SwedeSpeed - Volvo Performance Forum banner

1 - 20 of 30 Posts

·
Registered
Joined
·
123 Posts
Discussion Starter · #1 ·
Hello,

Today my wife somehow nudged the gearshift lever into manual mode while reaching for her purse at a stop light. When the light turned green she accelerated as usual, but the car of course didn't upshift. She realized something was wrong due to the engine revving and the car "not moving as usual" (her description), so she stopped, shut off the engine and called me. She thinks she was driving for less than 60 seconds.

Could this have resulted in engine damage? It's the 3.2 engine, by the way. Would the engine management system even allow the engine to rev past the redline? I drove it afterwards and it seemed completely normal but maybe it now burns oil - who knows? :(

Could shutting off the engine without a cool-down period cause overheating / warping of the head?

Thanks
Cinergi
 

·
Registered
Joined
·
2,147 Posts
i am willing to bet the car has a fuel cut off. go to a porsche club autocross and listen to the motors that bang the red line/cut off with no damage.
 

·
Registered
Joined
·
254 Posts
If she did this for 60 seconds or 5 minutes....should not make much of a difference. A one time event like this should not ruin modern cars, or we would see many more severe engine failures on this forum. Tell your wife (and yourself) to relax about it. Now she knows to react much sooner next time it happens. It even happens to me at times forgetting I am in manual mode.....sitting at a red light, shifting into manual and then after seeing green going and wondering why the car doesn't shift. Long traffic lights can do that....Plenty of margins in modern engine designs.

freezingalaskan
 

·
Registered
Joined
·
1,020 Posts
No harm done.. ECM has fuel cut off when RPM limiter kicks in.
 

·
Registered
Joined
·
1,329 Posts
Surely volvo has designed a device to protect against the un-intended shifting in the manual mode and blowing up motors. The valve train on an OHC motor is able to rev higher than the other rotating mass. The 3.2 is especially well balanced, not needing external balance shafts.

Most likely no harm at all unless there were other noises.

If it starts and runs, it should be good to go.

P
 

·
Registered
Joined
·
648 Posts
Your car is fine - a few encounters with the rev limiter is not going to damage anything, that's why it's there.

On my STi, we create a lower limiter at about 6k and use it to launch the car and shift, and often we will raise the limiter to give some extra headroom for auto-x. My engine has 75k miles of hitting the limiter at least once a day, and it's fine.
 

·
Registered
Joined
·
365 Posts
I agree with the masses, it should be fine...but dont let her off the hook yet.

You need to let her see you fret a bit, and then try to get a nice meal out of it, and who knows what other favors...... :p
 

·
Registered
Joined
·
2,147 Posts
Surely volvo has designed a device to protect against the un-intended shifting in the manual mode and blowing up motors. The valve train on an OHC motor is able to rev higher than the other rotating mass. The 3.2 is especially well balanced, not needing external balance shafts.

Most likely no harm at all unless there were other noises.

If it starts and runs, it should be good to go.

P
inline sixes are all inherently balanced. it is the four cylinders that are not, hence, audi's answer with an inline 5 followed by volvo's inline 5, and mitubishi's counter rotating balance shafts made famous by the people at porsche that brought us the inline 5.
 

·
Registered
Joined
·
386 Posts
Transmission

Every time I take my XC90 to the car wash they always engage the W button on the console when cleaning the inside of the car. I have always been able to catch it but I have always been afraid, I would not and then drive the car in the W mode at hwy speed and run the trans.
 

·
Registered
Joined
·
648 Posts
Every time I take my XC90 to the car wash they always engage the W button on the console when cleaning the inside of the car. I have always been able to catch it but I have always been afraid, I would not and then drive the car in the W mode at hwy speed and run the trans.
Driving the moose at highway speeds with the "W" mode on is not going to damage anything. All it does is tell the transmission to start in second gear instead of first. If you continuously accelerate harshly in "W" mode on dry pavement, you will fry the clutch packs in the transmission. Once it gets up to speed and shifts to third, it behaves the same as if "W" wasn't engaged.
 

·
Registered
Joined
·
1,329 Posts
inline sixes are all inherently balanced. it is the four cylinders that are not, hence, audi's answer with an inline 5 followed by volvo's inline 5, and mitubishi's counter rotating balance shafts made famous by the people at porsche that brought us the inline 5.
4 cylinder motors are inherently balanced as well, but only up to around 2000 cc. Then beyond 2000 cc they buzz, thus the balance shafts on the 2.3 Volvo 16v, the 2.5 inline 4 of the 944, and the 3.0 inline 4 of the 944S and 968. The 5 cylinder is inherently unbalanced and needs a shaft any way you look at it. The only V8 I ever heard about that needed a balance shaft is the Volvo, although there may be a few others.

P
 

·
Registered
Joined
·
1,329 Posts
FWIW, Just got back from a 400-mile trip all done on Sunday, mostly interstate highways in the 3.2 AWD XC90. There is virtually no problem maintaining ANY speed with this vehicle on the interstate. Traffic was basically flowing at 80-mph with a few rabbits now and then. We got up to 90 on a few occasions just to stay out of trouble and i never got into an occasion where I asked the car to kick down in anger. On several occasions I did select the gear I wanted to be in manually and eased into position where I wanted to be.

On secondary country roads we got into some long straights and passed some moving cars along with everyone else up ahead of us. On secondary roads where you have limited area to pass, naturally you need more power to do it safely or you need to be CONSCIOUS of what you are driving and compensate for it. On one occasion I selected a gear and found I might have been better off letting the transmission seek the maximum advantage automatically, however the wife never noticed it and I never heard a peep.

The main difference is the "perception" of power delivery between the 2.5 and 3.2, due to the way each of these motors work. If you think hearing a motor rev into the power band is bad or abusive, then you won't like the 3.2 but quite honestly I think that sound is quite nice. The wife seems to get a little nervous when she hears it start to whine but never said anything as I was just smiling and merging into traffic.

Tooling along at 80-mph at 2600 rpm is pretty relaxed. She said on several occasions, "this is a limo", and I agreed. I understand it is not a rocket-ship, but neither is the V8 by many standards. You adapt your driving style to the vehicle capability (and driver skill) you have, you enjoy the ride, and no whining please (not even from the passenger seat).

Regards,

P
 

·
Registered
Joined
·
668 Posts
4 cylinder motors are inherently balanced as well, but only up to around 2000 cc. Then beyond 2000 cc they buzz, thus the balance shafts on the 2.3 Volvo 16v, the 2.5 inline 4 of the 944, and the 3.0 inline 4 of the 944S and 968. The 5 cylinder is inherently unbalanced and needs a shaft any way you look at it. The only V8 I ever heard about that needed a balance shaft is the Volvo, although there may be a few others.

P
P do you know why 4Cly begin to buzz above 2L? I know that a 6 is smoother than a 4 just because you are constantly in a power stroke, but I do not see how a balance shaft could help with that. Obviously the higher the cylinder count the smoother the engine will be, provided you can get to an multiple of 360 using the cylinder configuration and number. Which begs the question why not put each piston on a different position on the crank? I assume the answer is the length of the crank.
 

·
Registered
Joined
·
1,962 Posts
Read these posts, and thought, "does my wife understand the manual/automatic shifting on my XC90", which she does drive, occasionally. She did not understand it. So while driving down to Denver today, I gave her a briefing on how the manual/automatic shifting works, and the symptoms of being accidently in manual. Everyone should check with their wives, to make sure they understand this.
 

·
Registered
Joined
·
668 Posts
Everyone should check with their wives, to make sure they understand this.
I would say there are plenty of husbands that have no clue either. I would venture to say that there are plenty of people who own a vehicle who have never read the manual. There are even more people who only want to know the bare minimum of how to make the vehicle go forward and backward, and they are purposely ignorant (to the point that you can show them how to check the air pressure in the tire and then they "forget") of anything else relating to the vehicle.
 

·
Registered
Joined
·
2,005 Posts
............. Everyone should check with their wives, to make sure they understand this.....
I checked with the dear one..... She said I was about as clueless about this as I was most anything else!
 

·
Registered
Joined
·
648 Posts
The V8 needs counter-balance shafts because in order to make it fit transverse-style in the engine bay, it had to be a 60-degree V8, not the traditional 90-degree V8. There's no particular need for a counter-balance shaft, but all it does is make the engine seem smoother.

A lot of turbo Mopar and turbo Mitisubishi people remove the balance shaft. Makes the engine appear to run with more vibration, but otherwise on a small engine there are significant power gains.
 

·
Registered
Joined
·
1,962 Posts
I would say there are plenty of husbands that have no clue either. I would venture to say that there are plenty of people who own a vehicle who have never read the manual. There are even more people who only want to know the bare minimum of how to make the vehicle go forward and backward, and they are purposely ignorant (to the point that you can show them how to check the air pressure in the tire and then they "forget") of anything else relating to the vehicle.
I know you're right about that. My wife is actually a very smart woman, and not a bad driver when she pays attention. She just has zero interest in cars or in their operation. And that's probably more true about the female gender than the male gender.
 
1 - 20 of 30 Posts
Top