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Old 22nd December 2015, 20:23   #736
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Default Re: What's that sound?

Good Evening good people of Team Bhp,

I have a persistent problem which is driving me wild. 2 problems in fact, but only 1 of them fits under "whats that sound"

The car in question is a 2011 comfortline Jetta 2.0 TDi (MK5).

The problem is the following: I have always been happy with the ride quality and ground clearance of the car.. and I have never noticed it scraping the underbelly... The car went for link rod change and replacement of bumper, radiator carrier, and radiator in october.. Of late, I have noticed that the car makes a scraping sound over undulations on the roads and over most hump shaped speed breakers (small and large).. The scraping sound occurs at speeds over 25 kmph.. It is a sound i havent noticed before.. I thought its probably the mud flaps, but to my surprise I realised that the car doesnt have any mud flaps!!

I have shown the car to a trusted mechanic as well as VW.. they both say that the underbody is fine, and none of the parts are loose and that nothing is hanging down to scrape the road.

any suggestions? any ideas on what is happening and why? I guess its the sound of a plastic component of the underbody, but I am reasonably certain thats its new and wasnt there a few months ago, surely the ground clearance doesnt decrease suddenly, right?

Any help would be much appreciated

Thank You
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Old 23rd December 2015, 13:24   #737
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Default Re: What's that sound?

@sidby: is it a scraping sound or something like a small bell ringing?
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Old 27th December 2015, 18:36   #738
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Quote:
Originally Posted by nareshov View Post
@sidby: is it a scraping sound or something like a small bell ringing?
Its not a small bell ringing.. the best description I can give is that its a sound like mudflaps scraping.. perhaps a creaking sound.. mostly from the rear, sometimes from the front (others claim)

can be elicited on hump shaped speed breakers at speeds greater than 25 kmph.. now, a sound produced while taking a hump doesnt bother me..

what bothers me is that the sound comes even when the car takes a minor "jump" due to uneven roads.. I will check carefully again today, but i think the frequency and the sound is increasing... The VW A.S.S. here is nothing to write home about and they cant really figure out much..
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Old 28th December 2015, 02:51   #739
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Originally Posted by lambuhere1 View Post
Mods : Kindly merge with existing thread, if any .

Issue : Swift Petrol 2007, Khat Khat sound before ignition

Hello Friends,

My swift vehicle is facing a unique noise " khat khat " sound from the enginebay. It happens randomly. Have been to the service station, but couldn't reproduce it before them. They just tightened the fan belt.

This is how it happens.

I push the key in, make one turn [ Ignition is not yet happened ] . All Pumps churn and then the "khat khat " sound starts continuously. Sometimes, it happens, sometimes it doesn't. It is as if something is getting hurt inside or something is turning and touching something before the engine is started.

Sound can be heard from the left of the engine bay, at the place marked in the picture attached.

Any help in finding the solution is highly appreciated.
The circle what you have marked is the engine mount. Since you mentioned that it happens when the key is in on position without cranking the engine- I think it could be the ABS actuator assembly. It does make some sound during the self-test but it shouldn't be loud enough for you to hear it from the driver's seat.

Last edited by interc00led : 28th December 2015 at 02:52.
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Old 28th December 2015, 08:10   #740
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Quote:
Originally Posted by sidby View Post
Its not a small bell ringing.. the best description I can give is that its a sound like mudflaps scraping.. perhaps a creaking sound.. mostly from the rear, sometimes from the front (others claim)

can be elicited on hump shaped speed breakers at speeds greater than 25 kmph.. now, a sound produced while taking a hump doesnt bother me..

what bothers me is that the sound comes even when the car takes a minor "jump" due to uneven roads.. I will check carefully again today, but i think the frequency and the sound is increasing... The VW A.S.S. here is nothing to write home about and they cant really figure out much..
Hi sidby,
You may be getting the sound from the shock absorbers. Is it like krrr krrr? Do you hear krrr sound when the car slowly climbs down a 3"-4" hump (say footpath)?
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Old 28th December 2015, 08:15   #741
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Default Re: Swift "Khat Khat" Sound From Underhood

Quote:
Originally Posted by lambuhere1 View Post
My swift vehicle is facing a unique noise " khat khat " sound from the enginebay. It happens randomly. Have been to the service station, but couldn't reproduce it before them. They just tightened the fan belt.

I push the key in, make one turn [ Ignition is not yet happened ] . All Pumps churn and then the "khat khat " sound starts continuously. Sometimes, it happens, sometimes it doesn't. It is as if something is getting hurt inside or something is turning and touching something before the engine is started.

Sound can be heard from the left of the engine bay, at the place marked in the picture attached.

Any help in finding the solution is highly appreciated.
Hi lambuhere,
When you hear the khat khat sound, do you still hear the pumps churning?
Do you notice anything else unusual while driving the car?
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Old 28th December 2015, 08:21   #742
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Quote:
Originally Posted by dass View Post
Car in question is a Dzire VDI. Done around 27kms.

Off late, when i take some bad roads (which are everywhere) there is a 'clunk' kind of sound coming from the right side and I think its from the front tyre. What could this be?

Recently, I had to get the vehicle checked for a juddering sound and vibration in the steering whenever the steering is tilted slightly to the left and I go over bad patches. The service center fixed it and they said they did not change anything, but greased the rack and pinion. Suggestions?
This may be from a stabilizer bush. The bush replacement won't cost much. Show the car to the ASS.
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Old 28th December 2015, 12:36   #743
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Quote:
Originally Posted by Rahul Bhalgat View Post
Hi sidby,
You may be getting the sound from the shock absorbers. Is it like krrr krrr? Do you hear krrr sound when the car slowly climbs down a 3"-4" hump (say footpath)?
Hi,

So the sound is a lot like a plastic scraping sound that one ordinarily gets from mud guards - could also be a creaking type of sound

Yes i do get the sound over humps and footpaths.. but its speed dependent, that's the main thing. I only get it at speeds of 20-25 kmph, and from what I know and understand, some sound over humps is normal. What bothers me is that its also elicited over uneven roads, when the car goes over small undulations at speeds of 40 kmph and above..

Shock absorbers? ok. Well mostly the sound is from the rear, but some claim its from the front too

I hope this info helps you in making a diagnosis, I'm quite confused about what it is.
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Old 28th December 2015, 15:09   #744
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Default Re: What's that sound?

@Sidby: IF your car has plastic/fiber cladding in the wheel wells, get those checked for snug fitment and missing hooks/bolts. You mentioning a bumper change triggered the thought. It may be the cladding material scraping the metal in wheel well(s), have seen this happen before and is nearly impossible to replicate on a stationary car so troubleshooting took a while.

P.S. I'm not sure how the radiator is mounted in your particular model, but getting the mounting bracket for missing bushes (if any) could also be worth a shot. Over-tightened/torqued bolts and missing bushes/washers are a common inducer of squeaks/grinding noises.

Last edited by Chetan_Rao : 28th December 2015 at 15:13.
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Old 28th December 2015, 15:13   #745
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Quote:
Originally Posted by sidby View Post
Hi,

So the sound is a lot like a plastic scraping sound that one ordinarily gets from mud guards - could also be a creaking type of sound

Yes i do get the sound over humps and footpaths.. but its speed dependent, that's the main thing. I only get it at speeds of 20-25 kmph, and from what I know and understand, some sound over humps is normal. What bothers me is that its also elicited over uneven roads, when the car goes over small undulations at speeds of 40 kmph and above..

Shock absorbers? ok. Well mostly the sound is from the rear, but some claim its from the front too

I hope this info helps you in making a diagnosis, I'm quite confused about what it is.
When the car travels over undulations, the body oscillates in vertical direction. The amplitude of oscillations depends upon the shock absorber design (and condition), the load and speed of the car. So, it looks that at a particular combination of load and speed, the car performs up-down oscillations over the shock absorbers and you notice the sound.

Just take the car to some FNG having lift facility. Observe the underbody for any signs of rubbing. If there are no signs of rubbing anywhere, this sound shall be attributed to the shock absorbers. Also observe if there are any oil leaks around any shock absorbers.

Shock absorber consists of a spring and a damper. Spring does not loose its stiffness normally but the damper may go bad. One test to check the shock absorber: push the car down 2-3 times by hand (push hard) and release your hand at the lowest position. If the shock absorber is good, it will bounce only once. If the shock absorbers are bad, the car will bounce more than once. The amount of bounce will reduce with each successive bounce. Carry-out this test in each of the 4 corners to check all four shock absorbers.

If shock absorbers are in good condition, some other part of the suspension might have been damaged. Take the car to ASS for inspection.

Last edited by Rahul Bhalgat : 28th December 2015 at 15:18.
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Old 31st December 2015, 00:35   #746
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Quote:
Originally Posted by Chetan_Rao View Post
@Sidby: IF your car has plastic/fiber cladding in the wheel wells, get those checked for snug fitment and missing hooks/bolts. You mentioning a bumper change triggered the thought. It may be the cladding material scraping the metal in wheel well(s), have seen this happen before and is nearly impossible to replicate on a stationary car so troubleshooting took a while.
Quote:
Originally Posted by Rahul Bhagat View Post
Just take the car to some FNG having lift facility. Observe the underbody for any signs of rubbing. If there are no signs of rubbing anywhere, this sound shall be attributed to the shock absorbers. Also observe if there are any oil leaks around any shock absorbers.
First off, thank you both for taking out the time to help me and offering detailed help!

1. I did check the wheel wells, all was well then. Will have to go to ASS to get the radiator mount checked.. Was hoping to avoid that since the A.S.S. here is a pain.. Also i am fairly certain the sound is from the back

2. Nothing loose on the underbody.. No real signs of scraping.. The mechanic took a picture and showed me something that he tried to pass off as the "underbody guard" with a few scrapes, but that wasnt uniform and I wasnt very convinced that its the source.. Did the press test for the shockers, had a few other people do it too, including some experienced drivers.. No one felt that the car bounced too much or anything of the sort..

Drove around over different roads and different speeds to gather more information:

- The sound can be elicited when climbing small inclides of 3-6 inches like a footpath.. It can be elicited especially when reversing off them and when the rear part comes in contact

-Sound is mostly speed dependent, easily heard over mild undulations on the road at speeds of 60+

-If i take a rather large hump shaped speed breaker at around 20-25 kmph, the sound is elicited after the rear wheels clear the speed breaker

-This is the most important clue in my opinion: Sometimes a sudden acceleration will also elicit the sound, though milder

Finally got my father to come check it out with me tonight as well.. He did, agreed that there was a sound and offered that it was either a "body sound" i.e. one of the many creaks and groans a 5 year old car with 67k on the Odo will have due to bad roads.. OR.. he suggested i check out the "leaf springs"

any ideas gentlemen? The drivers and mechanics i consulted also shrugged in the end and told me to ignore it... Another friend who has some little knowledge about cars said "if its driving fine and the sound isnt particularly scary, dont bother"

still a little confused and in need of some expert guidance.. I hope i was able to shed some more light on the situation to aid you gents in making a diagnosis!

thank you!
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Old 31st December 2015, 18:33   #747
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Default Re: What's that sound?

Won't claim this WILL help, but I do remember similar noises from my car's derriere that took a while to pin-point.

1. A grinding noise at the right rear when taking an incline sideways (e.g. turning into ramps at MLCPs). The noise was finally isolated to the damping rubber head (forgot the technical name) over the right rear suspension fork. Mine was cut and the head-bolt was grinding against its cover. Resolved by replacing the rubber part.

2. Rubbing noise in the cabin, right rear window-level area. Isolated to the seat-belt mechanism inside the C-Pillar plastic cladding. The belt spool had loosened over the years and was rubbing against the cladding. Resolved by tightening and greasing.

3. Rubbing/Squeaking noise from the boot area. Isolated to the spare-wheel clamp getting wrong-threaded and no longer able to hold the spare firmly. Replaced.

4. Metal-on-metal grinding noise from the boot. Isolated to the spare-wheel pan cover's metal edges rubbing against the boot body due to a misfit (my non-OEM alloy wasn't a perfect fit in the pan). Resolved by a generous dose of double-sided 3M tape at the offending contact spots.

5. If your car's boot door is spring loaded, check the mechanism out too. It may have loosened/marginally misaligned over the years, and may be rubbing against another part in certain situations.

Some or none of these may be causing your issues. Worth a try though. Let us know what you find, if anything.

Last edited by Chetan_Rao : 31st December 2015 at 18:45.
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Old 31st December 2015, 19:56   #748
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Default Re: What's that sound?

@Sidby: I would be extremely keen to know the outcome of your next level of investigations as I have a 2009 Jetta TDI and am experiencing some other sounds - but will hold on posting the details till your issue is resolved.
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Old 3rd January 2016, 01:04   #749
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Quote:
Originally Posted by Chetan_Rao View Post
Won't claim this WILL help, but I do remember similar noises from my car's derriere that took a while to pin-point.

1. A grinding noise at the right rear when taking an incline sideways (e.g. turning into ramps at MLCPs). The noise was finally isolated to the damping rubber head (forgot the technical name) over the right rear suspension fork. Mine was cut and the head-bolt was grinding against its cover. Resolved by replacing the rubber part.

2. Rubbing noise in the cabin, right rear window-level area. Isolated to the seat-belt mechanism inside the C-Pillar plastic cladding. The belt spool had loosened over the years and was rubbing against the cladding. Resolved by tightening and greasing.

3. Rubbing/Squeaking noise from the boot area. Isolated to the spare-wheel clamp getting wrong-threaded and no longer able to hold the spare firmly. Replaced.

4. Metal-on-metal grinding noise from the boot. Isolated to the spare-wheel pan cover's metal edges rubbing against the boot body due to a misfit (my non-OEM alloy wasn't a perfect fit in the pan). Resolved by a generous dose of double-sided 3M tape at the offending contact spots.

5. If your car's boot door is spring loaded, check the mechanism out too. It may have loosened/marginally misaligned over the years, and may be rubbing against another part in certain situations.

Some or none of these may be causing your issues. Worth a try though. Let us know what you find, if anything.
Ok so first thing tomorrow, I will put out the spare and drive the car around to check for the sound. I think that will help in eliminating or confirming he points 3&4. For 5, I guess i can pop the boot and try. To be honest i too feel it is something like the boot and not exactly the suspension or underbody. Like i mentioned, the noise can be elicited by sudden acceleration too. Also like all noises caused by wear and tear, the frequency and ease of illiciting the noise is also increasing, so i do feel like i am drawing closer to a diagnosis.

Cant be number : there are plenty of interior cabin noises, but this particular one that bothers me is not an interior noise for sure! Point 1 can only be checked at the A.S.S. and i am saving that trip for when I have a very strong suspicion/confirmation as to the source of the noise. You wont believe what a nightmare the VW service center in Chandigarh is.

Good news too by the way: As i had mentioned in my original post, there was a second problem too with steering being tilted to the left at first.. Puncture guy put it up on a jack and spun the tyres to check for a puncture.. Put it down and the steering was tilted to the right!!! Drove me wild, it would drive fine, but the steering was maybe 5-10 degrees to the right. Finally I realised that the rear left tyre was the goodyear spare from a while back. Immediately got the puncture in the ceat fixed and swapped out the goodyear. Did nothing else, especially no wheel aligment and guess what? The Jet now moves straight as an arrow, and the steering wheel is completely straight too, on its own. I could swear the car is possessed, haha, or maybe
Either way.. Will keep u posted!

Cannot thank you enough Mr. Rao.. you have been very kind
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Old 4th January 2016, 11:16   #750
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Quote:
Originally Posted by Rahul Bhalgat View Post
Hi lambuhere,
When you hear the khat khat sound, do you still hear the pumps churning?
Do you notice anything else unusual while driving the car?
Quote:
Originally Posted by interc00led View Post
The circle what you have marked is the engine mount. Since you mentioned that it happens when the key is in on position without cranking the engine- I think it could be the ABS actuator assembly. It does make some sound during the self-test but it shouldn't be loud enough for you to hear it from the driver's seat.
Thanks a ton guys for your guidance.

Yes, I did hear the sound continuously before the engine is cranked. It was audible inside the car.

Took it to the service center. They diagnosed that the "headlight level" assembly motor conked off. If we disconnect the headlight level assembly, the noise went off.

Now comes the interesting part. To rectify the same, I need to purchase the whole headlight assembly, which kind of sucks. Need to shed more than 3K for it. Thought of leaving it like that, since I don't use the headlight leveling. High beam and low beam are still working fine.

Will keep you posted if any issues prop up in future.

Thanks a ton for the guidance.
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