Saab Aero 95 2006 cold idle problem
Discussion
My partner's 9-5 Manual Aero Hot has developed a problem this week when I've been using the car. Car is a Dame Edna 2006 model year.
Drove to work fine, then when starting car several hours later the idle was lumpy, as if car running on 3 cylinders.
After 15 to 30 seconds it settles down and then drives fine.
I'd last put fuel in 2 weeks ago, almost filling car (98/99 RON) so took cap off in case it was a fuel pressure issue with low tank.
Car still the same. Put half a tank of fuel in, CEL was then off, but car still lumpy and seems to be getting worse on cold start up.
Have removed plugs, cleaned and still the same.
I'm thinking it must be something lot do with Throttle ECU, though would expect it to be problematic when warm? Car only does it for first 15-30 seconds, like it is flooded on one cylinder (or more maybe).
This seems to effect 9-3 not 9-5's when I've googled it.
Any thoughts welcome.
Drove to work fine, then when starting car several hours later the idle was lumpy, as if car running on 3 cylinders.
After 15 to 30 seconds it settles down and then drives fine.
I'd last put fuel in 2 weeks ago, almost filling car (98/99 RON) so took cap off in case it was a fuel pressure issue with low tank.
Car still the same. Put half a tank of fuel in, CEL was then off, but car still lumpy and seems to be getting worse on cold start up.
Have removed plugs, cleaned and still the same.
I'm thinking it must be something lot do with Throttle ECU, though would expect it to be problematic when warm? Car only does it for first 15-30 seconds, like it is flooded on one cylinder (or more maybe).
This seems to effect 9-3 not 9-5's when I've googled it.
Any thoughts welcome.
Yes, could be the DI Casette. No idea of life expectancy, but not recent anyway.
Today I've cleaned MAF, Throttle body (the part that opens) and checked hoses etc.
Car still the same, smokes and kind of judders from cold, with lumpy idle.
So I guess that is all I can do, the car runs fine unless cold, so has to be linked to DI really.
Cheers.
Today I've cleaned MAF, Throttle body (the part that opens) and checked hoses etc.
Car still the same, smokes and kind of judders from cold, with lumpy idle.
So I guess that is all I can do, the car runs fine unless cold, so has to be linked to DI really.
Cheers.
Edited by BlimeyCharlie on Friday 12th May 11:14
Maybe this update will benefit other people, but I've found the solution (so far).
Gave the plugs a proper clean last night, with a wire brush. They were double or triple Platinum Bosch R6 plugs (expensive but Saab specify NGK).
I also took the DI cassette out, inspected it for cracks etc, none found. Took it to bits (easy) just to check no scorching etc.
This morning I put old (cleaned) plugs back, but in different cylinder order, and car started from cold perfectly. The only thing that had therefore changed was the plugs (in firing order).
However, I had decided anyway to get NGK BCP R7 ES plugs, as these are suggested as 'colder' plugs for modified cars.
Didn't properly measure gaps, but a normal ruler said just a fraction under a millimetre, I figured I'd soon find out.
Car runs a treat, more responsive, and goes as it should.
So I spent just under £12.00 when it would have been easy to spend over £300.00 on a new DI cassette, plus the (wrong) expensive plugs. Easy to see how you can spend a fortune at a garage etc.
I also noticed that the car would 'stutter' when warm when sat at traffic lights, and this has now disappeared.
I'll update this if not properly solved, but so far all is good.
Gave the plugs a proper clean last night, with a wire brush. They were double or triple Platinum Bosch R6 plugs (expensive but Saab specify NGK).
I also took the DI cassette out, inspected it for cracks etc, none found. Took it to bits (easy) just to check no scorching etc.
This morning I put old (cleaned) plugs back, but in different cylinder order, and car started from cold perfectly. The only thing that had therefore changed was the plugs (in firing order).
However, I had decided anyway to get NGK BCP R7 ES plugs, as these are suggested as 'colder' plugs for modified cars.
Didn't properly measure gaps, but a normal ruler said just a fraction under a millimetre, I figured I'd soon find out.
Car runs a treat, more responsive, and goes as it should.
So I spent just under £12.00 when it would have been easy to spend over £300.00 on a new DI cassette, plus the (wrong) expensive plugs. Easy to see how you can spend a fortune at a garage etc.
I also noticed that the car would 'stutter' when warm when sat at traffic lights, and this has now disappeared.
I'll update this if not properly solved, but so far all is good.
Sadly they can be prone to head gasket failures. All it took for mine to go was a split coolant hose and a brief rise in temperature before I shut the engine down. I think it then developed a weak spot and slowly blew over a long period of time.
Hopefully your head is still in good shape and not warped.
Hopefully your head is still in good shape and not warped.
I was able to nip up a few bolts a small amount, but when I removed the spark plugs to see how they looked again I could see coolant in the combustion chamber, mainly where cylinder 3 spark plug sat.
So not using the car. It hasn't overheated so head shouldn't be warped, and still only smokes a little upon start up and goes away when warm. No oil in coolant or coolant in oil, so ok in many ways.
I've got a good quote from a SAAB specialist.
Will know in a few more days what I'll do.
Thanks for comments and advice.
So not using the car. It hasn't overheated so head shouldn't be warped, and still only smokes a little upon start up and goes away when warm. No oil in coolant or coolant in oil, so ok in many ways.
I've got a good quote from a SAAB specialist.
Will know in a few more days what I'll do.
Thanks for comments and advice.
Edited by BlimeyCharlie on Friday 12th May 11:15
Every cloud has a silver lining...
While the car was over at the Saab specialist I sold it to another customer there who'd seen our car. He was after that model and offered us a good price so that was that.
So car went a month ago and I'm already looking out for another again. Should have kept it. The novelty of driving a Mini soon wore off.
While the car was over at the Saab specialist I sold it to another customer there who'd seen our car. He was after that model and offered us a good price so that was that.
So car went a month ago and I'm already looking out for another again. Should have kept it. The novelty of driving a Mini soon wore off.
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