: 2000 SLS engine oddity

06-05-11, 03:39 PM
I have what appears to be a vacuum leak on a 2000 Seville SLS with 151k miles. It idles like crap, gallops, barely runs. If I give it any gas at all, it runs pretty well. This problem has slowly been creeping up, and due to other problems (oh so many problems...) the car has been parked a couple months, and now when warmed up the car barely stays running at idle.

Checked the intake bolts, they were a hair bit loose and they have been retorqued to spec, but no change. Car has a loud hiss from the engine that I believe has got worse with time and the retorque did not change this. I got some water and proceeded to spit it (directed spray, didn't have a spray bottle handy) around the intake and then around the throttle body. When I spit at the rubber 'donut' around the intake, I get a loud slurping sound. This doesn't seem normal.

Anyone else experienced a problem in this area? So far I've been unable to find just that donut, and it doesn't seem to come with an intake gasket set. Am I stuck going to the dealer (and am I stuck paying for a whole new intake?)...

Anyone want to buy a 2000 Seville with no TC lockup and a broken intake? Didn't think so.

06-05-11, 03:50 PM
Skrillions of posts on 2000+ vacuum leaks. In here, Deville, Northstar Performance, and tutorials in Discussions, Item Specific: Cadillac Tech Tips.

Pull your Diagnostic trouble Codes from the car's built-in scanner. Use the sticky post "How to pull codes" and read the whole post - all the directions and definition links are there.

Look for mixture codes - use a stethoscope to listen for leaks around the intake, at the throttlebody-to-intake rubber connector "plenum", at the intake duct resonator and clamps, and at the EVAP solenoid sticking out the rear of the throttlebody.

The "donut" - the intake plenum. Common source of a leak. Dealer item - $40. 2 hours DIY replacement, $250 at a GM dealer. Look in Tech Tips down below.

Try this for ease of maintenance...............(the clamp is on the airbox because I was seating a new foam gasket.)

Oh, Hey !!!!!!! Welcome Aboard !!!!!!!!!!!!:welcome:

06-05-11, 04:00 PM
Plenum...................3 bolts through the throttlebody, manifold off...........manifold bolt torque is only 7.5 ft/lb. Careful !!!

06-05-11, 09:27 PM
2000 SLS engine oddity
Not an oddity at all, but rather common as Sub has said.