GMC Acadia Forum banner

1 - 20 of 30 Posts

·
Premium Member
Joined
·
3,212 Posts
Discussion Starter · #1 ·
A couple of members have asked about ticking or clicking noise from the direct injection engines. It's normal operation, here the document:

#07-06-04-025A: Information on Clicking/Ticking Sound/Noise Heard During Cold Start, Sound/Noise Decreases But Continues as Engine Warms-Normal Operation of High Pressure Fuel Pump and Injectors - (Nov 26, 2008)


Subject: Information on Clicking/Ticking Sound/Noise Heard During Cold Start, Sound/Noise Decreases But Continues as Engine Warms - Normal Operation of High Pressure Fuel Pump and Injectors

Models: 2008-2009 Cadillac CTS, STS
2009 Buick Enclave
2009 Chevrolet Traverse
2009 GMC Acadia
2009 Saturn OUTLOOK
with 3.6L VVT Direct Injection V6 Engine (VINs D, V -- RPO LLT)
--------------------------------------------------------------------------------
This bulletin is being revised to add the 2009 model year to the Cadillac models and include additional truck models. Please discard Corporate Bulletin Number 07-06-04-025 (Section 06 -- Engine/Propulsion System).
--------------------------------------------------------------------------------
Do This
Inform the customer that this is normal operation of the high pressure fuel pump and injectors.

Don't Do This
DO NOT replace the high pressure fuel pump and or injectors.

The 3.6L SIDI engine (VIN V - RPO LLT) uses a direct injection fuel system that operates at very high fuel pressures. A direct injection fuel system produces a rapid clicking and ticking sound that can be heard from the engine compartment. The sound is more evident when outside around the vehicle or when the hood is open. The sound is more noticeable during idle and is more frequent during a cold start, but lessens once the engine is warm. The rapid ticking noise on cold start up is the fuel pump (located on the rear of the left cylinder head) building up high fuel pressure. When the engine warm-up is completed, the high pressure fuel pump will continue to tick at a lower rate of approximately one tick per second during idle. The clicking sound is the fuel injectors pulsing on and off under higher fuel pressures. These sounds are the results of a normal direct injection fuel system operating properly.

DO NOT attempt to repair or replace any parts for this kind of clicking or ticking concern. The clicking or ticking sound is not indicative of any concerns with the engine or the vehicle. You may wish to give the customer a copy of this bulletin.
 

·
Registered
Joined
·
30 Posts
Thanks GeoHawk, I have posted reference to this on Enclave Forum due to inclusion of 2009 Enclave. Gave due credit back to you of course.
BD
 

·
Premium Member
Joined
·
3,212 Posts
Discussion Starter · #3 ·
Thanks BD. Feel free to cross-post any stuff I list here. Trying to post this across 4 forums is more work than I have time for. :thumb:
 

·
Registered
Joined
·
30 Posts
GeoHawk said:
Thanks BD. Feel free to cross-post any stuff I list here. Trying to post this across 4 forums is more work than I have time for. :thumb:
Thanks for your attitude; I am just trying to cut down the load on our mods. I personally consider us all one big family anyway! We are entitled to our personal preferences in vehicles and I do not understand or support any snide references. Life is too short for that.
BD
 

·
Registered
Joined
·
533 Posts
I had noticed it on my '09 Acadia - and had I not known from the Forum what the source was - it would have bothered me a bit.

Thanks again Geo.

Smooth[/color] <><
 

·
Registered
Joined
·
540 Posts
I had noticed the noise when my Acadia was delivered on 12/02/08. I actually thought it was a belt or pulley problem. I asked the salesman when he was going over the car with me and he said it was the fuel injection. Then I read the bulletin posted above on 12/16/08 confirming the normal noise. It was a relief to see it in writing. I don't have to keep wondering if something is going to happen. You get use to the noise.


Bobby
 

·
Registered
Joined
·
1,208 Posts
Can you see this fuel pum under the hood?
Anyone have a picture of this fuel pump?
 

·
Premium Member
Joined
·
14,870 Posts
Copperhead13 said:
Can you see this fuel pum under the hood?
Anyone have a picture of this fuel pump?
I don't think the fuel pump is in the engine area
 

·
Registered
Joined
·
294 Posts
jsimms said:
Copperhead13 said:
Can you see this fuel pum under the hood?
Anyone have a picture of this fuel pump?
I don't think the fuel pump is in the engine area
The main fuel pump is in the fuel tank as in most GM vehicles. The DI engines have an aux. pump that is driven by the left bank exhaust camshaft (at least this is the location on the Caddy CTS). The aux. fuel pump ramps up the pressure to about 1740psi so that the injectors properly atomize the fuel in the cylinder.
 

·
Premium Member
Joined
·
14,870 Posts
xseler said:
jsimms said:
Copperhead13 said:
Can you see this fuel pum under the hood?
Anyone have a picture of this fuel pump?
I don't think the fuel pump is in the engine area
The main fuel pump is in the fuel tank as in most GM vehicles. The DI engines have an aux. pump that is driven by the left bank exhaust camshaft[/color] (at least this is the location on the Caddy CTS). The aux. fuel pump ramps up the pressure to about 1740psi so that the injectors properly atomize the fuel in the cylinder.
I'm not familiar with this function; is the pressure increased by exhaust pressure or by a mechanical linkage?
 

·
Registered
Joined
·
294 Posts
The camshaft provides the rotational force for an actual pump.
 

·
Premium Member
Joined
·
14,870 Posts
Thanks :thumb:
 

·
Registered
Joined
·
540 Posts
xseler said:
jsimms said:
Copperhead13 said:
Can you see this fuel pum under the hood?
Anyone have a picture of this fuel pump?
I don't think the fuel pump is in the engine area
The main fuel pump is in the fuel tank as in most GM vehicles. The DI engines have an aux. pump that is driven by the left bank exhaust camshaft (at least this is the location on the Caddy CTS). The aux. fuel pump ramps up the pressure to about 1740psi so that the injectors properly atomize the fuel in the cylinder.
I had no idea the fuel pressure reached 1740 psi on the Acadia. Thats a lot higher than the 35psi on my old 3800 engine.

Bobby
 

·
Registered
Joined
·
294 Posts
Yeah, that's just with the Direct Injection engine. It's required to get a proper spray pattern in the cylinder. With regular fuel injection, the fuel is injected before the cylinder and the air has time to swirl the mixture before ignition.
 

·
Registered
Joined
·
1,208 Posts
Here is an interesting fact about FI and DI engines.

The Germans had FI engines in the Messerschmitt fighters of WWII,
and the Japanese had DI engines in the Zero fighters of WWII.

I wonder why it took so long to come to the automotive industry?
 

·
Premium Member
Joined
·
14,870 Posts
Copperhead13 said:
Here is an interesting fact about FI and DI engines.

The Germans had FI engines in the Messerschmitt fighters of WWII,
and the Japanese had DI engines in the Zero fighters of WWII.

I wonder why it took so long to come to the automotive industry?
Technology for aircraft are always ahead of anything that we may drive; for example generators (alternators on cars) on aircraft engines are far superior to anything that is installed on cars.
 

·
Registered
Joined
·
6 Posts
The ticking sound in from my 09 Acadia is not a constant tick, tick, tick, tick, etc. It comes every half second- like it is on a rotation. Is this normal?
 

·
Registered
Joined
·
294 Posts
On most DI engines, the ticking sound becomes slower (at idle) as the engine warms up.
 

·
Premium Member
Joined
·
14,870 Posts
GeoHawk said:
A couple of members have asked about ticking or clicking noise from the direct injection engines. It's normal operation, here the document:

#07-06-04-025A: Information on Clicking/Ticking Sound/Noise Heard During Cold Start, Sound/Noise Decreases But Continues as Engine Warms-Normal Operation of High Pressure Fuel Pump and Injectors - (Nov 26, 2008)


Subject: Information on Clicking/Ticking Sound/Noise Heard During Cold Start, Sound/Noise Decreases But Continues as Engine Warms - Normal Operation of High Pressure Fuel Pump and Injectors

Models: 2008-2009 Cadillac CTS, STS
2009 Buick Enclave
2009 Chevrolet Traverse
2009 GMC Acadia
2009 Saturn OUTLOOK
with 3.6L VVT Direct Injection V6 Engine (VINs D, V -- RPO LLT)
--------------------------------------------------------------------------------
This bulletin is being revised to add the 2009 model year to the Cadillac models and include additional truck models. Please discard Corporate Bulletin Number 07-06-04-025 (Section 06 -- Engine/Propulsion System).
--------------------------------------------------------------------------------
Do This
Inform the customer that this is normal operation of the high pressure fuel pump and injectors.

Don't Do This
DO NOT replace the high pressure fuel pump and or injectors.

The 3.6L SIDI engine (VIN V - RPO LLT) uses a direct injection fuel system that operates at very high fuel pressures. A direct injection fuel system produces a rapid clicking and ticking sound that can be heard from the engine compartment. The sound is more evident when outside around the vehicle or when the hood is open. The sound is more noticeable during idle and is more frequent during a cold start, but lessens once the engine is warm. The rapid ticking noise on cold start up is the fuel pump (located on the rear of the left cylinder head) building up high fuel pressure. When the engine warm-up is completed, the high pressure fuel pump will continue to tick at a lower rate of approximately one tick per second during idle. The clicking sound is the fuel injectors pulsing on and off under higher fuel pressures. These sounds are the results of a normal direct injection fuel system operating properly.

DO NOT attempt to repair or replace any parts for this kind of clicking or ticking concern. The clicking or ticking sound is not indicative of any concerns with the engine or the vehicle. You may wish to give the customer a copy of this bulletin.
This may be the cause of the ticking
 
1 - 20 of 30 Posts
Top