2002 SAAB 95 Aero Engine Misfire / Ping

saab
misfire
9-5

#1

I have a 2002 SAAB 85 Aero with a problem that is driving me crazy. I had a problem with a brake booster. You could hear a slight hiss from a vacuum leak until you pressed the brake pedal and then it would stop. It was diagnosed as the brake booster and I had it replaced. Now it is quiet but when you press the brake pedal you here a quieter hiss that gets lower in volume as the car slows down. I probably wouldn’t have even noticed except that at about the same time I noticed a very faint noise that I describe as a ping when I accelerated very slowly at low speed. I took it back to the dealer and they said the couldn’t hear anything so I went for a drive with them and was able to demonstrate the problem. The checked everthing and said the couldn’t find a problem. I changed my driving habits and avoided the situations the caused the ping and then one day I went to accelerate onto a freeway and the slight ping sounded more like a knock so I backed off the accelerator. Weeks went by and this did not repeat until once again while accelerating onto a freeway. I took it to the SAAB dealer and they took it for a test drive and said the couldn’t reproduce the problem so I went for a drive with the technician and headed down the freeway where I was able to reproduce the problem. The technician said he didn’t find anything wrong and that it might be carbon deposits on the valve because, evidently, at 90000 miles my car has “a lot of miles on it”; or it might need plugs or it might need to have the fuel system cleaned. I asked if it could be anything else like a vacuum leak and he said no. I don’t want to hurt the engine so I’ve not done much hard acceleration lately. When I put the car in sport mode and step on the gas it accelerates very quickly except that sometimes you get a ping and sometimes you get loud ping. It seems like if you accelerate hard with the brake slightly depressed you are much less likely to get the ping. I only tried that twice and during acceleration I got the flashing engine light to come (the first time that has happened). It flashed and then turned off. The SAAB manual says that a flashing engine light means that a misfire was detected an that you should ease off of the accelerater because prolonged misfires can damage the catalytic converter. I really hate driving around being afraid to accelerate and having the mechanic tell me that it could be this or it could be that. Has anyone had a similar problem or any idea what is wrong? By the way, I was able to run pretty much any gas in the car but would typically use 89 octane unless I expected to drive hard or took a trip and then I would use 91. I live in Iowa so it is pretty hard to get away from ethanol so most of the gas I’ve used contained ethanol. It has mostly been BP or Shell gas. The car gets an all synthetic oil change every 5000 miles. Due to the ping I’ve been running 91 octane gas (or 93 if I can find it) in the car. The technician at the SAAB delear was trying to convince me that I should always use the same octane gas because the engine get used to whateve octane I use and that changing to a higher octane fuel could cause an engine to ping so lately I’ve just been using 91 octane.


#2
 I am not going to even take a stab at that mass of letters.  

 How about giving us some paragraphs?  It makes it so much easier to read.  
 
 My eyes can't handle that mass of letters. 

Howaboutgivingussomeparagraphs?Itmakesitsomucheasiertoread.

#3

I have a 2002 SAAB 85 Aero with a problem that is driving me crazy. I had a problem with a brake booster. You could hear a slight hiss from a vacuum leak until you pressed the brake pedal and then it would stop. It was diagnosed as the brake booster and I had it replaced. Now it is quiet but when you press the brake pedal you here a quieter hiss that gets lower in volume as the car slows down. I probably wouldn’t have even noticed except that at about the same time I noticed a very faint noise, that I describe as a ping, when I accelerated very slowly at low speed. I took it back to the dealer and they said the couldn’t hear anything so I went for a drive with them and was able to demonstrate the problem. They checked everything and said they couldn’t find a problem.

I changed my driving habits and avoided the situations that caused the ping and then one day I went to accelerate onto a freeway and the slight ping sounded more like a knock so I backed off the accelerator. Weeks went by and this did not repeat until once again while accelerating onto a freeway. I took it to the SAAB dealer and they took it for a test drive and said the couldn’t reproduce the problem so I went for a drive with the technician and headed down the freeway where I was able to reproduce the problem. The technician said he didn’t find anything wrong and that it might be carbon deposits on the valve because, evidently, at 90,000 miles my car has “a lot of miles on it”; or it might need plugs or it might need to have the fuel system cleaned.

I asked if it could be anything else like a vacuum leak and he said no. I don’t want to hurt the engine so I’ve not done much hard acceleration lately. When I put the car in sport mode and step on the gas it accelerates very quickly except that sometimes you get a ping and sometimes you get loud ping. It seems like if you accelerate hard with the brake slightly depressed you are much less likely to get the ping. I only tried that twice and the second time during acceleration I got the flashing engine light to come on (the first time that has happened). It flashed and then turned off. The SAAB manual says that a flashing engine light means that a misfire was detected an that you should ease off of the accelerater because prolonged misfires can damage the catalytic converter.

I really hate driving around being afraid to accelerate and having the mechanic tell me that it could be this or it could be that. Has anyone had a similar problem or any idea what is wrong? By the way, I was able to run pretty much any gas in the car but would typically use 89 octane unless I expected to drive hard or took a trip and then I would use 91. I live in Iowa so it is pretty hard to get away from ethanol so most of the gas I’ve used contained ethanol. It has mostly been BP or Shell gas. Due to the ping I’ve been running 91 octane gas (or 93 if I can find it) in the car. The technician at the SAAB delear was trying to convince me that I should always use the same octane gas because the engine get used to whateve octane I use and that changing to a higher octane fuel could cause an engine to ping so lately I’ve just been using 91 octane.

By the way, the car gets an all synthetic oil change every 5000 miles.


#4

My car goes ping when I go zoom.

The mechanic leaves much for me to assume.

If I go too quickly I might hear a knock.

I think it comes somewhere from the engine block.

Can you still drive cheeky when your vacuum is leaky?

Or is this problem destine to remain an illusive hobgoblin?


#5

Couple of issues here: 1) pinging is very likely carbon build up; SAABs are turbocharged and sensitive to spark knock / pinging with low octane gas and/or carbon build up. I’d suggest you try a can of Seafoam from the autoparts store - I’ve Seafoamed many SAABs with good results; 2) the misfire code is almost certainly a failing Direct Ignition Cartridge (DIC), which is a common failures in SAABs. I’d highly recommend that you go to RM European or other online Saab parts dealer and purchase a new DIC and the correct resistor NGK spark plugs for your car. At your mileage, its likely that you’re on your second set of plugs - and its also very possible that you have non-NGK plugs in there. With a new DIC, correct plugs and a Seafoamed engine, you’ll be good to go. Carry your old DIC in the trunk as a spare - when these fail you will get stuck on the side of the road, and a spare will get you back on the road in 5 minutes (very easy to replace). Good luck.


#6

Thanks for your reply. The really strange thing is that the mild ping is with very little pressure on the gas pedal and at low RPM (after the transmission shifts up). I bought plugs and ordered the direct ignition cassette (part number 55559955) so we’ll see if that helps. Still curious if I should here a vacuum noise when I depress the brake.

Thanks again for the reply.


#7

My experience with my 2001 Saab 9-3, including a lot of reading in the Saab owner web sites, is that the issue may also be a crank position sensor. I haven’t yet replaced mine, but occassionally have the flashing check engine light and poor performance. I’ve already replace the DIC, plugs (OEM), and Mass Air Flow sensor.

Check out the Saab owner sites. Some have great Q&A forums.