Can a bad A/C clutch cause misfire

Tiny
JEFF SORDYL
  • MEMBER
  • 2005 BUICK ALLURE
  • 3.8L
  • 6 CYL
  • 146,000 MILES
Replaced all plugs and wires and ignition coils. Replaced brake booster hose and valve. Ran better for a short time. But if I turn the wheel to fast the engine wants to stall. In neutral it idles fine but when I put in drive I can feel the engine dragging. New water pump, belt tensioner and power steering pump. The A/C compressor sounds strange and sometimes makes rapid tapping noise for a few seconds? Any help would be greatly appreciated.
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Tuesday, January 14th, 2020 AT 2:03 PM

13 Replies

Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi,

It sounds like you have either a vacuum leak or there is an issue with the idle air control valve (IAC). The IAC is responsible for maintaining idle speed. When you put it in gear or turn the AC on, do the RPM drop?

First, and I have a feeling you may have already done this because of the brake booster replacement, check for engine vacuum leaks.

Here is a link that explains how that is done:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Next, here are two links. One explains how to service the IAC and the other how to replace one. The IAC is located on the throttle body.

https://www.2carpros.com/articles/idle-air-control-valve-service

https://www.2carpros.com/articles/how-to-replace-an-idle-speed-control-motor-iac

If the check engine light is staying on when the engine is running, you really should have the computer scanned to retrieve diagnostic trouble codes that will help identify where the problem is coming from. Here is a quick video showing how that is done:

https://youtu.be/YV3TRZwer8k

I realize most people don't own a scanner, but most parts stores will do it free of charge or lend/rent a scanner to you.

Let me know if any of this helps or if you have other questions.

Take care,
Joe
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Tuesday, January 14th, 2020 AT 7:46 PM
Tiny
JEFF SORDYL
  • MEMBER
I think I have to buy a new throttle body, because this one on my car can't be repaired. It's a sealed unit made to not be repairable. But I'm sure it's cheaper than an A/C. Clutch unit. I'll try this first. Thanks
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Tuesday, January 14th, 2020 AT 9:17 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi,

Before you replace it, try cleaning the present one. Here are the directions from Alldata:

2005 Buick Allure (CANADA) V6-3.8L
Throttle Body Cleaning Procedure
Vehicle Powertrain Management Fuel Delivery and Air Induction Throttle Body Service and Repair Procedures Throttle Body Cleaning Procedure
THROTTLE BODY CLEANING PROCEDURE
THROTTLE BODY CLEANING PROCEDURE

REMOVAL PROCEDURE
1. Disconnect the air intake ducts from the throttle body.

CAUTION: Turn OFF the ignition before inserting fingers into the throttle bore. Unexpected movement of the throttle blade could cause personal injury.

2. Inspect the throttle body bore and the throttle valve plate for any deposits. It is necessary to open the throttle valve in order to inspect all of the surfaces.
3. Clean the throttle body bore and the throttle valve plate by using a clean shop towel with Top Engine Cleaner, GM P/N 1052626 (Canadian P/N 993026) or AC-Delco Carburetor Tune-Up Conditioner, P/N X66-P, or an equivalent product.

NOTE: Do not use any solvent that contains Methyl Ethyl Ketone (MEK). This solvent may damage fuel system components.

INSTALLATION PROCEDURE
1. Connect the air intake ducts to the throttle body.
2. Inspect for air leaks.

________________________________________

Let me know if that helps. Also, let me know if you checked for vacuum leaks.

Take care,
Joe
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Thursday, January 16th, 2020 AT 3:48 PM
Tiny
JEFF SORDYL
  • MEMBER
I cleaned the throttle body very good. Can't find any more vacuum leaks. I wonder if when I unhooked the battery for a while if it messed up the programming? Down the road the engine is strong. Just putting in drive it drops rpm's or when stopped at light.
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Thursday, January 16th, 2020 AT 5:31 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
If you cleaned the throttle body and there are no leaks, my first suspect is the IAC. However, on this vehicle, there isn't an IAC at least in the true definition of an IAC. In this case, there is a throttle actuator control module. I attached a picture of its location.

Let me know if you have checked wiring and connections there.

Joe
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Thursday, January 16th, 2020 AT 6:07 PM
Tiny
JEFF SORDYL
  • MEMBER
Could a failing alternator cause a random misfire? Lights are dimming up and down when I use power windows and new battery charge is low?
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Friday, January 17th, 2020 AT 6:39 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi,

Yes, low voltage can lead to a misfire along with other issues. Here is a link that explains how to test the alternator. Check to make sure it is producing enough power.

https://www.2carpros.com/articles/how-to-check-a-car-alternator

Let me know what you find.

Joe

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Friday, January 17th, 2020 AT 9:23 PM
Tiny
JEFF SORDYL
  • MEMBER
I purchased a new alternator (original was going bad) started up strong and started charging right up to 14.3 volts and the lights stopped flickering. The idle is much better now. Sounds like it's a little loaded up, but I think it will clear up after driving a little. Check engine light finally went out! Thanks again for your help! 2CarPros rock!
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Thursday, January 23rd, 2020 AT 10:34 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Happy to hear you got it fixed, and you are very welcome. Let us know if you need help in the future or ever have questions. We'll be here.

Take care,
Joe
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Friday, January 24th, 2020 AT 8:59 PM
Tiny
JEFF SORDYL
  • MEMBER
Well my check engine light came back on. New alternator makes a difference but still have rough idle? Do you have a vacuum diagram for my car? Also I'm going to take the serpentine belt off and see if idle smooths out (to check A/C compressor for dragging). Also when I use the electric window switch the lights go a little dim. Seems like a heavy draw on electrical system.
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Saturday, January 25th, 2020 AT 7:16 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi,

If the lights only slightly dim, I wouldn't be too concerned. It isn't uncommon. As far as vacuum diagrams, I attached the three schematics I have. Let me know if they help.

Let me know what happens when you take the belt off.

Take care,
Joe
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Saturday, January 25th, 2020 AT 7:31 PM
Tiny
JEFF SORDYL
  • MEMBER
Took the belt off and it wasn't dragging. But in a few minutes the idle was better then back to rough idle. Cannot find any vacuum leaks so I'm guessing it's going to the idle air control in the throttle body. It's non repairable sealed unit so I'm going to buy a new throttle body. I can't find anything else. Kind of expensive about $180.00 on Amazon in a few weeks. Unable to find a used one at the junk yards? Not sure what else I can do?
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Sunday, January 26th, 2020 AT 3:25 AM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Rather than making the purchase at this point, can you get your hands on a live data scanner and let me know what both the short term and long term fuel trims are? If you can get that, I can tell if there is a problem with low fuel pressure, vacuum leak, faulty pressure regulator and so on. Also, you mentioned that the check engine light is back on. What code is present?

I would feel better knowing the code and the fuel trims before having you spend the money and replacing the TB. If, however, you chose to replace it first, here are the directions. The attached pics correlate with the directions.
________________________________________________________________
2005 Buick Allure (CANADA) V6-3.8L
Throttle Body Assembly Replacement
Vehicle Powertrain Management Fuel Delivery and Air Induction Throttle Body Service and Repair Procedures Throttle Body Assembly Replacement
THROTTLE BODY ASSEMBLY REPLACEMENT
THROTTLE BODY ASSEMBLY REPLACEMENT

REMOVAL PROCEDURE

pic 1

1. Partially drain the cooling system. Refer to Draining and Filling Cooling System.
2. Remove the fuel injector sight shield.
3. Remove the air cleaner intake duct.
4. Disconnect the throttle body electrical connector.
5. Remove the throttle body nuts (4) and the bolts (5).
6. Remove the throttle body assembly (1).
7. Clean the throttle body gasket mating surfaces.

NOTE: Do not use solvent of any type when cleaning the gasket surfaces on the intake manifold and the throttle body assembly, as damage to the gasket surfaces and throttle body assembly may result.

Use care in cleaning the gasket surfaces on the intake manifold and the throttle body assembly, as sharp tools may damage the gasket surfaces.

INSTALLATION PROCEDURE

pic 2

1. Install the new gasket.
2. Install the throttle body assembly (1).
3. Install the throttle body bolts (5) and the nuts (4).

NOTE: Refer to Fastener Notice in Service Precautions.

Tighten the bolts and the nuts to 10 N.M (89 lb in).

4. Connect the throttle body electrical connector.
5. Install the air cleaner intake duct.
6. Install the fuel injector sight shield.
7. Fill the cooling system. Refer to Draining and Filling Cooling System.

__________________________________
Let me know.

Joe
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Sunday, January 26th, 2020 AT 5:22 PM

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