Can anything save my neighbors Passport engine?

[rangerdood]

My neighbor has a '94 Honda Passport with the 3.2L Isuzu motor. Engine has 186k miles on it, and sounds like this - http://www.youtube.com/watch?v=pJpXf1DND48

The most horrible thing I've ever heard

Any thoughts on what it could be, and why it goes away at higher RPMs? Oil pressure stays a steady 30psi at idle, and the sound only seems to be coming from the pass side...

As soon as I heard it tonight I went and got my spare bottle of A-Rx and dumped 'er in. The owner doesn't have the ability right now to take it off the road because it's the only vehicle for his family.

 

[kd5byb]

Is it possible that it's coming from something outside the engine rather than inside? Like a chunk of heat-shield or inner plastic fender being hit by one of the belt-driven accessories? Any then when you rev it up, the engine shifts a little bit to give it clearance and doesn't make the noise?

To me, it sounds like it's external to the engine. When my Probe had the typical Mazda collapsed lifters, it was a much duller, muffled sound. That sound doesn't seem muffled or "dull" to me - seems very sharp like there is little between it and the microphone on your camera.

Sure, I understand the limitations of video/audio diagnosis over the internet, but that's my thoughts.

Any maintenance history that you can share with us? Fuel mileage still okay? Any codes being thrown by the computer?

later,
b

 

[NYEngineer]

Check the oil for particles... I kinda don't think it's inside the engine either... Kinda fast for a valvetrain noise at idle and it goes away when the R's go up. Hmmm...

Is it possible it's an EGR valve or a PCV or something? That sure would be simple.

Can't wait to see hoe this plays out.

 

[Johnny]

Does it have a timing belt or chain? Almost sounds like a loose timing chain tensioner.

 

[Chris142]

http://www.youtube.com/watch?v=E35j-ndw08w

Really hard to tell what it is.

 

[rangerdood]

I don't know anything about the motor, really. Other than prior to this, it did have a pretty good tick to it on the passenger side, which suddenly became this. I'm thinking a timing chain tensioner might be a good place to start.

kd5byb- it really is as sharp of a metal on metal noise as it sounds in the video. Painful for me to hear in person, because I envision this engine being torn apart inside...

Oh, and he's currently running a FRAM filter on it

 

[Bulli]

sounds like a bent valve or somethign similar to valves

 

[Gary Allan]

I agree the sound seemed to go away off idle. It doesn't seem to be "drowned out" behind other engine noises. It goes away, imo. It sure does have metallic ring to it up close. I didn't detect any misfire or dead cylinder action. It appeared to rev up easy enough.

I'd ride it out with the Auto-Rx in it. Aside from the sound, and without any operational oddities ..ignore it for a while.

Is the noise the same hot and cold??

 

[NYEngineer]

If you do ride it out, you will find out what it is.

 

[Bob The Builder]

Don't forget to check the fan shroud and other areas where there could be rubbing going on. Better yet, invite us all over for donuts and coffee (your treat) and there will be like 5...maybe 600 bitog members mulling around discussing the finer points of ARX at 6 in the morning. haha

I can actually picture this.

 

[ms21043]

By the looks of the engine I'll bet it has a timing belt.

 

[Silk]

They have a silicon auto tensioner - they lose fluid and then rattle,more so at idle.It will be close to skipping a few teeth.

Just ignore it,I'm sure the noise will go away soon......

 

[Brett Miller]

My first thought was a timing chain tensioner that pumps up as RPM's increase but I think that engine has a timing belt.

 

[artificialist]

The last time I saw that happen, the harmonic dampener was coming apart. Once it was replaced, the engine then clearly made the noise associated with worn bearings, because the dampener was supposed to control the crankshaft movement.

 

[JTK]

Originally Posted By: Brett Miller
My first thought was a timing chain tensioner that pumps up as RPM's increase but I think that engine has a timing belt.


I'm fairly familiar with the 1992+ Isuzu 3.2L V6. I owned a 2002 and had several others in the family. It does indeed have a hydraulic timing belt tensioner, that once too weak will cause a ton of slack in the T-belt. Enough slack that the belt will slap the inside of the plastic cover, giving off a sound VERY similar to rod knock at idle. Definitely not the noise. The 1992-1997 version of this engine has hydraulic valve lash adjusters that can tick. It's not that either. I'm with the other fellas, in that this sounds like a belt driven, rotating element; A/C compressor, idler, alternator. The water pump is driven by the timing belt on these engines. They are non-interference which is nice.

Joel

 

[steve20]

definately coming from outside the engine IMO

 

[Gary Allan]

Something of this nature, if truly a vital operational problem, would show up in full spectrum performance. It's obviously either some harmonic oriented issue or one removed with higher rpms due some flow volume or frequency change of the harmonic.

That is, if this was a 60's engine, you could just raise the idle and it wouldn't be there to fret about. That's what I mean by "riding it out". It's only present at one state. Why is that (asked rhetorically)?

 

[NYEngineer]

Why is that (asked rhetorically)?

Time for my favorite reply to that question, a la the movie Capt. Ron...
No one knows...

 

[Tosh]

A mechanic's stethoscope would find this in about 30 seconds. Yeah, it's not from inside the engine. Fan clutch?

 

[kc8adu]

most of the noisy isuzu v6 i hear making noise are bottom end issues from running them low on oil.these engines use oil and folks think that since it is a low miles car it doent need to be checked.there is one at the garage now with a trashed bottom end.
the racket is deafening!