This Is Just Too Much Tension ... Or Not Enough!


#1

Our 1999 Dodge Intrepid 2.7L with about 135,000 miles was Making cold-start “ginding, singing” sounds which lessened in a minute after warm-up. I tracked it down to the A/C tensioner pulley using my “Doctor Motors” stethoscope.



I replaced the pulley, re-installed the ribbed belt (has self tensioner) and then also replaced the ribbed serpentine alternator/P.S. pump belt (not self tensioning) with a new one.



I now get a low-growl cold start noise (lasts about a minute). A TSB for this car/engine says that it is remedied by setting belt tension at 120-140 pounds.



I never know for sure if the tension is correct. Too tight, you’ll damage bearings. Too loose, you can have it slip and even burn the belt. I have a little Gates “Krikit” Tension Guage that I’ve had for 15 years. The thing just doesn’t look like it should work. I also have a Nippon-Denso Belt Tension Guage, the regular spring loaded hook type. It’s in kilograms and my specs are usually in pounds, so I convert. It won’t really fit in without taking out 13 bolts, first.



Does anybody use a Gates Krikit?



Does it matter how long the span of belt is between the pulleys where I check tension? Some of my cars have a long span and some only short.



I’m going out to adjust the belt when it warms up a little. Any tricks of the trade for ribbed serpentine, accessory, FEAD belts, would be appreciated.


#2

That Should Have Said “Grinding, Singing” Sounds.


#3

I have had the similar response. but replacing the one item (the tensioner) only let me hear the other (the ac compressor in my case) was grinding also.

possible the 1 noise was masking two.

i dont bother using tensioner gauge anymore. the self adjusting ones work, and around 100k replace 'em.


#4

Thanks. Only The A/C Belt Has The Self-Tensioner, Not The Alt/P.S. Belt. It’s DIY!


#5

Update:

I tried testing the tension on my car’s belt with the ND tension tester and the Gates Krikit. both indicated a rather low 80 pounds. I tried my wife’s car only with the Krikit as the ND won’t fit in there at all. It too was only 70 to 80 pounds. I tightened it up and rechecked it at about 120 pounds. When she leaves for work in the morning I will listen to it cold start. I hope to hear no low growl sound if the TSB is correct and these guages are working. When I reread the TSB it said to perform the adjustment if the tension was too low (nothing about being to high). This goes to show me that I’m not good at guessing correct belt tention.


#6

One rule of thumb I’ve used on flat belts is to grasp the belt between a thumb and forefinger on a straight run between 2 pulleys and attempt to rotate it 90 degrees.
It should be difficult to do, but doable.

Usually a singing belt is one that is too tight (assuming no idler, alt. bearing whine, etc.) and sometimes it can be caused by the belt construction.
I recently replaced the serpentine belt on my Lincoln and it would not quit chirping no matter what. Against my better judgement I even gave it a shot of belt dressing; a product I absolutely hate.
It still chirped so it was ditched in place of another and the problem is solved.


#7

Driveway Results:

Thanks OK4450.

We fired up the car this morning. It was cold soaked at a “balmy” 10F, the warmest morning in quite some time. The “low growl” was gone. The TSB worked. I hope the KRIKIT has it set at 120 pounds.
Any Krikit users out there?