I have a '99 V10 crew/shortbed with 122K miles and heard the brief clatter (1 second) of the timing chain hitting the timing cover when the engine was cold (had been running for 1 minute at 30 degrees F) on two occasions. The sound happens just as I hit 2800ish RPM before the 1-2 upshift on my steep driveway. It never occurs again as the truck is driven that day. I'm running 5w-30 oil, as recommended, and the engine is in good shape and appears to have had good maintenance during its life. The noise sounds exactly like the timing chain on my old 22RE 4Runner, at 203K miles, so I'm pretty sure it's a timing chain.

Is this likely just a sluggish hydraulic adjuster, or is there a known problem with the timing chains on these engines? I don't mind a brief clatter, but if the chain is in imminent danger of hopping a tooth and bending a valve, that is more serious.

Thoughts?

Thanks,

Steve

 

Well this is interesting,never heard of rattling of timing chain on a v-10.
We have heard of pinging,knocking,piston slap and sparkplug spitin!

What makes you think its the timing chain???????
Could you have a heat shield problem or loose muffler or cat.

This would be a first,that Ive heard of it.

Now I know if you lugg these motors bad you will here some strange stuff
valve train noise.
Rich

 

It's the classic sound of a timing chain hitting a timing cover - no other way to describe it. I used a non-Toyota tensioner in my 4Runner and heard the sound (and later learned that this was typical when this tensioner was used).

On the Ford, I've heard it twice and it sounded slightly different each time, but it wasn't piston slap (from what I understand) and I just replaced the serpentine belt. None of the other engine accessories appear to be on death row - so I don't suspect the water pump, PS pump, alternator, etc. I'll drive the truck tomorrow and see if I can reliably get it to make this sound again. If you've never heard the sound, it's not unlike that of a bicycle chain hitting a metal chainguard, but a bit more brash sounding and louder!

Steve

 

Steve ,I edited my post above.
Rich

 

Rich - per your edited post - It's an auto tranny - so no lugging here - just moderate RPMs, light load, cold engine. Clearly not an exhaust sound. I've heard lots of pinging, in other engines (and on rare occasions on this engine) and it's not that sound, either.

 

If it was the chain which I doubt it would do it all the time. Once it would start to do it how could it stop? Just a thought! Let us know what you find..Check belt? Water pump. Pulley bearings...Prob just normal piston slap.

Dick

 

Could this be the Super duty flutter that so many of us had to deal with?
If you don't know what that is, its the rattling noise that the inspection cover on the tranny makes and it only happens ocationaly and at around the rpm you describe, pop it off and see if the noise gose away.

 

i doubt is is the chain becuase for it to hit the case you would need over 1'' of movement and by then the chain would fall off

 

Thanks for the great suggestions/ideas - I was hoping someone was more familiar with the chain tensioner setup on this engine as ford390gashog is.

I hear about the piston slap at 'low temperatures' - is there typically a temp below which you hear it (always), if you have the problem?

 

MM ,you might be the man on this one.
I totally forgot about the inspection cover rattle on the 4r100 tranny.
Rich

 

the cover as fortyfords said is also common.

piston slap tends to happen when cold when the pistons are contracted .most see it when the temp is below 50 degrees. then when both metals (aluminum piston and cast iron cylinder wall)come up to temp the pistons expand and the noise is gone

 

I see piston slap with mine when its below freezing.
But the tranny plate might be it.

Rich

 

What is Super Duty flutter? I may have that . .

 

It has to do with the design of the y-pipe in the stock exhaust system.
At certain rpms it builds a resonance(sp) in sound or tone it will actually cause the 4r100 inspection cover to vibrate.
This coming from my memory of about 4 yrs back.
Rich

 

So how does one quiet the inspection plate cover? Do you bend it slightly to change its natural harmonic, or jam a wood shim under it to quiet it, or tighten the bolts?
This is a great thread, BTW.