Very wired issue after timing chain tensioner install

[ryan2022]

Ok, and by wired....I meant weird

I'm wondering if anyone has experienced this before. My truck had a very mild noise at 2500 rpm.

It wasn't so much as a rattle, could have been an exhaust leak even. It's got roughly 85k miles on it.

I replaced the timing chain tensioners, and then bam! Now it rattles at idle, and sounds shitty all the way through the rev range.

It didn't do this after I installed them, possibly slightly on startup which I heard was common.

The old front tensioner was stuck open and frozen. The new one functions well.

Could the old one have put enough tension on the chain that now it's exposed the famous guide rattle?

The truck is an '05.

Any help is really appreciated. I like this truck, but she's been hard on me lol

 

[RonD]

The bad cassettes(guides) were on earlier 4.0l SOHCs.

reads like tensioner isn't getting oil pressure, these are hydraulic tensioners, oil pressure is what holds them tight.
Pull it out, disable coil, crank engine a few times, the oil pumping thru should clear out any obstruction, make sure tensioner hole is clean.

 

[ryan2022]

Thanks Ron,

That's a good point. Ok, I'll try that. blah. this one was tough to get to. The t-stat housing, throttle body and a bunch of other stuff had to come out. It was tight in there!

Do you think it might be, because the seized tensioner caused the chain to wear through one of the cassettes? I'm tempted to pull the valve cover and see if it's still in one piece.

Worth a shot though before I take it to a shop. Thanks,

Ryan

 

[gw33gp]

Did you replace both timing chain tensioners? If not the rear one is easy to get to and could be the one that is causing the noise. As I recall, one has a washer/seal on it and the other does not. I don't remenber if there is any other difference between the front and rear tensioners. Might be good to make sure it or they were installed correctly.

I know about how difficult it is to replace the front one.

 

[ryan2022]

Thanks for the reply.

Yes, I did the rear as well. I drove it with just the rear done and it sounded fine.

What really strange is it seemed to sound ok for a while with the front done, then started to really rattle a day later.

If there anything special to installing these? I just pulled the old ones out and screwed the new ones in, and torqued to spec.

 

[ryan2022]

The bad cassettes(guides) were on earlier 4.0l SOHCs.

reads like tensioner isn't getting oil pressure, these are hydraulic tensioners, oil pressure is what holds them tight.
Pull it out, disable coil, crank engine a few times, the oil pumping thru should clear out any obstruction, make sure tensioner hole is clean.

Hi Ron,

Do you have to prime these at all before install? I tried dunking them in oil and working the plunger in and out and had no success.

Is there anything special I needed to do to get them to pressure up? They seem fairly simple.

 

[gw33gp]

You don't need to prime them. The spring provide tension to the chain at start up until oil pressure from the engine takes over. As long as there is not blockage of the oil passage to the chain tensioner, it should work fine.

Again, I don't know if there is any difference between the front and rear tensioners. If there is a difference in length and you got them mixed up you could possibly get incorrect tension on the chain. That is totally a hypothetical guess and may have nothing to do with reality.

 

[ryan2022]

Thanks,

I may pull the front off this morning and reinstall it.

The front tensioner has a noticeable tail on It, and the rear tensioner sits flush with the block. I'll compare the new and old front tensioner for length when I pull it just to double check that its ok.