Intake or Gasket leak? Or????
My trusted mechanic and I checked fuel pressure, fuel injectors, compression, coils, plug wires and plugs. Everything checked out great. I have a lean code on Bank 1, and cylinder number 1 has a random, not constant, misfire when on the scanner. The old school starting fluid check didn't change the idle either.
We hooked the smoke machine up and the intake is leaking somewhere.
He suggests changing the intake and the gaskets at the same time, because for the prices he is going to charge to do it, it probably makes sense. I figured I'd do it myself. Is it worth it to try just the intake gaskets? They're $20 instead of $600+ for a new intake?
Do these intake gasket O-rings ever go bad? Is there any way to test and see which one it is while it's on the car?
What should I do? I need my baby to get better. Thanks.
Intake gaskets do go flat overtime but if you've never had the intake off, its probably not your problem
Not a surefire test, but if its sucking air, you should see a change in vacuum from the MAP sensor
The gaskets do flatten and leak, typically a vacuum leak will be worse when the engine is cold since things expand once they are warm. That is unless it is a hose like sj said. My PCV hose also had a hole in it. Check that real close, its the hose that has a big bulge in it that connects to the intake right behind the throttle body.
How did you figure out it was your PCV hose setup?
Did your PCV hose problem cause your car to run like mine is now?
I tried to old school trick of spraying carb cleaner and starting fluid to check for leaks. There was no change in idle so I couldn't find a leak that way.
A vacuum leak will raise you idle speed.
Have you swapped the ignition coil from the offending cylinder with a good one from another cylinder? If the PCM still reports misfires from number one, this will confirm the coils is not intermittent.
(While these coils do not "wear out" or go down in power, they can go out completely and then "come back")
If it is your intake manifold gasket, you can get a set of gaskets. Like Pocket said, the intake manifold itself doesn't go bad.
If you're taking off the intake, I would suggest you do the change to the LS6 PVC system. It'll make your half day project a full day project. Full details and instructions are here:
http://ls1howto.com/index.php?article=18
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How did you figure out it was your PCV hose setup?
Did your PCV hose problem cause your car to run like mine is now?
I tried to old school trick of spraying carb cleaner and starting fluid to check for leaks. There was no change in idle so I couldn't find a leak that way.
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