Engine Noise - Sounds Expensive

[dkryan]

2005 Highlander with 142k well maintained miles.

The timing belt was changed at 96k, as was the pre-tensioner, the idler pulley, the belts, plugs, and the water pump.

Yesterday, I got out of the SUV to get something out of the garage. As I walked by the front-end (the engine was running) I immediately noticed the engine sounded louder than normal.

I popped the hood and isolated the noise to the area of the belts/pulleys (I think). I shut off the engine and checked the belts and tension, all of which was fine.

The "sound" seemed metallic to me and had me thinking "bearing."

I took the SUV to my indy mechanic and he agreed there was a mild but noticeable metallic sound.

Unfortunately, we both agreed the sound seemed to emanate from under the cam cover which is fairly close to the pulleys.

I made an appointment for two weeks from now. He's going to pull the belts and run the engine to see if the noise goes away. If so, that sounds like a cheaper fix.

If the noise remains without the belts on, he wants to remove the cam cover and go from there.

I have not seen any Toyota forum comments concerning any issue involving the cam with this vehicle.

Any thoughts on possible causes?

Thanks!

 

[Bottom_Feeder]

I'm sure he's right about the belt pulley(s). It's a common issue and not a big deal to repair.

I had one go on my Subaru once and it did indeed sound expensive. I thought either the alternator or AC compressor was failing. One removed, the old pulley sounded like it had gravel in the bearings. A new one from Gates was a cheap and easy fix.

 

[dkryan]

Here's hoping that solves it!

 

[L_Sludger]

dkryan,
you do neglect to mention which engine your Highlander has.
Does it have the 4 cylinder, or the 6 cylinder?

 

[Merkava_4]

I'm wondering why you have wait two weeks to pull the belt off. All you do is release the tensioner pulley and pull the belt off. Then to reinstall it, a belt routing diagram is probably on a sticker under the hood.

 

[dkryan]

Originally Posted By: L_Sludger
dkryan,
you do neglect to mention which engine your Highlander has.
Does it have the 4 cylinder, or the 6 cylinder?


3.3L V 6

 

[Tiir]

Were OEM parts used when the timing belt job was performed? I also didn't see you mention the cam seals being replaced.

 

[michaelluscher]

3MZ has no idler pulleys per se

Just the belts running over the things they run

Remove both,and start to hear

Sure the A/C isn't on and it's compressor noise?

Not the VCV clicking?

No misfires or CEL?

Where did all the timing belt/water pump parts come from?

 

[The Critic]

Was the hydraulic t-belt tensioner and pulleys replaced during the last t-belt service? If not that may be your culprit. Do not delay- the 3.3 is an interference engine.

 

[dkryan]

Wow!

Lots of info and some differences of opinion.

I was told the Highlander 3.3L was NOT an interference engine.

I always replace the timing belt pretensioner and I did so with this vehicle.

All Toyota parts.

Cam seals? I have never replaced cam seals in 42 years of driving Acura/Honda/Mazda/Toyota/Saab/Nissan automobiles.

No misfires or CEL.

What is a "VCV?" There is no valve noise, i.e., ticking from the valves.

I triple checked the A/C compressor and the mechanic checked it, too. No issues.

 

[SirWired]

My wife's 3MZ in her '06 Solara made the same noise, and it was the serp belt.

 

[Silk]

I don't know if it has one, but the over run clutch on the alternator can make some weird noises, but usually they kick the auto tensioner around. Easy to spot just looking at the tensioner.

 

[dkryan]

Originally Posted By: Silk
I don't know if it has one, but the over run clutch on the alternator can make some weird noises, but usually they kick the auto tensioner around. Easy to spot just looking at the tensioner.


The Toyota branded belts were installed only 46k miles ago.

Which means..................exactly nothing.

Maybe it's the Amsoil SSO 5w-30 that's causing all that noise!

 

[Merkava_4]

Originally Posted By: SirWired
My wife's 3MZ in her '06 Solara made the same noise, and it was the serp belt.


In that case, dkryan would know immediately after starting the engine with the belt off.

 

[kc8adu]

take the belts off and if the noise is still there you can now do a better job with a stethoscope now that there are fewer rotating parts to get tangled up in.
i had a neighbor that bought a buick reatta cheap since it sounded like the bottom end was ready to fly apart.
he had even arranged to buy an engine when he asked me to have a look.
i pushed an axe handle against the balancer and the knock went away.
cheap easy fix.
nice car for $500.