Updated - "W" serpentine belts by Dayco - Anybody out there with real life experience?

The Vehicle:
1999 Dodge Intrepid, 2.7L V-6, 307,000 miles

My 16 year-old daughter drives my wife’s former car, this old Intrepid. She drives about 40 to 50 miles per day (High School, golf, soccer practice, & back).

The Problem:
As you can guess, this vehicle has some wear on it. As the weather gets colder and wetter the serpentine belt (runs the alternator and P/S pump - has manual adjuster/tensioner pulley) sometimes slips (does not squeal) to the point that the “Battery” light comes on and I know it’s not charging. Also, it is now dark when the car first starts and lights are on and power steering is a little colder, etcetera, adding a load. Usually the belt heats up and starts gripping, but I’m not sending my daughter out and taking the chance. It happened this morning and I just got back from transporting my student.

I have cleaned the pulleys the best I could before and tightening the belt as much as I dare to and it solves the problem for a while (all summer, actually), but the problem’s back. I don’t want to put a lot of money into this car as it’s just not a sound investment.

The Question:
Dayco advertises their “W” belt and claims it has an advantage over regular belts on cars with worn pulleys and quiets belt squeal that they say is caused by slipping, but they stop short of saying it will help with my excessive slipping.
Anybody have experience with these belts ?
Solution or gimmick ?

Thanks, CSA

It does look a little gimmicky to me, but could help. I would try it out as long as the price difference is minimal compared to a cheap, regular belt. I think your problem is just a worn belt, though, if it’s more than a year old (given the amount your cars get driven and taking into consideration that some belts just don’t last all that long). I have seen the same thing out of belts that look and even feel perfectly fine, but replacing them with new solves the slippage problem. I say replace the belt with any new belt.

Dayco makes a quality product, and it’s what I stock to service customer vehicles. I’ve never used the “W” belt, but if it’s not too much more than a regular belt, I would go for it and see what results.

My wife has a 2.7 in a Sebring, and at 89K, I just completed rear top strut plates, struts all around, brakes all around, both belts… and the PITA intake manifold set and thermostat. Your claim of 300K on this car makes me want to cry, as my wife convinced me to do this big repair rather than trade it in on something a bit more reliable. I thought for sure this thing would grenade by 175K.

Also, are you checking the tension of the belt when you put a new belt on and “tighten it down as much as you dare to?” You’re better off keeping the tension of the belt down to where you’re still able to twist the belt slightly by hand, rather than tightening it down like a piano wire. Excessive tension will work great at first… no slippage, but then as the belt stretches prematurely, it will start to slip, glazing the rubber.

I have used Dayco belts in everything feom autos to commercial refrigeration. They make a good belt.
You dont mention ever changing the belt so if you have 307k miles on this belt, quit playing around with tightening and whatever and change it.


Daycos are good belts that the W belt looks a bit gimmicky to me also and I wonder how long the tips of the W are going to last with the tips of the pulley Vs bearing down on them.

It Warmed Up Outside, So I Went Out In The Driveway And The “Battery” Light Was Still Coming On When I Started The Car Without Heater Fan, Lights, Etcetera.

I tightened the belt and started it and the “Battery” light went out and stayed out even running the fan, lights, P/S (turning steering wheel).

The belt’s quite tight now, but I can still twist it 90 degrees with my fingers, midway on a span of 10" or 11". I’ve got a couple of types of tension gauges, but there’s not much wiggle room in there without taking the car apart.

The belt was new last March and it’s a Car Quest. I replaced it then after taking care of a P/S pump that was slinging fluid from the shaft/pulley when the “Battery” light problem began. I tried cleaning all pulleys at that time and thought I had them pretty clean.

The harmonic balancer has a little wobble, but I’ve experienced this before. I’m not sure if it should be replaced, but how long is it going to need to last on this old bucket of bolts ?

I’m thinking of trying one of those “W” Dayco belts. It’s in stock at my nearest Advance for less than 20 bucks. I’ll ask the guys there if they’ve had any feedback from customers. One guy there moonlights in his own auto repair shop (or moolights at Advance). I would also try cleaning all the pulleys again at that time.

Thanks everybody for all the comments and if you’ve got more, keep them coming.


Put a socket/ratchet on the alternator pulley and try to rotate the alternator. If the belt is grabbing like it should then the alt. pulley should be near impossible to turn with the ratchet.

For what it’s worth, I went through an odd deal a few years ago with a reman alternator. At first the alternator charged and the light went out. Within a few miles the alt. light popped on and it ceased to charge. All tests showed the alternator was good and the belt/tensioner had been replaced at the same time as the alt.

The ratchet test showed the new belt was simply not grabbing the alt. pulley like it should have. The closest of inspection could reveal no problem with the alt. pulley but assuming the pulley had to be the problem anyway I took the reman alt. back and exchanged it for another. The next reman grabbed the belt fine and it’s been trouble-free for several years now. Just something for consideration.
(As to the possibility the first alt. could have had a pulley contaminated with excess paint, oil film, or whatever those possibilities were weeded out.)

OK, I Did The “Wrench On The Alternator Shaft/Pulley Nut” Back In March When This First Started. It Turned Within The Belt. You Have To Get On The Ground To Get To The Alternator And This Time I Had Just Taken A Shower, So I Tried Tightenting The Belt From Above. It Worked For Now.

The alternator has never been replaced or serviced. It came with the car and I bought this 99 in 2000 with 10,000 miles on it, under full warranty.


November Update, For What It’s Worth.

The “battery” symbol continued to intermittently illuminate when my daughter was using the car to get to and from high school (“Zero Hour” class at 7:00 a.m.). I grounded the car and she had to catch rides.

I finally got on the ground and put a wrench on the alternator pulley nut and it did not slip in the belt . . . darn.

$75 later, after new brushes, commutator ring, and the new Dayco “W” serpentine belt, it’s been percolating without incident. By the way, that belt seems to be a fine piece of equipment and wasn’t much mose expensive than a regular one, about $20 at Advance.