Lucky me, a new worrying noise! Possible RTH?

[NaterGator]

Just gone done getting dinner tonight and on a whim I got out of the cruiser with it running...

At idle (without AC, didn't try it w/ AC) I'm hearing what I can only describe as a worrying noise. Here is my best attempt at describing it: most audible from the rear of the motor standing on the drivers side, it has a sort of indirect/muffled clanking-knocking quality to it. I got under the cruiser and it sounds :gulp: low and far back on the motor.

Other factors to consider: I'm still getting pinging on acceleration, temps are normal, a bit of coolant loss but the heater valve above the valve cover on the firewall is leaking a bit, still throwing P0401s, threw a P0420 and my ps floor is hot so I assume my cats are toast, original HG, my latest blackstone report shows absolutely nothing amiss
Here is the blackstone ~2,000 mi ago w/ 6,500 mi on the oil for reference:

I will try to grab a digicam and get a sound byte. From my last $2,500 escapade here I've learned not to ignore new noises... and right around this time last year my GMC had an oil delivery issue in the lower end and grenaded the motor while someone else was driving it, so needless to say I'm not keen on having that happen again one year later on a much finer (and way more expensive to fix) automobile.


Help? Is it possible this is a leaky exhaust manifold at cyl 6?

 

[NaterGator]

As promised, a sound clip of the noise. The more I hear it the more it worries me.

The first version has a filter applied to cut the extra engine noise down so you can hear the knocking:
http://www.nate-online.com/filtered_knocking.mp3

This second one is the same clip, but without filters:
http://www.nate-online.com/knocking.mp3



Expert opinions?

 

[GXO]

no help here, but that doesn't sound good.

 

[Trunk Monkey]

It doesn't sounds like exhaust, that tends to be more of a tick tick tick. Sounds like it might be rod knock. Does it increase in frequency with RPMs?

 

[LockedLX]

This isn't an expert opinion, but..

How long has it been pinging under load? Assuming this is detonation, it can and will eventually destroy your engine.

Have you tried to remedy the problem? You say the passenger floorboard is hot, possibly due to clogged cats. If the already small exhaust on these trucks is restricted much more than stock, I'm sure it would be a contributing factor to detonation. I'm gonna need more info before I can make an educated guess on the noise, though it does sound like a rod. Let us know if it gets worse with RPM as FZJFillmore suggested. Also..

Does the noise get louder/quieter under load?
Has your gas mileage gone downhill recently?
Is the noise louder/quieter when the engine is cold/warm?
How's the oil pressure?
Maybe try unplugging the rear injectors one by one and see if the noise changes at all?

That's all I can think of right now..

 

[LandyLover]

I couldn't hear the noise increase in speed with your RPM increase. Your knock also sounds random... it doesnt appear to have a rhythm. Have you isolated the noise to the bottom end?

 

[NaterGator]

I haven't isolated the noise to anywhere, I can't tell where it is coming from and I don't have any resources, time, tools, or money to take care of it asap. It is either completely masked by regular engine noises when under load or goes away with any amount of throttle; I can't hear it at all.


My hope is to limit my driving as much as possible until next week and then make the 645mile trek home where I can properly take care of it. I *just* noticed this today and it may have been going on for some time; I don't think your average driver would pick it up and notice it, because you can't hear it well anywhere except standing next to the truck by the driver's side.


It is intermittent and it seems to only happen at idle. Other than this the truck shows no signs of engine problems; what I worry is the few WOT (and still decelerating) runs up the steep grades here have caused some otherwise latent problem to rear it's head.

What I don't understand is how an engine as bulletproof as the 1FZ with such religious maintenance would develop a problem like this with 120k miles on the clock when people take their motors apart with 180k on them for the first time and the bottom end looks great. Nobody and I mean nobody seems to have trouble with the motors short of HG problems or neglecting regular maintenance. What the fudge; I'm looking for the answer here that it is option a or b and not the seemingly immensely rare choice of a 1FZ-FE self destructing at such low mileage.



Edit: Update: I am worried as hell over this so I just went out to the cruiser and started it up now that it has cooled. Immediately when it settled to idle the noise began, so yes it happens on cold motor/oil too. I also determined that it is possible it is *not* coming from the rear of the motor, although I'm not sure. It sounded as if perhaps the water pump was an option... would this make sense? The roar of the fan on a hot engine could, I suppose, cloak the noise. I'll check for play in the bearing tomorrow when I get some light; is it normal for water pumps to need service/be replaced at these miles? If so, how difficult is the task?

 

[LockedLX]

It's intermittent and doesn't seem to get louder with RPM/load.. I'd say this is a good start.

Keep an eye on oil pressure (with the highly accurate stock gauge Mr. T blessed us with ) and keep on truckin'. Let us know if it gets worse.

Are you headed to Tampa or Gainesville? If you're in Tampa and need a hand, let me know..

 

[NaterGator]

Heading to Tampa for about a week before I move back to Gainesville.

I do have a scangauge so I will be religiously monitoring water temp, load, rpms, and ignition timing. If anything starts to go nutso I'm gonna be off the road in a flash.

If the noise doesn't get worse over the course of the week I'm going to try to deal with it in Tampa. If it does get worse I'll stick it out here for a few days after work ends and try replacing the water pump (if it turns out the be a likely source of the noise tomorrow)


Of note: my York OBA compressor is in with the 3 groove pulley. I'll have to take pics of a strange behavior I've noticed which I believe may be a result of the pulley.

 

[LockedLX]

"Go Advanced" ate my edit, so here goes..

If you don't have a mechanic's stethoscope and want to try and determine where the noise is coming from, a long screwdriver works in a pinch. Slide under the truck and press the tip of the screwdriver to the oil pan and the handle to your ear (while plugging the other, engine running of course). Do this on a few different areas of the engine--front and rear of the valve cover, head, block, wherever you can get to with the screwdriver really. You'll look like an idiot doing it, but it may help you pinpoint the noise.

Good luck!

 

[NaterGator]

Upon more careful examination it does not seem to be coming from the water pump, it does not seem to be intermittent, and it does seem to be coming from the bottom end of the motor.

I'm beginning to think I won't make the 650 mile trek home.

 

[Trunk Monkey]

To rule out rod knock you can pull the plug wires one by one, if it goes away with one of them pulled, you've got your culprit.

 

[whodat]

How many miles did it have when you bought it?

Do you know the maintenance history pre natergator?

Keep us posted.

 

[NaterGator]

Bought it with 100k on the clock. I know the previous owners very well and they bought it new. They had all maint done at our local Lexus dealership and I have full records of maint on the truck. Nothing major in it's lifetime; since I've had it I've been running synthetic oil, started with 4k intervals and have since moved up to 6k intervals. Did valve cover gasket and blue fan clutch about 10k miles ago; truck currently has 123k miles but a little more since I switched to 33" tires somewhere in there.

It's going into the Asheville Toyota dealership tomorrow at 8am for a diagnosis. Once again I'm stuck in a situation where I would love nothing more than to diagnose and tear down and clean up the motor if necessary, but I dont have the time or resources. I'm hoping something totally wildcard is going to be the culprit and not something in the lower end of the motor. I figure if it is a bearing or something down in the bottom they're gonna have to pull the motor and parts/labor is going to be in excess of $4000 which is more than twice what I made this summer.


Total bummer.

 

[Trunk Monkey]

I figure if it is a bearing or something down in the bottom they're gonna have to pull the motor and parts/labor is going to be in excess of $4000 which is more than twice what I made this summer.

Guy in my club (liverust here on Mud) just went through a rebuild from rod knock, I think his tab was just shy of $6k with parts and dealership labor.

 

[NaterGator]

Guy in my club (liverust here on Mud) just went through a rebuild from rod knock, I think his tab was just shy of $6k with parts and dealership labor.

Ugh. Do you have any idea what was done? If it was akin to LX_EXTREME's rebuild where the motor was basically brought back as close to 0hrs as possible without replacing the block/head/pistons then it may be less painful than if that was just fixing one piston/rod/bearings.


This is making my stomach ache. I just poured $2500 in thinking for sure the cruiser would be able to get me home at the end of work, and now it gets twice as bad.

 

[Trunk Monkey]

New bearings (slightly larger due to the wear), rebuild of the bottom end while it was out. Don't make yourself sick, it's not a rod yet.

 

[NaterGator]

Dealership says they can't reproduce the sound


Oh well, I'll just take it back and go from there...

 

[Proven]

Hey Nate,
Mine began making that calypso sound just after I changed to Eneos 0W50 Fully Synthetic engine oil from my dino Mobil 5000 10w40.

I have been able to determine that the sound appears to be coming from the oil pan area, just because that is where it sounded the loudest before I burnt the holy hell out of my shoulder poking around a hot running engine.

To be honest, I have 500 miles on mine with that funky non-rhythmic calypso beat and I don't hardly think about it. I did take a stethoscope to the topside thinking it could be coming from there and I don't hear it through the engine block.

My advice to you and ME would be to go up in viscosity to see if the sound follows or goes away. I didn't notice mine until I went so thin.

My rig has 170,000 on the ticker and I don't take the absolute best care of her...meaning I don't use a diaper to buff the paint for crying out loud.

 

[NaterGator]

I'm the same way, and I would have let this develop more if I didn't have a 700 mile "I can't stop" journey ahead of me.

The odd thing is I just moved up to 10W-40 M1 from 0W-40 M1, and my oil consumption has gone down. Apparently the dealer did top off an additional quart of oil, and I don't know what they used, but I plan to only run this oil for another 1k and then change it and blackstone this batch to see if anything shows up.


Who knows.