2004 Toyota v8 Timing Belt breaks at 65mph

I have a Toyota V8 I’m driving down the highway at 65mph. Had it towed to closest privately owned shop. Fuel pump ok spark ok no compression on 4 cyl Shop says timing belt most likely but engine is shot. Engine has 197,000 with previous belt change at 175,000 again at a private shop. I had vehicle towed home and going to inspect pistons and valves with a bore scope. My question is if I see no valve strikes on pistons or marks on valves would this mean that even though the garage said I had no compression in 4 of the holes that the engine may be worth putting a new timing belt etc...and trying it to see if by some miracle that it is ok. Or does “no compression in the 4 holes” mean that the valves are all bent at least on one side of the engine? Trying to figure out if it is worth the gamble or do I sell for what ever I can get for it. 2004 Sequoia Limited seats about a million people. Thanks in advance for the opinions.

 

I’m no authority on this, but I didn’t think you could do a compression test with a broken timing belt?
If the pistons look fine, and nothing else looks wrong in there, I would try a new belt, they’re not that expensive, might save your truck.

 

No timing belt means the valves aren't moving and are just sitting where the belt broke and left them. Sounds like a load of BS to me. Good chance they jacked up the valves more than they already may of been if they're hitting the starter and thinking that somehow proves something when the valves can't be actuated. If the valves and pistons look fine I would try to throw a belt on and see what it does. Or if you want to spend more time pull the heads and check the valves and replace any that are jacked.

 

If you deem it repairable either find better shops or a trusted mechanical friend to help you repair it. And use only Aisin parts. The first belt replacement was either done improperly or with inferior aftermarket parts or both to fail so quickly.

 

There is a site that can tell you if it is a non-interference engine. If so you should be fine. I don't recall seeing timing belt engines with interference.

 

Forgot to mention I looked it up on line and it is an interference engine. Also tow truck driver the works for a different company but does a lot of towing for the garage seemed very anxious to buy from me “If the price was right” something didn’t seem right with this whole string of events.

 

Just curious if you heard any crazy noise when this happened....as if a piston was meeting a valve for first time

The 4.7L 2UZ-FE Tundra up thru 2004 uses a timing belt and is an interference engine. The 05 on up 4.7L 3UZ-FE VVT-I Tundra uses a chain....if I am not mistaken !

 

They are both belts.

 

Are you saying they didn't inspect the timing belt, but they know the engine is shot?

If so, that makes no sense to me.

 

Yeah I feel like the shop that installed the belt has the responsibility to investigate the cause, so that they can clear their name on the timing belt install. That would be good customer service. Not sure what their guarantee policy is, but at 22k miles those parts are expected to last at least 80k with many people unknowingly going double that.

If it was installed correctly and the belt broke I would be talking to the manufacturer.

 

The 3UZ-FE was a 4.3 and was not in the truck/SUV

Wups, I meant to quote @BubbaW, but you get it.

 

I'm willing to bet that if the belt did break the shop used cheap aftermarket parts and not the Aisin kit. We've seen a few members here deal with the same issue.

 

Ah, youre right. Selective reading missed that as I assumed he was talking about the non-VVT-i vs VVT-i 4.7s.

 

No worries, I was reading what you quoted and quoted you in error. D'oh.

 

As I recall/understand, the engine became interference in 2005, with the advent of the variable valve timing. The earlier non-VV engines were not interference. So, you should be ok.

If the shop doing a compression check is doing it with the broken belt in place, they are remarkably clueless.

Now perhaps I'm misunderstanding, and they are saying there is no compression on one side of the engine, while there is compression on the other. That would explain the 4-hole comment. That would also indicate the likes of a broken camshaft, or perhaps a jumped sprocket on that side of the engine.

 

I would take the motor apart and see what’s broken instead of guessing and thinking about what’s broken, rebuild/ replace parts or get another motor. Until you take it apart, you really don’t know,

 

For what it's worth, Gates considers it to be an interference engine (scroll down to timing belt components and look under comments)...

https://www.gates.com/us/en/ymm/search/vehicle/result?equipment-clazz=Passenger+Cars+&+Light+Trucks&vehicle-type=Light+Trucks&year=2003&make=Toyota&model=Tundra&engine=V-8+4.7+L

Having said that, I think there have been cases of people losing timing belts on these without a lovemaking session between piston and valve...

 

Two words: Bore Scope

https://www.amazon.com/s?k=borescop...HEW80&sprefix=bore,aps,177&ref=nb_sb_ss_i_9_4

If you see nothing amiss...install new timing belt (if needed) after inspection. At the first hint of piston, cylinder wall or valve damage, install used or reman engine.

 

I’d love to hear a good post-mortem analysis on:

1) The brand of said failed belt.

2) All the other parts (tensioner especially) that were/were not replaced during said TB.

3) An honest written opinion from the mechanic that eyes on investigates this engine.

 

Heard no metal clanking sound or grinding when it died. Repy to #7
They did not take timing belt cover off to come up with diagnosis of shot engine #9
No chance of getting garage that installed belt to stand behind it I am the 2nd owner #10
I bought the bore scope that was on the page you sent a link on thanks#18

 

Tensioner was replaced same time belt was #20

I will try to post post Mortem once I get this figured out#20

 

The more people you ask the more wrong answers you will get. From people who don’t know,they are guessing. Just take the engine apart and you will know

 

You're mistaken all 2uz engines are timing belt and interference engines.

The 3uz is a 4.3L not found in Toyota trucks.

 

Simply asking and just want to learn but what is the difference of what I said above and what you just said ?

"The 4.7L 2UZ-FE Tundra up thru 2004 uses a timing belt and is an interference engine"

 

The 2UZ-FE was used 00-09. They added VVTI in 05, all iterations used timing belts and are considering interference engines.

The 5.7 3UR-FE uses a timing chain.

 

I've lost the belts twice on my motorcycle first time I got lucky, second time grenade

 

Never hurts to check. You may have gotten lucky. Be prepared for the worst, but thank you're lucky stars if you didn't smack a valve. I've noticed that on the cam belt spindles on the wife's V6 that when you rotate them and are opening valves, they will bounce off the spring tension back to a position with no valve spring tension. Even a head job could be much cheaper than just saying screw it.

Or just put a belt on it, turn it over by hand, then fire it up and see.

 

All 2uz engines are interference engines and all 2uz engines use a belt vs a chain. So not just 2000-2004 Tundras, but 2000-2006 as well as the handful of 2nd gens with the 4.7L and Land Cruisers and LX470 and GX470 and the 4.7L 4Runners all fit into this equation. This also includes non vvti and vvti 4.7L. the vvti started in 2005.

"The 05 on up 4.7L 3UZ-FE VVT-I Tundra uses a chain.."
Maybe you didn't mean to say 3uz but you did, so I corrected that as well. I know I can be blunt but this thread is chalk full of misinformation just reading the first page. So i tried to cut to the chase. However there is also some.very good info in here as well.

 

Gotcha

Can assure you I take most comments as constructive and yours were no different. Learning more and more everyday !

 

Just wanted to clarify because it seems the OP is new at navigating the "reply" tools on here. He posted and PMd me that he is the 2nd owner and was not the one to have the belt done. So he feels like going back to the shop isn't an option. I think he's somewhat right that a guarantee wont transfer over, but if there is record that the service was performed on that VIN truck regardless of the owner I think they should at least work with him.