Low Torque and rattling
#1
11-24-2011, 03:14 AM
Low Torque and rattling
I have a 2004 Mini Cooper, R50. I bought it second hand and it was pretty clean and smoothly running.
Nowadays, my Mini is not capable of producing enough torque when acceleration is needed. When I apply the gas mildly, the car's response is OK. But, when I step on it, it does not produce enough torque to accelerate and rattles for 3-4 seconds and it does not accelerate swiftly, compared to its past performance. Yet interestingly, this problem does only appear when the engine reaches its operational temperature. The car's response to throttle is very well when the engine is cold.
I encounter this problem since I had the head valve cover and gasket replaced by my mechanic. I had to have those changed, since the coolant fluid almost always boiled up and splashed through the little hole on the coolant container. Changing the gasket and head valve cover resolved this coolant boiling problem, but resulted in this low throttle performance problem when the engine is hot.
I and my mechanic are trying to figure out the root problem. I have done extensive search on the Internet and Mini Maintenance Manual and tried many things. I hope that it does not go somewhere scary.
What we have done to resolve the problem: We first checked whether there is a vacuum problem on the way to the MAP (Manifold Air Pressure) sensor. We checked whether there is loss of vacuum indicating that there is a hole and we observed that there is no vacuum problem. We changed the MAP sensor, but nope, no improvement. We checked all around the valve head and the gasket, but nothing... No cracks, no leaks. Yet, there is no fault recorded by the MCU. The firing timings seem appropriate when we connect it to the maintenance computer.
Next steps ahead: We will try to replace the Crank Shaft sensor first. If that does not work out, we will have to proceed with replacing the gasket and the head valve again.
The strange thing is that; the problem appears when the engine temperature raises to its normal level. Just after car start, there is no problem with the throttle response. So, I ask to myself; what changes when the engine gets hot and finally causes these problems? Is it the gasket that deteriorates when it gets hotter? Or something else?
Any help/comment will be very much appreciated. I love my Mini so much and I would do anything to see it perform well again, cause driving it is such a pleasure.
Nowadays, my Mini is not capable of producing enough torque when acceleration is needed. When I apply the gas mildly, the car's response is OK. But, when I step on it, it does not produce enough torque to accelerate and rattles for 3-4 seconds and it does not accelerate swiftly, compared to its past performance. Yet interestingly, this problem does only appear when the engine reaches its operational temperature. The car's response to throttle is very well when the engine is cold.
I encounter this problem since I had the head valve cover and gasket replaced by my mechanic. I had to have those changed, since the coolant fluid almost always boiled up and splashed through the little hole on the coolant container. Changing the gasket and head valve cover resolved this coolant boiling problem, but resulted in this low throttle performance problem when the engine is hot.
I and my mechanic are trying to figure out the root problem. I have done extensive search on the Internet and Mini Maintenance Manual and tried many things. I hope that it does not go somewhere scary.
What we have done to resolve the problem: We first checked whether there is a vacuum problem on the way to the MAP (Manifold Air Pressure) sensor. We checked whether there is loss of vacuum indicating that there is a hole and we observed that there is no vacuum problem. We changed the MAP sensor, but nope, no improvement. We checked all around the valve head and the gasket, but nothing... No cracks, no leaks. Yet, there is no fault recorded by the MCU. The firing timings seem appropriate when we connect it to the maintenance computer.
Next steps ahead: We will try to replace the Crank Shaft sensor first. If that does not work out, we will have to proceed with replacing the gasket and the head valve again.
The strange thing is that; the problem appears when the engine temperature raises to its normal level. Just after car start, there is no problem with the throttle response. So, I ask to myself; what changes when the engine gets hot and finally causes these problems? Is it the gasket that deteriorates when it gets hotter? Or something else?
Any help/comment will be very much appreciated. I love my Mini so much and I would do anything to see it perform well again, cause driving it is such a pleasure.
#2
01-17-2012, 03:25 AM
Finally found the problem. 
It was caused by a very dirty gas filter.
When we were checking all our options to find the cause of malfunction, we removed the back seat and opened up the gas pump. We opened up the gas pump and we have seen that the filter is so dirty that it almost blocked the gas flow. When we replaced it, it was like a kaiser.
Now the car's performance is not sluggish anymore, it accelerates like a bullet.
But, we have faced another interesting problem. The details are on another thread. Just search "Auto gear Shift in high revs" if you are interested.
It was caused by a very dirty gas filter.When we were checking all our options to find the cause of malfunction, we removed the back seat and opened up the gas pump. We opened up the gas pump and we have seen that the filter is so dirty that it almost blocked the gas flow. When we replaced it, it was like a kaiser.
Now the car's performance is not sluggish anymore, it accelerates like a bullet.
But, we have faced another interesting problem. The details are on another thread. Just search "Auto gear Shift in high revs" if you are interested.
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