Rev-specific rattle with video–please help!

[Tarim]

Hello All,

A few months ago my 94' with 216K miles on it started making a strange rev-specific rattling sound from the lower right side of the engine if you're sitting in the driver's seat. It's been below freezing for about a month here in VT so that's not helping at all, but on a cold start you hear the noise pretty constantly in park until it warms up, then when you rev in park or neutral the sounds starts at about 1200-1400 RPM and goes away at about 2200. Then in drive, it starts at about 1600-1800 RPM and also goes away at about 2200.

At first I though it was external, but couldn't find anything wrong with the body. I got some outsider/mechanic opinion and he said it was the timing chain tensioner, so I changed that out, but nothing changed. Another mechanic told me it was the lifters, but I really doubt that's it because it sounds different than lifter issues would. Then, after getting really worried, I asked a mechanic to take a look at the engine and he mentioned that he found a little piece of metal inside the bell housing, but that everything else looked OK.

After reading bunch, it sounds like it could be something to do with the torque converter, timing chain setup, or what I fear most, something with the transmission.

The video below shows the dash and the sound. If anyone wants, I could get some more videos with the hood open, or while moving.



Any help would be immensely appreciated guys!

All the best,

Tarim

 

[gummycarbs]

These engines don't have valve lifters.

I would get a mechanic's stethoscope and see if you can narrow down the location of the problem.

Do you have the piece of metal that the mechanic found?

 

[panamacruiser]

does it vibrate? sometimes is as common as the tansmission mount

 

[Tarim]

Thanks for the replies guys.

Nothing vibrates when I rev...

I never saw it, but the piece of metal was described to me as a small, metal half-collar. I think you're right, I should take it to the mechanic and have him use a stethoscope to narrow in on the problem. I've been using the car for months now with this problem and nothing has changed. As we all probably know too well, mechanics are expensive in this country so it would be great if I could get a better grasp on what exactly the problem is so I could bring it to them and say "here, have at it!"

For what it's worth, the sound started when the car was being used by a friend and I was out of the country for an extended period, I don't know what oil they were using but when I got it back, changed the oil, and started using it, I noticed both the sound, and that the oil pressure was reading less than usual. Now, on warm idle the needle sits just above the first line.

 

[slow95z]

I know one thing that helped mine with start-up rattle was the Ford 90 degree oil filter adapter.

 

[flintknapper]

I know one thing that helped mine with start-up rattle was the Ford 90 degree oil filter adapter.

 

[Bigdrewbowski]

To me (for what it's worth) it sounds like a bracket or part of the exhaust. I think the term is Sympathetic Vibration.

 

[Proven]

You're video is in neutral and sitting still. I think everything drive-train related is excluded at that point.

That sounded to me like a washer or bolt in a fender well rattling around. You can also check where the air intake hose goes into the passenger side fender. There is a silencer in there (black plastic bottle) that on mine will rattle from time to time against the fender.

Could you get a recording of the sound walking around the engine with someone else pushing the throttle to the sweet spot? start standing on the driver side and walk slowly around the front to the passenger side.

I am thinking this is just harmonic vibrations causing something to rattle. could be wrong, but I tend to look for the lesser evils first.

What about the fan clutch? I've never had one go bad before...just wondering...

 

[CoffeeGeek]

I get a very similar rattle that is RPM specific, closer to 2k for me though. I have not been able to narrow down using a mechanic's stethoscope. What I need are chassis ears as the stethoscope just does not have enough length to it. Been driving a while like that and nothing has blown up yet.

Good luck narrowing it down.

 

[Proven]

Just remembered something else, don't exclude exhaust pipe leaks either. They can sound very metallic.

 

[mingles]

Are your exhaust manifold heat shields still in place? Mine had fatigue cracks around the bolts and would make a RPM specific rattle. I ended up removing them and have been running without them for the last year with no issues. No more rattle.

 

[izzyandsue]

^^^^^
Sounds like the heat shields to me, I had the same issue. You can open the hood and rev the engine from the cable, will find it quicker that way

 

[Warpigg]

Video didn't have sound for me but mine had a rattle on cold start up and driving around at that rev point. It ended up being the heat shield for the body mount on the passenger front side where the exhaust goes by it. I just got tired of it one day and looked under and ripped it off. And where are you located in vt? I'm from Rutland area and would be happy to help if you would like a second opinion. My father was a Toyota master tech for 20 years so between the both of us we know some things.

 

[Tarim]

Guys,

My apologies for having dropped off the radar these last few days. Was out in the woods with some friends and didn't even think to go online. I can't thank you all enough for all the help and support! It gives me faith in humanity to see how a bunch of guys can come together over their shared love for what was probably the best Toyota, if not the best car model ever made (except for the fuel economy, am I right ?) Thanks again.

Either way, Proven, what you're saying makes perfect sense. I didn't even think that it probably has nothing to do with the drivetrain given in what gear it makes noise. About the harmonic vibration, I thought that as well for a while and there is a small leak in the exhaust that you guys can see in the attached videos, but when the hood is up, you can definitely tell that the sound is coming from inside the engine.

With regards to the heat shield, I thought it might have been that as well cause my heat shield always did make noise, but it's not cause my heat shield still does rattle...

Take a look at these new videos and tell me what you guys think...

Warpigg, thank you immensely for the offer. I might take you up on that. I live in Middlebury and would be happy to drive down to Rutland if you say you'd be willing to take a look at the old beast. Let's see how this thread progresses and keep in touch if need be.

Here are the vids:

 

[Warpigg]

That sounds like a timing chain to me. Not sure how the valve system works in the cruiser since I've never really worked under the valve cover but it could be something in there.

 

[izzyandsue]

For exhaust leaks, if you have a shopvac, blow air into the tailpipe and a spray bottle with soapy water will tell you where it/they are

 

[Tarim]

Thanks again for the help Warpigg. I've always thought it was something to do with the timing chain as well. What's the definitive way to diagnose that though?

 

[Funner]

Possible early spun rod bearing, would probably also show lower oil pressure on gauge. Redo the second video with the phone under the truck to see what the bottom end sounds like?

 

[Proven]

I'd agree that from your video it sounds like it is coming from inside the engine. Your in the cab video made it sound like a harmonic.

If this were me, my next steps are likely to pull the valve cover and at least look at the timing chain and cam shafts.

I might also send an oil sample off to blackstone.

 

[Warpigg]

I would use a stethoscope. That will help you narrow it right down