[fighterace]

Two days back i revved my Zen a little too hard. The engine started to make a clattering noise which disappeared once I eased on the accelerator. Bit it appeared again next morning on starting after I pressed the accelerator, but disappeared once the engine warmed up a bit. Today morning it wasn't there. My mechanic couldn't detect anything in a warm engine, but says a bearing may have spun, and he'll see in the next service. The car is an MPFI. Please help me decide what to do.

[Jaggu]

When you say clatter, what exactly is the sound like? Is it a mechanical squeak or is it something like clanking? Can you describe in little more detail or get a video and post up (when this happens). And is it only during cold start ups?

[paragsachania]

As a first step, please check the Engine oil levels first using the Dip stick.

Secondly, the noise may never be from the engine and could be one of those belts too that may have aged.


A hard belt can make clattering noise (and not just the typical squeaking noise) too.

You can start your car, open the bonnet and try pouring some water on the spinning belt(s) and listen to the noise change (In case if it's the belt causing the noise).

What bearing is your mechanic referring to? If its the alternator bearing, you can start the car and turn on all the electricals and listen to the noise change upon full electrical load.

[jeeva]

Its always a better idea to idle the engine nice and slow for a minute or two every morning, when you start, so that the oil reaches the head and other nooks and crannies. Be it a petrol, diesel, turbocharged or otherwise, instant revving @ morning starts can kill the engine in no time.
Your's being an MPFI, you need not provide any throttle input during start whatsoever.

[Trust_In_Thrust]

I think it is idler bearing . This noise will typically come on till engine is cold .If you drive through water , after car wash this noise will not be there .You can either change the idle bearing alone or along with pulley or along with mounting too .
MASS has three types based on what company AC you Zen has Delphi , Subros, Sanden.MASS will not change just the bearing , they will want you to change as a set with pulley or with mounting depending on make of AC . I recall parts cost of just bearing with replacement from your local garage is under 300Inr , from MASS bearing plus pulley for Delphi is 450Inr (part alone) , Sanden is 850Inr , Subros is 4500INR (comes with mounting too). Labour at MASS will be 650Inr minimum.

[vasanthn21]

I had a similar issue with my mpfi Zen.

But, this was not during cold starts, I typically noticed this when AC was in use while driving in 2nd gear on an uphill, and probably the rpm was not high enough (no tacho).

I did not mention this when I gave the vehicle for serivce at MASS, but the issue never recurred after the service. Just drop-in at MASS, and they should be able to sort it out.

[fighterace]

Originally Posted by Jaggu

When you say clatter, what exactly is the sound like? Is it a mechanical squeak or is it something like clanking? Can you describe in little more detail or get a video and post up (when this happens). And is it only during cold start ups?

It is a metallic clatter. It appeared for the first time when I revved too hard in 2nd gear. It disappeared as soon as I decreased the rpm. The car performed well for about 8 km after that. The next start was 6 hours after that. I heard the clatter again on even slight acceleration, but again it disappeared once the engine warmed up. Next morning I heard it when I applied a little throttle to move over a hump at the parking space. I had idled for 30 seconds and the engine had moved to the fast idle warm up mode, but any revs over and above that caused clattering. Again it disappeared on warm up. The mechanic couldn't find anything wrong with the warmed up engine.

Today when i started the engine at 11:30 a.m., the noise was not there.

Originally Posted by paragsachania

As a first step, please check the Engine oil levels first using the Dip stick.

Secondly, the noise may never be from the engine and could be one of those belts too that may have aged.


A hard belt can make clattering noise (and not just the typical squeaking noise) too.

You can start your car, open the bonnet and try pouring some water on the spinning belt(s) and listen to the noise change (In case if it's the belt causing the noise).

What bearing is your mechanic referring to? If its the alternator bearing, you can start the car and turn on all the electricals and listen to the noise change upon full electrical load.

Engine oil is between the full and empty mark, but a week before it was full. Oil was changed in December. I'll check again after I give it 24 hours rest.

It is not a belt noise as both belts are new.

The mechanic is referring to either the crank or the main bearings. He says he'll open the sump at the next oil change and check and replace if necessary through the sump only. In the meanwhile he has asked me to be as gentle to the engine as possible.

Another mechanic says he'll have to take down the engine if repairs are needed and do a full overhaul, which'll be known only when he checks the engine himself.

Originally Posted by jeeva

Its always a better idea to idle the engine nice and slow for a minute or two every morning, when you start, so that the oil reaches the head and other nooks and crannies. Be it a petrol, diesel, turbocharged or otherwise, instant revving @ morning starts can kill the engine in no time.
Your's being an MPFI, you need not provide any throttle input during start whatsoever.

I always do that- idle for 30 seconds after start, and minimal throttle till the temp gauge is at the normal operating position. And no touching the accelerator before the 30 seconds.

Originally Posted by Trust_In_Thrust

I think it is idler bearing . This noise will typically come on till engine is cold .If you drive through water , after car wash this noise will not be there .You can either change the idle bearing alone or along with pulley or along with mounting too .
MASS has three types based on what company AC you Zen has Delphi , Subros, Sanden.MASS will not change just the bearing , they will want you to change as a set with pulley or with mounting depending on make of AC . I recall parts cost of just bearing with replacement from your local garage is under 300Inr , from MASS bearing plus pulley for Delphi is 450Inr (part alone) , Sanden is 850Inr , Subros is 4500INR (comes with mounting too). Labour at MASS will be 650Inr minimum.

Are you referring to the engine bearing at the pulley end? If damaged, will there be an oil leakage?

Originally Posted by vasanthn21

I had a similar issue with my mpfi Zen.

But, this was not during cold starts, I typically noticed this when AC was in use while driving in 2nd gear on an uphill, and probably the rpm was not high enough (no tacho).

I did not mention this when I gave the vehicle for serivce at MASS, but the issue never recurred after the service. Just drop-in at MASS, and they should be able to sort it out.

No, this is not a lugging issue, its happening at high RPMs.

[Trust_In_Thrust]

I am referring to the pulley which is exposed towards the ac compressor side (usually protrudes and can be seen clearly when car is on lift). No oil will not leak from this bearing.

[Jaggu]

If its clatter, check for any loose bits around the engine bay. Sometimes a single bolt can cause lot of worries.

From engine, things that can cause issue are, tappets or tappet spring (mech can check these by opening the valve cover), Valves (again a good mechanic can figure that out through valve cover), engine or bearings in alternator and ac. Also next time check if the sound disappears when the clutch pedal is depressed, if so it can be failing clutch release bearing.

How much has the engine done? and has the timing belt attended to in the recent past?

Originally Posted by fighterace

It is a metallic clatter. It appeared for the first time when I revved too hard in 2nd gear.
===========
No, this is not a lugging issue, its happening at high RPMs.

[fighterace]

Originally Posted by Jaggu

If its clatter, check for any loose bits around the engine bay. Sometimes a single bolt can cause lot of worries.

From engine, things that can cause issue are, tappets or tappet spring (mech can check these by opening the valve cover), Valves (again a good mechanic can figure that out through valve cover), engine or bearings in alternator and ac. Also next time check if the sound disappears when the clutch pedal is depressed, if so it can be failing clutch release bearing.

How much has the engine done? and has the timing belt attended to in the recent past?

Thanks, I'll follow up the leads.

The engine is 11yrs/68000 kms old and well cared for. To the best of my knowledge its running the original timing belt.

[Jaggu]

Originally Posted by fighterace

Thanks, I'll follow up the leads.

The engine is 11yrs/68000 kms old and well cared for. To the best of my knowledge its running the original timing belt.

High time you changed the timing belt, tensioner etc. These are rubber parts and can wear, not very expensive job as a preventive maintenance, but if it fails its going to be very expensive. IIRC 75k kms is the life, but 11 years is too long.

[jeeva]

Well, metallic clatter at high rpm often has something to do with the connecting rod play and crankshaft journals. Pray, its got nothing to do with them.

[fighterace]

Originally Posted by Jaggu

High time you changed the timing belt, tensioner etc. These are rubber parts and can wear, not very expensive job as a preventive maintenance, but if it fails its going to be very expensive. IIRC 75k kms is the life, but 11 years is too long.

Originally Posted by jeeva

Well, metallic clatter at high rpm often has something to do with the connecting rod play and crankshaft journals. Pray, its got nothing to do with them.

Apart from the timing belt and tensioners, what else should I get checked? Removing the valve cover will ensure examination of the valves, removing the pan will tell about the main bearings and con rods. If bad main/conrod bearings are detected, will it be possible and advisable to replace them without removing the engine?

[humyum]

I know what you are talking about. Its your engine oil 99.99% get it changed. I think it has lost some of its properties and hence at high rpm this clatter. Happens in my Swift D too when the oil is around 6 to 7 thousand km or some months old.

[Jaggu]

Originally Posted by humyum

I know what you are talking about. Its your engine oil 99.99% get it changed. I think it has lost some of its properties and hence at high rpm this clatter. Happens in my Swift D too when the oil is around 6 to 7 thousand km or some months old.

Definitely NOT! what oil are you using? that loses property in 6-7k kms? The clatter in DDiS is injectors/pump, no relation to oil.