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Luck has run out on '99 5.7L

You know the story, a '99 5.7L has 79K miles on it and is beginning to lose coolant!!! Changed the oil this evening and discovered white streaks trailing down the front of each side and along the bottom of the oil pan and a closer look shows white powder on the front half of each head.... :-(

This engine has also been throwing P0304 codes lately indicating a misfire on cylinder 4. It only does this when climbing a hill at highway speeds or entering a highway. Was just hoping for a bad injector on cylinder 4, but can't get that lucky! I guess the increased RPMs and slight heat buildup may cause some coolant to seep inside and mess up the firing of #4. No white clouds out the back or anything like that, but it runs horrible when #4 is messing up. Get off the gas a bit and it settles right back in and runs fine.

My question. What is an "average" cost to have a shop replace the head and intake gaskets. I'm in Ohio. I just don't have the time to tackle this project myself, like I'd prefer.

Good ol' Chevrolet.....

Tnx, Kevin

Reply to
K
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Whatever you do, don't just go into some shop telling them that you need head gaskets. I can tell you the ratio of intake gasket replacements to head gasket replacements on that engine in our shop.......5000 to 1....maybe!

It's most likely to be the intake gasket. Along with the coolant leaks on that engine, the intake gasket is also known to warp around the cylinder head ports. Often, it is bad enough to cause a vacuum leak at the port. You get a nice miss that is virtually impossible to detect by the old "spray" method along the exterior of the intake manifold to cylinder head parting line.

Ian

Reply to
shiden_kai

Ian,

Thanks for the reply. The odd thing is that there are coolant trails down both forward sides of the block and down the sides of the oil pan. I could see one head gasket weeping, but both simultaneously seems incredible! It runs great, never overheats, but does have the cylinder 4 misfire, more often these days, when on strain that settles down once you get off the gas. Could some coolant be getting into #4 or a vacuum leak on the intake at #4 cause this misfire code?

I do plan on taking a very close look this weekend, before taking into a shop, to see if there is an indication of a trail from the intake manifold all the way down..

Kevin

Reply to
K

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