Another Misdiagnosed Dead Engine After a Broken Timing Belt 2004 2UZ

[Fzj80 1997]

I just wanted to put out another heads up in not trusting your mechanic when they say you need a new motor after a broken timing belt.

I rolled the dice on an 04 that snapped a timing belt a few weeks ago and got a chance to throw in a new belt today. Scoped the cylinders before starting on the belt and no piston/valve contact seemed evident. She fired right up after I plugged in the cam sensor I initially forgot to plug in. Before that, the truck sounded like it didn’t have any compression while cranking for whatever reason which momentarily made my heart sink.

I talked to the mechanic that misdiagnosed the truck before I bought it and he said he performed a leak down test and it failed 5 out of 8 cylinders. Not sure if he actually did it, but the coils were all unplugged and the bolts were loose. Anyways, screw that guy because there’s totally some missing bolts and sorry to the guy that was mislead into selling me his truck. Hope this data point helps someone that runs into this issue in the future

Also, this truck had a timing belt and water pump service around 100k according to the sticker and was overdue by ~1,200 miles. The belt was a Continental and the pulleys seemed fine. Just go OE Mitsuboshi

 

[Patassa]

1200 over and it snapped a belt? Whew. I went 25,000 over and the belt looked like it wanted to tell me I was wasting my time changing it.

 

[BullElk]

Mine was was 230k miles "overdue" and changed it anyway caused I was bored.

 

[mesa man]

I bought a 99 UZJ100 with 244,000
Miles on the ORIGINAL OEM timing belt
From original owner. On the phone he said the belt had been replaced, when we bought it for
4,400 $ and went thru the receipts no timing belt service ever! He had the serpentine belt replaced. The 2uz still ran good but I replaced the old cracked belt, aftermarket belts will not last that long!

I repaired 3 different motors with snapped belt (02’ 2UZ, tundra, 03’ 2UZ Seqoia and 5vz, 03 Tacoma) or shredded teeth and both 2uz motors were declared trashed by the “shop mechanic. The tundra owner cried when I fixed it and took her for a test drive, her friend , a Mercedes mechanic said I was ripping her off and she needed a new engine! Some people don’t know what the F#*c% they are talking about!

 

[Gartenmeister]

So where does the conventional wisdom come from that snapping the timing belt damages the motor?

 

[2001LC]

Sweet, one more for the books. I've yet to see a proven interference in a 4.7 2UZ-fe (98-05).

BTW: A leak down test, can not be done, with broken T-belt. We must have a T-belt on and timed properly, to do compression or leak down test.

Thread 'Timing belt job just done. Blown engine or savable? This is interesting guys!'

Jan 1, 2020

Happy 2020 all.

Well, I spent last day of 2019, inspecting a 2005 LC w/~200K, that was towed to me. That had a Timing Belt installed a few days before coming to me

Let me know your thoughts:

Blown engine from interference or is there hope?​

• Also what do you think happened?

Skip story and go to items 1-15 if you'd just like to just get to the data.

Here's the story. I received an email from Cairo, He was responding to a CL ad I posted for 2UZ engines and parts. Subsequently speaking with Cairo I learned, he had purchased a clean 2005 LC w/~200K miles about 30 days...

• 2001LC
• Replies: 154
• Forum: 100-Series Cruisers

• 

 

[97 AZ LC]

So where does the conventional wisdom come from that snapping the timing belt damages the motor?

From Toyota, who obviously has considerable ability to influence popular thought. Why they said and didn't retract it is not clear. It is of course true for VVT engines which muddies the picture a bit.

 

[Dirt J]

To pile on: I seem to remember a timing belt thread on here that tried to determine if anyone had ever seen an OE timing belt snap on a 4.7...