Wide open throttle on an old 5.7 vortec? Good or bad?

[BerHntr]

So still thread jacking. thats like the best scenario you can have for a cracked head gasket i assume. i mean besides swelling upper radiator hoses and losing possible coolant out of overflow right.

My dad always told me to crack her open every once in awhile and blow the carbon out. he also said if there is any underlying timing issues it may be the only time you feel it.

I agree with this, mine drives perfect under normal throttle but on a hard run it has a studder step at about 3500 rpm.

On topic though, everything I drive gets a healthy dose of throttle on a daily basis.

 

[GregB]

About 2 weeks go I took my 1999 Tahoe (5.7 Vortec, 4L60, full Police Package ) and since it just went over the 100,000 mile mark had the orange antifreeze changed, which had been in it since 2008 when I bought the Tahoe with 78,000 miles on it to the green stuff and a new Stant Thermostat . It was a Fire Dept. Batallion Chiefs Unit from Gilroy California and I store it from October to April May every year so its never seen snow . The body is pristine and I say it will be part of my Estate and yes, I'm old. I've only done about 100 miles since with driving around the City since I had that done. This morning I headed out of town and about 30 miles out my temp gauge starts to really go up. I've seen the temp gauge fluctuate a bit before so kept driving but the gauge kept climbing. When it hit 260 I pulled over and shut her down. Lifted the hood and saw a little water, not antifreeze, dripping on the pass side from near the air cleaner. I didnt blow a hose and no antifreeze leaked out. Truck would turn over but not start. Called a tow truck and he took about an hour to get there. Just before he hooked up I checked and

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temp gauge was down to cold. I tried starting the truck and it started but ran rough and I didn't hear any obscene noises from the engine. I am clueless as to what may have happened here, has anyone

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got an idea. Oh yea its a California vehicle if that makes any difference cause of the extra emissions thing. Hopefully I didnt lunch the motor. Drivers side pic is from 2008 when I bought it from EBay and Pas side pic is October 2016 as I was heading to put her in storage for the Winter.

 

[SAATR]

Did you happen to check the oil level or pull the cap to check the antifreeze level in the radiator? Intake gaskets on these have a tendency to blow around the water passages, sometimes internally. You may have blown it out and filled the sump with antifreeze. If that's the case, then the engine is toast. Otherwise you may have lost a head gasket in similar fashion to mine, and the overheating was from combustion gas getting into the cooling system. Could also have a cracked head and caused the same thing.

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