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Rough Idle/Almost stalling

20K views 6 replies 5 participants last post by  oliversexpedition  
#1 ·
I have a 2003 Saab 9-5 Linear 2.3t. I recently replaced the turbo because the last one went to hell. Prior to replacing it, the car smoked like crazy and had a super rough surging type idle with the tachometer jumping up and down and it would nearly stall out. I thought it was from the bad turbo but after replacing it (upgrade to the TD04HL-15t) the turbo seems to work great and very little smoke at initial start up but the car still runs really rough and surges bad and nearly stalls out at just idle in park. Check engine Light is on and has been for a while now but I was told the code thrown (don't remember) was not an issue and was cleared by a guy at AutoZone. I am mechanically able to work on most things that aren't too difficult but I don't know much about turbos and not sure what this could be. I wish I could get it to a place to have it scanned again or even looked at by a Saab mechanic. I am new to any foreign cars. I would imagine it would not be good to drive the car in this condition and I would be lucky to get it there; it runs very rough and would most likely stall on when putting it into gear etc. It is doing all of this in Park and all the time.
 
#2 ·
If the CEL is on there is no use guessing, since the code will direct you to specifically what's wrong.

If there isn't a nearby place or an Autozone to get the codes read, do yourself a favor and buy a cheap code reader. I have a couple little Autel Maxiscan MS300's because they are cheap, or get an MS309 for a little more money that shows the code description right on the screen.

Don't believe anything an Autozone employee tells you about a code not being a big deal.

Get the codes read and post them here and we can be of more help.

Sounds like you might have a big vacuum leak somewhere, or the throttle body has dropped into Limp-Home-Mode, but scanning the codes will tell you that for sure.
 
#3 ·
After reading the codes with a cheaper Actron Pocket Scan, I had the codes P0456 and P1300 which apparently are Evaporation Emission leak such as a gas cap and a misfire code. I cleared them since it was the first time it had been scanned since installing the turbo and then started it and for the first 5-10 sec it ran normal then it seemed to run rougher and rougher and miss more and more. Also, the longer it ran the more white smoke continued to come out of the exhaust; started with no smoke and after running for about 30-40 sec the smoke was coming out good and filling up the pole barn fast. I tried to hold the rpms steady at 2000 but that was impossible, as soon as it got there it would hold steady for a few secondes then violently bob between 1000 and 2000 rpm. WhenI put it into gear they dropped low right away then went back to the strong surging but never stalled.

The turbo was clearly a problem, the compressor wheel was just flopping around so is all this smoke just from the oil from the bad turbo? There was also white smoke coming out from under the heat shield under the hood but my first thought there was oil that might have fallen on the manifold.

This is exactly how it was acting prior to the new turbo and like I said the old turbo was clearly bad.
 
#4 ·
After reading the codes with a cheaper Actron Pocket Scan, I had the codes P0456 and P1300 which apparently are Evaporation Emission leak such as a gas cap and a misfire code. I cleared them since it was the first time it had been scanned since installing the turbo and then started it and for the first 5-10 sec it ran normal then it seemed to run rougher and rougher and miss more and more. Also, the longer it ran the more white smoke continued to come out of the exhaust; started with no smoke and after running for about 30-40 sec the smoke was coming out good and filling up the pole barn fast. I tried to hold the rpms steady at 2000 but that was impossible, as soon as it got there it would hold steady for a few secondes then violently bob between 1000 and 2000 rpm. WhenI put it into gear they dropped low right away then went back to the strong surging but never stalled.

The turbo was clearly a problem, the compressor wheel was just flopping around so is all this smoke just from the oil from the bad turbo? There was also white smoke coming out from under the heat shield under the hood but my first thought there was oil that might have fallen on the manifold.

This is exactly how it was acting prior to the new turbo and like I said the old turbo was clearly bad.
Anyone?
 
#6 ·
sounds like a big vacuum leak. I'd check the hose on the back of the throttle body.
IIRC, it goes to the evap system, which could cause both CEL's.

As for the smoke....white smoke is usually steam. steam is usually coolant mixing. you sure it's white, and not blue?

Pull your intake pipes and if you have the means, the IC and clean them out. depending on how badly the turbo let go, it could have a quart or two of oil in there.

If you're sure it's white, check your coolant overflow for mixing, or really low coolant.
if it's mixed, or missing, there's a good chance of a bad head gasket.