2007 cold start engine noise

mattrudella · March 15, 2007

Hello I'm new to the forum and I own a 2007 Silverado (new body style) w/ LMG engine (DOD/flexfuel/iron block). I have a noise on cold start (temps below 20 degrees). The engine knocks for approximately 3 seconds or until the oil pressure reads ~40psi. The knocking noise sounds like engine parts without oil, 2 knocks per second for about 3 seconds. The noise is very noticeable, I started the truck with remote start from 50 feet away and still heard it. I don't think the knocking is piston slap, since after the first couple of seconds the engine is completely quiet and smooth. Does anyone else in the colder climate areas experience this noise? Is it due to the lack of oil pressure on start up? Suggestions? I don't think there is anything wrong with the motor, just seeing if others have experienced this. Thanks for the help.

Matt

[email protected] · March 15, 2007

I grew up in Alaska and during the winter we allways had block heaters and ran the recommended cold-weather wight oil. Check your manual for the recommended oil in a cold climate.

pwall · March 15, 2007

Welcome to

If you have an older truck (~2000-2002) I would say piston slap. But a 2007 already making noise......I'd be back to the dealership for sure.

TEE · March 15, 2007

Welcome to

If you have an older truck (~2000-2002) I would say piston slap. But a 2007 already making noise......I'd be back to the dealership for sure.

Dam...I thought GM got their heads out!

Apparently not...I'm not hearing good reports on the 07's

TBLAZER · March 16, 2007

Hello I'm new to the forum and I own a 2007 Silverado (new body style) w/ LMG engine (DOD/flexfuel/iron block). I have a noise on cold start (temps below 20 degrees). The engine knocks for approximately 3 seconds or until the oil pressure reads ~40psi. The knocking noise sounds like engine parts without oil, 2 knocks per second for about 3 seconds. The noise is very noticeable, I started the truck with remote start from 50 feet away and still heard it. I don't think the knocking is piston slap, since after the first couple of seconds the engine is completely quiet and smooth. Does anyone else in the colder climate areas experience this noise? Is it due to the lack of oil pressure on start up? Suggestions? I don't think there is anything wrong with the motor, just seeing if others have experienced this. Thanks for the help.

Matt

This doc does not pertain to your truck but it may help you.

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Document ID# 1822727

2007 Cadillac Escalade

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Subject: Cold Start Lifter Noise - keywords 6.2 arm engine knock L92 oil pressure push pushrod rattle rocker rod starting tick up valve

Models: 2007 Cadillac Escalade

Equipped with the 6.2L Engine RPO Code L92

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The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

The customer concern may be a cold start lifter noise that lasts only 1 to 3 seconds.

Recommendation/Instructions:

Verify the customer concern of a short duration cold start lifter noise. Compare the noise to a like vehicle with a 6.2L engine. The short duration lifter noise is not detrimental to the performance, reliability or durability of the engine. No engine mechanical repairs should be attempted for a noise lasting only a few seconds.

If a small air pocket is present at the lifter during initial start-up, a lifter noise may be heard. If the customer feels the cold start noise is excessive, change the oil with the Mobil 1 5W30 synthetic oil and evaluate the noise.

Note: All L92 6.2 engines built after 3/3/06 are filled with Mobil 1 at the assembly plant.

mattrudella · March 16, 2007

TBLAZER,

Thanks for the reply and that seems to be the exact condition I have with the 5.3. Do you have any documentation relating this condition to the 5.3L? Would the 6.2L have most of the same internal engine components as 5.3L, just a different bore/stroke?

Matt

TBLAZER · March 18, 2007

TBLAZER,
Thanks for the reply and that seems to be the exact condition I have with the 5.3. Do you have any documentation relating this condition to the 5.3L? Would the 6.2L have most of the same internal engine components as 5.3L, just a different bore/stroke?

Matt

No,I could not find any doc's on the 5.3,and yes the 4.8,5.3,6.0 and 6.2 are based on the same design engine block ane heads,they are built with different internal components to change displacement and the way the operate for different applications.

Have you changed the oil and filter? If soo,did you use the original GM type filter?

redvett · March 19, 2007

The 6.2L has variable cam timing that the 5.3L does not have but both have AFM.

mattrudella · March 19, 2007

TBLAZER,

This noise was occurring on the factory fill oil at ~2000 miles. I changed the oil and filter at 2,100 miles with GM oil and ACDelco filter. Since the oil change, I have not started the truck on days as cold as the ones I have heard the noise on. The factory oil was actually pretty dirty when I changed it. Do you know if GM uses any special wieght oil or additives to help with break in? I just hope the noise I am hearing is normal; I had a Subaru that I traded in on the truck that had a cold start knock and that engine failed at 8,000 miles. I'm a little paranoid about these noises after that experience.

Matt

trailrider325 · March 20, 2007

why is every thing normal to chevy and gm when it come's to there car's and truck's. when you spend 30,000 dollar's on a truck you don't exspect it to sound like a twenty year old truck that's ready to die. no wonder why there losing money

TBLAZER · March 20, 2007

TBLAZER,
This noise was occurring on the factory fill oil at ~2000 miles. I changed the oil and filter at 2,100 miles with GM oil and ACDelco filter. Since the oil change, I have not started the truck on days as cold as the ones I have heard the noise on. The factory oil was actually pretty dirty when I changed it. Do you know if GM uses any special wieght oil or additives to help with break in? I just hope the noise I am hearing is normal; I had a Subaru that I traded in on the truck that had a cold start knock and that engine failed at 8,000 miles. I'm a little paranoid about these noises after that experience.

Matt

I dont know of if GM uses a special break in oil,I don't think they do,but GM does not recomend the use of any additives,It is a good idea to take it to the dealer and at least get it documented,Just in case,The current generation of GM engines are excelent engines and have a very small failure record,since it was introduce in the 1997 corvett it's been upgraded and many of the faults have been corrected,thats why GM is backing them up with 100'000 miles.