music box

Wednesday, December 24, 2008

What a Waste

My Suzuki ERV 1.3 litre (2002) has clocked 83,000km, which mean it's time to have the timing belt changed. I was informed by Suzuki that when I change the timing belt, I should also change the water pump as well because if the water pump need to be replaced (after I changed the timing belt), I will have to replace the timing belt again. But, replacing the water pump, which is still in good working condition, sounds wasteful. Also, is it true that cars which use timing chains instead of timing belt, do not need to have their timing chain replaced.

The mechanic may be correct in a way he may have found out in the practice that the water pump usually fails not long after the timing belt is replaced and therefore suggests you replace it at the same time. However, you do not have to replace it as the labour to replace the pump at a later date is not that high and if it is not making any noise and operating perfectly well, I see no reason why you should throw away something that is still good.

Timing chain, being made of steel, tend to last for a very long time and are seldom replaced, at least during the car is with the first owner.

Light Just Doesn't Go Off

My Kancil's door ajar light (the indicator on the dashboard) is on all the time. It happened after I washed the car. Does anybody know where the fuse for that light is? It's quite dim but when I open the door, it brightens up. When I close the door, it is dim again but it won't go off.

The door ajar light is wired to the door switches and works by earthing the bulb to the body when the door is opened. What probably happened is the water goes into the contact of the switch of the switch, allowing the indicator bulb to earth to he body and so causing the bulb to glow. You can try spraying WD40 into each of the door switches to displace any water. The reason why the interior light is not coming on is that light requires a higher current through the same switch but probably due to the poor contact, is not sufficiebt to light it. That may be the explanation but the problem is still the water ingress into the contact.

Friday, December 19, 2008

Changing Rear Axle

I drive Mercedes 190E 2L 1991.
1. I have changed the rear axle assmbly (wih a used unit) from the original ratio of 3.23 to 3.27. Is performance affected? Does this affect the car when going uphill? What about fuel consumption?

2. The motor box does not illuminate brightly after I changed to new bulbs and maximised the dinner control knob. Any other way to brigthen it?

3. If I changed from 2.0L to 2.6L, does it really save petrol?

1. Theoritically, your hill climbing wil improve with a slightly loss of top end speed. You may find a slight increase in fuel consumption but that would depend a lot on how you drive. As difference in the ratios is not much, you may not even notice any improvement or loss in performance.

2. If by motor box, you mean instrument cluster, you may want to check the earthing of the instrument panel. Sometimes when there is insuffucient earthing, the lights will be dim.

3. Normally a larger capacity engine will give you better consumption if the gear ratio match the engine. In your case I think that if driven correctly and not revving the engine excessively, you should have better consumption. This is only guess and you will need to find out in actual case.

Wednesday, December 17, 2008

Accelerating Noise

I drive a nine-month 0ld Myvi Automatic. Recently an intermittent noise has developed, and this sound only occurs when I accelerate. It sounds like a fainy metallic whirring noise. I am unable to diagnose the problem, as it does not occur frequently or long enough for the mechanic to listen to it. Otherwise, the car perform normally. Have you ever come across this problem or noise?

Based on you information, it is difficult to give you any pointers because it is not clear when this noise occurs and under what circumstances. For example, does the noise occur when you are at low speeds and in top gear or in low gear at high speeds? My feeling is that the problem is in the engine compartment and frankly even technician at the service centre may not be able to pin it down unless he can drive the car under the same conditions to replicate the sound.

Fuel Pump Changed

I changed the fuel pump of my Honda Civic 1.6 (1993) model recently. After changing the fuse, spark plug, and checking the wiring, I still cannot start my car engine.

1. Your fuel pump is mechanically operated, if I am not mistaken. And if you could remove the hose connecting it to the carburettor and crank the engine, fuel should flow out. If no fuel flow out, then check the pump or replace it with one that you are sure is working. Also, have you connected back the hoses correctly and not reversed the connections?

2. If there is fuel coming to the carburettor and the engine is cranking but not firing. Check if you have any spark to the spark plugs. An easy way is to pull off one of the spark plug leads and connect it to a spark plug and lay it anywhere on the engine for an earth connection. Crank the engine and see if there is any spark at the plug. If there is not , then you need to check the ignition system, from the ignition switch to the coil and the distributor.

When an engine does not start, you have to sort it out by a process of elimination and do not assume anything. Often when one does some work, one may accidentally disconnect some wire or forget to fit one back and so a systamatic check is necessary to get it started again.

Friday, December 12, 2008

Changing Battery With Engine Running

1. I own a Toyota Vios 1.5E auto (2004 model). I have just replaced the wet battery with a dry battery. But I saw the mechanic change the battery with the engine running at a idle speed. He said if he changed the battery after the engine is switched off, the car would have engine tuning problem and other minor side effects. He added that even on changing a wet battery, he would also have the engine running at idling speed. It seems the latest cars, which have many of their system running on computer circuits and electronic sensors, must be treated this way.

2. I used to disconnect one of the battery car terminals (wet battery) when I did not use it for more than two days (to avoid depolarisation and damage to the battery). Which terminal should be disconnected in term of safety? I always disconnect the (-ve) side.

3. Now that I am using a dry cell battery, and will not be using my car for 10 days next month. Do I need disconnect one of the battery terminals? If i do it, will the problem as in question no.1, surface again after I reconnect the battery?

4. What type of battery (in term of quality and maintenance) is more suitable for cars - wet or dry?

1. The standard rule is to turn off the engine and switch off all accessories whenever removing or replacing batteries. One should not have the engine running because if the positive terminal is to touch any part of the battery being replaced, it would short out the alternator and cause severe damage to the coils and diodes, let alone the possibilty of fire.

2. Two days are a short period to disconnect the battery. While I do not disagree with the practice, it is mainly to prevent discharge through the clock and some equipment that may have small current draw and if if left uncharged, the battery could become sulphated. By the way, it makes no difference whether it is a 'wet' or 'dry' battery because there is still sulphuric acid in the battery that would cause sulphation. I think by 'dry' battery, you mean a 'no maintenance' battery. Generally 'no maintenance' battery are sealed so that you do not need to top up with distilled water but if you notice that the electrolyte level is very low, the cells can be opened and topped up.

3. You can remove the battery connection while you are away or even leave it connected because I do not think it would be so weak when you get back as to be unable to start the engine. What is important when you get back is to run the vehicle for some time to charge back the battery.

Stiff Suspension

I own a 1987 Mercedes 190E. A month ago, I changed all the bushes plus the four shock absorbers and its mountings which cost me a little more than RM4,000. The shock absorbers a bBilstein 36 1389. I am unhappy as the ride is bumpy and get a thud noise when going over depressions or potholes. My feeling is that the shock absorbers may be of the hard type or the coil spring are "dead". The mechanic said that he has used the standard shock absorber for the car and it might be that the coils also need changing. What is your opinion?

You did not mention what shock absorbers were fitted to the front but I will assume that they are also Bilstein. The number that you have given, 36-1389 is for the rear shock absorbers and is actually a heavy duty unit and that maybe the reason why you feel that the ride is bumpy. I think you should be using the "comfort" specification which is:
Front: F4-V36-0199-HO
Back: F4-b36-1405-HO

I do not think the standard shock are heavy duty units and there is no need to replace the springs. I think the real problem is that the shock are too hard.

Right Tyre Formula

Appreciate if you could provide the formula for the 3% rule on changing tyre size. I remembered that you had published this formula sometime back but unortunately I did noyt keep it.

I wanted to change my tyre from 175/65 R14 to 185/60 R14 or 195/60 R14 but i can't remember the formula to check whether this is within the 3% rule.

To calculate the overall diameter of the tyre:
The formula is: (D x 25.4) + 2(S x A)
D= Rim diameter in inches
S= Tyre width in mm
A= Aspect ratio in decimals

If the tyre is 165/65 R14:
The overall diameter would be (14 x 25.4) + 2(165 x 0.65) = 570mm

For the 195/60 R14
The overall diameter would then be (14 x 25.4) + 2(195 x 0.60) = 589mm

The difference is 19mm which is 3.33%, a bit over the recommended 3%.

Mystery Jerk

My Sunny 5-speed manual jerks a lot. Here's a history of the repair and modification done.

1. Originl E13 engine upgraded to E15 complete with gearbox in 1999.
2. Changed to a new clutch kit including clutch bearing, clutch plate and cover in 2002.
3. Changed to electronic ignition system including ignition coil.
4. Changed to a new carburettor with auto choke in 2005.
5. Did a top overhaul in 2006 (due to blown head gasket and water sipping into the engine). Did a pressure test too.
6. Changed all four shock absorbers and springs, and front right and rear right lower arm bushes.
7. Changed three of five engine mountings (right gearbox and firewall mountings).
8. Changed to new spark plug cables (five cables)
9. Changed to a new fuel filter.
10. Tried Bosch and NGK spark plugs. Now using Bosch.

When I let off the accelerator during slow driver (especially in 1st or 2nd gear) the car jerks two to three times. The problem occurs even when in 3rd, 4th or 5th gears, but the jerks isn't as bad. I tested my friend's Sunny (1.3) and to my surprise there was no jerk at all. The mechanics have no idea what is causing it.

There is another problem. Sometimes when I open the air-filter pod cover, there will be some engine oil inside the pod. I presume this is deposited from the hose connecting the air-filter pod to the engine valce cover. Why does this happen?

If I read you right, the jerking is not caused by carburetion but rather there is a 'clunk' or juddering whenever you depress the accelerator. If that is so, I would look at all engine mountings again and the front and rear 'buffers' or stabilisers for the engine/transmission assembly. There should not be any noticeable movement of the engine/transmissiona ssembly if one rocks the engine back and forth and left and right. If there is movement , tha could be reason for your 'clunking' and you need to check all the mountings especially the ones that were replaced. The reason is that these mountings are supposed to be fitted in a certain position to take the weight of the engine and torsional movement of the engine on acceleration and deceleration. If not fitted correctly, it can collapse, resulting in plenty of engine movement. Check the front and rear buffers for any cracks or signs of collapsing. You may have to replace the mountings if they show signs of wear or collapse. You should use original parts and not replacement units as some of the replacement parts do not use the correct rubber and are too soft and collapse after some time or are affected by oil, etc.

2. The hose connected to the valve cover is to recirculate the oil fumes from the engine so that they get burnt up in the combustion process. If there is a lot of oil in the air cleaner housing, it could mean that the pistons and rings are worn, and combustion pressure is blowing past the pistons and coming through from the crankcase.

Sunday, December 7, 2008

High Coolant Usage

Some problem is causing me to replenish the coolant of my Naza Ria every fortnight, which I find is very irregular. The authorised service centre did not give me any satisfactory answer.. irregular diagnosistic, faulty gasket, and so on. After I lodged a report, the engine is now due for a complete check-up, pending confirmation from Naza.

Secondly, I can hear some noise occasionally fom the engine while driving. My wife is driving the car to Malacca for outstation work. I will send the car for a complete engine check-up whether or not I get an approval from Naza.

High coolant consumption does not necessarily mean there is an engine problem but it needs to be investigated. If the basic checks like leaks and radiator cap replacement do not solve the problem, then a proper diagnostic check is needed to determine if there is cylinder head leakage, i.e coolant leaking into the combustion chambers. You can also check with a dipstick to see if there is any indiaction of water droplets on the stick or the oil becoming milky.

Regarding the engine noise, it is difficult to give you an idea, as you need to actually drive the vehicle. Your suggestion to get the engine checked is correct, but make sure it is done by someone who knows what he is doing, preferably the franchise holders themselves.

Friday, December 5, 2008

How To Calculate?

I have Satria Neo 1.6 and Myvi 1.3. The tyre and wheel/rim sizes for both cars are standard 195/50R/16 and 175/65R/14 respectively. I like to change to wider and bigger rims (to improve stability and aestheticism) for both cars, and I have read about the 3% rule. How can I calculate myself in order not to exceed the 3% rule? Is there any reputable website that offers such calculation? What are the tyre and rim choices for my cars if I want to change to wider and bigger rims?

You will see among this week's replies the formula calculating the overall diameter of a wheel assembly and from there, you should be able to work out the best combination for your vehicles.
Please remember that the 3% rule is only as far as overall diameter, and you must consider you have sufficient space under the wheel arches, and the wheel offsets will remain the same because once the wheel offsets change, your handling will also change. Lastly, bigger wheel means more unsprung weight, which may affect your suspension set-up. Also, big fat tyres may give you very good grip in dry weather but could be difficult to drive in the wet, as they would hydroplane much easier.

'On-Wheel' Tyre Balancing

Some tyre shops offer "on-wheel" tyre balancing services in addition to the usual wheel balancing. They do this on the wheel (while it is still attached to the car) by jacking up one side of the car, resulting in only one wheel spinning while the other is stationary. Would this cause any damage to the drive shaft, and other parts?

Your fear are rightly founded. On car-balancing is normally done only on non-driven wheels, and should not be done on the drive wheels of a front-drive car. The reason is that when you spin only one wheel with the other still on the ground, the differential side gears are spinning at speeds they are never intended to under normal circumstances. This results in severe wearing of the side bearings.

In some cases, where it was really necessary, we lifted both wheels off the ground and spun them using engine power. But this is a procedure that can be quite dangerous because if the rear wheels are not chocked properly, the handbrake fails or the car fails off the stands, it can lunge forward and cause a lot of damage.

I would never recommend this procedure, because if the wheel balance cannot soed out with all the sophisticated electronic balancing equipment available today, there is really something wrong either with the wheel, tyre or even the hub assembly.

Noisy Engine From E240

I bought E240 Mercedes (year 2000) when new. It's mileage now is 55,000km. It is always serviced and the engine oil used is fully synthetic 5W-40. After four years, the engine became noisy (similar to noisy teppettes). The problem started after an engine oil change at workshop (fully sythetic oil 5W-40 was used).

I was later advised to drain the engine oil after only 1000km, and this time I used Revenol 5W-40 as replacement. But the noisy engine still persists. The mechanic used an approved additive to lubricate the teppettes, but it did not help. After just 3000km using the changed oil, I was reminded to check the oil levels. I had to add two litres of Revenol 5W-40 to bring the oil level to normal.

Now, my mechanic want to open the engine to check the problem. I am skeptical, as the car has only done 50,000km. I am also worried about the sudden increase in engine oil consumption after just 3,000km.

I hate to say this. As you did not mention the brand of synthetic oil used, can I assumed it is something that the workshop recommended and is not one of the major brands? If that the case, one really does not know the quality of the oil, even if it was suitable for your car. There is this allusion that synthetic oils must be used for modern engines, and asa result there are all kinds of oils being sold that claim to be synthetic or semi synthetic.

I fear there is damage to your valve train and even the pistons and rings because at 55k, your car should not be consuming oil. You mentioned using Revenol 5W-40, but I couldn't find such a brand anywhere. You may need to open the engine as it appears that the oils you have been using have caused quite a lot of wear.

In future you should use well-known brand. Petronas, for instance, has a comprehensive range of synthetic lubricants under the Synthium brand.