Coolant Problem

[zibzer]

hello,

 

i have a 2000 silverado with a 4.3l and this morning when I ran my truck i was getting a gushing sounds coming from the passenger side dashboard. I suppose it was air in the line... but how could air get in the line? does this happen occasionally or am I in trouble??

[zibzer]

oh by the way, after 20 minutes of driving the sound almost completely dissappeared.

[cmoore74]

How many miles and has your coolant ever been flushed?

 

Check to see if you have heat.

 

I had a 2000 S-10 P/U with the 4.3L and one day the heater wasn't blowing hot air. Turned out the heater core was clogged from the dex-cool coolant. This was at 85k miles. I was lucky and caught it early enough as a full chemical flush cured the problem. This is a very messy job so I ponied up the $ for the stealership to do the work. Cost was about $250 for the full chemical flush and refill with new fluid.

 

If you don't catch it early enough you end up replacing the heater core $$$.

 

Not saying this is it, but there are tons of complaints against dex-cool in the 4.3L motor...

 

http://www.consumeraffairs.com/automotive/gm_dexcool.html

 

http://www.automotivehelper.com/topic83185.htm

 

http://forums.hotrod.com/ubbthreads/showfl...184&an=0&page=0

[zibzer]

How many miles and has your coolant ever been flushed?

 

Check to see if you have heat.

 

I had a 2000 S-10 P/U with the 4.3L and one day the heater wasn't blowing hot air. Turned out the heater core was clogged from the dex-cool coolant. This was at 85k miles. I was lucky and caught it early enough as a full chemical flush cured the problem. This is a very messy job so I ponied up the $ for the stealership to do the work. Cost was about $250 for the full chemical flush and refill with new fluid.

 

If you don't catch it early enough you end up replacing the heater core $$$.

 

Not saying this is it, but there are tons of complaints against dex-cool in the 4.3L motor...

 

http://www.consumeraffairs.com/automotive/gm_dexcool.html

 

http://www.automotivehelper.com/topic83185.htm

 

http://forums.hotrod.com/ubbthreads/showfl...184&an=0&page=0

 

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heat works fine. I let it cool down for about 2 hours and took it for a spin for another 15 minutes.. at first it was nice and quiet, but by the time i got back home it was starting to make the gurggling sound again.

[cmoore74]

I never had a gurggling sound with mine, the heat just wasn't hot indicating a clogged heater core. You might want to try some of those links, some are forums, to see if someone else had that same sound.

[zibzer]

well i was out driving and the gurgling sound was getting very annoying.. i hit the gas at WOT and by the time I got to 80mph i heard a big crack coming from the heater core area so i let off the gas. I immediately noticed it wasn't gurgling anymore ...so for the time being it seems to be fixed... well... tomorrow morning i may have the same problem again though

[zibzer]

well it came back today.. anybody know whats going on?

[fossil]

Is your coolant level low? Ensure its up to spec and let your truck warm up. When fully warm loosen the hose clamp on the heater outlet line ( be carefull you dont get burnt by hot coolant) and let a little leak out while the engine is running. If there is any air in the system that should get rid of it. Again make sure that your coolant level is fully topped off to its proper level.

[zibzer]

Is your coolant level low? Ensure its up to spec and let your truck warm up. When fully warm loosen the hose clamp on the heater outlet line ( be carefull you dont get burnt by hot coolant) and let a little leak out while the engine is running. If there is any air in the system that should  get rid of it. Again make sure that your coolant level is fully topped off to its proper level.

 

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coolant level is fine.

 

where would the heater outlet line be located?

 

there is a small screw on the drivers side of the radiator is that some sort of bleeder screw? if so how do i use it properly. I left it open (as well as the reservoir cap) off and let the engine run for about 5-10 minutes .. although it didnt even get up to operating temperature because it is pretty cold outside. every time i revved the engine quickly i could see lots of bubbles bubbling to the top of the reservoir tank.. is that normal>?

[ken1mod]

What you are describing is often caused by a head gasket leaking combustion gasses into the coolant. I hope it isn't so.

 

Ken

[zibzer]

What you are describing is often caused by a head gasket leaking combustion gasses into the coolant.  I hope it isn't so.

 

Ken

 

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well if it is the head gasket it will be covered under my warranty. Is there any way for me to check if it is the head gasket.. the company will pay to replace a head gasket but i have to pay to get the thing diagnosed.. and id rather diagnose it myself than pay someone if it isnt in fact the head gasket.

[ken1mod]

There are lots of posts on this but I believe the typical symptom is continuous bubbles in coolant. Our cooling systems automatically purge air to the coolant tank so continuous bubbles are very suspicious. I would think a compression test or cylinder leakdown test might give useful info. Do you have to add water much or at all?

 

Glad you are under warranty. Your gurgles and bubbles are definitely wierd.

 

ken

[zibzer]

There are lots of posts on this but I believe the typical symptom is continuous bubbles in coolant.  Our cooling systems automatically purge air to the coolant tank so continuous bubbles are very suspicious.  I would think a compression test or cylinder leakdown test might give useful info.  Do you have to add water much or at all?

 

Glad you are under warranty.  Your gurgles and bubbles are definitely wierd.

 

ken

 

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there is not continuous bubbles in the reservoir tank.. but there are a LOT of bubbles if i quickly rev the engine up and let go the throttle cable. It has only been happeneing since saturday so i dont know if im loosing much coolant... it doesnt appear i am losing any.. The oil looks brand new, the engine heats up nicely and runs as good as any other time. I suppose ill bring it to my normal mechanic and see what he says.

 

with christmas shopping and just getting off a vacation and only recently buying this vehicle i am a little strapped for cash.. i sure hope it doesnt cost me much.

[zibzer]

There are lots of posts on this but I believe the typical symptom is continuous bubbles in coolant.  Our cooling systems automatically purge air to the coolant tank so continuous bubbles are very suspicious.  I would think a compression test or cylinder leakdown test might give useful info.  Do you have to add water much or at all?

 

Glad you are under warranty.  Your gurgles and bubbles are definitely wierd.

 

ken

 

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oh and btw thanks for your help

[ToddZ]

I also had the 4.3 in my 2000 S10 ZR2 and noticed the gurgling. I'm sorry, but I never got it straightened out. I looked into everything as well. I guess it wouldn't hurt to fully flush the coolant system. Have plenty of rags and a 5 gallon bucket handy!! By the way, I had plenty of heat and drove it like that for 2 years so I doubt your in any immediate trouble, other than the fact that the noise is really annoying