# 2006 2.5L timing chain



## zxxflyer (Jan 27, 2013)

Anyone have any experience with timing chain replacement on a 2006 Frontier 2x4 2.5L?????

It's had chain whine since 70K miles.. It's now at 140K and I've got it torn down... 

Will be replacing timing chain & guides... and balance shaft chain...

The timing chain wasn't horrible to get off, but I'm about to pull my hair out over the balance shaft chain.

You can't replace the balance shaft chain or tensioner/guide without removing the oil pan!!!

....And that's not an easy task.. 

I had to unbolt the two engine mounts and raise the engine hi enough for the pan to clear the steering rack. 

Even then, the pan will just barely come out.

....And now that I have the balance chain tensioner removed, the chain will not come off over the gears?!

Am I really going to have to remove the balance shaft gear to change the chain???


I joined this forum and posted because I found NOTHING on the web or youtube regarding 2.5L timing & balance chain replacement..

I would like to also note that the timing chain guides WERE NOT worn thru to the metal... or even close for that matter... Definitely NOT like what's happening to the 4.0L engine.

....I'm a 31 year old mechanic whose been working on cars since before I had a drivers license... This is the first 2.5L chain job I've had, and I believe I'm gonna make it my last. 

I will upload a bunch of pics in hopes of helping anyone out that tackles this job in the future.


Thanks


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## rogoman (Dec 16, 2004)

When you were removing the chain tensioners, did you insert a stopper pin into them. If you didn't you'll have a difficult time installing the tensioners. In order to remove the balance chain assembly, the chain, crank sprocket, and balancer sprocket slide out together as a complete assembly.


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## zxxflyer (Jan 27, 2013)

No, I never put a pin in while removing tensioners...

I clean and lubricate them on the bench, and then compress them and pin em'. It's not that difficult... It's only bad if you are trying to do it with the tensioner still bolted to the block..

=)


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## zxxflyer (Jan 27, 2013)

*Pics!*


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## zxxflyer (Jan 27, 2013)

Intake system is removed ONLY because this truck is getting spark plugs replaced... and the valve cover gasket was leaking anyways...


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## zxxflyer (Jan 27, 2013)

Update:

Ok.. Timing chain failure on this truck was due to clogged oil passages in the timing cover. There is a sprayer nozzle with 3 TINY holes in it right above the crank gear. They were plugged solid and so was the larger(straw size) passage that leads to them..
I'm surprised the chain guides weren't worn thru to the metal...

I will upload pictures of the trouble area..


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## zxxflyer (Jan 27, 2013)

Clogged oil passages:





















This screen was also clogged:


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## zxxflyer (Jan 27, 2013)

It took soaking the clogged passage, and then poking and prodding with TINY safety wire before the nozzle would flow again... and lots of air pressure.

The main timing chain tensioner also gets fed pressurized oil... and has a TINY mesh screen on the inlet... The screen was destroyed, and the tensioner oil passages were clogged.. It will have to be replaced. Check yours carefully or replace it for $85....


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## smj999smj (Jan 1, 2006)

Good info!


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## veesix (Jul 18, 2004)

This looks like a lot of oil sludge. Are we looking at an engine that missed a few oil changes?


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