[kikuma25]

My two year old (20,000K) Hyndai Tucson developed distinct diesel clatter in Feb. I have been since then to figure out the cause.

Yesterday I discovered that there is a Hyundai Technical Service Bulletin (#05-20-002 JUL 05) which says:

"Some vehicles may experience an engine knock noise with the use of an aftermarket oil filter. Aftermarket oil filters may use different materials, construction and specifications than genuine Hyundai oil filters, which may lead to pressure variations within the engine, thus contributing to an engine knocking noise."

Does this make any sense?

I did an oil filter change in Jan. Hence, if this TSB is correct, my diesel clatter could be due to the new oil filter.

I was suspecting Shell Premium fuel (which I used in Jan - Mar) all along.

[krisna]

Yes. Even my car started giving the knocking noise with Shell petrol.

[Atlblkz06]

First off - is your car a diesel? You can get that damned diesel clatter noise out of a gas engine from the valve train as well.

The oil pump is a positive displacement pump, so I think this is BS.

[SS-Traveller]

Originally Posted by kikuma25

"Some vehicles may experience an engine knock noise with the use of an aftermarket oil filter. Aftermarket oil filters may use different materials, construction and specifications than genuine Hyundai oil filters, which may lead to pressure variations within the engine, thus contributing to an engine knocking noise."

Does this make any sense?

Yes it makes sense. The valve train in these engines (esp. the rockers actuating the valves) are hydraulically damped using a high-pressure stream of engine oil to reduce/eliminate the clattering noise of their repeated contact with the camshaft and valve stem.

If an aftermarket oil filter is used, it may have a thicker element, which can cause pressure loss and reduce some of the oil flow to the head; as a result, the rockers can make a clattering noise not present earlier.

On the other hand, Shell Premium diesel may cause a clatter by removal of some of the carbon deposits in the valve seat/cylinder head/piston crown - I am not sure if Shell fuels have cleaning agents added in to have such an effect. Perhaps Dr. Sumit Bhatti would be in a position to answer this.

[Raccoon]

Yes, Shell premium petrol has a "double dose" of detergent additives in it... this is as claimed by Shell (when I contacted them about this). They said the ordinary petrol has about half these detergents. I didn't ask specifically about Diesel (as I don't use it), but I guess this will hold true for their Diesel also.

And its very likely that these additives might have caused these problems in vehicles that have carbon built up inside them.

[SS-Traveller]

Originally Posted by Raccoon

Shell premium petrol has a "double dose" of detergent additives in it... this is as claimed by Shell

That's interesting... but is that a good thing?

[Raccoon]

Who knows... we can only trust Shell on this.

I prefer to use ordinary petrol + IFTEX. But in Poona, Shell is only selling premium petrol. :(

[gd1418]

The OP was done in Aug'08 and all responded 8 months later....

[SS-Traveller]

Originally Posted by gd1418

The OP was done in Aug'08 and all responded 8 months later....

Unfortunately so! Hope this gives someone else some more information that they seek.

[cyneverdie]

Shell V power ie shell's best fuel has 7 times normal detergent level

[Dr.Sumit Bhatti]

Originally Posted by SS-Traveller

On the other hand, Shell Premium diesel may cause a clatter by removal of some of the carbon deposits in the valve seat/cylinder head/piston crown - I am not sure if Shell fuels have cleaning agents added in to have such an effect. Perhaps Dr. Sumit Bhatti would be in a position to answer this.

Originally Posted by Raccoon

Yes, Shell premium petrol has a "double dose" of detergent additives in it... this is as claimed by Shell (when I contacted them about this). They said the ordinary petrol has about half these detergents. I didn't ask specifically about Diesel (as I don't use it), but I guess this will hold true for their Diesel also.
And its very likely that these additives might have caused these problems in vehicles that have carbon built up inside them.

Originally Posted by SS-Traveller

That's interesting... but is that a good thing?

Originally Posted by cyneverdie

Shell V power ie shell's best fuel has 7 times normal detergent level

Please refer to my post #331 in the thread http://www.team-bhp.com/forum/indian...ml#post1207383

Firstly, I would replace the oil filter with the original OE make as against an after-market one or simply replace the oil filter and engine oil and observe any change.

As discussed in great detail in the thread 'How to ascertain purity of Diesel', many factors are at play. Cars, like individuals, behave and react differently.

High levels of detergents can dislodge carbon, soot, gum and varnish deposits which can also clog oil filters and the flow of oil and fuel flow through the engine.

Assuming that the engine noise is engine knock, it could signify impending failure of anti-knock sensors.

Other questions arise: Is there a role for a friction modifying additive in a previously corroded engine in which the deposits have now been flushed out?

[Psycho]

I would agree with Dr. Sumit, the diesel could be a culprit but only for cleaning out the engine. An aftermarket filter would depend on the brand and the quality. Purolator for example is a good one. I too would suspect the knock sensor if it there.

[SS-Traveller]

Originally Posted by Dr.Sumit Bhatti

...replace the oil filter and engine oil... ...detergents can dislodge carbon, soot, gum and varnish...
...the engine noise is engine knock...

Originally Posted by Psycho

I too would suspect the knock sensor if it there.

To summarize, the noise that members have been experiencing can most likely be from one of 3 sources:
- Valve-train noise due to reduced hydraulic damping caused by non-standard oil filter/higher viscosity oil (an oil + filter change should sort it out).
- Combustion clatter due to a cleaned-out combustion chamber, thanks to Shell detergents (that's a good thing).
- Ignition / combustion knocking, due to failing / failed knock sensors (more likely in a spark-ignition engine, less likely in a compression-ignition engine).

[nitrogary]

very interesting indeed. i have a 2001 zen which has a similar problem. its gasoline. and i fill at shell. i have replaced the oil filter with purolator.
well, the sound is tak-tak-tak-tak... something like that.
i think its the valves hitting their seats. and it happens if i am full throttle. if i back off the throttle to a reasonable level, it stops. another thing i noticed is it is minimum with indian oil extrapremium petrol.
does timing play a role in this? should i consider retarding the timing? or is it the injectors?

[Psycho]

Originally Posted by nitrogary

tak-tak-tak-tak... and it happens if i am full throttle. if i back off the throttle to a reasonable level, it stops. another thing i noticed is it is minimum with indian oil extrapremium petrol.
does timing play a role in this? should i consider retarding the timing? or is it the injectors?

Yes please back off on your timing as that is a knock and not a valve sound.