Greets,
My 1999 XKR SC 'chirp-chirp-chirp' constantly when engine is idling ~700rpm when engine is warm.
Engine revved approx 850rpm chirp disappears to be returned again while idling.

Ran engine w/o SC belt and no chirp can be heard. Also checked SC pulleys & belt and they seems to be Ok. Tensioner pulley mark is well between belt wear limits.

Listening w/stetoscope it sounds like chirp is louder near throttle body -> can needle bearings cause this sound?

Any suggestions how to proceed with this?

Here is video of very similar idle chirping as mine (this is not from my car):


Thanks!

 

Chirping usually means a worn belt. You could try some "belt dressing" and see if that helps. If so, it's only a temporary fix and a new belt is in order.

 

There's a revised double sided belt and tensioner. You might get away with just a new belt.

 

Sounds like mine, even after replacing belts and the tensioner. I know it is the belt as a spray with some water and it goes away for a bit. Let me know if you solve it (long term that is).

 

Which car of urs is making the noise ?

 

Will do. Ordered new tensioner & belt kit from britishparts and I'll install them on next week.

Noticed that tensioner mounting bolt was almost loose , tightened it but chirp was still there. Maybe less than before. Water spray also lessened sound a bit.. at least I think so. And yea this is SC belt here.

 

That noise sounds like a tensioner going bad.

 

Installed upgraded tensioner, idler pulley and belt.. No dice, same chirp is still there @ idle ~700rpm

Again used scope to listen and pretty sure that SC rear bearings are making noise so next step is SC rebuild.. bah!

 

Get yourself a mechanics stethoscope and place the end against anything that rotates with the crankshaft. When you hit the culprit, you will definitely know it. You can try to use a very long screwdriver or steel rod up against your ear, but the stethoscopes are far better. They only cost $5-10 on line or auto parts store.

 

supari,

GordoCatCar has your answer for now....I had the same problem and replaced the belt and tensioner and it stopped but apparently you did that and still have the problem...As GordoCatCar says, the next step is the stethoscope or you might want to change the Supercharger's oil....The oil should be changed every 25,000 miles and makes the Supercharger quieter (No howl) and it will last longer also....Remember, It uses a special type Oil. I use GM Supercharger Oil and it works fine! Get it at GM Parts at a Dealer.....

Billy Clyde

2005 XKR Coupe

 

Finally got that annoying chirp solved: it indeed was caused by SC rear needle bearings

-changed rear needle bearings
-changed original & cracked SC coupler to standard green aftermarket one
-new SC oil

-> no more chirp @ idle . Now there is quiet whizz prob caused by aftermarket coupler.

Also cleaned TCM & ECM connections and got rid of resilient P1601 code!!! (which did not cause any CEL lights or other symptoms.. except annoy to owner and JGATE gear selection lights not lit up).

Next full coolant flush & new standard red coolant.