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I do know this much. The bearing housing for the tensioner has grease in it. It heats up and liquidizes. (is that a word?). Anyway, if the seal goes bad...no more grease, therefore the bearings wear out.
I do know this much. The bearing housing for the tensioner has grease in it. It heats up and liquidizes. (is that a word?). Anyway, if the seal goes bad...no more grease, therefore the bearings wear out.
I guess you are talking about the pulley bearing, which is a sealed unit. As far as I can tell, the ends of the tensioner housing does not have bearings, at least not with grease. I may try to remove the inserts for a look.
I guess you are talking about the pulley bearing, which is a sealed unit. As far as I can tell, the ends of the tensioner housing does not have bearings, at least not with grease. I may try to remove the inserts for a look.
Yes. The pulley bearing. I believe it's called a idler pulley?
Last edited by joemessman; 12-27-2017 at 09:59 AM.
I wonder why they over engineered this part?
The C6 tensioner was so easy to work with. And affordable.
GM may have tried to improve the part because it has to deal with 4 cylinder mode. Most of the failures I have read about seem to result in the tensioner making noise in 4 cylinder mode.. though mine never made noise, just started leaking fluid.
Yes. The pulley bearing. I believe it's called a idler pulley?
You can see the pulley in the background. I found no signs of leakage from the bearing..
Also, I think of an idler pulley as one that is fixed to the engine just to change directions of the belt...so I would not call this pulley and idler.
Had my car at the dealer today for track prep and they called me back and said belt tensioner was leaking. They ordered the part and replacing Monday. If your warranty is up soon you may want to have your dealer look at it.
Mine had oil seeping out, coating the body of the tensioner. Dealer replaced it last week under warranty. Wanted to get it done before my bumper to bumper ran out this year.
2017 Grand Sport.... Doing a pre-track day undercarriage inspection and I found leak from the belt tensioner (Hydraulic) spring area. Looks to be a very simple repair. ordered part and will change out myself Was surprised taht this seemed to be 2014-2016, now I can say it is happening on 2017 as well. (i am pushing 19K miles and I do run it hrd at the track so no complaints
I'm wondering if the OP ever got his answer as to the purpose of the oil? I threw my defective part away so I can't dissect it, but I suspect that the hydraulic action takes place inside the piece that extends with the spring pressure and the oil acts as a dampener. The area around it may be simply a reservoir much like a hydraulic bottle jack. When the piston is fully retracted, the reservoir is full and as it extends the oil is drawn inside and the reservoir level goes down. If the oil leaks out there won't be enough to keep the inside of the ram full and with no cushion the parts rattle.
This is all just a guess, BTW, but it makes sense to me.
My rattle came after the warranty ran out so I changed the part myself and it stopped the noise which seemed to occur only at the transition from V4 to V8. A Range Device solved the problem altogether.
2017 Grand Sport.... Doing a pre-track day undercarriage inspection and I found leak from the belt tensioner (Hydraulic) spring area. Looks to be a very simple repair. ordered part and will change out myself Was surprised taht this seemed to be 2014-2016, now I can say it is happening on 2017 as well. (i am pushing 19K miles and I do run it hard at the track so no complaints
it "looks" simple enough, and you can do it yourself like I did... But..
You will want to read this thread I posted after changing my Tensioner last month at 26,000 miles
I'm wondering if the OP ever got his answer as to the purpose of the oil? I threw my defective part away so I can't dissect it, but I suspect that the hydraulic action takes place inside the piece that extends with the spring pressure and the oil acts as a dampener. The area around it may be simply a reservoir much like a hydraulic bottle jack. When the piston is fully retracted, the reservoir is full and as it extends the oil is drawn inside and the reservoir level goes down. If the oil leaks out there won't be enough to keep the inside of the ram full and with no cushion the parts rattle.
This is all just a guess, BTW, but it makes sense to me.
My rattle came after the warranty ran out so I changed the part myself and it stopped the noise which seemed to occur only at the transition from V4 to V8. A Range Device solved the problem altogether.
I believe you are correct. The oil acts as a dampener. The purpose of this is to even out the force that is applied at any instant in time so that the belt will never see a large spike in load to the belt. This will also take loading off the bearing. FYI, GM recommends the belt be replace every 10 years or 150,000 miles which ever comes first.
My tensioner is leaking, noticed leak two thousand miles ago (rag wrenched the leak), leak is still persistent. The car now has nine thousand miles and the tensioner is scheduled for replacement next week. Other then the oil mess, seems to operate normally.
Forgot, the car is a 2017 Stingray. Additionally the tensioner is designed to absorb four cylinder pulses (evidently the uneven power pulses in four cylinder operation need dampening), the oil keeps the tensioner’s internal spring from bouncing creating noise. I never operate in the four cylinder mode, go figure.
12-27-2017, 09:44 AM
Was surprised taht this seemed to be 2014-2016, now I can say it is happening on 2017 as well. (i am pushing 19K miles and I do run it hrd at the track so no complaints 
it "looks" simple enough, and you can do it yourself like I did... But..
