Can a timing belt change make an engine fail? (2 Viewers)

[lxfourseventy]

This is a weird question but roughly 400 miles after a timing belt replacement on an lx470 maintained well and up to date just had apparent engine failure. One different mechanic said we can't crank the car and it sounds like valves are hitting or something. Timing tensioner is tight... belt in tact but they couldn't access the timing marks to see if they were off or not.

 

[JunkCrzr89]

“Engine failure” is too broad of a term. But incorrect timing can cause a lot of issues on the vvti version of the 2uz that your 06 has. One of those issues is pistons and valves making contact, which could cause destruction.

 

[nissanh]

Yeah, but you drove 400 miles after the repair. If timing marks are incorrect at the install, then valves and piston will come into contact during the first crank. Did you use OEM or Mitsuboshi (belt provided in Aisin kit)? Did you replace all the parts usually get replaced in a timing belt job?

 

[lxfourseventy]

Yeah, but you drove 400 miles after the repair. If timing marks are incorrect at the install, then valves and piston will come into contact during the first crank. Did you use OEM or Mitsuboshi (belt provided in Aisin kit)? Did you replace all the parts usually get replaced in a timing belt job?

I believe the shop used an Aisin Kit, or some kit was mentioned in the invoice..along with usual water pump/coolant and I had them throw in heater tees as well.

“Engine failure” is too broad of a term. But incorrect timing can cause a lot of issues on the vvti version of the 2uz that your 06 has. One of those issues is pistons and valves making contact, which could cause destruction.

car was crusing for hours on the high way that day, 120 miles morning, then 70 miles way back after a couple bumps in the road, took an exit and at the first light the engine shut off. I cranked and gassed it 50ft to a gas station where it wouldnt even start since.

Could it be unrelated... sure, but it hurts my head that 0 mechanical issues then suddenly after timing belt change this happens

 

[nissanh]

You probably want to get it properly inspected with a qualified technician. Let's find out the kit they use. If the tensioner is tight and a good belt has been used, then I do not expect the belt to skip a tooth.

The shop took the valve cover off to fix a chewed wire? Still it should not do ticking unless they removed a camshaft and misplaced a shim between the cam and the lifter.

How is the engine oil level?

 

[hickuptruck]

I can bet the shop installed a cam sensor wire wrong, which lead to it rubbing against the serpentine belt or timing belt over the 400 miles, and then has now completely frayed.

Installed wrong as in should've been behind a mount, but instead is in front, etc.

 

[NE Snowman]

Not exact same but I did have the oil pressure wire get cut by a belt after a Tbelt change, took 10k miles and 9 months till it rubbed enough to cut through though. That said I like @hickuptruck idea of cam sensor.

 

[baltistyle]

Sounds like when my belt broke on a different vehicle. I’d worry about the mechanic you’re using.

 

[lxfourseventy]

You probably want to get it properly inspected with a qualified technician. Let's find out the kit they use. If the tensioner is tight and a good belt has been used, then I do not expect the belt to skip a tooth.

The shop took the valve cover off to fix a chewed wire? Still it should not do ticking unless they removed a camshaft and misplaced a shim between the cam and the lifter.

How is the engine oil level?

good question... i think they were nervous since it kept breaking down and started taking things apart. They didn't give me full info but i saw new bolts on the valve cover and asked about it... since that chewed wire repair, the car smelled like oil ever since...ive brought that up and they brushed it off saying its fine and there are no leaks

Sounds like when my belt broke on a different vehicle. I’d worry about the mechanic you’re using.

my luck i asked them, are you able to do this timing belt job, they said totally very straight forward.

Not exact same but I did have the oil pressure wire get cut by a belt after a Tbelt change, took 10k miles and 9 months till it rubbed enough to cut through though. That said I like @hickuptruck idea of cam sensor.

intersting you said this...so the oil pressure gauge on the dash... since getting the car back i've noticed it was on the lower side more so... now at one point it was unplugged for a while a year ago so i kinda forgot aobut it, but then before the timing it was moving around a lot but never in the low range as much as it was the last 2 weeks... and i still smell oil by the driver front wheel

 

[Bisho]

Another maybe interesting point to mention was the car had 6 months of 'ticking' or valve tapping after the same shop spent 3x breakdowns diagnosing a chewed wire and in one of the diagnose opened up the valve cover and after reinstalling it a tapping/ticking started and they said it's not a big deal.

"Trust us, the new ticking sound we caused is no big deal..." I would have made them fix that and then found a new shop after that. If I used shops.

 

[lxfourseventy]

I can bet the shop installed a cam sensor wire wrong, which lead to it rubbing against the serpentine belt or timing belt over the 400 miles, and then has now completely frayed.

Installed wrong as in should've been behind a mount, but instead is in front, etc.

wow! that sucks... for me if that is what happend, im going to ask the first shop who evaluated it if it's even something they noticed. My brain hurts...I'm trying to figure out what makes 100 series engine just break, the eval mechanic said the valves are hitting pistons

"Trust us, the new ticking sound we caused is no big deal..." I would have made them fix that and then found a new shop after that. If I used shops.

the sad part about being a car guy like me that can't repair his own s*** is learning that MOST shops are lazy AF and do the bare minimum... im always showing up with print outs of torque specs and forum information prior to repairs. sad times

 

[94SRUNNER]

You may want to cross-post in the MA-NH Clubhouse. You may be able to find a local to you Cruiser head who is knowledgeable enough to give you an experienced second opinion in person or point you in the direction of a reputable shop.

MA/NH- Yankee Toys

forum.ih8mud.com

You may also want to cross-post on one of the 100 Series Facebook groups. You may get some additional feedback there.

Sorry to hear about your troubles with this.

 

[lxfourseventy]

You may want to cross-post in the MA-NH Clubhouse. You may be able to find a local to you Cruiser head who is knowledgeable enough to give you an experienced second opinion in person or point you in the direction of a reputable shop.

MA/NH- Yankee Toys

forum.ih8mud.com

You may also want to cross-post on one of the 100 Series Facebook groups. You may get some additional feedback there.

Sorry to hear about your troubles on this.

thank you!!

 

[Kamran Khan]

Majority of engines needs to be set at TDC for timing belt removal but not this one and I believe this where the mechanic may have made a mistake.

 

[BnvS]

wow! that sucks... for me if that is what happend, im going to ask the first shop who evaluated it if it's even something they noticed. My brain hurts...I'm trying to figure out what makes 100 series engine just break, the eval mechanic said the valves are hitting pistons


the sad part about being a car guy like me that can't repair his own s*** is learning that MOST shops are lazy AF and do the bare minimum... im always showing up with print outs of torque specs and forum information prior to repairs. sad times

Bro you should have brought this info up a while back. You then had oil smell and you still didn't bring this up. C'mon bro. Trust but always verify, always.

In this case your mechanics are idiots.

I was somewhat green thumbs on doing timing belt changes. But with lots of video watching and preparing it can be done.

So your mechanics need to be fired. As besides this TB and oil problems this engine is bulletproof.

wow! that sucks... for me if that is what happend, im going to ask the first shop who evaluated it if it's even something they noticed. My brain hurts...I'm trying to figure out what makes 100 series engine just break, the eval mechanic said the valves are hitting pistons


the sad part about being a car guy like me that can't repair his own s*** is learning that MOST shops are lazy AF and do the bare minimum... im always showing up with print outs of torque specs and forum information prior to repairs. sad times

Bro you should have brought this info up a while back. Trust but always verify.

In this case your mechanics are idiots.

I was somewhat green thumbs on doing timing belt changes. But with lots of video watching and preparing it can be done.

So your mechanics need to be fired. As besides this TB and oil problems this engine is bulletproof

Edit: Was using phone. Didn't see that your a new member.

 

[OregonLC]

Majority of engines needs to be set at TDC for timing belt removal but not this one and I believe this where the mechanic may have made a mistake.

Just to clarify, I believe the 50 degree is for VVT-i engines (06-07). I've always done them at TDC by following scott's writeup. And the 98-05 are non-interference. I've had cam turn on me under spring force when re-installing the belt with no ill effects. I believe the 50 degrees is to put the VVT-i off center so they won't inadvertently spring down.

That said, this is an 06. However, I'd be doubtful that piston/valve contact during the job would result in a smooth running engine that later develops problems. A bent valve is a bent valve. I'm leaning more toward something wasn't torqued. Either a cam gear spun off it's pin, then tensioner wasn't fully seated, or something else. That is, if it's even timing related. Needs to be torn into to determine exact causation.

 

[JunkCrzr89]

I believe the 50 degree is for VVT-i engines (06-07).

It’s for all model years, including non-vvti 2uz. Here’s the FSM for my 2000 LC.

 

[OregonLC]

It’s for all model years, including non-vvti 2uz. Here’s the FSM for my 2000 LC.

Gotcha. I think Scott was one of the first to write this up about a decade ago and I've been following his procedure through five timing belt jobs thus far. AFAIK, the non VVT-i engines are non-interference so the 50 degree setting shouldn't matter, at least from a damage prevention measure. But I'm not disputing the FSM, by all means that should be the gold standard. Thanks for sharing.

It does bear noting that you do end up rotating them back to TDC at the end of the job, leading me to believe that the 50 degree setting is just to allow the cam to rest at it's lowest energy state.

 

[lxfourseventy]

Majority of engines needs to be set at TDC for timing belt removal but not this one and I believe this where the mechanic may have made a mistake.View attachment 3156567

woah, very insightful, thank you for this Kamran!

 

[lxfourseventy]

Gotcha. I think Scott was one of the first to write this up about a decade ago and I've been following his procedure through five timing belt jobs thus far. AFAIK, the non VVT-i engines are non-interference so the 50 degree setting shouldn't matter, at least from a damage prevention measure. But I'm not disputing the FSM, by all means that should be the gold standard. Thanks for sharing.

It does bear noting that you do end up rotating them back to TDC at the end of the job, leading me to believe that the 50 degree setting is just to allow the cam to rest at it's lowest energy state.

View attachment 3156835

thank you, also very good info!

Bro you should have brought this info up a while back. Trust but always verify.

In this case your mechanics are idiots.

I was somewhat green thumbs on doing timing belt changes. But with lots of video watching and preparing it can be done.

So your mechanics need to be fired. As besides this TB and oil problems this engine is bulletproof

Edit: Was using phone. Didn't see that your a new member.

this.