Clicking noise when engine is cold..
Thread Starter
Racer
Joined: Jan 2011
Posts: 393
Likes: 1
Clicking noise when engine is cold..
I hear a clicking, almost knocking noise coming from the front of the engine. Only does this when the car is first started and the engine is cold.....once the engine warms up the noise goes away.....did a search but did not find any "clicking issues" that matched mine.....
Race Director
Joined: May 2005
Posts: 15,960
Likes: 21
From: West Norriton PA
St. Jude Donor '08
Well I would begin by popping open the hood and starting the car up and trying to isolate the noise.
A general noise like you described could be anything. It could be a belt, pulley, loose rocker, etc ...
Whatever it is, it goes away when the engine warms up meaning that the clearance is tightening up and making the noise go away.
I would also check the DIC for codes.
A general noise like you described could be anything. It could be a belt, pulley, loose rocker, etc ...
Whatever it is, it goes away when the engine warms up meaning that the clearance is tightening up and making the noise go away.
I would also check the DIC for codes.
Race Director
Joined: May 2005
Posts: 15,960
Likes: 21
From: West Norriton PA
St. Jude Donor '08
Crank pulley is not suppose to wobble. It's a sign that the balancer is starting to seperate or the front bolt is coming loose
You have front tensioner on both the AC and serpentine belts.
I would pull off both belts and start the car. If you hear no noise then you isolated it to the front drive componets.
Start with the AC and if no noise, look at the belt and check the grooves to see that they are not damaged and then check the other pulleys for free play or wobble.
Re-install the belt and figure out which items is causing the problem.
Le Mans Master
Joined: Jul 2010
Posts: 6,005
Likes: 723
water pump
I hear a clicking, almost knocking noise coming from the front of the engine. Only does this when the car is first started and the engine is cold.....once the engine warms up the noise goes away.....did a search but did not find any "clicking issues" that matched mine.....
Burning Brakes
Joined: Jan 2010
Posts: 763
Likes: 0
From: Murfreesboro TN
My 99 doesn't do it, but only has 43,000 miles.
My 2000 Silverado 5.3 started this at around 50,000 miles and does it mostly in cold weather on the 1st start of the day. It makes the noise for about 2 minutes at idle, then it disappears. The truck now has 124,xxx miles and doesn't burn oil. =)
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Burning Brakes
Joined: Jan 2010
Posts: 763
Likes: 0
From: Murfreesboro TN
But to be honest, it isn't worth the money.
My truck has had piston slap for over 5 years and I have tried additives, 0-30w Mobil 1 and really no change.
The only thing I have noticed is that right after an oil change with fresh Mobil 1, it doesn't seem to do it the first couple of cold starts for some reason.
If you aren't burning oil and it is piston slap, I would not worry about it.
It only happens when it is cold and as long as you don't drive the car hard when it is cold, you should be fine. Always run the 5-30w synthetic in the car too, changing weights could cause engine damage, especially in cold weather.
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
The ticking isn't coming from the valve cover areas? If it is, then its more likely lifters bleeding down when cold but unless you have a ton of miles, its rather unlikely.
Burning Brakes
Joined: May 2010
Posts: 1,167
Likes: 2
From: Pittsburgh Pa
Piston slap...wtf. Forged pistons yes, hyperuetectic pistons...no. A forged piston requires more piston to wall clearance due to the nature of expansion in that material to obtain proper piston to wall clearances at operating temp. Hypereutectic pistons have a high silicone content and don't expand in the same manner, but also can't sustain high heat like a forged piston can, plus forged is stronger...hence why big power motors go forged. Aluminum "block" has nothing to do with piston to wall clearances becuase your bores aren't aluminum.
If you have piston slap in a stock motor you got problems due to wear. A motor can have piston slap and run somewhat fine, but I highly doubt a lower mileage LSx motor is gonna have blown out piston-wall clearances or bellmouthed cylinders. Piston slap is a misdiagnosis. I'd look more to a lifter needing replaced or something in the pulleys. Lifters will tick until they "pump up" upon startup sometimes or they'll just tick endlessly...and sometimes heavier weight oil quiets them down. Heavier weight oil than needed costs you horsepower though...it's a fact.
If you have piston slap in a stock motor you got problems due to wear. A motor can have piston slap and run somewhat fine, but I highly doubt a lower mileage LSx motor is gonna have blown out piston-wall clearances or bellmouthed cylinders. Piston slap is a misdiagnosis. I'd look more to a lifter needing replaced or something in the pulleys. Lifters will tick until they "pump up" upon startup sometimes or they'll just tick endlessly...and sometimes heavier weight oil quiets them down. Heavier weight oil than needed costs you horsepower though...it's a fact.
Instructor
Joined: Feb 2011
Posts: 126
Likes: 1
From: Corpus Christi Texas
I never hear it coming from my C5, but I've got a 1997 Z-28 with an LT1 that has done it since it was new. I always thought it was rattling lifters. As soon at the temp guage starts rising, the clattering stops.
200,000 miles on it now, with no problems. I just never romp on it until it's nice and warm.
200,000 miles on it now, with no problems. I just never romp on it until it's nice and warm.
Last edited by Pewter Scooter; Feb 14, 2011 at 11:48 AM.
Burning Brakes
Joined: Jan 2010
Posts: 763
Likes: 0
From: Murfreesboro TN
Piston slap...wtf. Forged pistons yes, hyperuetectic pistons...no. A forged piston requires more piston to wall clearance due to the nature of expansion in that material to obtain proper piston to wall clearances at operating temp. Hypereutectic pistons have a high silicone content and don't expand in the same manner, but also can't sustain high heat like a forged piston can, plus forged is stronger...hence why big power motors go forged. Aluminum "block" has nothing to do with piston to wall clearances becuase your bores aren't aluminum.
If you have piston slap in a stock motor you got problems due to wear. A motor can have piston slap and run somewhat fine, but I highly doubt a lower mileage LSx motor is gonna have blown out piston-wall clearances or bellmouthed cylinders. Piston slap is a misdiagnosis. I'd look more to a lifter needing replaced or something in the pulleys. Lifters will tick until they "pump up" upon startup sometimes or they'll just tick endlessly...and sometimes heavier weight oil quiets them down. Heavier weight oil than needed costs you horsepower though...it's a fact.
If you have piston slap in a stock motor you got problems due to wear. A motor can have piston slap and run somewhat fine, but I highly doubt a lower mileage LSx motor is gonna have blown out piston-wall clearances or bellmouthed cylinders. Piston slap is a misdiagnosis. I'd look more to a lifter needing replaced or something in the pulleys. Lifters will tick until they "pump up" upon startup sometimes or they'll just tick endlessly...and sometimes heavier weight oil quiets them down. Heavier weight oil than needed costs you horsepower though...it's a fact.
The following is a quote from this link: http://en.wikipedia.org/wiki/GM_LS_engine
"Problems:
In the early production run of the LS-series engine, some engines encountered abnormal amounts of 'piston slap' - a problem caused by too much clearance between the cylinder bore and the piston.[11] 'Piston slap' sometimes sounds more like a knock or the sound of a diesel engine running. It is typically worse when the engine is cold and lessens as the engine reaches operating temperature. The noise of 'piston slap' often is louder when listening for it below the oil pan.
"
I have a 2000 Silverado with a 5.3L engine that I bought new that now has 124,xxx miiles and it started the piston slap at ~50,xxx miles. It never burns/uses oil in its 5000 mile oil changes with Mobil 1 but in cold weather sounds like a diesel engine for about 2 minutes while idling.
Though it may not be the OP's actual issue, it sounds a lot like it.
For anyone wanting more information on GM's Piston Slap:
http://www.pistonslap.com/index.html
Last edited by TN Vette; Feb 14, 2011 at 02:14 PM. Reason: added piston slap link
Safety Car
Joined: Jan 2007
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From: The Great Truth: "There ain't no free lunch"
St. Jude Donor '08-'09-'10-'11
I also have an older Z-71 (5.3) w/186,XXX miles that makes the diesel noises on cold start-up. Changed oil about a month ago to Mob 1 10W30....haven't heard the noise since........Will it return? Probably! But, for now I can start without scaring little children and women.....
Burning Brakes
Joined: Jan 2010
Posts: 763
Likes: 0
From: Murfreesboro TN
I also have an older Z-71 (5.3) w/186,XXX miles that makes the diesel noises on cold start-up. Changed oil about a month ago to Mob 1 10W30....haven't heard the noise since........Will it return? Probably! But, for now I can start without scaring little children and women.....
Thread Starter
Racer
Joined: Jan 2011
Posts: 393
Likes: 1
The oil change deal may be the reason I didnt hear this when I was trying out the car....the dealer had just changed the oil.. I have put about 800 miles on the car since I started driving it and the dip stick still shows right on the full mark.......makes you wonder what is going on with the oil itself that it would stop slapping when fresh and not after only a short time...
Instructor
Joined: May 2010
Posts: 233
Likes: 1
From: San Benito TEXAS
noise
its piston slap engine oil us at the bottom of oil pan at start up till oil flows through engine this noise is normal you might want to add lucas synthetic oil staibilizer to quiet this a little.