Timing Chain

My car has 134k on it and I've never had to mess with the timing chain and gears...should this task be a "time change" or should I go on the assumption "if it's not broke don't fix it"? Thanks.

i wouldnt mess with it until you break it, or you happen to be in the doing something else and its easy to get too (like a cam install, or engine rebuild).

On a stock 3800. If it ain't broken don't fix it. Unless your swapping a cam.

To give you a reference point, there are many 3800's out there with stock timing chain and over 200K miles.

I beat mine to 186K before replacing it while doing a cam.

That's good info. I was thinking of replacing mine (just beacause), but I won't be doing it now.

Thanks

I changed mine at about 160k-165k miles in the process or diagnosing a tricky problem I was having. I probably could have gone without doing it but I'm quite glad I did. The tensioner looked like shit and there was slight slack in the chain due to wear. It was enough to have a small effect on low rpm performance in the engine.
I really don't hear of them straight up breaking much so I would say letting it go for now would be ok. If you think you'll be taking it apart some time in the future to do something else like a cam, just wait. If not, I might just do it soon just because you technically should.

turtleman wrote:

I changed mine at about 160k-165k miles in the process or diagnosing a tricky problem I was having. I probably could have gone without doing it but I'm quite glad I did. The tensioner looked like shit and there was slight slack in the chain due to wear. It was enough to have a small effect on low rpm performance in the engine.
I really don't hear of them straight up breaking much so I would say letting it go for now would be ok. If you think you'll be taking it apart some time in the future to do something else like a cam, just wait. If not, I might just do it soon just because you technically should.

what TRICKY problem was, that did it ever get found??

Quote :

what TRICKY problem was, that did it ever get found??

https://rivperformance.editboard.com/series-ii-engine-transmission-f4/the-big-problem-t1503.htm?highlight=problem

When the timing chain went in my Charger it didn't break, but the car would quit when I wanted it to run and run after I shut off the ignition.

Jack the R wrote:

When the timing chain went in my Charger it didn't break, but the car would quit when I wanted it to run and run after I shut off the ignition.

One thing to know is that unlike the old charger, our engine has an interference valve train which means if the chain actually does go, say bye to at least 2 of your valves and god can only guess what else. it is possible if you have the luck of a leprechaun to have almost no damage but its also possible to need a new motor. Odds are not favorable enough to take the chance if it's your only car, which is my case.

It's not really that hard to change the thing if you have tools and a couple days nor is it overly expensive parts wise.

The odds are also likely that the chain will never break, or at least last to 200k in a modded car. I plan to replace mine something this year. Waiting on a good reason to go in there...

AA...Cam?

While we're on the topic i will never drive a car with a timing belt. I had two friends over the summer who had one go on them and 1 bought a whole new motor and the other needed a top end rebuild. 2 months later my friend who had the top end rebuild had a defective belt and the engine blew out again. I dont trust the timing belts for anything...chains are much more durable...

No cam. My 1.9 rockers are awesome. They are the INTENSE (Harlan Sharp) Gen IIIs, the same ones that received all the bad press for being defective and dumping metal shavings into the oil. I just passed 75,000 miles with my Gen III rockers installed. Don't believe all the hype!

Me too. I've been running the Gen III HS rockers for 75000 miles. Not a single problem.

Interference motor?!?

Is that only with the modifications?

Quote :

Is that only with the modifications?

I deleted previous post. I think it is the interference type, but I'm reading mixed responses on the subject. I really hope I'm wrong and it's non-interference!

AA wrote:

The odds are also likely that the chain will never break, or at least last to 200k in a modded car. I plan to replace mine something this year. Waiting on a good reason to go in there...

I know this was dated early 2008. Procrastination or Procrastination.?

Well, I did buy the chain and sprockets shortly after posting that comment. At least I had good intentions! I probably decided it could wait till 200k, and now I'm finally there, so it really should be done.

Unless we find out it's not an interference engine...

AA wrote:

Well, I did buy the chain and sprockets shortly after posting that comment. At least I had good intentions! I probably decided it could wait till 200k, and now I'm finally there, so it really should be done.

Unless we find out it's not an interference engine...

Random question - are you using stock valvespring retainers or LS1 style retainers?

They are LS6 retainers.

When I started reading this thread I got a little worried considering my mileage and I started researching online and so far I found a couple of forums where guys are saying that the 3.8L engine is a free wheeling engine, not an interference engine. They also say that modifications such as changing the valve timing, valve lift or compression ratio can and does turn some non-interference engines into interference engines. Can anyone confirm if our motors in stock from are non-interference or not?

I would like a definitive answer as well.
Because i will put in a new chain and tensioner this summer before the winter slows me down.
Mainly because I ran the engine for about 7,000 miles with the incorrect valve retainers on it, that supposedly cause premature wear on the tensioner and chain. I now have the LS retainers on which don't pre-load the springs too much.

On older cars with distributors it was so much easier to check your timing chain. Not on this engine.

I'm thinking the same thing about the interference. They probably made the valves just clear the pistons in a worse case scenario. The 1.9:1 rockers could easily change that formula, as the valves move 20% further to open. I do not wish to find out the hard way!

AA wrote:

I'm thinking the same thing about the interference. They probably made the valves just clear the pistons in a worse case scenario. The 1.9:1 rockers could easily change that formula, as the valves move 20% further to open. I do not wish to find out the hard way!

That's what I think... The general consensus on the Web is that the 231/3800 is a non-interference motor, and I think I would probably have heard otherwise over the years if it was.

Yeah, but we're always finding things out we didn't know, and threads like this one make me wonder some:

http://www.a-body.net/forums/showthread.php?2131-Timing-gear-repair-LG3-3-8-SFI-1987-Century