1996 LX450 - engine noise

[jsix321]

Below is a video of my motor. Wanting to see what y’all think this noise is, is does this sound like a healthy engine. Going to have the rig repainted and want to wrk through anything mechanical before I do. Want to see if y’all think this is rod knock or what. I varied the rpms and brought it down to idle a few times for the video.

 

[jsix321]

Here’s another video

 

[BILT4ME]

Power steering pump gear.

Any recent work done to anything?

 

[jsix321]

Parts replaced due to hard start where fusible link, fuel pump, in-tank screen, fuel filter, spark plugs, plug wires, engine oil and cap/rotor. I’ve fixed the hard start issue and in the process of baselining engine. Trying to make sure the noise I’m hearing is valve train related and not an engine knock. I’ve never owned an 80 series before and not sure of the sounds they make. If y’all think this doesn’t sound like engine knock I’m going to move forward with getting it running the best it can. If y’all think it is engine knock, don’t want to through hood at bad. I did change the type of oil after reading about what others on mud are using. The PO used 5w20 synthetic, at least that’s what the window sticker said, and I switched it over to 15w40 rotella.

Areas I’m still working on are replacing the knock sensors and pigtails, looks like there where previous repairs done by a 2 yr old and it’s throwing a code. Also working on temp cooling sensor, throwing a code there as well. Also need to go throw or delete the EGR system, throwing a code there also. I did get online and looked through all the past maintenance the PO had that was available for me to see and they declined fixing the EGR system. The service record said EGR pipe was clogged.

 

[jsix321]

Motor has 176k miles

 

[jsix321]

Would it be easier to tell if I post a video of it just idling?

 

[ppc]

Yes, just at idle but move slowly around the engine bay from different angles so the noise can be better pinpointed .

 

[jsix321]

Here’s another video closer up and at a idle moving slowly. Let me know what y’all think. I can’t tell where it’s coming from or if’s normal, no frame of reference.

 

[jsix321]

I did notice there was no sounds when I started it a bit ago before I took it to the store. After I let it set and come up to temp it sounds like this. When I first start it it is idled up a bit. It’s cold here. Don’t know if that makes a difference or means anything.

 

[LongDuck]

I notice your spark plug wire covers are off - have you checked to be sure the spark plugs are torqued down properly? I had a similar noise that was present all the time but worse on cold starts, and it turned out to be 3 loose spark plugs which were only in finger-tight. I literally spun them out with my fingers on the socket extension. The plug boots also showed signs of exhaust and carbon blackening from blowby, when the tight ones were bright red.

Tightening them down helped with the clatter on cold starts, but didn't remove it entirely. After reading a lot here, I added Lucas Engine Honey (oil stabilizer) and 10w30 Mobile 5,000mi synthetic oil which removed about 80% of the noise, but it was still there. Crawl under the engine and listen closely. If your noise is significantly louder, it's likely in the block though from the top it sounds like valves.

Mine turned out to be pistol slap, but don't get discouraged. Check the easy stuff first,

 

[jsix321]

I notice your spark plug wire covers are off - have you checked to be sure the spark plugs are torqued down properly? I had a similar noise that was present all the time but worse on cold starts, and it turned out to be 3 loose spark plugs which were only in finger-tight. I literally spun them out with my fingers on the socket extension. The plug boots also showed signs of exhaust and carbon blackening from blowby, when the tight ones were bright red.

View attachment 2584526

Tightening them down helped with the clatter on cold starts, but didn't remove it entirely. After reading a lot here, I added Lucas Engine Honey (oil stabilizer) and 10w30 Mobile 5,000mi synthetic oil which removed about 80% of the noise, but it was still there. Crawl under the engine and listen closely. If your noise is significantly louder, it's likely in the block though from the top it sounds like valves.

Mine turned out to be pistol slap, but don't get discouraged. Check the easy stuff first,

Thanks for the thought and will double check the spark plugs. I’ll also look into that engine honey, anything to protect it. Trying to figure out if this thing is in good shape and worth the effort.

On yours with piston slap, does that mean the pistons are hitting the valves and is repairable with rebuilding the head?

 

[LongDuck]

NEWP,... piston slap is in the centering of the pistols in the bores, and can only be fixed through a full rebuild or new short block. The 'slap' is caused by the piston tilting somewhere in the stroke and the skirt hitting the cylinder wall.

Start with the easy and simple (*and cheap), and go from there. That your sounds get worse when it heats up is significant, but I don't know what would cause that. As the engine heats up, everything expands and gets looser...

 

[ppc]

Seems loudest towards the front. You may want to remove the belts and see what changes there may be.

 

[jsix321]

Seems loudest towards the front. You may want to remove the belts and see what changes there may be.

Sounds good and will try this next. Hoping for the best.

 

[jsix321]

NEWP,... piston slap is in the centering of the pistols in the bores, and can only be fixed through a full rebuild or new short block. The 'slap' is caused by the piston tilting somewhere in the stroke and the skirt hitting the cylinder wall.

Start with the easy and simple (*and cheap), and go from there. That your sounds get worse when it heats up is significant, but I don't know what would cause that. As the engine heats up, everything expands and gets looser...

That sucks and hope that’s not what mines doing. Have you looked into costs of the rebuild or replacement?

 

[Stevesnj]

I'm diagnosing the exact sound. Mine isn't as loud but close. Get an automotive stethoscope and put it on the timing chain tensioner. Thats where mine is coming from. Tensioner could be bad or some have said oil filter and oil are incorrect. Waiting for my Toyota oil filter to try out otherwise it could be a bad slipper guide which requires a timing chain replacement to. $4k have been my average estimates.

 

[BILT4ME]

He makes a good point.

What oil filter do you have on there?

 

[jsix321]

Not sure what oil filter is on there, whatever jiffy lube uses. The oil is rotella 15w-40.

That seems high to change the timing belt guide and/or tensioner. Not that I know the amount of worked involved, but seems high. Does anyone know what it takes to do this?

 

[jsix321]

Going to try taking the belts off and seeing what I hear. Going to remove the belts when the engines warm as I don’t hear anything when it’s cold. It’ll be a couple days and it’s bad weather right now. I also ordered a mechanics stephoscope and mechanics camera scope to probe around. Thanks for all the replies and we’ll figure this out.

 

[BILT4ME]

Not sure what oil filter is on there, whatever jiffy lube uses. The oil is rotella 15w-40.

That seems high to change the timing belt guide and/or tensioner. Not that I know the amount of worked involved, but seems high. Does anyone know what it takes to do this?

Get a photo of the oil filter. Try and get a pic of the part number sticker.

If they used a Wix or a NAPA Gold oil filter, you MAY be experiencing a problem and may need to get an attorney involved. If you have one of those, don't run it anymore. You may be doing more damage.

I'm being a bit over the top here because there have been a number of oil filter failures with those two (made by Wix) and can give similar sounding issue because it's starving the engine of oil.