Edmunds Answers



  • zaken1 05/09/10 8:49 pm PST

    I understand that you said it is not the belt; but I don't know how you determined that. Belts on modern engines will often squeal; even if they feel tight when you press on them, and even when they do not make any noise while the engine idles. This has fooled experienced mechanics, who have not yet become familiar with how much tighter modern belts must now be adjusted; compared to the way they used to be adjusted. Modern alternators generate much more electrical power than the older ones did; and thus create much more resistance to being turned by the drive belt. This is why modern drive belts are so much wider and stronger than they previously were; and why the factory belt tension specs are so much tighter than they previously were. Since a loose belt is one of the only likely causes of a squealing noise, and it typically will not be heard unless you press on the gas, I believe that you'll find that this is the cause; despite what you have been told or what you previously believed.

  • Stever@Edmunds 05/10/10 9:30 pm PST

    You can reply in this thread by clicking the Answer this Question button and that will help keep all the information in one spot. Thanks!

  • zaken1 05/11/10 12:21 am PST

    I received a notification that you had posted an additional question; but your question was deleted because it was posted as a new question. This site only allows responses to existing questions to be posted in the original thread; by clicking the "answer this question" button. So if you want me to be able to see your question; please click the "answer this question" button, and post it here. Thanks.

  • wayo12 05/11/10 9:58 am PST

    have you checked the tensioner

  • brynnmarie31 05/11/10 8:43 pm PST

    The car still makes the noise when the belt is off, that is how the mechanic determined that that was not the problem. He suggested that maybe a bearing was going in the motor and someone else suggested that it may be the timing chain. I am a complete idiot when it comes to cars so I have no idea. Any other suggestions?

  • zaken1 05/12/10 12:22 am PST

    Thank you for getting back with your second question. I don't believe a worn timing chain would make a squealing noise, but a bad timing damper might. Since the timing chain and damper are easily accessible without taking the whole motor apart; it would be worthwhile to use a stethescope to determine whether the noise comes from the timing cover area. If it does; it would be worth removing the timing cover and inspecting the timing damper.

    There is one other type of engine problem which can produce a squealing noise, and that is a rocker arm which is not getting lubrication. If the noise comes from the valve cover area; it is easy enough to remove the valve covers and inspect the rocker arms and their pivots. These parts can be replaced at a relatively small cost without going deeper into the motor; but if the type of wear indicates that other parts of the engine are also probably affected; I would not go deeper into the motor.

    If there was a bad bearing in the engine; the cost of repairing it would be nearly as much as the cost of buying a freshly remanufactured motor, and there would still be a significant chance that other internal engine parts were also worn. So I would not recommend tearing down the engine to find and replace a bad bearing. Instead, if that was the problem, I would replace the engine with a remanufactured one. You can buy a completely remanufactured engine for that vehicle for about $1,400 from www.rockauto.com. I would also contact Hiperformer engines at the link posted below, and compare their prices and warranties. Those two places have better prices and better quality motors than you can find elsewhere. The regular Grand Prix has a 3.8 liter V-6 motor The Grand Prix GTP has a 3.8 liter supercharged motor, and the Grand Prix SE has a 3.1 liter V-6 motor. You'll need to find out which model motor is in your car; before ordering a replacement.

    Source: http://www.hiperformer.com/engines/pont


Top Pontiac Grand Prix Experts View More

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3. zaken1 380
4. 0patience 130
5. tony78 120
6. docj 115
7. Stever@Edmunds 105