Vacuum Leak or Intake gaskets?

Corabar

Registered User
I have a 1989 SC with 245,000 miles and i have devloped an idle problem. Ive noticed a few things actually. I have a little mix of yellow fluid in my oil. I have also noticed all my cylinders are running lean because of unburned gas on the spark plugs. The main question i have is that when i rev the engine no matter how high i can only obtain 5 pounds of boost. My vacuum does not read more than 21 psi though. Im leaning towards an intake gasket. Theres also a little yellow fluid coming from around IC tubes where the connect into the intake manifold. Rpm idles at 500 and sometimes drops to even 200. Any suggestions?
 
freely revving the engine is not going to put enough load on it to build boost.

Are you blowing smoke out of the exhaust? Could be a head gasket as well. This yellow fluid is going to be antifreeze and intake gasket failure on these cars is extremely rare, almost unheard of. Head gaskets on the other hand are very common.

21 inches of vacuum is really good for idle.
 
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I have a 1989 SC with 245,000 miles and i have devloped an idle problem. Ive noticed a few things actually. I have a little mix of yellow fluid in my oil. I have also noticed all my cylinders are running lean because of unburned gas on the spark plugs. The main question i have is that when i rev the engine no matter how high i can only obtain 5 pounds of boost. My vacuum does not read more than 21 psi though. Im leaning towards an intake gasket. Theres also a little yellow fluid coming from around IC tubes where the connect into the intake manifold. Rpm idles at 500 and sometimes drops to even 200. Any suggestions?

I would immediately check for head gaskets first. I would also limit run time as nothing will eat engine bearings up faster than coolant in the oil. Intake gaskets could cause these symptoms. To be honest with 245k on the clock I would pull the engine and go through it from bearings, rings, to gaskets.
 
I bought the car with 238,500 miles. The guy before me did a lot of work to it such as doing an egr vavle delete, making a custom supercharger cooler snd changing the motor mounts. I wouldnt be suprised if the head gaskets have already been changed. No white smoke comes from my exhaust. It doesnt stall or anything and it drives okay just not prefect. I drove it and i could get it up to 12 psi but my boost gauges jumps around sometimes. There is a misfire on cylinder 2. I took it to a mechanic today and he said i have an intake gasket leak and that i have a bad fuel injector or stuck valve for cylinder 2. Does that sound right to you guys? Thank you for the responses.
 
Check the #2 plug wire first and see if there are any burns or bad spots....

Have you tried to pull any codes.....
 
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