Using coolant? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

WELD4DAYS · 03-04-2009, 05:03 PM

I have a 2002 Silverado with the 4.3. About 87,000 miles. I have the water fall sound under the dash.I have to fill up my coolant every so often. I think its using a little more as time goes on. I heard these motors might have intake issues or water pump problems. I never see water on the ground. Maybe it leaks internally and is evaporating. My question is, can I put some of the old school stop leak in the overflow tank. The gray powder stuff you might use on your old Chevy? I'm not sure how the newer vehicles might react to something like that. Please give me your thoughts. Thanks

**truckdude239** · 03-05-2009, 07:58 AM

do not use stop leaking in a new vechicle it sounds liek your heater core is going out

billsbowtie · 03-05-2009, 09:45 PM

i have a 2002 silverado same eng 4.3 with 55,000 miles i can smell coolant just about everytime i drive it but don't see any leaks. but it hasn't got low but 1 time i pull about a quart in it. i was thinking maybe the water pump is getting ready to go out. it does not run hot either.

**bwood** · 03-05-2009, 11:10 PM

The 4.3L is prone to the intake leaks that the 5.0/5.7L Gen I Vortecs suffer from. Check you oil and see if it is higher than normal. Also remove your oil fill cap and look for a light colored sludge stuck to it. The oil will get hot enough to cook off some of the water and the vapor collects as a oily white sludge at the top of the engine, valve covers and in the crankcase ventilation route.The waterfall sound on the NBS trucks generally is due to air circulating through the heater core due to low coolant. Another indicator of low coolant is the heater really won't blow hot until the truck starts moving. If you do suspect intake gaskets, get a Chilton manual and make sure to get the Fel Pro Problem Solver Gasket Set #MS98002T. This set has the newest rubber-over-steel design that replaces the OEM rubber-inbedded-in plastic design. The water pump leak issues only apply to the V8 Gen III small blocks (4.8, 5.3, 6.0).
It is also possible for these to leak externally. Look at the rear of the pass side head and down the front of the driver side head for a trail of burned off coolant.

03-04-2009, 05:03 PM	#1
WELD4DAYS Registered User Join Date: Nov 2007 Location: Phoenix,AZ Posts: 107	Using coolant? I have a 2002 Silverado with the 4.3. About 87,000 miles. I have the water fall sound under the dash.I have to fill up my coolant every so often. I think its using a little more as time goes on. I heard these motors might have intake issues or water pump problems. I never see water on the ground. Maybe it leaks internally and is evaporating. My question is, can I put some of the old school stop leak in the overflow tank. The gray powder stuff you might use on your old Chevy? I'm not sure how the newer vehicles might react to something like that. Please give me your thoughts. Thanks

03-05-2009, 07:58 AM	#2
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,217	Re: Using coolant? do not use stop leaking in a new vechicle it sounds liek your heater core is going out __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube

03-05-2009, 09:45 PM	#3
billsbowtie Senior Member Join Date: Feb 2003 Location: rose hill V.A. 24281 Posts: 17,997	Re: Using coolant? i have a 2002 silverado same eng 4.3 with 55,000 miles i can smell coolant just about everytime i drive it but don't see any leaks. but it hasn't got low but 1 time i pull about a quart in it. i was thinking maybe the water pump is getting ready to go out. it does not run hot either. __________________ i have 67/72 chevy truck parts f/s.

03-05-2009, 11:10 PM	#4
bwood Registered User Join Date: Jan 2003 Location: Denison, Texas Posts: 1,919	Re: Using coolant? The 4.3L is prone to the intake leaks that the 5.0/5.7L Gen I Vortecs suffer from. Check you oil and see if it is higher than normal. Also remove your oil fill cap and look for a light colored sludge stuck to it. The oil will get hot enough to cook off some of the water and the vapor collects as a oily white sludge at the top of the engine, valve covers and in the crankcase ventilation route.The waterfall sound on the NBS trucks generally is due to air circulating through the heater core due to low coolant. Another indicator of low coolant is the heater really won't blow hot until the truck starts moving. If you do suspect intake gaskets, get a Chilton manual and make sure to get the Fel Pro Problem Solver Gasket Set #MS98002T. This set has the newest rubber-over-steel design that replaces the OEM rubber-inbedded-in plastic design. The water pump leak issues only apply to the V8 Gen III small blocks (4.8, 5.3, 6.0). It is also possible for these to leak externally. Look at the rear of the pass side head and down the front of the driver side head for a trail of burned off coolant. __________________ 1998 GMC Sierra SLE 1/2 ton 2WD 305 Vortec -Gibson Stainless Cat Back Swept Side -SS Wheels 2005 Honda CRF250R 2006 Honda CRF150F Last edited by bwood; 03-05-2009 at 11:26 PM.



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