My Baleno had to go for a complete engine overhaul to fix an issue that popped up all of a sudden. It probably may not be all of a sudden, but the damage was being created for a while and finally it surfaced out.
Car: Maruti Suzuki Baleno 2004 Model
ODO: 1.4 L Kms
Reason: Severe drop in pick up
Cause: Crank shaft key way worn out
Work Done at: Sejal Motors, Bangalore
History:
I have been hearing a slight noise emanating from the engine bay while I was driving around. It wasn’t so loud to catch an attention nor it was very frequent. But there was something amiss. I didn’t pay much heed to it and ignored and drove around and finally a damage was done on the crank shaft.
Present:
At the start of one of a long drive, the noise from the engine became loud and since I didn’t have a choice to cancel the drive, I continued the driving hoping there is nothing as bad could happen. Probably because the car never gave a problem for the past 7 years that I have been driving it, I was over confident about that. There wasn’t any issue with the drive except this noise which was not very frequent but sometimes louder. Towards the end of the trip, the noise became terrible and it sounded like some metal part being grind inside. Managed to complete the trip, and the next day took it to a local mechanic who had a quick check and immediately figured out that the crank shaft pulley bolt is broken and the pulley is wobbling, which could be the noise about. He got a new bolt and fastened.
The pulley back in place and the noise went away. But then I was welcomed with a terrible loss of pick up and while driving on an inclined road, the car was even stalling. After a while, figured out that if I switch off the A/C, it was better and it was not stalling on uphill roads but the pickup was very bad. At some instances there wasn’t any response to the throttle. I had to drive back to Bangalore if I have to do any repair job and managed to drive back without switching on the A/C. (The A/C was not the real cause, but it was just acting as a load to the crippling engine)
Took it to the workshop (Sejal Motors, Bangalore) and Mr.Suresh there, whom I knew well, received the car and started the diagnosis. I left the place and later got a call from him asking me to visit the workshop. Probably it was difficult for him to explain on the phone and I headed. He had removed the timing belt cover to reach out to the crank shaft pulley from where the noise for coming from. Since I had explained him earlier about the history of crank shaft pulley bolt broken, I guess that is the reason he could narrow it down to the same area. He showed me that the crank shaft pulley was damaged and grinded into pieces in the inside, and it was all metal debris lying inside. The notch on the pulley which the crank shaft sensor uses to detect the rotation and speed has broken and there is no way the sensor could be transmitting the correct speed/position information to the ECM. It was only a plain luck that the car was able to run with all these mess inside.
We suspected it could have happened due to the wobbling of the pulley that I mentioned earlier. Though we had fixed it earlier by fastening the crank shaft bolt, the damage was already done before. Not only the pulley was damaged, the pressure created on the key way coupler due to the wobbling of the pulley has
worn out the key way on the crank shaft. Due to this wear out, there was a slight slip in the timing belt which must be causing inconsistent timing and effectively dropping the mileage.
Crank shaft Key way – This is a small groove at the end of crank shaft where the pulley is engaged to the crank shaft using a small wedge called as ‘key’. One end of the timing belt is connected to this pulley, meaning, this pulley plays a major role in maintaining the timing of the engine. If the pulley is offset by even few mm, there will be a variation in timing which will result in the changes in combustion strokes and loss of power and ultimately engine cessation if the timing goes too way around.
How a good "key way" should look like:-
(PC: Internet)
How the damaged "key way" in my car is looking like:-
So, this key way was worn out or eaten up quite too much that the timing of the engine was affected.
We discussed on how to go about with this and figured out the only way to resolve is to change the crank shaft as a whole. And that needs a complete engine re-build. I was insisting on a possible repair work on the damaged key way, by using a metal adhesive like loctite etc. But he was not very keen on doing that considering the risk involved. Without having another choice, I had to give a go ahead to remove the engine and replace the shaft. MGP ones were costing a bomb, and hence we went in look for an aftermarket one. He managed to find one at half the price and in good condition. The engine was taken out by the mechanic and the head was separated from the block. Cylinder block was taken to the lathe shop for further work on it such as removing the crank shaft, putting the new one, replacing the bearings, cleaning up the cylinder, replacing the piston rings and so on.
And then the block was brought back to the workshop for assembling and putting back into the car.
The old crank shaft taken out of the engine:- The Key way of old and new shaft:- The new shaft placed on the block:- All assembled back and the engine ready to go into the bay:- Things are back in place and the car is ready to start:-
Had some initial hiccups when the car was started. There were some jerks and initially suspected whether it could be a leak in the combustion through the head/valves or faulty ECM. But both were diagnosed to be not at fault and then the next suspect was the crank shaft position sensor. Replaced it, and that was the culprit.
Not only the original pick up issue was resolved, but there has been a tremendous improvement in the performance. The engine revs super smoothly and the response is lovely. Awaiting to run in for about 2000kms at least, before pushing it beyond 60kmph.
Parts Replaced:-
Head gasket
Oil pump gasket
Throttle body gasket
Exhaust manifold gasket
Oil case gasket
Water pump gasket
Big end oil seal
Cam shaft oil seal
Crank pulley assembly
Crank shaft (the most expensive of all)
Crank shaft position sensor
Stainer O ring
Key
Main bearing
Connecting bearing
Thrust washer
Bore sleeve
Piston ring
Lathe charges
Sealant
Learnings:-
- Never ignore even a slightest abnormal sound coming out of the engine. Pin point the root cause and fix it up immediately if required.
- Have a close eye on any repairs that you do around the engine. (Here, I have replaced the timing belt a few months back. I vaguely suspect the mechanic would not have tightened the crank shaft pulley bolt with the right torque and that could have caused the bolt to get loose and create all the damage thereafter. That is just a guess, it could be something else as well)