My son has a '99 Blazer with a 4.3 which is losing coolant, and was told it is the intake gasket. Is this a common problem on those engines? Where exactly does the coolant typically leak? Anything out of the ordinary to consider when fixing it (other known potential problems to look for, etc.)? TIA
Yep and on it's bigger brother the 5.7
It depends. Externally the leaks are usually right at the ends of the intake flanges, most of the ones I have seen were on the front drivers side or rear passengers side. Internally were about the same. However the internal leaks are FAR worse because coolant and oil don't mix very well. Plus the coolant eats the metals they use in the bearings.
Well, the gaskets are not that hard. Just make 100% sure you clean the surfaces very well, use the newer gaskets that have the metal core if possible. And be sure to follow the torque specs for that gasket.
While you have it apart you might consider cleaning the injectors and making sure they are OK. Also check all the vacuum lines for leaks/rot. And it isn't a bad thing to replace hoses do a flush job as well.
Make sure you get oil/filter since you WILL get some coolant in the engine. I usually drop the oil and then do the work and pour some trans fluid over the cam/lifters to flush the crud down and out prior to installing the new pieces.
Yep.
The last time I did one, it was on a 5.7l engine and the leak was on the passenger side front end of the intake manifold.
The last time I fixed one of these I found the casting for the head had been eaten up a bit by the leak. We used fel-pro gaskets, and I smeared a thin coat of RTV over the area that had been eroded a bit before we put the thing back together. It seemed to hold up just fine, last I heard the guy had sold the truck and it was still running okay when he sold it.
Change your oil when you're done. And I hope you don't have coolant in the oil right now..that will eat up the engine bearings faster than you can say "SpunBearing".
Good luck with it.
Chris
Depending on the age and mileage of your vehicle that casket may be covered under GM's extended warranty for gasket failures
Yep.
The last time I did one, it was on a 5.7l engine and the leak was on the passenger side front end of the intake manifold.
The last time I fixed one of these I found the casting for the head had been eaten up a bit by the leak. We used fel-pro gaskets, and I smeared a thin coat of RTV over the area that had been eroded a bit before we put the thing back together. It seemed to hold up just fine, last I heard the guy had sold the truck and it was still running okay when he sold it.
Change your oil when you're done. And I hope you don't have coolant in the oil right now..that will eat up the engine bearings faster than you can say "SpunBearing".
Good luck with it.
Chris
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