Our 2000 Saab 9-3 has only 120,000miles and has been well cared for,synthetic oil, top grade fuel, religous maintenance. We recently allowed our 19 year son to use it to do a 10 minute commute to college. He had it 3 weeks. In that time he discoverd Sport Mode. Can sport mode damage the car also it has been an extremely cold winter. The pistons just melted on the car and the engine is toast.
The answer is apparently…yes. A 19 year old boy can tear up an anvil. Sport mode allows manual shifting of the transmission so he probably ran the rpm to the limit in the lower gears. This will fry an engine. I believe the engine is a 2.0 so it did not have a chance. These cars look and sound sporty but they are really little more than grocery getters.
What is the anvil, our machanic tried to tell us it was running lean and that Saabs from 1999 to 2003 have issues and it probably wasn’t from our son using Sport Mode. When the car was towed away from the front of our house there was a large rainbow of an oil left behind.
Unfortunately, this problem is about 99%+ Juniors fault. The math works like this:
Lead foot + turbocharger + low octane gas = melted pistons and toasted engine due to pre-ignition and the failure to ease up on the throttle.
Many SAAB drivers love the feel of that turbo pull…
Your mechanic is incorrect. The ECM (computer) controls the fuel/air mixture and if an engine is running so lean that it will roast pistons then it will not be driveable unless one likes very low speeds, bucking and jerking, flashing engine light, etc.
So what does Junior have to say about how this happened?
Well, before we even allowed him to use the car we told him to put only 93 grade gas in it and to let it warm up after turning it on and to cool down before turing it off, a few minutes on each end. He insists he contiued to baby it and the only thing he did different from us was use the Sport Mode, which I didn’t even know existed. Most of his driving was around town, he took it snowboarding once.
I’m not going to accuse your son of flogging your car but will only relate reasons why pistons can be melted.
- Low octane gas (pre-ignition rattle, etc.)
- Air leak (lean condition, but one bad enough to cause this kind of damage will have the CEL flashing, engine running poorly, bucking/jerking, etc.)
- Base distributor timing has too much advance (same effect as No. 1 above)
Normally the base dist. timing is a factory set and forget thing unless there is service work performed that involved movement of the distributor.
If the dist. timing has been altered there should only be one of two reasons for this.
One is someone advancing the timing up a bit to get a bit more “oomph” out of the car; bad news if more than a few degrees.
Two would be if the engine had recent service work that involved the distributor in some way. (timing chain, etc.)
Did this incident occur around the time he went snowboarding and did this involve mountains, steep ascents by the car, etc?
Low octane gasoline, too much timing advance (both do the same kind of damage), etc. can be magnified quite a bit when climbing steep grades.
If the pistons are knocked out this means there must have been some serious rattling going on in that engine before it died; and a few minutes of rattling will not do this. It has to be something that continued for a length of time.
Hope some of that helps anyway. That’s about my best guesses without car in hand.
I doubt “sport” mode is the problem, maybe contributed in some way but not the main reason for the motor failure.
Sport mode simply changes the shift points on the automatic transmission. It will up shift slower letting the motor rev up about 1,000 more rpm or less, and downshift to lower gears quicker. Neither of these changes by themselves would “toast” the engine.
It is possible the young man pulled the gear selector out of “drive” and into 1, 2, or 3 in effect manually shifting the transmission. Doing that would possibly run the revs up much higher that “sport” mode in drive would allow.
In the process of fixing the motor it is likely the real reason for the blown pistons will be identified. There is a waste gate on the turbo which keeps the turbo from putting too much air in the cylinders. If the waste gate was stuck open and not functioning that is another way this could have destroyed the pistons.
The open waste gate theory would have resulted in a motor not running properly, either more noise or some bucking and jerking. Junior may have been so focused on getting somewhere that he pushed on despite this evidence that the motor wasn’t running as normal. Kids don’t seem to know what normal is and they just drive until the car stops.
First of all when he took it snowboarding he was probably at 10,000+ feet, and yes, a very steep grade, we live in Colorado. Second, we just had an oil change by our Saab mechanic about 3 weeks before all this trouble began. Third, he drove it home a few miles to get it to the house the day he heard it knocking.
“When the car was towed away from the front of our house there was a large rainbow of an oil left behind.” Your mechanic should try to find out where this puddle of oil came from. He should have check the oil level, and the coolant level (looking into the radiator).
Either one, low oil or low coolant, can destroy an engine. He should try to determine WHERE the fluid came from, specifically.
There is a powerful need to get “home”, like a bowl of chicken soup and all will be well. Driving the car the last couple of miles to get home is likely when the most damage to the motor took place.
When a car is sick getting it home doesn’t help much unless you have a garage full of tools to work on it. Best to stop a sick car on the side of the road, call home for advice, and if in doubt call for a tow to a service facility. You son just followed human nature and can’t be faulted for that.