Inconsistent popping noise after timing belt change (1 Viewer)

[joshtowe]

So I had a mechanic friend (yeah I know, obviously should’ve just taken it to a shop) replace my timing belt/water pump on my 2003 GX470. After everything was put together, I go to start it and there’s this inconsistent/non-rhythmic clatter noise coming from the engine bay. Sounds like something is loose and not valves hitting pistons as that would have a more consistent noise? Obviously I shut the engine off as soon as I hear the noise. We check the timing belt and it’s off by one tooth on the passenger side cam. Ive gotten it towed to a shop and as soon as I told them that timing was off, they immediately say that the engine is blown. I’ve read that the non-vvti engines might be non-interference? Should I have them redo the timing belt job anyway and hope there’s no engine damage? Not sure what to do

 

[vipergrhd]

First you don't let friends work on your car unless it's free or he is the only mechanic you trust, the shop that you took it are a bunch of morons they just don't want to deal with another mechanics mistake. The noise you describe is not consistent with a belt being off by a tooth you need to call around before driving your vehicle to them and see who is willing to look into and avoid the dealer if possible. I don't think your problem is serious it's just a matter of finding what's causing it and double check the TB job your friend did.

Looks like you are a newbie here let me be the first to WELCOME you on Mud. You can get a lot of help here and give you sound advice, official MUD welcome

(Mud salute). Keep us posted and I'm sure someone else will follow up more advice on your situation.

 

[joshtowe]

First you don't let friends work on your car unless it's free or he is the only mechanic you trust, the shop that you took it are a bunch of morons they just don't want to deal with another mechanics mistake. The noise you describe is not consistent with a belt being off by a tooth you need to call around before driving your vehicle to them and see who is willing to look into and avoid the dealer if possible. I don't think your problem is serious it's just a matter of finding what's causing it and double check the TB job your friend did.

Looks like you are a newbie here let me be the first to WELCOME you on Mud. You can get a lot of help here and give you sound advice, official MUD welcome

(Mud salute). Keep us posted and I'm sure someone else will follow up more advice on your situation.

He told me that he had done his buddy’s belt on his 4.7 Sequoia, only to tell me later that he joined in on the tail end of the process. He did do it for free though, but obviously I wouldn’t have asked him do it if he had told me that earlier. He did double check timing marks and rotated the motor twice before putting everything back together so he is just as confused as I am

 

[joshtowe]

 

[vipergrhd]

He told me that he had done his buddy’s belt on his 4.7 Sequoia, only to tell me later that he joined in on the tail end of the process. He did do it for free though, but obviously I wouldn’t have asked him do it if he had told me that earlier. He did double check timing marks and rotated the motor twice before putting everything back together so he is just as confused as I am

If your friend is willing and have the time go over it with him again and recheck the timing marks and maybe you will find the source of noise too. Did you replace WP and the tensioner?

 

[joshtowe]

If your friend is willing and have the time go over it with him again and recheck the timing marks and maybe you will find the source of noise too. Did you replace WP and the tensioner?

Yep WP and tensioner were replaced

 

[kwkshift]

If one cam is off 1 tooth, the engine might be fine. It could just be backfiring through the intake. The valves might be uncomfortably close to the pistons, but not making contact. You could rent or buy a scope to put down the spark plug holes to see if there is any damage to the pistons from the valves. If there is not, I would tear it back down and fix the error, first. It might be ok, after that.

 

[aztoytec]

Non VVt 4.7 are non interference. I’ve had them towed to to shop with broken or shredded timing belts and never had a problem.

 

[joshtowe]

Non VVt 4.7 are non interference. I’ve had them towed to to shop with broken or shredded timing belts and never had a problem.

That’s what I’ve read and I’m hoping that’s the case. That means the clattering noise isn’t valves hitting pistons right?

 

[aztoytec]

I doubt it. If the valves were being hit that hard it wouldn’t run for long! Tear it down again and see what you find. Hopefully it will be obvious

 

[joshtowe]

Update: shop called me back today, said they think everything will be fine. They said the rattle was loose nuts holding the fan clutch to the fan pulley