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'99 Blazer S-10 4.3l:


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So heres something I don't understand, We have a 99 Blazer (S-10) 4.3l Vortec V6. I have coolant dripping out of the exhaust around the Y-pipe, it is Coolant (its red, GM uses Dex-cool Red anti-freeze) Anyway I noticed it while I moved it and let it run in the driveway - it makes a good puddle, 2 or 3 dripps every second. Funny thing is it doesn't over heat, and the coolant is full (I checked it afterwards) and there is nothing but Oil in the crankcase, so its not a HG, right? or is there another way for coolant to get into the combustion chamber without getting into the oil system on these 4.3l ? I smell coolant really strong and have been for a few months (I just never saw a leak like this before) The exhaust keeps steaming pretty heavy even when up to running temp and be driving for a while (So thats one clue theres water/coolant in the exhaust)

 

But why do I not see anything in the oil, plus it runs damn good, has power, sounds normal. Juts leaks alot.

 

Any ideas?

 

-Tom :)

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But if it was, wouldn't there be something in the oil? Plus wouldn't you hear a leak depending and wouldn't it run crappy?

 

Plus how would a Head or Block just crack? Its always be takin care of well (My dad always fixed it, and knows what he's doing I might add)

 

I just don't get it, From everything I know about bad HGs, there is coolant in the oil, and it runs crappy, plus you can hear a leak if the outer side of the gasket gos. But NON of this is happening. Plus the coolant is NOT dropping much from what I can tell. So WTF? How does coolant get into the exhaust without being in the oil/crankcase/combustion chamber? This doesn't add up to me.

 

The Truck/engine only has 146,000 on it, not hard miles. Just DD, city/highway sometimes interstate, but now its been sitting off and on cause the new DD is a Toyota FJ. I drive the Blazer if I need to fix the Roo or whatever.

 

Ideas??

Edited by TheLoyale
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When a head gasket fails - where the coolant goes depends on where and how the failure has occured. This is true of all engines. Some have "typical" failure modes that always do the same thing - a "weak spot" if you will. Even with Subaru's there are typical failure modes for specific engines - EA81's and older pushrod engines tend to blow the gaskets into the oil passages and you get that mixing effect. EA82's seem to like to burn the coolant or leak it into the exhaust. EJ25 Ph. 1 pressurize the coolant and EJ25 Ph. 2 leak on the ground.

 

There are many, many possiblitilies - I'm not in any way familar with that 4.3 Chev motor, but it's entirely possible that it could be leaking coolant into the exhaust port of the head though a crack to a coolant jacket. I would think that it would be a crack rather than a head gasket as otherwise in order to get from the head gasket to the exhaust it would have to first enter the combustion chamber and go through a burn cycle - that would likely flash it off to steam rather than expel liquid coolant through the exhaust valve.

 

But that's just a guess. At any rate it doesn't sound like a good sign to me and I would be scheduling some serious down-time for that unit ASAP. Check some Blazer forums if you can find some good one's - I bet it's not an uncommon issue and someone will have posted about it already. Amazing what you can find with a search or two.

 

GD

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GD, thanks for this great knowlege! This does help me with understanding HG failures more, and how diffrent motors react to diffrent failures ect..

 

Hmm that does seem plausible about being a cooling jacket. I still don't understand why it would crack just now, unless cause it sits alot and with these cold temps, whatever coolant was left in the jacket from the last time it ran, somehow froze - expanded and cracked it. Hmm? I will see what I can find for New gen Blazer forums or GM forums. Either way, I think this is gonna be a lost cause. I hope nothing else go's on the Soob where I would need to drive the Blazer, as seeing its pretty much not going to happen. Stay Strong Subaru!

 

Thanks again for your help!

 

-Tom :)

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Going to go ahead here and post my opinion. I had a 99 malibu which had a similar problem. It turned out to be the intake gasket had failed. When i had it repaired i was explained typical GM iron block with aluminum intake. All they did was pull the intake replace the gasket and put some RTV on it. No problems after that. I later learned that this is a common problem on GM vehicles. Not saying that this is your problem but i had all the symptons you were having. Im not saying its impossible to blow the headgasket in a 4.3 gm motor, one of the most durrable motors gm has produced. Im just saying its improbable. Improbable yes but definately possible. Check around the intake and see if you see any leaks. And make sure its leaking out the exhaust not just on it.:grin:

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Ben, thats also some good knowledge. I will check around the intake for anything. I know that theres some old built up oil around the front of the intake but don't remember seeing any coolant - I will check.

 

Now did you notice any drop in power since you had a intake leak? I would assume that if fluid can leak out, air could be sucked in causing major bogging ect. As for the leak being above the exhaust - I don't think it could be, theres nothing in that area and that far back that carries coolant, it looks to be dripping out two small rust holes in the y-pipe.

 

I know the 4.3 is a pretty durable engine, but there are also alot of complaints to go along with it aswell. I beleive that the Block is Alloy, not Cast steal, Am I wrong? I know it has plastic valve covers :rolleyes:

 

-Tom

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My problem was in a 99 malibu car, and it had an iron block. I couldnt tell where it was leaking out and i dont remember having a loss of power. Infact i kept driveing it for a while filling it up occasionally untill i could afford to fix it. How many miles are on your blazer, mine had less then 50k when this happened. I dont remember if the mechanic said it could leak internally and externally. Might be worth looking into though. If its got a ton of miles it could be a HG i guess.

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Ben, it has 146,000 on it (All original) and I have been doing some searching and it does seem like the Intake gaskets are common issues with these GMs from everything I've been reading on sites.

 

Miles, I suspect your right. GMs qulity has really gone down hill these days, the 4.3 Vortec is a good motor but it has alot of faults from what I've been reading. Looks like we're gonna get a Jeep sooner now Lol.

 

This really isn't a big deal, its just a back-up car incase of. Its a great runner though! We had it since 2001, and its a 1999.

 

We'll see what we can do and what we diside.

 

Thanks guys

-Tom :)

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GM has a lot of gasket issues in general on their newer stuff. My boss's S-10 blew a head gasket not long ago at around 150k.

 

Not that Subaru seems a whole lot better with some of their engines though :rolleyes:

 

GD

 

I'm starting to think all auto manufatures are loosing their qulity aspect that they once had, I'd still buy a Toyota or Subaru over a GM, Ford or Dodge though.

 

Thats why I bought an old car (Wells 90s car, 80s technolegy) I've had less issues with my car then my parents had with the Blazer.

 

-TJD

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In my world - simpler is better. Seems to work for me anyway.

 

GD

 

 

 

Those are my words down to a Tee.

 

I watch alot of things about new vehicles, for instance, lastnight I was watching info on th 2010 Lincoln MKT EcoBoost V6. The motor is so complex and so cramped that theres no way you could or would want to fix it your self (I would if I had one though, don't like shops) anyhoo, theres just sooo much stuff on these new engines - that their getting to the point where you can't do you own work (And thats what the Manufature wants) Now for Subaru, I looked at the New outback, engine doesn't look to complex, sure theres lots of wires and whatnot, but it looks more simple then alot of the vehicles I've been seeing. Maybe causes its not a V or Inline style engine, so it looks as if theres more room. I just hate these big plastic covers they stick on top of the engines nowdays..

 

-TJD

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When everything goes electric it's going to be like building PC's or RC cars. :lol:

 

You just buy the peices you want and bolt it all together. And people that drive an HP or Dell will get laughed at. :)

 

GD

 

Lol! Mac is where its at :-p Then I roll past in an old skool Subaru :banana:

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  • 1 month later...

Get some fluorescent dye from the parts store. They have ones that dissolve in coolant, and one for oil. get the coolant one, pour it in the radiator, start it up, and look around the area with a blacklight and yellow glasses. Clean everything first. You will see exactly where it's coming from.

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  • 4 weeks later...

you fix this thing yet? I have a 96 S-10, and it did exactly what you described, and sure as ************, it was a head gasket. took me a bit to figure it out, cuz it ran great, didn't overheat...just leaked a bit (impossible to see where it was coming from, too), and smelled of anti-freeze.

I used the opportunity to port match the heads, gasket match the exhaust side, add headers and a computer flash. runs Fn great now!

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