Rough running ls

Just put the covers back on too. O well should be quickens at it now.
 
Yikes, yup oil inside your intake is the least of your problems now,
that timing chain is eating away at the inside of your engine.

Prob has jumped a tooth already.

Keep driving it like that and you'll need a new one of these,

140146.3-lg.jpg

140146.3-lg.jpg
 
when I inspect the timing gears cams and chains what am I looking for? Is this something that could be as small as chaining a tensioner?
 
Cams-76 said:
when I inspect the timing gears cams and chains what am I looking for? Is this something that could be as small as chaining a tensioner?
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the top two tensioners are fairly easy to get to...the bottom two, much more difficult.


the engine needs pulled out (it CAN be done in the car, but VERY difficult), you need to change 4 tensioners, 8 guides, and two timing chains....if you broke a tooth on the sprockets, you will need to replace them as well...

this is a major job!


before i went to buy my sons LS, i scoured this site looking for common issues...i passed on at least six different cars because of the sounds they were making (all were timing chain).

i found one that needed a trans solenoid, and suspension parts, but ran great....i bought that one for $2500, by the time im done i will have spent ~1000 on repair, but its cheaper than the timing chain issue....not to mention they all wanted between 3k and 4k for those cars...
 
LS2001 said:
P0171 is System Too Lean (Bank 1) this could be the MAF or PCV..or a vacuum leak.

it DEFINITELY sounds like you are doing this car no favors by driving it...that knock could be a bad sign.
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I don't understand why everyone keeps saying PCV on a 3.9. The 3.9 doesn't use a PCV like the 3.0, it's basically a tube that runs from the drivers side valve cover to the intake tube. The misguidance people are receiving about PCV valves on the v8 is frustrating.

To the OP. I went back and forth with Joegr on this, I have the same code p0171 or whatever bank 1 lean is. There are a few posibilities to this:

1. Vacuum leak in intake - use starter fluid, propane, whatever you want, and start inspecting around passenger side intake manifold and intake. See if the rpm's change when spraying - if it does, you have a air leak.

2. Misfire in pass side coil.

3. Fuel pump isn't putting out enough. Simple test to do with fuel pressure gauge, 30-55psi is normal range. Not likely scenerio, but possible.

4. Clogged fuel injector. Harder to test. This would be a dealership or decent shop that can test them.

5. Possible a really bad timing issue, especially with the knocking sound. Like the last few members mentioned, take off the valve cover and check to see if the cam flats line up.

Along with the fuel pump and injector issues, you can have a clogged fuel filter. When was the last time that was changed out? Not sure if it would cause your "knocking sound" but anything can happen when fuel/air mixtures are out of wack and detonation is off
 
Broseph said:
I don't understand why everyone keeps saying PCV on a 3.9. The 3.9 doesn't use a PCV like the 3.0, it's basically a tube that runs from the drivers side valve cover to the intake tube. ...
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Yes, but still it does have a PCV, Positive Crankcase Ventilation system. It just doesn't have a PCV Valve. While rare, sometimes the PCV tubes do crack and cause problems. There are a few cases of that on this site.
 
That link is helpful. Wat he did looks a lot easier than what I saw on a different post. What I saw involved removing the timing chain cover. Looked like a lot of work and you're right removing the engine might be easiest
 
Is replacing the parts needed to fix the problem ok? Or when things start going they all start going?
 
The secondary tensioners (on the head) are the problem. The primary tensioners are pretty reliable and have an easier job.
If you pull the timing cover then you can replace all the gaskets and replacing the secondary tensioner is somewhat easier. It's a ton more work to get that thing off, though.
 
I just did the valve cover gaskets so I know about taking valve covers off. I didn't think about looking at the timing chain. I'll tear into it tonight, sounds like I might luck out and have lease work ahead of me than I thought.
 
Well I found out the problem. The drivers side small timing chain that connects the two cams is almost broken. The tensioner fell apart and a piece of the plastic is wedged between the sprocket and chain. Can this small chain and tensioner be replaced easily? My thought is to buy the new drivers side chain and replace both side tensioners before the passenger side lets go also.
 
Cams-76 said:
Can this small chain and tensioner be replaced easily?
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that depend on your ability to work on cars...if you take it somewhere the labor cost will eat you alive..


Cams-76 said:
My thought is to buy the new drivers side chain and replace both side tensioners before the passenger side lets go also.
Click to expand...
i would replace the top tensioner on the pass. side..as well


i wouldn't start this car again...not unless you want the chain to break and a massive internal game of "whack-a-valve" to ensue.
 
... internal game of "whack-a-valve"


~ good way of putting it.
 
No I'm not going to start it. The driver side upper chain looks like its real close to breaking. One link is half broken. I will do both upper chains and tensioners I guess. Is it a waste to replace the passenger upper chain when doing the tensioner? Only another $50 for the second chain and at this point I'm not worried about skimping on the $50. What else do I need to look at ? The sprockets look ok to me. Do I need to look for bad valves?
 
Yes the timing was off. Maybe drove 10 miles since it started running rough
 
so i am going to take the pass side valve cover off tonight and inspect before i order timing chain for driver side and the two new tensioners. any opinions on leaving the pass side upper timing chain? while im in there should i just do it also? thinking of ordering the chains with the master links to make it easier.
 
I wouldn't bother with the inspection. Replace all the chains. I guarantee that if you only replace the ones that show damage now, the one you don't replace will break within a month, on decel, and there goes a head.
 
I dont think im going to do the lowers that seems like a lot more work than the uppers.
 
So I have been reading other posts about this issue. Sounds like when the tensioner fails it can cause valve or engine damage? The car aside from running rough and knocking had good power and ran good before I stopped driving it. I want to order the new chains and tensioners this morning but not if the car has bigger problems. How can I tell if valves or anything else is damaged?
 
One way to look for bent valves would be to take the cams off, measure the valve stem heights and do a leak down test on each cylinder.
You could also look down the spark plug holes with a borescope to see if any of the pistons are damaged on their top surface.

The most reliable way would be to remove the heads and examine everything.
 
I went out and looked at rhe cams before i went to work. I dont think it junped time the cam flats are ljned up. I thknk the vibration is from the tweeked timing chain.
 
You're probably okay (as far as valve damage does).
 
Cams-76 said:
Well I regapped all the spark plugs and now have all new cops. Still have the same rough idle issue. I noticed it has quite a bit of white or gray smoke at start up and stinks. The check engine light is now on with these four codes. P0121, p0175, p1152, p0122. On the short drive to the auto parts store I stomped on it a little and it doesn't seem to be lacking power at all. Just runs real rough.
Click to expand...

Ever figure out what was wrong? Kinda having the same problem myself /:
 
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