Has anyone changed out the timing chain tensioner only?
Did it make any difference?

-Problem: Low rpm (1600-2300rpm) rattle getting worse. Using 20w50 helped for a few thousand miles but now it rattles as soon as the oil is warmed up.
Startup is quiet, and medium to hard throttle clears it up.

Thoughts?

 

I’d encourage you to experiment more with your motor oil.

I’m thinking the 20-50 isn’t the right stuff ... thicker isn’t always better.

I had used a full synthetic 15-40 for a while in my ‘99 VQ30DE but experienced recurrent noise, mostly at startup and after extended stop and go operation.

Bottom-line, for me anyway ... I switched back to a high quality conventional 10-30, change it religiously at 3K miles or less and I’ve got no complaints.

And BTW ... all of this after I changed out my tensioner.

 

Yikes and a new tensioner!

I've tried 5w30, 10w30, 10w40, 0w40, and 20w50 over the last 13,000 miles.
With 5w30 @ 70mph, it's a nonstop rattle. Heavier oils seem to help quiet it down a little.

 

I also had the famous timing chain rattle. I opened the timing chain cover and replaced the main timing chain guide and tensioner. Engine runs like new. Perfectly silent.

 

That all being the case, then I’d agree it’s likely time to do the tensioner.

We are talking about a VQ30, correct?

Its not a difficult job, technically, but it is frustrating due to the location and angles and such. There’s quite a bit of working blind and by touch, if I recall correctly.

If you haven’t already done so, there are several write-ups/commentaries on the forum you might want to read through ... tips and tricks and such.

Be sure to read through those posted in the 4th Gen forum as well.

 

This would be an 03 Max so VQ35 - Appears to have an access hole.

 

Did the chain guides break off and slip down?

Worst case scenario would be doing this... but it would be crazy expensive.

 

My chain guide did not slip down. Upon removing the tensioner, I noticed the plastic part on the chain guide was brittle. It eventually fell apart. But after 175,000 miles, that is not surprising. If you decide to take this on, be prepared to replace other parts.

 

Parts are cheap but labor is expensive. If you do this yourself, it is not expensive. Also, you can try just replacing the tensioner using the access hole but you cannot replace the chain guide that way. You have to remove the timing chain cover which becomes a even bigger project. Either way, you have little room to work with. Hopefully, you are born with small hands :-)

 

You can easily just put an extension on the piston that extends it about 3/8. I used a brass fitting.

I saw on a forum that someone fabricated this:

 

I get what that extension does, but how on earth would you prevent it from slipping or falling out of place?

I'm debating if I should take a chance and just replace the tensioner.

 

There’s certainly nothing inappropriate in taking things a step at a time.

 

Timing chain, guides and tensioner are vital parts to your engine. This is one job that needs to be done right the first time. I personally would not risk doing anything that would mess up my car’s engine. While the little metal addition seems interesting, I would rather spend the time just replacing the tensioner vs rigging a piece of metal to put inside the engine. But that it is just me.