3.5 knock

I have a ‘16 3.5 just barely hit 126k it sounds like the vaccuum pump knock but I also hear it worse when giving a rev up and down lightly right around 2500rpm but I’m also hearing this knock off the driver so I’m a bit stumped

 

Videos with good sound is the only way anyone could give any advice.

 

For some reason it won’t let me upload the video but the best way to describe it is it sound like a stock 6.0 powerstrokes engine noise when the sound happens

 

Did you replace the vacuum pump at 120k as directed in the maintenance booklet?

Edit: The book interval is 120k, not 100k.

 

Vids have to be uploaded elsewhere (like you tube) and then you put the link here.

My lunch beverage says 'no'. It also says that it's a rare occurrence that anyone does. Suspect waiting till there is a problem is SOP

 

^It'll be interesting to see how people neglect this later on 4th gen, where even the OR relies on the vacuum pump for braking power.

 

I have not replaced the vacuum pump I was unaware it was a common issue but I will call and see if Toyota will still warranty at least the part I doubt it cause that’s how every manufacturer works warranty is up just before the issues start

 

^Vacuum pump replacement is scheduled maintenance, a bit like timing belt replacement in 1st gens. There's no warranty for scheduled maintenance.

However, do make sure your truck is up to date on recalls and service campaigns. I seem to remember campaigns on the vacuum pump and high pressure fuel pump.

 

I think some of the maintenance manuals just say to inspect it, while some say to replace.

Regardless, you don’t really have to replace it and can rebuild it with a new OEM vane instead.


https://www.tacomaworld.com/threads...e-item-120k-miles.815269/page-2#post-30560970

 

^Looking into this a bit further. Vacuum pump was not mentioned in the 2016 maintenance booklet. It was added in later years in response to failures in service. 2017 has it as an inspection at 120k. 2018 onwards has it as a straight replacement at 120k.

As with the timing belt in 1st gens, the majority of the cost for vacuum pump replacement is in labor for access. The instructions say to unbolt the transmission mount and tilt the engine forward to increase working room at the firewall.

 

Yeah, for some reason I thought it was more random, but I never sat down and checked multiple maintenance manuals at once. I see now that it was not mentioned at all in 2016, it was mentioned to inspect in 2017, and 2018+ it was listed to replace at 120K. In that case, if I had a vacuum pump equipped truck, I would do that or at least disassemble and replace the vane like the guy in my link did.

So now I look at the 2024 maintenance manual and it is back to recommending to inspect it, but includes a footnote to replace the vane and end caps when you do. So essentially, it is telling you to bare minimum rebuild the vacuum pump at 120K.

 

https://youtube.com/shorts/8bCe8CyhANY?si=waW9-6AuJKU5m2tC Here is the video of the sound I’m getting

 

Just to confirm, Off Road and Pro models utilize a hydraulic pump, not a vacuum pump, correct?

 

Correct

 

Thanks, I can scratch 'vaccum pump' off my list of 'things that aren't just injector noise' in my engine bay Pretty sure the noise I hear all the time is the high pressure fuel pump. Truck hasn't exploded yet, we'll let it keep on keep'n on