Need Some Opinions - Engine Noises

[LiquidFlame]

Hey guys,

I recently picked up a 2008 V8 4x4 for a steal, but she's been neglected and has some engine noises. I had a couple 3rd gens awhile back, so I was able to log back in.

Luckily, I have some love to give and am excited to start working on this project. It does run and drive just fine, but the previous owner stopped driving it due to some engine ticking/noise/sounding a bit like a diesel. He was told it was lifters and needed about $2500 worth of parts/machining to fix the issue. It is not low on power, no codes, passed emissions without issue, has 160,000 on the clock. Timing chain was done at 150,000

I'm going to tear into this thing pretty soon and probably start with checking valve clearances, but I wanted to post here with a video to see if anyone can help pinpoint my issue. I've heard ticking come from bad cats (passed emissions so don't think so), improper cam gear spring tension, exhaust leaks (noise does not change with time/temperature, happens instantly on cold/warm start and varies with engine RPM), VVTi components, etc. The noise is seemingly worse on the passenger's side.

Let me know what you guys think and what you'd do if you were me. Places to start, leave it alone, take it somewhere, etc. I know there are a million "what is this noise my vehicle is having" threads, and I've done my searching. I just want to get some second opinions from some people more knowledgeable on these 2uz's than I am-

2uz VVTi Engine Noise - YouTube

 

[AuSeeker]

Hey guys,

I recently picked up a 2008 V8 4x4 for a steal, but she's been neglected and has some engine noises. I had a couple 3rd gens awhile back, so I was able to log back in.

Luckily, I have some love to give and am excited to start working on this project. It does run and drive just fine, but the previous owner stopped driving it due to some engine ticking/noise/sounding a bit like a diesel. He was told it was lifters and needed about $2500 worth of parts/machining to fix the issue. It is not low on power, no codes, passed emissions without issue, has 160,000 on the clock. Timing chain was done at 150,000

I'm going to tear into this thing pretty soon and probably start with checking valve clearances, but I wanted to post here with a video to see if anyone can help pinpoint my issue. I've heard ticking come from bad cats (passed emissions so don't think so), improper cam gear spring tension, exhaust leaks (noise does not change with time/temperature, happens instantly on cold/warm start and varies with engine RPM), VVTi components, etc. The noise is seemingly worse on the passenger's side.

Let me know what you guys think and what you'd do if you were me. Places to start, leave it alone, take it somewhere, etc. I know there are a million "what is this noise my vehicle is having" threads, and I've done my searching. I just want to get some second opinions from some people more knowledgeable on these 2uz's than I am-

2uz VVTi Engine Noise - YouTube

Go to an auto part store and for about $10+/- buy yourself a mechanic's stethoscope and use it to pinpoint where the ticking/tapping is coming from, once you know where the noise is coming then you can decide much better on a course of action, let us know where the noise is the loudest using the stethoscope.

Also just an FYI, the V6 has a timing chain, the V8 has a timing belt.

I'm assuming the previous owner had the timing belt replaced(?), if so did he mention if the noise was there before the replacement, or only after?

 

[LiquidFlame]

Go to an auto part store and for about $10+/- buy yourself a mechanic's stethoscope and use it to pinpoint where the ticking/tapping is coming from, once you know where the noise is coming then you can decide much better on a course of action, let us know where the noise is the loudest using the stethoscope.

Also just an FYI, the V6 has a timing chain, the V8 has a timing belt.

I'm assuming the previous owner had the timing belt replaced(?), if so did he mention if the noise was there before the replacement, or only after?

Good idea, will do that tomorrow. Thanks!

Yes it is the belt (oops) that was replaced about 10k ago. He didn't say it happened because of that, I'm just guessing. It it did start happening a few months after the belt was replaced. Coincidence? Maybe, maybe not.

 

[LiquidFlame]

Upon probing with the stethoscope, there seems to be a much more pronounced noise coming from the passengers side cam gear area as compared to the drivers side, where it is still present but quieter. Almost sounds like a pair of claves (the percussion instrument) hitting each other.
Like this but a bit higher in tone: Claves Demo - YouTube

Possibly cam gear spring tension not set properly or stuck? Going to pull valve covers today and see what I find.

 

[LiquidFlame]

Pulled covers and checked clearances. No visible damage to the lobes or anything loose, scratched, or gummed up.

Clearances are as follows:
Cyl2 Intake front = 0.008"
Cyl2 Intake back = 0.008"
Cyl2 Exhaust front = 0.011"
Cyl2 Exhaust back = 0.011"
Cyl4 Intake front = 0.008"
Cyl4 Intake back = 0.009"
Cyl4 Exhaust front = 0.012"
Cyl4 Exhaust back = 0.012"
Cyl6 Intake front = 0.009"
Cyl6 Intake back = 0.009"
Cyl6 Exhaust front = 0.012"
Cyl6 Exhaust back = 0.011"
Cyl8 Intake front = 0.009"
Cyl8 Intake back = <0.004"
Cyl8 Exhaust front = 0.012"
Cyl8 Exhaust back = 0.010"

Given the specs via the Toyota service manual, Exhaust should be between 0.011" and 0.015", Intake should be between 0.006" and 0.01".

So, the only one I'm worried about is the rearward intake on cylinder 8. My feeler gauges don't go below 0.004" so I can't check what it actually is currently. Would this low clearance cause that much of a sound issue? My stethoscope didn't reveal much noise in the back of the engine.

Seems I need to go one layer deeper...

 

[rdruss]

Somebody else can chime in on this but I thought I read a post about the fuel pressure regulator making a noise like this when it goes bad?? It's easy to get to, just above D/S rear of valve cover.

 

[LiquidFlame]

Somebody else can chime in on this but I thought I read a post about the fuel pressure regulator making a noise like this when it goes bad?? It's easy to get to, just above D/S rear of valve cover.

An interesting thought, I'll have to sniff around that area and see if I can find anything out of place.

Haven't had much time to work on it this week, hoping I can find some time this weekend.

 

[MikeinNH67]

So, the only one I'm worried about is the rearward intake on cylinder 8. My feeler gauges don't go below 0.004" so I can't check what it actually is currently. Would this low clearance cause that much of a sound issue? My stethoscope didn't reveal much noise in the back of the engine.

I can't see how that would make for a noise as the lash is just about gone, too much lash would make some noise. That is a tight valve though that could get burned as it eventually may not seat all the way.

As for the sound, are you sure you don't have an exhaust manifold leak?

 

[LiquidFlame]

I can't see how that would make for a noise as the lash is just about gone, too much lash would make some noise. That is a tight valve though that could get burned as it eventually may not seat all the way.

As for the sound, are you sure you don't have an exhaust manifold leak?

My thoughts exactly.

It definitely doesn't seem like an exhaust leak, but its hard to tell. Its very much louder on top of the engine and when I probe with my stethoscope it gets quieter as I move away from the valve cover.

I still couldn't find anything, so I took it to a reputable local shop just to diagnose and they couldn't figure it out either. Their best guess is the spring tension on the cam gears, so that's a point towards my initial thought, but its still a guess. Picking it up later today.

Might take it to the Toyota dealership to see what they think. I have no problem pulling the timing cover off and checking the cam spring myself, but would rather not shoot in the dark if it can be helped.

If anyone has any other ideas I'm all ears-

 

[MikeinNH67]

Maybe whoever did the last timing belt service put cheap parts in there.

 

[LiquidFlame]

Maybe whoever did the last timing belt service put cheap parts in there.

Also possible. One suspect is the timing belt tensioner either sticking or stuck all together.


I pulled my valve cover again to look at the back of the cam gear alignment. I was able to thread the service bolt all the way through both divisions of the split gear, which tells me the gear is aligned properly. The only way this could be the problem now is if the spring itself is broken. Is there any way to check the spring tension without pulling my timing cover?

 

[LiquidFlame]

So..... I did something stupid.


The morning I was supposed to bring it in to the dealer I went to start it up. Turned the key and all hell broke loose. Turned the key off, heard dripping fluid.

Turned it off, kicked my drain pan underneath and went to look. Turns out I left my breaker bar on the crank bolt and it spun around.... A few things happened:
- My fan absolutely exploded into 100 pieces.
- Fan shrapnel hit the radiator and poked some holes in the bottom, which was the dripping I heard.
- It threw my breaker bar but did not bend/break it or the socket.
- It spun out my crank bolt. Pulley remained seated and bolt is unharmed.

So yeah. That was exciting. Honestly it was only $250 for a new koyo radiator and a fan and everything else was fine. Got pretty lucky I'd say.

Received everything last week and she runs again. Dealer appointment is Wednesday. Will report back with their findings.

 

[aemravan]

:jaw:

That's always been a fear of mine with leaving the breaker bar on the crank bolt since I very regularly use the "starter" method to bump the crank bolt loose.

I was in the process of going to bump the key with the breaker bar in place when I was gearing up to do my timing belt change and then something clicked in my brain and I realized I don't have the ability to "bump" the starter... I was pretty close to a similar situation. Glad it wasn't worse, radiator and fan are simple enough and now you can check coolant flush and new radiator off your list

 

[MikeinNH67]

Yikes, that could have been really bad.

 

[LiquidFlame]

Well... Even toyota couldn't figure out what's wrong with it. They agreed its not a normal noise, but said it didn't seem to be anything mechanical and should be fine to drive.

What do you guys think? Should I continue to dive into this and figure out what it is? Or should I just let it go? My fear is that it decides to grenade when I'm camping in the middle of nowhere.

This is a second vehicle, so I'm thinking I'll drive it around to and from work for awhile to see if anything changes.

 

[AuSeeker]

Well... Even toyota couldn't figure out what's wrong with it. They agreed its not a normal noise, but said it didn't seem to be anything mechanical and should be fine to drive.

What do you guys think? Should I continue to dive into this and figure out what it is? Or should I just let it go? My fear is that it decides to grenade when I'm camping in the middle of nowhere.

This is a second vehicle, so I'm thinking I'll drive it around to and from work for awhile to see if anything changes.

Did the Toyota dealership look at that one valve with little clearance, if so what did they say, if not what's the latest on that issue.

That valve would be my most worry on keeping on driving it at this point, if that doesn't get corrected you could as mentioned end up burning that valve and that means pulling the head to replace it, a lot of work to do that, getting it to have proper clearance can be done without pulling the head by using compressed air via the spark plug hole to hold the valve in place to remove the spring, but it will still require a lot of work removing the cam to replace the lifter/cup with one that will correct the clearance issue.