

I cannot replicate this noise at a standstill. Only when in gear and moving/ load

 

[LukesCougar]

I may revisit the idea of jacking the rear of the car up and revving in drive

 

[LukesCougar]

Ok so i put the rear on stands and locked out second trying to create the noise. Nothing. Gone..

I assume this is because even in gear whatever is noisy doesnt have enough load without the car moving>?

 

[XR7-4.6]

Don’t do that, you can kill the CV joints running them with the suspension at full droop. It doesn’t prove anything either as the load needs to be coming from the road, not just the extended drivetrain, running the engine with the wheels spinning is functionally no different than free revving in neutral

 

[LukesCougar]

ah shit, i hope i didnt screw them too bad then :/ didnt feel nothing too weird aside from i accidently had tcs on and it was locking up.



but also- i am a huge dumbass.



I found the noise. If anyone remembers me deleting my AC compressor i may of not given details but i did so somewhat lazily. I left all the hoses in there ziptied to the frame. Well while feeling around i found that one of the lines i had tied up was just close enough to another line to bump into it and rattle at certain loads. I zip tied the hose that could slightly move and then the noise mostly went away besides a small whisp of a rattle...

All this because i was too lazy to clean up the engine bay after installing a bypass





edit: on a similar topic_ if my engine is healthy i should probably drop this 10w40 and go back to 5w30 no?

 

[XR7-4.6]

ah shit, i hope i didnt screw them too bad then :/ didnt feel nothing too weird aside from i accidently had tcs on and it was locking up.



but also- i am a huge dumbass.



I found the noise. If anyone remembers me deleting my AC compressor i may of not given details but i did so somewhat lazily. I left all the hoses in there ziptied to the frame. Well while feeling around i found that one of the lines i had tied up was just close enough to another line to bump into it and rattle at certain loads. I zip tied the hose that could slightly move and then the noise mostly went away besides a small whisp of a rattle...

All this because i was too lazy to clean up the engine bay after installing a bypass




edit: on a similar topic_ if my engine is healthy i should probably drop this 10w40 and go back to 5w30 no?

Glad it was something simple! Been there done that!

Yeah that oil’s too thick but it won’t harm anything really, I used to run 10w40 Rotella in my 2V when it had stock 94 heads to slow the oil consumption