Coolant Leak

Good day all,

New to the site, I have been creeping around for awhile, and find the site to be a wealth of information and help.

I have a question, about my "new to me" 2000 Silverado 4X4 with 5.3l, it has 263000km on it, I purchased it from a friend that was the orginal owner from brand new. He has maintained this truck 100%, in fact I have gone through all his service invoices, and have noticed that this truck has NEVER gone past 5500km between oil changes. It is in imuclant condition.

My question is, prior to me purchasing the truck, it sat for 3 weeks, I seem to be able to smell coolant, comming from the vehicle. I parked it in the garage last night and noticed this morning that there was some coolant on the floor. The coolant on the floor was no bigger then the size of a coolant jug CAP (round).

I have crawled under, over and through the truck, and have found a wet area on the passanger side at the front of the engine, and looks as though it may be comming from between the head and block. I have never encountered this before, if it was a head gasket, wouldn't it leak either into the oil, or bun through the exhaust. and wouldn't the temp go up in the truck.

I can not smell coolant out the tailpipe, and I don't think the truck is overheating, as it is running just below the 100 degree mark on the gauge. (not to sure what it should be running at to be honest) I have lots of heat in the cab as well

I put 1 litre of cooland in the resivour.

I have spoke with the previous owner, and he has never had an issue with leaking coolant, except when the waterpump had to be changed last year.

I am a little concerned because I have been searching this site, and it appears there seems to be issues with the heads and head gaskets with these trucks and engines.

I am confused. Thanks for your input and help, SORRY for the long post.
Brian

the coolant leak in this area is hard to see. removal of the air intake hoses/air box/maf..use a white cloth and check for the leak location when the engine has cooled. hoses to engine/thermostat/small hose to the throttle body etc....

the next area would be the water pump gaskets. these gaskets leak when the coolant has been not properly maintained and the coolant gets acidic and conductive. the use of dexcool and distilled water is required at high concentrations of 50-70 %..

this engine has about 4.25 gallons of coolant ..only about 2 gallons can be removed..

the weep hole of the water pump is hard to see use a small mirror / use you finger to touch hole to see if it is discolored with pink residue.

Just a update to see if anyone can help.

I have now searched out the coolant leak, and it seems to be comming from a bolt with silcone on it. this bolt seems to be behind the starter on the passangers side of the truck.

As my previous post, It is not leaking alot. It is leaving the size of a dime on the garage floor.

Can anyone tell me if it would be comming from this bolt or from somewhere above the bolt, and can anyone tell me if it is the bolt, then what is the purpose of this bolt.

Would I have to just reseal the bolt, or does it leak due to a bigger issue.

Thanks
Brian

Just a update to see if anyone can help.

I have now searched out the coolant leak, and it seems to be comming from a bolt with silcone on it. this bolt seems to be behind the starter on the passangers side of the truck.

As my previous post, It is not leaking alot. It is leaving the size of a dime on the garage floor.

Can anyone tell me if it would be comming from this bolt or from somewhere above the bolt, and can anyone tell me if it is the bolt, then what is the purpose of this bolt.

Would I have to just reseal the bolt, or does it leak due to a bigger issue.

Thanks
Brian

explain how we go from the front of the engine to the back ?
you stated front cap sized spot on floor . now a bolt under the starter , this is the rear passengerside.

lets say it is the rear of engine . dont mess with any bolts ! get a clean white cloth and wrap this around the two heater hose connections at fire wall. could be they damaged the fittings when replacing the water pump.

he said behind the starter so on the side of the block prob by the mount, My guess is a coolant drain plug that was not re-installed correctly. I would take it out, clean the threads and try to seal it again.

he said behind the starter so on the side of the block prob by the mount, My guess is a coolant drain plug that was not re-installed correctly. I would take it out, clean the threads and try to seal it again.


the drain plug is not possible to remove. I tried and also consulted with a dealership tech that had done much engine work on these 5.3L engines/2000 yr. it appears they used a very tough thread sealer/locker.

this guy stated he breaks the drive bits all the time or destroys the plugs/bolts. the drain plug under the starter could be leaking this is a 1.5 inch sized plug need a 7/8 allen to remove.

If this has been in there for 11 yrs good luck..I tried 7 yrs ago !

with a powerful air compressor and a 1 inch air gun I bet it would come out..

If the drain plug is corroded this would mean the coolant system has very bad issues to yet occur...his dexcool better be niece and clear pink. if black thats all the metal [THE BLACK]

Brian: The key words here are "a bolt with silicone around it". Now you need to get back to the prior owner and ask some serious ?'s. Or clean it up and use a good degreaser spray and put some more silicone on it.

Brian: The key words here are "a bolt with silicone around it". Now you need to get back to the prior owner and ask some serious ?'s. Or clean it up and use a good degreaser spray and put some more silicone on it.

some genius may have drilled into the block a drain hole.tap some threads and use silicone for sealing..I hope that bolt is aluminum..

Well, I couldn't figure things out, so did the smart thing and took it into the shop. HEADGASKET was leaking between the head and the block on the passanger side at the front of the motor.

Lucky though the head was ok, just the gasket. I just don't understand how the gasket would go. O well all is good now.

Would like to say THANK YOU for everyones help
Brian

Well, I couldn't figure things out, so did the smart thing and took it into the shop. HEADGASKET was leaking between the head and the block on the passanger side at the front of the motor.

Lucky though the head was ok, just the gasket. I just don't understand how the gasket would go. O well all is good now.

Would like to say THANK YOU for everyones help
Brian

that is an odd one. gasket let go where its not under great stress.

could be a bad gasket at that spot , that finally blew out.

thanks for your input and report on this.

explain how we go from the front of the engine to the back ?
you stated front cap sized spot on floor . now a bolt under the starter , this is the rear passengerside.

lets say it is the rear of engine . dont mess with any bolts ! get a clean white cloth and wrap this around the two heater hose connections at fire wall. could be they damaged the fittings when replacing the water pump.

i had same thing started in the back and leaked on the floor that sais heater core to me that has the a problem. unless there trieng to screw him?
hope not?