5.7 Tensioners replaced and Camshaft tower resealed success (updated title)

Hi,

On a mission to get rid of the rattling noise and reseal my camshaft towers. Posting this in General discussion due to engine specific and not year specific question.

There is slack in both of the passenger side timing chains. The Driver's side is tight which is opposite of what I expected based on youtube videos and other forum posts on this subject.

So, why is the slack on the opposite side of the tensioner for the longer chain? Is the timing off? Should I just remove the cam gears to do my riser sealant, and then worry about the timing later, or should I mark them as they are before removing?

Edit: disregard for now, thought it was at TDC but guess not. Also slack was just due to how it was rotated.

Second Edit: After all said and done, engine is much quieter and is not making the rattling noise, which was happening all the time. Once I figured out the timing marks it wasn't too bad a job but time consuming. Not sure yet why the engine is so varnished and had some sludge - there are two rather large gaps in maintenance records from the previous one-owner. This job is a Pain and I would much rather be changing timing belts in the 4.7 2uzfe engine which is one of the best engines ever built IMO (along with Chevy 4.3 V6 Vortec).

In regard to the tensioners - they seem to be designed to ratchet out to a firm position and after that, the oil pressure allows the plunger to move slightly in and out (mine was stuck). The new tensioner has a slightly larger oil port than the old one. I will add a picture to the thread.

 

How many do you have on the truck? Curious as to what all that "dust" looking stuff is in the first couple pictures

 

There is about 140,000 miles. Haha, it is actual dust falling from the rubber padding that sits below the plastic engine cover.

 

Well, finally got it all out back together. Now has P0300 random misfire code pending after revving up. Funny thing is when it was revved at 2500 it actually seemed very smooth. Idles rough and it did somewhat prior to my work.

Too dark and rainy so I called it a night.

Just hoping it’s a coil pack or loose or mixed up coil plug (or vvt solenoid - I think these are only ones that could be plugged in wrong).

I did also have a bad spark plug tube seal on one of the cylinders so maybe that coil is bad. Guess I’ll poke around tomorrow.

Edit/Udate: forgot to clean out the fouled plug tube and also plug in one connector that is mounted to the fuel rail, which I think controls the coils.

 

Oil port is bigger in new tensioner. Mine was stuck from all the gunk and varnish in my engine though. If your engine is noisy it is possible to unstick it via oil filler port in valve cover and/or inspection port on timing cover.

 

Congrats on finishing a huge job successfully. I noticed the dark varnish film on everything, but that is after 140K miles. Care to share what brand/type oil you've been using?

 

Looks pretty much what I would expect at 140k. There is a "new" high mileage mobil 1 full synthetic formulation out that promises to remove sludge in one oil change haha. Bold claim and likely just a marketing effort but just put it in my wife's 11' mdx with 109k with no complaints.

 

I have only owned it for 10,000 miles. The Honda dealer where I bought it changed it but I don’t think they changed the filter considering I had to destroy the cap to get it open when it was my turn.

The records indicate valvonline instant oil change as well as a Toyota dealer otherwise.

 

Fantastic thread.

Thanks for the great information.

I've seen front cover off of another 5.7 that had higher mileage (180k I think) and the original owner did all the maintenance and used Mobil 1 full synthetic and there was practically 0 varnish build up anywhere and he did 5000 mile OCI.


The level of varnish seen here to me indicates previous owner probably used the wrong oil for a good portion of that 130,000 miles.

 

I suspect the PO knew little about required maintenance, and/or not too conscientious/particular about the truck's maintenance. They left the techs to make the decisions about what products to use. When the oil has been changed, I suspect your truck saw a lot of "house blend" bulk oil without too much discrimination re viscosity or type; i.e. conventional or synthetic.

My thinking is the varnish reflects the vaporization of the motor oil as in the "tests" Project Farm runs on YouTube. The more vaporization there is of the motor oil, the more likely varnish accumulates on every internal engine surface. Synthetic oil's tolerance for higher temps should help with the vaporization and varnish. I haven't seen that kind of varnish even with high quality conventional motor oil, but that is after 140K miles.

It's too bad we don't see more threads like yours that actually provides the community with real-life data on these OCI problems and the resolution. If your truck had been changed regularly at 10K mile intervals (we don't know, but suspect unlikely), I would begin to doubt the efficacy of the OEM recommended 10K OCI.

Great write-up. Thanks.

 

236k, Mobil 1, 5000 mile oci


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@blanchard7684 Check your link. Appears to be an image I'd like to see.

 

fixed....aws doesn't like to embed jpg apparently.

 

Doubt it was the wrong oil, or a certain OCI. More than likely oil changes were neglected, the 2 large gaps in the maintenance records support this.

 

A simple click doesn't get it done.

 

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Just an fyi about these type of tensioners even if the pressure or oil or whatever you wanna say happens the tensioner still has a lock on the outside so even if it locks with lack of pressure or no pressure or whatever it still has some play so that ticking sound is still going to be prevalent until you actually replace the tensioner.

now with that being said could we say shit oil changes or lack of pressure and sludge caused this sure. It’s a high mileage truck and we all know people don’t service every 5,000 miles. But, that in itself would not stop that tensioner from doing what it needs to do and that’s to keep the chain tight and from falling off.

the tensioner is shit , people with perfect oil changes see this common problem and it could happen to anyone.