Antifreeze Leak!

IrishNinja · February 13, 2009

Hello all,

I have a 2000 Silverado Z71. I can sometimes smell antifreeze after I shut my truck off and if I role down the window while running. I hear a gurggling sound behind the glove box. Which I looked up with a guy at work and that said the radiator was low on antifreeze. So after I filled the tank with more coolant it was fine. Now it will go low every other month, sometimes every month. Been doing it for awhile. Temp is ok, never a leak under the truck. A mechanic friend I know thinks it could possibly be the waterpump. That is were the most prominent smell is when you open the hood. But its not wet like it is leaking there. Any ideas would help. I am new here and not much of mechanic myself, but you guys seemed pretty helpful. So though I would ask.

Thanks!

mr_bots · February 13, 2009

Check your oil. Is it foamy or whitish? If its leaking antifreeze and you don't ever see any under the truck its got to be going somewhere, maybe into parts of the engine it shouldn't be.

IrishNinja · February 13, 2009

Check your oil. Is it foamy or whitish? If its leaking antifreeze and you don't ever see any under the truck its got to be going somewhere, maybe into parts of the engine it shouldn't be.

Oil is fine. I agree it must going somewhere. Thanks for the help!

Bucknut · February 13, 2009

Intake Manifold possibly , my C1500 and many other Chevy and GMC trucks experience this slight leak..Problem is it happens towards the cowel , and usually smokes off before ya can see it..

Spurshot · February 13, 2009

Josh,

Z71 tells us what kind of springs, shocks and swaybars your truck came with. But what engine does it have?

mattjulien · February 13, 2009

yes it is probably your intake manifold gasket. i just went through this two weeks ago with my 98. (not a fun repair). it smelled for like a month and i did not know what was going on until it started spurting crazy down the back of my engine. from what i've heard these intake manifold gaskets have a very small leak at first that just evaporate or burn off...then they turn into a more serious leak.

txab · February 13, 2009

You can add a special dye to the coolant to help in finding the leak. A black light will show it.

IrishNinja · February 13, 2009

You can add a special dye to the coolant to help in finding the leak. A black light will show it.

I suppose that would be valuable info spurshot. LOL! It has a 5.3L

kal el · February 13, 2009

The gaskets for the water pump will sometimes leak. They leak just a little and before it hits the ground it burns off the engine. after it is warmed up get underneath it with a ligt and look at where the pump mates to the block. the drivers side is easier to see. the gaskets are easy to change and I usually just flush the dex cool and replace it at the same time. I have done many of these and it is very easy.

VMax2007 · February 13, 2009

Intake Manifold possibly , my C1500 and many other Chevy and GMC trucks experience this slight leak..Problem is it happens towards the cowel , and usually smokes off before ya can see it..

yes it is probably your intake manifold gasket. i just went through this two weeks ago with my 98. (not a fun repair). it smelled for like a month and i did not know what was going on until it started spurting crazy down the back of my engine. from what i've heard these intake manifold gaskets have a very small leak at first that just evaporate or burn off...then they turn into a more serious leak.

His truck is a GMT800, they have dry intakes (no coolant flows through them).

Could either be a small leak that only leaks steam under pressure, or possibly a head gasket.

98 Z71 SLT · February 14, 2009

Easy one

Coolant pump

Don't let these other guys get you all paranoid..

Smitty00Z71 · February 14, 2009

same issue with my 2002, I can smell it when I open the hood... but never see it.....no leaks. Have only had the truck for a month... antifreeze level has remained the same ???????????

shibby1485 · February 15, 2009

funny this thread just came up! i need help with my fathers truck

2005 Suburban 5.3L

leaving antifreeze pretty bad all the sudden. you can smell it and see it. so far from what i see without taking too much stuff apart i believe the leak is coming from between the water pump and the pulley? and then it comes out there, leaks down the underside of the water pump housing and is dripping onto the frame and onto the ground.. when the truck is running it jsut slings it everywhere and burns it off. if i let it idle for a long time, shut the truck off, i can see a very very steady drip, and this is where i believe i see it coming from.

what do u make of it? what needs replacing u think? ... and how hard of a job is it? (i'm very mechanically inclined)

shibby1485 · February 15, 2009

having some bad luck with this truck... this is our 4th suburban... 1990, 1994, 2000, 2005 models are what we've had...

the 2005 has 47,000 miles.... warranty ran out at 36,000 of course

at 40,000 the transmission blew, needed total rebuild (and it still does scary funky things)

the steering shaft was replaced twice

you get all sorts of weird poppy click noises from behind the dash when you come to a stop sitting at red lights

sometimes the AC will blow HOT AIR when it's all the way cold with a/c... restart the car a few times, hit lots of buttons and slide the temp control up and down violently and eventually it'll go back to cool.

and now we have antifreeze leaking out of the truck... front of the engine near the water pump housing area behind the pulley.. hard to see... but it's a very stready constant drip

really sucks because the truck is babied, washed every week, looks showroom condition, has very low mileage with jsut 47k on it, oil changed religiously on time every time

Spurshot · February 15, 2009

Steve,

I'd make that Suburban go away if possible. If you can't do that now, the waterpump is a fairly straightforward replacement. It'll cost about $150 in parts and take you about a Saturday afternoon to replace. Less time if you have a lot of mechanical experience.

The noise may be low coolant with air causing the noise. Hard to say without hearing it in person of course.

The lack of cool air could be a number of issues. One could be it's low on freon. When these vehicles get low on freon, the a/c will stop working. They usually get intermittant before they quit making cool air. A way to tell is to hook up some a/c gauges and measure the pressures with a jumper on the low side pressure switch to cause the compressor to engage. You can also look at the compressor when it won't make cool air and see if its engaging. The compressor not engaging could also mean it's a controller issue too.