Intake manifold leak
Intake manifold leak Ok here it goes guys, My car started to have a slight miss in it at idle, So I hooked it up to the Modis to see what was going on. Well #1,3,5 have a miss in them but bank 2 and #7 are not effected. So while it was idling I sprayed a little bit of brake clean around the manifold by those cylinders and the misses jumped and # 1,3,5 started to miss more. So I hooked the scope up to the wires and watched them and the KV's were throught the roof on them 1,3,5. Here is the funny thing though. The car runs fine under boost not one studder or miss. But at an Idle it runs rough and it is not always notice able and gets worse then is fine. Also when my oil cap is off you can see blow by if you will coming out of the filler neck and you can also feel the pressure. So I put a rubber glove over the neck to see if it would fill up. When I gave it some throttle it got a little bit of air in and when I let off the glove sucked in. Now after all this I was wanting some input on whether or not this could just be just an intake manifole leak that is causing the miss or could my rings be causing this, If it is the rings why is it not a constant miss? Sorry for the long post. Thanks
why are you thinking intake? did you remove it recently? Is this a new motor or one with miles? What about a cam? do you have any unmetered air (besides possible intake leak) just need a little more info.
Well the motor is all stock intake has never been off and I put the turbo kit on at 86,000 miles and it has 94,000 on it. The reason I was thinking intake leak is because it started to miss more when the brake clean was sprayed around the Intake manifold around those cylinders, and I could see the misses on the Modis Scanner. I also thought since under boost it is no longer pulling vaccume and just basically loosing a little bit of boost out of the leak.
If you sprayed it there, and the rpm changed it might be a good idea to get some new gaskets and change them. They were 25 bucks from advance when I did mine. It doesn't take that long to do it.
