[amit_mechengg]

actually the MUL A.S.S people recommended me valve tappet setting as there was a slight noise from one of the tappets. they also said that at 50000 kms u need to do the tappet setting. so i thought that i should do it at 40k interval.

when i rev the engine there is no tappet noise at all now, but in the idling engine vibrates, in the sense the gear lever and the whole engine vibrates. its not that tappets bang or make noise.

and yes the RPM can be set with the idling screw on the throttle body. but i dint complain about low F.E, so they shouldnt fiddle with the idling setting.

[Vid6639]

Originally Posted by amit_mechengg

and yes the RPM can be set with the idling screw on the throttle body. but i dint complain about low F.E, so they shouldnt fiddle with the idling setting.

Well after setting the valve clearance they will tune the engine i.e. set the idling correctly. Probably they didn't use the tech2 to check the idle rpm .

[headers]

you could also check your engine mounts!

[Jaggu]

Originally Posted by SirAlec

Now! again its a simlar case of 'Don't fix that ain't broke'

Why do you have to go out and set the tappet in such a low mileage vehicle. That too in a car like Alto which is one of the least maintainance needing car in this Planet.

There is a chance that the Gap on valve and cam-lobe is not appropriate, that changed the timmings. Hook it up with a scanner at any MASS.

40k kms is a good time to do valve setting, i used to do it every 10k kms in my old esteem and zen results were a very good cylinder power balance, overall power and FE.

Originally Posted by amit_mechengg

actually the MUL A.S.S people recommended me valve tappet setting as there was a slight noise from one of the tappets. they also said that at 50000 kms u need to do the tappet setting. so i thought that i should do it at 40k interval.

when i rev the engine there is no tappet noise at all now, but in the idling engine vibrates, in the sense the gear lever and the whole engine vibrates. its not that tappets bang or make noise.

and yes the RPM can be set with the idling screw on the throttle body. but i dint complain about low F.E, so they shouldnt fiddle with the idling setting.

Its an idle issue, maybe compounded by a weak engine or gear box mount. If tappet setting is off, your power, mileage and engine refinement at higher rpm would suffer.

Just matter of going to a good A.S.S and set the idle RPM to normal limits, double check if the AC circuit RPM is also set to normal limits.

[SirAlec]

^^^
10k kms for tappet setting! Thats too early man.

It was in those days when engine came with push road. OHC/DOHC need very little maintainance.

[sushrutha]

I think the vibration is because of improper Valve settings.
The valve setting has to be done when the engine is cold.
Also check your timing of your car, that might also be a culprit here.

[amit_mechengg]

Originally Posted by sushrutha

I think the vibration is because of improper Valve settings.
The valve setting has to be done when the engine is cold.
Also check your timing of your car, that might also be a culprit here.

valve setting was done when the engine was cold. i had parked the car in the A.S.S the whole night and they did the setting in the morning without starting the car. they did the setting with the gauges provided by the company.

[amit_mechengg]

hooked a TECH2 to my machine and checked the rpm. it was 898-908 i.e within the limits.

what happens is when i am driving and when i pull the gear to neutral on the signals or for a stop the engine vibrates, i feel the RPM goes down and again springs back. at constant idling the engine vibrates a bit.

what is this indicating? the throttle body is also cleaned twice. is it related to TP sensor or any other problem?

i am clueless and so are the A.S.S people.

[vikram_d]

Did they check only idling RPM or other parameters also? They should have checked to see if there were any error codes showing up on the Tech2. Did they check the engine mounts?

[amit_mechengg]

Originally Posted by vikram_d

Did they check only idling RPM or other parameters also? They should have checked to see if there were any error codes showing up on the Tech2. Did they check the engine mounts?

yes we checked the DTC codes too. there were no error codes. other parameters also seemed to be okay. actually earlier there were no vibrations of any sort before i gave my car for valve tappet setting. this has all started after the valve setting.

is it anything related to sticking of valves or over tightening of one of the 12 valves?

[headers]

SIR, AFAIK, it is your engine mounts that need replacement. Basic mechanical diagnosis methods are not revealed as error codes in any machine!

[anupmathur]

Amit, a couple of questions:
1) What is the idling rpm with AC on, and with AC off? Is there vibration under both conditions?
2) At what rpm do the vibrations just about disappear?

[amit_mechengg]

Originally Posted by anupmathur

Amit, a couple of questions:
1) What is the idling rpm with AC on, and with AC off? Is there vibration under both conditions?
2) At what rpm do the vibrations just about disappear?

with AC on the vibrations disappear. the vibrations are only without the AC. the vibrations are present at 900 rpm which is the recommended idling RPM for an alto.

Originally Posted by headers

SIR, AFAIK, it is your engine mounts that need replacement. Basic mechanical diagnosis methods are not revealed as error codes in any machine!

what i wonder is why will engine mounts have problem after the valve setting. there were no vibrations at all before i left my car in the A.S.S for valve tappet setting. will check the engine mounts again.

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[anupmathur]

Originally Posted by amit_mechengg

with AC on the vibrations disappear. the vibrations are only without the AC. the vibrations are present at 900 rpm which is the recommended idling RPM for an alto.

Amit, you haven't answered all the queries.
At what rpm do the vibrations disappear? At 950? Then get the idling set to that. Maybe that is what idling was set at earlier.
I remember an M800 that a friend used to have had unacceptably high vibrations at recommended rpm. The service centre had set it just a wee bit higher to 'solve' the problem.

I do not think the engine mounts are the culprit here.

[amit_mechengg]

Originally Posted by anupmathur

Amit, you haven't answered all the queries.
At what rpm do the vibrations disappear? At 950? Then get the idling set to that. Maybe that is what idling was set at earlier.
I remember an M800 that a friend used to have had unacceptably high vibrations at recommended rpm. The service centre had set it just a wee bit higher to 'solve' the problem.

I do not think the engine mounts are the culprit here.

if that is the case i wonder that after the valve setting the rpm might have reduced a bit as the valve clearance might have reduced. and after the valve setting the A.S.S people might not have done any engine tuning or idling setting. and yes if i pull the accelerator cable on the throttle body i.e increase the rpm then the vibrations go.

** One more thing which i doubt is the exhaust cleaning which has been done on my car. they have removed the CATCON. may be due to this the backpressure has reduced. Can it be that reduced backpressure causes engine vibrations?