The Stretch
09-21-2009, 11:51 AM
I had been getting the classic CEL in the cold mornings at stop lights and a whistling sound on decel every know and then, as well as leaky valve cover gaskets. This past weekend i replaced:
valve cover gaskets
intake gaskets
PCV plate with its gasket and TB gasket
Plugs-replaced with stock NGK's
I cleaned and backflushed the injectors, cleaned up all the crap in the intake and got the ICV moving again.
Reset computer
After i put everything back together and avoided the rain, it started with a really rough idle, though a quick blip of the throttle produced a quicker response than before. As soon as it went into closed-loop mode, CEL with lamda control stop 1&2 and O2 sensor 1 came on and stayed on regardless of engine speed. Then it started hunting for idle, kicking up to almost 1000rpms, staying for a bit, then dropping back down, repeating every min or so. It got a slight bit better when it warmed up, but not much. Took it for a drive and still real sluggish under 3k, after that it's like the trans downshifts the difference is so noticable. Still feels quite underpowered though.
When warm and idling, i pulled the MAF connector, and the rpms shot up to 1000, and then it found its way back down with the same rough idle. Plugged the MAF back in and then pulled the dipstick out. The engine almost died before it recovered. I Also gave all the gaskets and hoses a shot of carb cleaner with no results. This would point to a non-vaccuum related problem, no?
After I got back from the drive, it started whining quite loudly. Slightly lower pitched than a belt squeal. It did it up until about 2000rpms then got progressively quieter. It seems like it's comming from the rear of the engine/front transmission. It almost seems like a pulse, for when i shut the engine off, i get a slight break that seems to correspond to engine rpm. I'm hoping its not the trans since the sound doesnt change in drive vs park. Even if it was, how would this have been caused by the work i did?!?
If you have gotten this far, I commend you. I suspect the cats are atleast partially clogged, due to the slow response and low power, even before the gasket job. There is also heat oxidation on the stainless exhaust at the cat and before the cat, but nothing after. Would clogged cats cause the computer to get that screwy? That still wouldnt explain why it got so bad imediately after i changed the gaskets though, or the whine that popped up. If anybody has ANY ideas, I would greatly appreciate it. I am at a loss.
******Update**********
the squeal appears to be intake related, and originating from the front of the engine. It appears when the engine warms up, gauge about 10 oclock. When i pull the dipstick out, the squeal stops, and starts up again when i re-insert it. Vacuum at idle is around 15 inmg. When i do pull the dipstick out, there is a strong audible suction comming from the tube. It never did that before.
valve cover gaskets
intake gaskets
PCV plate with its gasket and TB gasket
Plugs-replaced with stock NGK's
I cleaned and backflushed the injectors, cleaned up all the crap in the intake and got the ICV moving again.
Reset computer
After i put everything back together and avoided the rain, it started with a really rough idle, though a quick blip of the throttle produced a quicker response than before. As soon as it went into closed-loop mode, CEL with lamda control stop 1&2 and O2 sensor 1 came on and stayed on regardless of engine speed. Then it started hunting for idle, kicking up to almost 1000rpms, staying for a bit, then dropping back down, repeating every min or so. It got a slight bit better when it warmed up, but not much. Took it for a drive and still real sluggish under 3k, after that it's like the trans downshifts the difference is so noticable. Still feels quite underpowered though.
When warm and idling, i pulled the MAF connector, and the rpms shot up to 1000, and then it found its way back down with the same rough idle. Plugged the MAF back in and then pulled the dipstick out. The engine almost died before it recovered. I Also gave all the gaskets and hoses a shot of carb cleaner with no results. This would point to a non-vaccuum related problem, no?
After I got back from the drive, it started whining quite loudly. Slightly lower pitched than a belt squeal. It did it up until about 2000rpms then got progressively quieter. It seems like it's comming from the rear of the engine/front transmission. It almost seems like a pulse, for when i shut the engine off, i get a slight break that seems to correspond to engine rpm. I'm hoping its not the trans since the sound doesnt change in drive vs park. Even if it was, how would this have been caused by the work i did?!?
If you have gotten this far, I commend you. I suspect the cats are atleast partially clogged, due to the slow response and low power, even before the gasket job. There is also heat oxidation on the stainless exhaust at the cat and before the cat, but nothing after. Would clogged cats cause the computer to get that screwy? That still wouldnt explain why it got so bad imediately after i changed the gaskets though, or the whine that popped up. If anybody has ANY ideas, I would greatly appreciate it. I am at a loss.
******Update**********
the squeal appears to be intake related, and originating from the front of the engine. It appears when the engine warms up, gauge about 10 oclock. When i pull the dipstick out, the squeal stops, and starts up again when i re-insert it. Vacuum at idle is around 15 inmg. When i do pull the dipstick out, there is a strong audible suction comming from the tube. It never did that before.