: 94 Deville Concourse Billowing White Smoke



HalScott
02-17-04, 09:49 AM
Hi,

I own a 94 Deville Concourse that is having some problems. It just started blowing white smoke out of the tailpipes. At first it was having some rough idiling, but that seemed to stop. It still runs strong, I haven't noticed a drop in power. I changed the spark plugs, checked coolant levels (no noticable drop), and there dosen't appear to be any water in the oil? It looks like a classic head gasket or cracked head issue but I'm not sure. Does anyone else have any suggestions. Also, does anyone have the percs on the head bolts for a 94 Deville Concourse?

Thanks,
Scott

BeelzeBob
02-17-04, 10:47 AM
Hi,

I own a 94 Deville Concourse that is having some problems. It just started blowing white smoke out of the tailpipes. At first it was having some rough idiling, but that seemed to stop. It still runs strong, I haven't noticed a drop in power. I changed the spark plugs, checked coolant levels (no noticable drop), and there dosen't appear to be any water in the oil? It looks like a classic head gasket or cracked head issue but I'm not sure. Does anyone else have any suggestions. Also, does anyone have the percs on the head bolts for a 94 Deville Concourse?

Thanks,
Scott

I don't think you need to sorry about a head gasket....you have a stuck open injector or failed fuel pressure regulator sounds like. Much more likely cause of a sudden case of billowing white smoke.

Take the perimeter row of screws out of the intake manifold top cover...the silver top cover of the engine. Leave the inner 4, recessed bolts in place. Take the intake manifold top cover off and you will see the inside of the intake including the fuel rail the fuel pressure regulator near the throttle body end, etc. First, check the fuel pressure regulator. Locate it and watch the vacuum nipple on it when someone turns on the key to pressurize the fuel system. Fuel should NOT come out the vacuum nipple. This would be my first guess...a failed vacuum diaphragm in the FPR. If not, then lift up the fuel rail so that the injector tips are exposed and reenergize the fuel pressure to see which injector is stuck open and leaking.

The engine will still make good power at WOT even with this failure as the extra fuel is near to what the engine needs but it will drown out a cylinder at part throttle and make the white smoke.

You really should consider an immediate oil change also as the excess fuel has likely diluted the crankcase fill severely.

NOTE: Just turn on the key to energize the fuel pump with the top cover off the intake.....DO NOT start the engine with the top cover off as the engine will run away...that lid really is the top of the intake and the engine will be unthrottled with it off.

HalScott
02-17-04, 12:42 PM
Thank you so much, I will definately check that.