Yes, Another Tensioner Question

[BobRob]

I have an '02 with the 4.0 SOHC V-6 and after perusing this forum for common problems and their solutions, I have some concerns about the whole timing chain/tensioner set up on this vehicle and want to do whatever I can to keep potential issues at bay.

That said, I bought the truck two weeks ago with 135,000 miles on it. Carfax shows it was a fleet vehicle until 2004 and 30,000 miles, then used as a grocery getter until 2009 where it accumulated another 80,000 miles. The owner before me put on the remaining 20,000 or so. It appears to have been well maintained as it runs beautifully and still gets 19-20 MPG, fires right up every morning (I'm in NH) and rides smooth as glass. The PO replaced the rear calipers and put 4 brand new Wranglers on it shortly before selling it.

So my question: Would it make sense to go ahead and replace the tensioners as a preventive maintenance step? There is a barely detectable rattle (almost sounds like a diesel knock) from the what appears to be the passenger side during acceleration after it has reached normal operating temp, but otherwise it's still a quiet engine. No rattling at start-up, no codes, no rough idle..

Thoughts?

 

[Number4]

Need to narrow down the noise. If it's the V6, catch it early, don't press your luck, pull the engine and do the repair.

Just make sure it's the issue first.

 

[Tyleryac]

I'll second Number4.

If you have any timing chain issue whatsoever, fix it now. It's better than waiting and needing a new engine.

 

[BobRob]

I'm not sure if there's an issue at all since this noise only comes under that one circumstance. Driving in this morning, I paid closer attention to it and it only happens between 1800-2000 RPM while accelerating or otherwise putting a load on the engine. It's as quiet as a church mouse when idling or just cruising along at speed. In my experience with other engines, timing chain rattle is pretty constant, but this engine is a different animal.

I guess I'll replace the tensioners out of an abundance of caution and see if anything changes.

 

[Tyleryac]

The tensioners are a good place to start. Easy enough to replace.

 

[Tech By Trade]

If you have skills, you can have the intake and valve covers off in less than half an hour. Then you would be able to look and see if the guides are shot or not. Odds are the top half of the passenger side is sitting in the bottom of the oil pan. The other option is to pull the lower oil pan and see if you have any plastic next oil change. 15 bolts to pull, a 5 dollar gasket is all it would cost you.

 

[BobRob]

Think I'll do that (pull the pan and VC's next oil change and take a looksee) instead of just swapping parts for the hell of it.

Reading some posts, I noticed guys have changed tensioners only to make things worse because the new ones are crappier. Suckers quiet now, no sense in upsetting the apple cart.

Makes me long for the simple old small block Chevy's of my youth.

 

[Number4]

Just keep in mind, if it goes south, your engine can be gone in a heart beat. With the V6, it seems people lose an engine without much warning.
The V8 seems to go longer being problematic before catastrophic issues.

I'd drive it as little as possible until you know.

Read up on [MENTION=253206]Tyleryac[/MENTION] experience a little and you'll see the issues. His seemed compounded by the dealer, but his engine ended up toast.

 

[BobRob]

Thanks all..

I'm going to keep an eye (ear) on it and see if I can narrow it down some more before I throw parts at it. I've read a ton of threads about this issue and mine isn't exhibiting the same symptoms as others so it may be that it's something less worrysome.

This isn't a job I'm afraid to tackle, only right now, I don't have a garage to do the work in since I just moved here and am renting a house until I find something suitable to buy.

If I do discover that a chain job is needed, I may just go with a crate motor and swap it out, rather than mess with this now.

 

[BobRob]

OK... I went ahead and pulled the intake and valve covers today. I was pleasantly surprised when I pulled the covers and found a very clean head/cam/valve train and the right chain guide looks great. You can definitely tell this truck was very well maintained the first 135,000 miles of its life.

Cleaned up the TB and put her back together, fired right up and purrs, plus I don't have that pesky oil leak at the back of the left VC anymore. Over all a pretty easy job, took about 4 hours start to finish.

Next weekend I'm gonna pull the timing cover, change out the front guide and tensioner to quiet down the little bit of rattle between 1800 and 2000 under load and should be good to go. I'm also going to change out the cam chain tensioners as well. Gonna get those from Ford directly.

Anyone contemplating doing the V/C job, one thing I would do differently is get a hold of a new set of valve cover bolts before hand. 3 of mine were rusted to the point of having to use extractors to get them out. Ended up getting some regular bolts from the hardware store because NOBODY carries the OEM ones, at least not around here.

 

[2000StreetRod]

2WD or 4WD?

Did you pull up on the rear cassette guide to make sure it wasn't broken below?

I agree that is a clean engine compared to mine at 150K miles.

If you have a 4WD/AWD vehicle your balance shaft chain tensioner may be broken.

 

[BobRob]

Yep, everything was as it should be, as far as I could tell. Obviously, you can't see everything but I satisfied that the passenger side is OK. I'll be looking at everything up front next weekend. I decided that if it came down to having to pull the engine for any reason, this truck and I will part company, but so far, so good.

 

[BobRob]

OK... I went ahead and pulled my timing cover this weekend. Found the balance shaft chain tensioner was gone, most likely in the pan. The primary tensioner wasn't broken, but it was the old style, with three leafs. I replaced the main tensioner with the updated 6 leaf version, the guide, the water pump and HB while I was at it and buttoned it back up. I thought I might still hear the rattle due to the balance chain tensioner being gone but that was not the case. My engine is whisper quiet through the whole RPM range it was rattling through before. Next weekend, I'm going to drop the pan, and maybe the cradle, if I find I can work that balance chain tensioner, and dropping the cradle isn't too much of a pain in the ass.

The HB was a PITA to get off since I didn't pull the radiator. I had to cut 2" off my HB puller once the bolt was all the way out. The old HB was coming apart so it's a good thing I decided to have it on hand. The new balancer did not come with a new bolt so I smoked down the old one and will replace it as soon as I get a new one.

 

[2000StreetRod]

replacing balance shaft chain tensioner

The cradle must be removed in order to replace the entire balance shaft chain tensioner because the bolts that retain the base are vertical. I've read that it's a pain to remove the cradle with the engine in the vehicle. As I recall the motor mounts have to be loosened so the engine can be raised enough for the cradle to clear front drive components and other things. There is also an alignment of the cradle to the block that's supposed to be done on reassembly which is difficult with the engine in the vehicle. Some members have just cut the balance shaft chain and removed it when the tensioner fails. At least two members have replaced the tensioner mechanism but not the base. See post 20 of the following thread for one description: SOHC V6 Timing Chain Inspection & Repair

 

[streetessencems]

Did you get the new timing kit yet? Where did you or are you getting it from and cost? Mine just started making serious noise so its parked until i can get to it.

 

[BobRob]

The cradle must be removed in order to replace the entire balance shaft chain tensioner because the bolts that retain the base are vertical. I've read that it's a pain to remove the cradle with the engine in the vehicle. As I recall the motor mounts have to be loosened so the engine can be raised enough for the cradle to clear front drive components and other things. There is also an alignment of the cradle to the block that's supposed to be done on reassembly which is difficult with the engine in the vehicle. Some members have just cut the balance shaft chain and removed it when the tensioner fails. At least two members have replaced the tensioner mechanism but not the base. See post 20 of the following thread for one description: SOHC V6 Timing Chain Inspection & Repair

Thanks.

I'm going to do a little more research and self evaluation before I decide whether or not to pull the cradle. I did give some thought to cutting the balance shaft chain while I had the timing cover off but opted against doing so for a few reasons. I wasn't sure I could get it out in one or two pieces or remove it without removing the main chain and crank sprocket. I felt it was best to just leave it rather than get into all of this in my driveway for now.

 

[BobRob]

Did you get the new timing kit yet? Where did you or are you getting it from and cost? Mine just started making serious noise so its parked until i can get to it.

All I planned on doing was the tensioners. After replacing them, the engine is nice and quiet though mine never developed the horrifying rattle you read about on this forum. Mine was just a slight rattle(almost like it was knocking) while accelerating from 1800-2200 RPM. It never had a cold start rattle and was always super quiet when idling.

I did pull the valve covers to inspect the cam chain guides to make sure I wasn't dealing with anything too involved. My plan going forward is to maintain 3,000-5,000 mile oil changes and drive it. If the front guide should fail, I may consider replacing it, but if the rear guide fails and starts clattering, I will just get another vehicle.. I'm not messing with pulling the engine and going through all of that.

 

[streetessencems]

Mine only had the slight noise you spoke of until I replaced the left (drivers side) external tensioner. Now it sounds like a diesel. I'm not gonna mess around at this point. I'm just going to pull the engine and do them all.

 

[Number4]

I'd rather pull the engine than do any of this on the 4.0 installed. Engine pulling isn't that big a deal. Easier to grab the trans as well and install together.

 

[BobRob]

Mine only had the slight noise you spoke of until I replaced the left (drivers side) external tensioner. Now it sounds like a diesel. I'm not gonna mess around at this point. I'm just going to pull the engine and do them all.

I read that the aftermarket replacement hydraulic tensioners can be junk. I got mine from Ford and the spring tension seemed a bit stronger than on the ones I took out.