How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Steve Your Own Question

Steve
Steve, Service Manager
Category: Ford
Satisfied Customers: 5494
Experience:  25+ years experience as a professional technician ; ASE L1 master Technician
Type Your Ford Question Here...
Steve is online now
A new question is answered every 9 seconds

what is causing my serpentine belt to squeal on my ...

Customer Question

what is causing my serpentine belt to squeal on my 1998 chevy truck engine is a 350. I have replaced everything, and I mean everything. When I take the belt of and start the truck it does not squeal??????? MAKING ME CRAZY!! Thanks.
Submitted: 6 years ago.
Category: Ford
Expert:  Steve replied 6 years ago.

Hello!

A belt can squeal for 3 reasons.

(1) Pulley misalignment.

If even one of the pulleys is slightly misaligned, the belt will constantly correct by slipping sideways on a pulley. This results in a constant chirp or squeal. After a whle the belt may start to show some edge wear if the misalignment is severe enough. Often you can see where the misalignment is occurring by closely watching the belt as it is running. Check to see if the power steering pump pulley is pressed on flush with the end of the shaft; PS pulleys can start to walk off after many thousands of miles. If a component such as an alternator was recently replaced, that may be related; many rebuilt parts do not have the pulleys correctly aligned (especially if from discount parts stores like Autozone, PepBoys, or Advance). If your engine bracket design is of the type used on late 80's/ early 90's GM trucks where there is a large sheet metal bracket that covers much of the front of the engine and to which all of the belt driven components are attached, check carefully for cracks or loose mounting bolts that hold the bracket to the front of the engine (common failure). Check to make sure the harmonic balancer is not coming apart or walking off of the crankshaft. If any pulleys have been replaed, count the number of grooves to make sure the pulley is correct and matches the belt ribs. I have seen instances where an alternator, for example, has come with a 7 groove pulley to fit a 6 groove belt vehicle.

(2) Incorrect Tension.

It is extremely important that the belt be properly tensioned, or it will slip under load (such as when the engine is started). If the belt tensioner is original, it should be replaced as teh internal spring does become fatigued with age and use. I would recommend using a GM tensioner; many discount parts store tensioners have given us problems over the years because of poor manufacturing tolerances such as incorrect spring tension, bearing play, and pulley misalignment.

(3) Belt contamination.

If any foreign substance such as antifreeze, oil, or power steering fluid should contact the belt surface it will be absorbed and cause a change in frictional properties at that point in the belt surface. This also applies to greasy fingerprints, or any kind of "belt treatment" spray. IF a belt should become contaminated, it will never run quietly and must be replaced, making sure it is clean and dry. Check for water pump leakage, PS pump leakage, or for any other kind of substthat could be causing contamination of the belt surfaces.

Also, I have found that some brands of belts are very stiff, and tend to slip when cold. I have personally run into this with Kelly brand belts and the cheap line belts sold at Autozone and NAPA stores. If you are installing one of these brands, you may want to try using a different premium line belt from a different supplier to see if it resolves the problem.

I hope this is helpful!

 

 

 

Steve, Service Manager
Category: Ford
Satisfied Customers: 5494
Experience: 25+ years experience as a professional technician ; ASE L1 master Technician
Steve and 10 other Ford Specialists are ready to help you
Customer: replied 6 years ago.
Steve, thank you. I am accepting this answer before I try any of your suggestions, simply because I don't think I could get a better answer. Thanks again and wish me luck.
Expert:  Steve replied 6 years ago.
Thanks for the accept; if you need any further assistance wwith this problem, please dont hesitate to ask...

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • AlvinC answered a question about my Ford truck that only someone with an in-depth knowledge of his subject would have known what was going on. Rich D USA
< Last | Next >
  • AlvinC answered a question about my Ford truck that only someone with an in-depth knowledge of his subject would have known what was going on. Rich D USA
  • Because of your expertise, you armed me with enough ammunition to win the battle with the dealer. They are installing a fuel filter and fuel pump at no charge to me. Molly USA
  • I needed help with my car on Saturday morning....got a response in 5 minutes, and it was the perfect solution. Thanks again to your service. Jason V. Kirkland, WA
  • I do know, after going though this with JustAnswer, that I can somewhat trust my mechanic but I will always contact you prior to going there. BR New Jersey
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P Elm City, NC
  • used your service this weekend with "Trecers" help. thank you ,thank you, thank you. replaced an A/C fan motor. Local Auto Zone had part. $15.00 "tracer" fee and $40.00 for parts, I saved several hundreds of dollers at a shop. i will recommend you and use you in the future. David L. Richmond, TX
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil Marysville, CA
 
 
 

Meet The Experts:

 
 
 
  • Ron

    ASE Certified Technician

    Satisfied Customers:

    20942
    23 years with Ford specializing in drivability and electrical and AC. Ford certs and ASE Certs
< Last | Next >
  • http://ww2.justanswer.com/uploads/FO/fordguy4u/2011-12-17_222940_HPIM1257.64x64.JPG Ron's Avatar

    Ron

    ASE Certified Technician

    Satisfied Customers:

    20942
    23 years with Ford specializing in drivability and electrical and AC. Ford certs and ASE Certs
  • http://ww2.justanswer.com/uploads/MU/muddyford/2012-6-13_1204_1.64x64.png Chris (aka- Moose)'s Avatar

    Chris (aka- Moose)

    Ford Technician

    Satisfied Customers:

    22382
    16 years experience with Ford.
  • http://ww2.justanswer.com/uploads/JM/jmcdo28/2012-2-23_01655_resized.64x64.jpg John Mc's Avatar

    John Mc

    Ford Technician

    Satisfied Customers:

    5493
    19 years Ford Lincoln Mercury experience
  • http://ww2.justanswer.com/uploads/wmarti7/2009-4-18_04332_Avatar.jpg Chuck's Avatar

    Chuck

    ASE Certified Technician

    Satisfied Customers:

    1684
    33 Years Experience,Ford Senior Master,ASE Master,L1 Advanced Engine Performance
  • http://ww2.justanswer.com/uploads/CR/crzydrvr00/2013-11-3_12123_246347.64x64.jpg Richard's Avatar

    Richard

    ASE Certified Technician

    Satisfied Customers:

    1518
    12 years at a Ford Lincoln/Mercury and Jaguar dealer as a technician and shop foreman.
  • http://ww2.justanswer.com/uploads/BA/baddad1/2014-4-1_23659_avatar.64x64.jpg Mike V.'s Avatar

    Mike V.

    Auto Service Technician

    Satisfied Customers:

    789
    25 years experience on all makes and models, Licensed NYS Inspector.
  • http://ww2.justanswer.com/uploads/lostrider/2009-9-26_23144_php4VNWAA_c1PM1.jpg lostrider's Avatar

    lostrider

    Ford Technician

    Satisfied Customers:

    2940
    ASE Master Technician, Ford Senior Master Technician,Diesel certified, ASE Master, 22 yrs FORD exp.