02 Silverado V8 5.3 losing antifreeze - The 1947 - Present Chevrolet & GMC Truck Message Board Network

ncmike · 06-26-2014, 06:08 PM

Leaks about a pint or so every 200 miles with no noticable sign where leaking at. Should I try some stop leak or do I have a bigger problem.

**Boog** · 06-26-2014, 07:01 PM

You should have your cooling system pressure tested. They can put in a die to help find the leak.
I just went through this with my 06 crew cab. Mine turned out to be a cracked head. It started losing a small amount then much faster. Keep a check on your oil level. The crack in mine sent the coolant directly into the crankcase. Normally you would associate a cracked head with an overheated engine. Mine had never been overheated in the 3 years we owned it.

stepside67 · 06-27-2014, 12:29 AM

I had the problem on my 2001 Suburban at 214,000 miles. Initially I only had to add antifreeze once every couple of months and then it started getting much worse. I took it to a shop and they ran pressure test and found the pressure dropping very quickly and no outward signs of leakage. Next step they pulled valve cover on drivers side and you could clearly see the antifreeze leaking from the top side of the head. A set of fully rebuilt heads installed with all the needed gaskets, new head blots, plugs, etc.. was around $2400.00 with a 2yr/24,000 warranty. I was able to catch it early enough and there was not any sludge buildup from the oil/antifreeze or damage to the engine.

I would not add any type of stop leak as this could introduce new problems...A good shop should be able to diagnose this pretty quickly and determine if the heads are the problem. You can google 'CASTEC' and get plenty of information on this topic.

I would also check the water pump gasket and the heater hose quick connects for leaks. Both of these are very common for the 5.3

T3AMCH3VY · 06-28-2014, 09:32 AM

Look closely around the heater hose couplers on the firewall. Its a common spot that is easily overlooked. Plus at the rate you are losing coolant you might just see residue from the leak.

Leinie · 07-06-2014, 08:19 PM

Don't forget to check the hose on the bottom of the overflow tank. My last two trucks had that hoes start to crack and drain coolant from the tank even though the radiator level remained constant.
Also, intake manifold gasket leaks are common.

06-26-2014, 06:08 PM	#1
ncmike Registered User Join Date: Oct 2010 Location: Thurmond, NC Posts: 6	02 Silverado V8 5.3 losing antifreeze Leaks about a pint or so every 200 miles with no noticable sign where leaking at. Should I try some stop leak or do I have a bigger problem.

06-26-2014, 07:01 PM	#2
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 12,957	Re: 02 Silverado V8 5.3 losing antifreeze You should have your cooling system pressure tested. They can put in a die to help find the leak. I just went through this with my 06 crew cab. Mine turned out to be a cracked head. It started losing a small amount then much faster. Keep a check on your oil level. The crack in mine sent the coolant directly into the crankcase. Normally you would associate a cracked head with an overheated engine. Mine had never been overheated in the 3 years we owned it. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

06-27-2014, 12:29 AM	#3
stepside67 Registered User Join Date: May 2005 Location: Cypress,Tx Posts: 63	Re: 02 Silverado V8 5.3 losing antifreeze I had the problem on my 2001 Suburban at 214,000 miles. Initially I only had to add antifreeze once every couple of months and then it started getting much worse. I took it to a shop and they ran pressure test and found the pressure dropping very quickly and no outward signs of leakage. Next step they pulled valve cover on drivers side and you could clearly see the antifreeze leaking from the top side of the head. A set of fully rebuilt heads installed with all the needed gaskets, new head blots, plugs, etc.. was around $2400.00 with a 2yr/24,000 warranty. I was able to catch it early enough and there was not any sludge buildup from the oil/antifreeze or damage to the engine. I would not add any type of stop leak as this could introduce new problems...A good shop should be able to diagnose this pretty quickly and determine if the heads are the problem. You can google 'CASTEC' and get plenty of information on this topic. I would also check the water pump gasket and the heater hose quick connects for leaks. Both of these are very common for the 5.3 __________________ Stepside67 2016 Silverado LTZ Crew Cab 2001 Suburban 2000 Sportside Reg Cab 4.8 (Stolen) 1967 SWB Stepside Project

06-28-2014, 09:32 AM	#4
T3AMCH3VY Registered User Join Date: May 2014 Location: Anderson South Carolina Posts: 14	Re: 02 Silverado V8 5.3 losing antifreeze Look closely around the heater hose couplers on the firewall. Its a common spot that is easily overlooked. Plus at the rate you are losing coolant you might just see residue from the leak.

07-06-2014, 08:19 PM	#5
Leinie Registered User Join Date: Feb 2001 Location: USA Posts: 2,613	Re: 02 Silverado V8 5.3 losing antifreeze Don't forget to check the hose on the bottom of the overflow tank. My last two trucks had that hoes start to crack and drain coolant from the tank even though the radiator level remained constant. Also, intake manifold gasket leaks are common.



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