cjbenavidez

Had a drive belt tensioner failure on my 2016 Z51 Auto. Diagnosed by the ridiculous rattling noise when the car went into V4 mode and every so slight leaking of oil from the tensioner. Has anyone else had this issue? Only have 18,000 miles and I dont drive the car very hard it hasnt been tracked...yet. I guess my main question is does anyone know what causes this? Just a bad batch of tensioners out there? or does the V4 mode some how cause this?

Thanks for the help.

joemessman

I have 69,000 miles on my car and the belt tensioner went south at about 36,000 miles and replaced under warranty. It had a whining noise, but did not leak. That part takes a lot of punishment, as it is dynamically changing the tension. it is not uncommon for that particular part to fail. V4 mode in my opinion would have no effect on it.
That is actually the only issue with the car I have ever had. It has been a perfect machine. I drive the bajeesus out of it!

mcginna

'14 had tensioner failure at about 5,000 miles. Replaced about 4 years ago, no problems since.

AORoads

Haven't heard of many on here going bad. If you think about it tho, so many items on an engine that can go wrong if they're not made of improved quality and possibly improved materials for different engines. Here, I'm comparing a Corvette engine of long years ago that had 120+ hp less, and 120 lb.ft.+ less torque. RPMs have stayed about the same, but underhood temps have gone up, too which can affect stress on parts. I'm sure it's all tested for and improved but that doesn't mean failures won't happen.

TEXHAWK0

I never run my car in V4 mode, so my tensioner never started to make noise, but I noticed it did start leaking hydraulic fluid, so I changed it a few months ago on my 2014 Stingray... I was surprised when I looked under the boot of the tensioner that it was not hydraulic, but simply a spring with fluid around it... I still am not sure why it needs the fluid since there are a lot of other cars that have spring tensioners and nothing else.
This is actually a pretty common problem and as far as I know, GM has not changed the design. Some people may have fluid leaking and just do not know it since it is not making any noise.. One guy only found his was leaking when they were doing a track inspection. I suspect that running in V4 mode does accelerate the problem because of imbalances and the tensioner must compensate more, and that is when most people notice a noise....

I changed it myself and it was not difficult except that you have to remove the air intake ducting and you can only reach the lower bolt from underneath the car...

joemessman

^^^ That's a good point. I believe the hydraulic portion of this simply provides damping action and it still uses a tension spring like traditional belt tensioners?

1 HOT 07

I had my belt tensioner replaced at about 7500 miles...2016 Z06 / Z07. It was making a clattering noise at low speed.

4thC4at60

Mine failed on my '15... I don't remember the mileage.... my car now has 68K miles.... MN7

And now, today, February 26, 2020 - I now have 96,000 miles on my car and everything's fine....

SRQStingray

cjbenavidez

nice, great info. and TEXHAWK0 that is perfect, exactly what I was thinking and looking for. I was also curious cause when I get my supercharger on and if this fails again Im pretty sure the dealer is not going to warranty for me so good to know its an easy swap.

Red C8 of Jax

Common problem on the 2014's.

Kenafin

Replaced 13 months ago on mine....and it might need to be replaced again - I'll know for certain tomorrow whether it is just the water pump or the water pump and the tensioner pulley. (Along with the good ole torque convertor flush...)

Kracka

My car just missed that cutoff date listed above (built 3/25/14) in the TSB and no issues here yet [knock on wood] @ 40k miles.

Poltergeist

Just had mine replaced last week. 2015 Z51 built June of '15. I thought it was the transmission warble that others have had issues with.

sykr0n

2017 Z51 M7 built Oct 2016. Belt tensioner replaced a few weeks ago at 5500 miles. I came in for other issues and the tech diagnosed this faulty issue.

cjbenavidez

B-Vette

My 2016 was diagnosed with noticeable wear on the serpentine belt upon a out of province inspection, (just a money grab for the government in these parts). Just wondering if this was due to a faulty belt tensioner?

TEXHAWK0

Unless the pulleys are out of alignment, that would be my guess too...that the belt tensioner is not maintaining the right tension to keep it from slipping.

VettemeisterRed

I decided it was time to stop the noise at 21,000 miles on my 2016 Stingray. Replace my Tensioner under warranty with Part Number 12686272.

Kracka

I posted above back in 2018 that so far my 2014 had escaped the issue. Yeah...guess who replaced his tensioner and belt last summer? My OEM tensioner was covered in that hydraulic fluid. The belt has been updated as well so I went ahead and replaced it with the revised part since it had to come off anyway.

The revised belt you want is:
ACDelco part #6DK650
or
Gates part #DK060650