[arun_josie]

Originally Posted by bluevolt

Here are the pics of my WagonR's all four tyres. Please have a look and tell for how long I can use these tyres? Current Odo reading is 42700KMs.

Considering that the tyres are already 6 years old, 42K Kms done and small cracks already seen, I would change the tyres immediately. It might work for city drives for few more KMs but it doesn't make a difference unless you have decided to use it for another 10-15K KMs.

[Floating Axle]

Originally Posted by bluevolt

Here are the pics of my WagonR's all four tyres. Please have a look and tell for how long I can use these tyres? Current Odo reading is .

Treads on your tyres appears enough for their further use. Side cracks may be because of keeping tyre standstill with low air pressure.

[bluevolt]

I recently got my WagonR's wheel alignment done and here is the report. Please tell if everything is fine as I don't know what these values actually means? The guy who did the job told that all is well. He also said that tyres are ok for some more time.

[Sherlocked]

Hi bluevolt, I too own a WagonR but mine is the rare Lx model and we are completely satisfied with the car although it lacks power steering and its a pain maneuvering the car in tight spots but at least I don't get the 'dead steering' feeling which many have reported due to the EPS.

I read in one of your earlier post that you got 4 wheel caps costing 500 bucks, I too intend to put those on my car.
Are those wheel caps you installed are bolt onto the wheel type or are simply the ones which clicks onto the wheels and also are they durable ?

Another query is that my WagonR gives me very bad fuel efficiency of around 10-11 kmpl with AC on 60% of the time with in city limits and sometimes while waiting at a traffic signal, the idle rpm rises automatically and then becomes normal after around 10-15 seconds. What could be the reason ? Mine is a Dec 2004 model and has completed just 40k kms.

[saket77]

Originally Posted by Sherlocked

Another query is that my WagonR gives me very bad fuel efficiency of around 10-11 kmpl with AC on 60% of the time with in city limits and sometimes while waiting at a traffic signal, the idle rpm rises automatically and then becomes normal after around 10-15 seconds. What could be the reason ? Mine is a Dec 2004 model and has completed just 40k kms.

Sorry to bump up the question meant for bluevolt but my 2 cents on the issue:

The fluctuating RPM is normal. Though, If you have not changed the air filter in the last 7-8K, I would suggest you change it. This should bring along some FE and a stable RPM. Also check your tyre air pressure and you may put about 2psi extra for better FE.

Regards,
Saket

[paragsachania]

Originally Posted by saket77

Sorry to bump up the question meant for bluevolt but my 2 cents on the issue:

The fluctuating RPM is normal. Though, If you have not changed the air filter in the last 7-8K, I would suggest you change it. This should bring along some FE and a stable RPM. Also check your tyre air pressure and you may put about 2psi extra for better FE.

Regards,
Saket

The fluctuating RPM is basically the way the ECM adjusts the car's Idle to the desired Idling speed.

This is dependent on various factors like Engine Temperature, Electrical load, AC Compressor Relay ON/OFF.

For instance, the ECM has a fixed value for "Desired RPM". Lets say that you Turn the headlights on and other electrical components like Hazards, Radio and etc, the Alternator gets loaded at this instance and in turn puts the load on the Engine. Since the engine is driving the alternator, it experiences this load and hence starts to spin slower.

The ECM detects this drop in the RPM and hence signals the IAC (Idle Air Control) Valve on the throttle body to spin faster and suck more air to compensate for this drop in the RPM and bring it up to the desired RPM.

The IAC on the throttle body is electrically connected that has a Solenoid that helps the valve spin accordingly by supplying adequate voltage (till 5 volts).

Another instance with the AC :

Lets say you turn your AC on. This will also put additional load on the Engine as it has to drive the compressor. Hence the RPM drops. To compensate this, the IAC is again signalled to suck more air and bring the RPM to the Desired RPM. The Desired RPM under Electrical load or AC load is usually different. Hence you will notice that whenever you turn the AC ON (Compressor Relay ON), the RPM Increases and whenever the compressor relay cuts off (No load, with just Fan spinning), the RPM Drops back to normal. Again when the Relay turns ON, the RPM Increases again.

It is because of the IAC (and the ECM) that whenever you turn your car on during cold conditions, the RPM is usually at a very higher side (1500-2000) for a few minutes so that this can help your engine oil "Wake up". Once the temperature warms up, ECU reads this signal from the Engine Temperature sensor, it will signal the IAC accordingly to bring the RPM Down to normal (900/950).

Under normal circumstances the desired RPM with No load is 900 +/- 50 RPM for the F10D Engines.

To best way to judge if the car has fluctuating RPMs is by parking in Neutral with no electrical load (AC Off), Blower Speed not more than 1 (WagonR's ECM considers blower speed of 1 as Zero load), No Torque on Power Steering and when the engine has warmed up, notice of the Idle stays at a constant level. If yes, there is no need to bother about it.

Of course, as soon as the Cooling Fan Turns on, you will suddenly notice the RPM move down and immediately up again.

[saket77]

Originally Posted by paragsachania

The fluctuating RPM is basically the way the ECM adjusts the car's Idle to the desired Idling speed.

And now the Wagon-R master has spoken! +1 to Parag's post. This is why one could hear the engine adjusting to the idle rpm after coming from a drive, after turning off all the electricals, etc.
Its a problem only when the car does not idles smoothly, keeps fluctuating the RPM or even worse, does not idles at all, running well over 1100-1200 RPM. That is where one should think of abnormality.

Regards,
Saket

[paragsachania]

Originally Posted by saket77

And now the Wagon-R master has spoken! +1 to Parag's post. This is why one could hear the engine adjusting to the idle rpm after coming from a drive, after turning off all the electricals, etc.
Its a problem only when the car does not idles smoothly, keeps fluctuating the RPM or even worse, does not idles at all, running well over 1100-1200 RPM. That is where one should think of abnormality.

Regards,
Saket

Another reason for fluctuating RPM could be a stuck IAC valve. Sometimes, due to dirt the valve is unable to spin freely and gets stuck at a position. This is the reason why I mostly DIY Throttle body cleaning on a regular basis.

Secondly, if the IAC Solenoid is not getting adequate voltage (till 5 Volts), it causes the IAC to perform abnormally.

The best way to identify this is by the following method:
Warning: Unless you are thorough about the components of the Throttle body, it is better not to fiddle with these things on your car.

When the car has warmed up, with no Electrical and AC load, notice the RPM. Open the bonnet and while the engine still running, disconnect the IAC Valve connector on the throttle body. As soon as you do this, the engine will cry for breath and will almost stall down as the RPM is as low as 550-600.

The moment you connect the IAC connector, the RPM shoots up again. This is an indication that the IAC is doing its job correctly.

However, like you mentioned above, before going to this level of troubleshooting, it is better to check the following basics:

• Spark Plug Gap
• Clean the Spark plugs
• Clean the Air Filter
• Ignition coil pairs supplying current to the Spark plugs
• Dirt in Injectors due to bad quality fuel

[bluevolt]

Originally Posted by Sherlocked

.

I read in one of your earlier post that you got 4 wheel caps costing 500 bucks, I too intend to put those on my car.
Are those wheel caps you installed are bolt onto the wheel type or are simply the ones which clicks onto the wheels and also are they durable ?
.

The wheel caps are the click onto the wheels types and are durable as they are just holding fine for almost a year now in my case.

The other query has been nicely answered by saket & parag.

[Sherlocked]

Originally Posted by saket77

The fluctuating RPM is normal. Though, If you have not changed the air filter in the last 7-8K, I would suggest you change it. This should bring along some FE and a stable RPM. Also check your tyre air pressure and you may put about 2psi extra for better FE.

Thanks for your reply Saket. I will get it checked.

Originally Posted by paragsachania

Under normal circumstances the desired RPM with No load is 900 +/- 50 RPM for the F10D Engines.

Thanks a lot Parag. That was a detailed description but one question, how do I know that my idle RPM is normal since mine doesn't have a tachometer. Also in the mornings when I start the engine I find the idle RPM to be on a higher side. Is it normal ?

Originally Posted by paragsachania

Another reason for fluctuating RPM could be a stuck IAC valve. Sometimes, due to dirt the valve is unable to spin freely and gets stuck at a position. This is the reason why I mostly DIY Throttle body cleaning on a regular basis.

The best way to identify this is by the following method:
Warning: Unless you are thorough about the components of the Throttle body, it is better not to fiddle with these things on your car.


However, like you mentioned above, before going to this level of troubleshooting, it is better to check the following basics:

• Spark Plug Gap
• Clean the Spark plugs
• Clean the Air Filter
• Ignition coil pairs supplying current to the Spark plugs
• Dirt in Injectors due to bad quality fuel

I will probably get these things checked at the MASS where I always service my car and probably opt for a throttle body cleaning just to be on the safer side. One question, how do I check that they have actually cleaned the throttle body since they don't allow the owners to roam around their cars while it is getting serviced.

Originally Posted by bluevolt

The wheel caps are the click onto the wheels types and are durable as they are just holding fine for almost a year now in my case.

Thanks. I will probably get them installed tomorrow and sorry for hijacking your thread.

[saket77]

Originally Posted by Sherlocked

how do I know that my idle RPM is normal since mine doesn't have a tachometer.

The ASCs have handheld tachometers which they just hook up to a few points and get the reading on it.

Originally Posted by Sherlocked

Also in the mornings when I start the engine I find the idle RPM to be on a higher side. Is it normal ?

Pretty normal with an MPFI engine. They are programmed to keep the rpm on the higher side with a cold engine so as they reach their optimal working temperature as soon as possible. Once the engine warms up a little, it will come down to the specified RPM level.

Regards,
Saket

[paragsachania]

Originally Posted by Sherlocked

Thanks for your reply Saket. I will get it checked.

Thanks a lot Parag. That was a detailed description but one question, how do I know that my idle RPM is normal since mine doesn't have a tachometer. Also in the mornings when I start the engine I find the idle RPM to be on a higher side. Is it normal ?

The ASC can connect the Scan Tool to the OBD Port on your car and get all the details including the RPM Reading. It is a simple task that will take less than 5 minutes.

Regarding your second question on higher RPMs in mornings, I guess I have answered that as well that due to colder engine temperature, the ECM sets the target RPM a bit higher than normal till the warm-up temperature is achieved. This High RPM for those initial 2-3 minutes is to ensure Engine oil starts circulating internally in all sections of your Engine and preserve engine life.

Here's a sample of the readings from my car:


This was when the Engine was warmed up and with no Electrical load. Hence you see that the desired Idle speed is 800 RPM and the actual idle is 804.

[saket77]

^ That is one more device for the job, though there are standalone analogue tachos too, which look like old analog multi tester meters (electronics).

[paragsachania]

Originally Posted by saket77

^ That is one more device for the job, though there are standalone analogue tachos too, which look like old analog multi tester meters (electronics).

Yes but the reason I asked to use the OBD Scanner is to check the parameters like the desired idle and then check the actual Idle and other parameters like Throttle valve opening, Engine Load, AC, Electrical and how the RPM will behave.

Of course, the best is to install a DIY Ritz Tacho that I have done in my Waggy and keep drooling at it whenever you want to check RPMs at various stages

[saket77]

Originally Posted by paragsachania

Of course, the best is to install a DIY Ritz Tacho that I have done in my Waggy and keep drooling at it whenever you want to check RPMs at various stages

Yes, probably its the best tacho which can be fitted on some other cars, as it looks a DIY even in the RITZ! Actually, when the first time I saw that in a Ritz, I thought that its an aftermarket fitment.