Replaced secondary cam chain tensioner, now what???

twinbopilot

twinbopilot

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'01 V8 Sport Model -

Bought the car last week with an engine issue. Determined it to be the secondary cam chain tensioner. Had the usual issues of knocking from right side of engine, rough idle, random misfire codes, bank one lean code, etc.

Replaced the tensioner yesterday. Since the timing chain did not break, I just left the cam sprocket in the chain where it was while I switched out the tensioner.

Started it up and the knocking sound (my dad said it sounded like a washing machine!) was gone, but the engine still idles rough. Runs good at higher RPMs, showed 25 mpg on the freeway, and DID NOT throw any codes!

The exhaust still smells too rich. It was doing this before I did the repair.

The previous owner, in an attempt to fix the problem, ordered a set of Ebay COPs and replaced all eight. Could the cheap aftermarket COPs cause the rough idle without throwing any misfire codes? He gave me a box with all the original COPs that he removed - should I re-install them?

What could be causing the slightly rich smell to the exhuast that wouldn't throw a code? Wouldn't a bad O2 sensor throw a code?

So before I tear the engine apart again and re-verify the exhaust cam timing, does anyone have a suggestion for me?

Thanks and everybody have a GREAT weekend!
 
Just switched the COPs to the factory ones that came with the car. No effect on symptoms.

Looks like another tear-down is on my to-do list today...

Still checking here periodically for any ideas.
 
Getting ready to tackle the same thing on mine, horrible noise coming from the right front VC area and has the same really rough idle. One of the things I will be checking to see when I have it torn down is if the chain may have jumped a tooth.
 
If you have a bad plug, all the cops in the world won't fix things. Check for oil leaking into plug wells and be prepared to do a cam cover re-seal as well. Good luck.
KS
 
ITS FIXED! :) I moved the exhaust cam sprocket 1 tooth on the chain so the flat spots on the cams were even, and that took care of the problem. I thought they were "close enough" before, but obviously they weren't.

WORD OF WARNING: The screws for the tensioner are the same thread and length as the cam bearing screws. DON'T GET THEM MIXED UP! If you accidently use one of the tensioner screws on the cam bearings, you will snap the screw into two pieces when you torque them down. Easy way to tell the difference: cam bearing screws have a built-in washer, tensioner screws do not.

Now on to fixing the DCCV and installing two window regulators. Front end needs ball joints too. Always something to do on an LS!!!
 
twinbopilot said:
ITS FIXED! :) I moved the exhaust cam sprocket 1 tooth on the chain so the flat spots on the cams were even, and that took care of the problem. I thought they were "close enough" before, but obviously they weren't.

WORD OF WARNING: The screws for the tensioner are the same thread and length as the cam bearing screws. DON'T GET THEM MIXED UP! If you accidently use one of the tensioner screws on the cam bearings, you will snap the screw into two pieces when you torque them down. Easy way to tell the difference: cam bearing screws have a built-in washer, tensioner screws do not.

Now on to fixing the DCCV and installing two window regulators. Front end needs ball joints too. Always something to do on an LS!!!
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I would suggest taking the timing cover off and replacing everything behind it. All the guides, chains, crankshaft seal, and the rest of the tensioners. Replacing just one tensioner is like putting a band-aid on something that needs stitches. Sure it might work, but you risk further damage.
 
Slick, maybe in an ideal world I would, but the plastic secondary tensioners are the weak spot in the valve train. I had a talk with the local Jag dealer's service dept and was told that they came up with a new tensioner design for the 3.9/4.0 V8 that has a metal body instead of plastic. They replaced so many of the plastic ones under warranty that they invested in a redesigned replacement part. I'm pretty sure even Ford uses it now, even though its a Jag part #.

When they do the work, they will recommend to a customer that both secondary sides be replaced even if only one is bad, but they don't recommend replacing the entire timing chain system unless there are other symptoms that would warrant it. I know its just one guys opinion, but he believes the timing chain system should be good for 200K other than the plastic secondary tensioners.
 
twinbopilot said:
Slick, maybe in an ideal world I would, but the plastic secondary tensioners are the weak spot in the valve train. I had a talk with the local Jag dealer's service dept and was told that they came up with a new tensioner design for the 3.9/4.0 V8 that has a metal body instead of plastic. They replaced so many of the plastic ones under warranty that they invested in a redesigned replacement part. I'm pretty sure even Ford uses it now, even though its a Jag part #.

When they do the work, they will recommend to a customer that both secondary sides be replaced even if only one is bad, but they don't recommend replacing the entire timing chain system unless there are other symptoms that would warrant it. I know its just one guys opinion, but he believes the timing chain system should be good for 200K other than the plastic secondary tensioners.
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You're right, but why take a chance like that if you have the skills to work on it yourself. My secondary chain snapped upon starting my car. No problem with the tensioner, but I replaced everything behind the cover just to be safe. I think fbird just replaced a tensioner and a week later snapped a chain or something. Maybe he will chime in and verify.
 
Slick, how many miles on your car when it broke the chain? Did it bend the valves or damage the pistons? What was the car's maintenance history, if you know?
 
twinbopilot said:
Slick, how many miles on your car when it broke the chain? Did it bend the valves or damage the pistons? What was the car's maintenance history, if you know?
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The chain snapped at 125,000 miles and the car has been babied since I got with 80,000 miles. Always maintained on time and I check over everything at least once a week(all fluids, tire pressure, check for leaks, and check connections to ensure proper connection). Yes it did bend a couple of valves, but no damage to the pistons. I pulled the head off with the motor in the car and it was a PITA. You can get by fine with what you did, but if you have the skills then why not use them to make sure your car runs with no problems for a long time. It wouldn't take that much time at all seeing you wouldn't have to remove a head like I had too. It's your car so do what you want, I just told you what I did when I had one timing part go bad.
 
I probably will do it if I wind up keeping this one for awhile. I still have my eyes open for an LSE though...:D
 
twinbopilot said:
I probably will do it if I wind up keeping this one for awhile. I still have my eyes open for an LSE though...:D
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The LSE model is nice. I would like to do an 06 front conversion, but will prolly only just color match the grille and rear surround. If I buy a new car it will be a G8. You can make them sooo fast for the low low.
 
There is a guy on Ebay that sells everything you need for a secondary tensioner swap. When I did my 2000 Ls, I purchased the secondary kit which included both tensioners, vc gaskets, and 2 secondary chains with the master links. I also rented his timing tool kit for $50 ($275 deposit). I considered doing the job without the tool kit, but decided against it. I had no intention of tearing the engine down again if I got the chain 1 tooth off. Also with the tool kit, I was able to leave both cams in place.

The car now runs perfectly at a cost of $500 (new plugs/coils as well) and 3 hours of work.
 
Is there a revised bolt that should be used on the 2001 when changing from the plastic to the metal tensioner? I have seen some say to use a 3mm washer to make up for the difference in the tensioners but I figured there should be a revised bolt if they made a revised tensioner. I also need the bolts for my 2006 LS for the secondary upper tensioner as one of them broke. I figured I would just order a set for both cars then I know it's done right. I just need to figure out the part numbers. The Dealership gave me a part number (for the 2006) but that bolt I am not sure is the correct one -W500301-S300 - Ford Parts Giant
And they gave me another part number (for the 2001) but Pretty sure it is for the v6 model as the Ford Parts site shows it for a v6 not a v8
https://www.fordpartsgiant.com/part...n&Model=LS&Year=2006&Submodel=&Filter=(30925)
 
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