Do timing chains need to be replaced on a 3.7l v6, and what happens if they're not?

[No H2O]

Coming up on 200k miles, assumed the PO did it at 100k miles, he said it wasn't necessary since they're so durable. Is this true? and what happens if/when one of the chains take a dump, is it CEF (catastrophic engine failure) or just non-running, pull over, tow-to-shop, and then get it done?

 

[Atcer2018]

Coming up on 200k miles, assumed the PO did it at 100k miles, he said it wasn't necessary since they're so durable. Is this true? and what happens if/when one of the chains take a dump, is it CEF (catastrophic engine failure) or just non-running, pull over, tow-to-shop, and then get it done?

Chains rarely break. When they wear you will hear it. Quite noisy suckers when they are on their last legs. Chains typically last the life of the engine but not so much for guides and tensioners.

 

[No H2O]

Chains rarely break. When they wear you will hear it. Quite noisy suckers when they are on their last legs. Chains typically last the life of the engine but not so much for guides and tensioners.

should the guides/tensioners be replaced at certain intervals and would they also make a lot of noise when they're about to go?

 

[Atcer2018]

should the guides/tensioners be replaced at certain intervals and would they also make a lot of noise when they're about to go?

It’s a 2006 so it’s not unheard of the guides and tensioner(s) wearing out. The issue is cost. It’s expensive to pull everything to get the front cover off. If you do it yourself it’s a PITA especially if you get in there and everything is satisfactory. On the other hand if something breaks the 3.7L is an interference engine and it would have substantial damage that most likely would not be cost effective to repair at 200k miles. It’s your call because you’ll be the one doing the work or paying the bill. If the truck has no other issues it would give you peace of mind knowing the internals were ok or the failing parts were replaced. It can’t hurt anything replacing old parts. Please keep in mind that a failing timing chain and related components will make noise when they are on their way out.

 

[Daw14]

With the mileage up there, if I opened to check the tensioners I would probably put chains and tensioners in. Just because of all that’s involved .

 

[Wild one]

Coming up on 200k miles, assumed the PO did it at 100k miles, he said it wasn't necessary since they're so durable. Is this true? and what happens if/when one of the chains take a dump, is it CEF (catastrophic engine failure) or just non-running, pull over, tow-to-shop, and then get it done?

If the chain breaks or jumps a couple teeth,good chance you'll be putting a new engine in.The hemi is an interferance engine,which means if the chain goes out and the cam jumps a couple teeth,the valves will usually hit the pistons,and it's game over.The early engines did have issues with the tensioners going out,allowing the chain to jump teeth.

Edit:Ignore me,it was just pointed out to me you have the 3.7 V6.I know nothing about them.

 

[No H2O]

thank you all for the feedback, I have a clear idea of my options now

 

[jws123]

As someone who rebuilds 3.7 and 4.7 engines often Yes you need new timing chains and guides every 100k miles they guides break they are plastic and the chains do stretch dont use one of the cheap amazon kits ive wasted alot of time.

 

[Zoe Saldana]

As someone who rebuilds 3.7 and 4.7 engines often Yes you need new timing chains and guides every 100k miles they guides break they are plastic and the chains do stretch dont use one of the cheap amazon kits ive wasted alot of time.

What about the 6.4L HD?

 

[jws123]

What about the 6.4L HD?

nope no issues with them same as the 5.7 hemis I have re used my chain/guide when I did my camshaft at like 180k. However they are cheap to do if you ever have the engine apart.

 

[Wild one]

What about the 6.4L HD?

The earlier Hemi's had issues with the guides wearing out,and then the chain would jump,and bend valves,but they went to a better guide set-up in the later redesigned 09 and newer blocks,so the issue isn't as common on the newer Hemi's. But if you have a few miles on the engine,and have the dreaded cam/lifter issue,it's usually a good idea to replace the guides and chain while it's apart as JWS stated.
If the chain jumps a tooth or 2,it always puts the cam into ret&rd mode,as it's vitually impossible for the cam to go into advance mode when a chain jumps

 

[Zoe Saldana]

nope no issues with them same as the 5.7 hemis I have re used my chain/guide when I did my camshaft at like 180k. However they are cheap to do if you ever have the engine apart.

Not something I look forward to. I have 90K on it now and no chain sounds.

 

[jws123]

Not something I look forward to. I have 90K on it now and no chain sounds.

yea dont wait til you have sound thats how i get my blown engines lol usually around 110k.

 

[El Huapo]

At 200K miles, I'd wager that a timing chain system replacement would wake your engine up. Do a valve job at the same time and it should run much stronger. But you need to compare the time and money vs the value of the truck. If you love it, fix it.

 

[Zoe Saldana]

At 200K miles, I'd wager that a timing chain system replacement would wake your engine up. Do a valve job at the same time and it should run much stronger. But you need to compare the time and money vs the value of the truck. If you love it, fix it.

I predict that the value of V8 gas trucks will go up as V8s are eliminated and electric trucks take over the market over time.

 

[Lloyd33]

I predict that the value of V8 gas trucks will go up as V8s are eliminated and electric trucks take over the market over time.

Does that mean my V10 will be worth even more?

 

[Zoe Saldana]

Does that mean my V10 will be worth even more?

Maybe in the RV rebuild market.