Mileage drop on my santro I raised this earlier on a new thread to have specific discussion about the problem (undectable so far) we have in our Santro. Unfortunately that thread got deleted so raising on this thread. Please go through the details below and let your suggestions come in. Many thanks in advance. Some history:
We have a Jan 2005 Santro with 131k km's on the ODO. Car is used in Punjab and we have open roads with very less traffic signals and jams. So till about 115k km's we were getting a mileage of 18/19 w/o AC. Then the power steering pump of the car started creating whining sound and we got the pump bearings+seal+oil changed. This was done at the local mechanic as HASS wanted to change the entire PS unit. Apart from this, we have never had any component failure in the car. It's serviced regularly at HASS in Chandigarh. Engine oil, filters, gear oil etc has always been changed as per schedule. Problem:
At about the time the steering pump bearings were changed, mileage in the car reduced to 14/15 from earlier 18/19 Work Done So far:
After detecting the drop in mileage, at about 122k km's I got the following things done:
1. A major service. Engine oil, oil filter, air filter, fuel filter, gear oil, spark plugs, coolant, brake fluid etc were changed. Injectors and throttle body was cleaned. TB was opened and cleaned.
2. Since the car was on original clutch at 122k km, got the clutch changed. Again due to open roads of punjab, original clutch lasted this much.
3. Doing the above did not solve the problem, so went to HASS and got the engine scan done with OBD. This did not detect any problems whatsoever. All sensors are working fine and according to them, everything is okay
After all this the car is still on 14/15 mileage. Driving the car does not give any clue of any problem whatsoever. There is no loss of pick-up, no jerks, no missing, new clutch seems to be okay. Infact driving it gives the feeling that it's almost a new car with no problem at all. That's the reason we don't want to sell it but use for another couple of years. It's in perfect shape mechanically and otherwise. Also we have not done any mods to the car, it's on stock size tyres.
So we are not able to detect the reason for drop in FE. And it was a sudden drop not gradual which can be associated with the age of vehicle. We have another Santro in family which returns a mileage of 18/19 in similar conditions.
There are two wrong symptoms though which might help lead to the issue.
1. If the car is started on a clean floor, I can see soot coming from car's exhaust. It's not pure carbon, but black water. I checked it on hand, it's water, not petrol or engine oil. But then coolant level in car does not drop, neither does oil level. So where is this water coming from?
2. The engine oil of the car is turning black more quickly than it should in a petrol car. After oil change, within 2k km's it's brown and in 5k km's it black. It's not normal for a petrol car.
But I am not sure what these problems mean so need advice on what to check/ fix. I know this is a long shot but as a next step I intend to the following:
1. Do a compression test. This may not lead to anything as the pick-up seems okay.
2. Get head gasket checked. What are the exact symptoms that it might be bad?
3. Get Tappet adjustment checked. HASS folks at the time of engine scan said that this does not need to be checked as if bad, tappets will create sound. So they did not check on it. Can this be the issue for low FE?
Will the above help, other than this, I do not have any idea of what to do. Can there be a possible timing problem (like off by nano seconds)? My local very reliable mechanic tells me that changing PS bearings can not have this much drop in FE. Even if it's tight (let's say heavy to move) it will have very little impact on FE. Wheel alignmet, balancing etc is also done recently. Driving car does not tell that anything is wrong just that it's expensive to run (and more polluting as well).
Please let your suggestions come in on what could be the possible causes of this and what should I do?
Last edited by amit1234singla : 7th January 2011 at 15:39.
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