Loud Knocking

[TonksyDC5]

Hi All,

Hoping some of you may be able to offer some suggestions (non scary please ha ha) about what just happened.

So, I was driving down the road at normal speeds (30mph honestly!) and all of a sudden I get a loud knocking noise from under the car. I could feel it through my seat. It felt like something was rotating and knocking around the centre console/driver side seat of the car.

Car was driving completely fine before and I think shortly afterwards. I say think, because now i'm thinking about every noise and how the car drives and thinking, is that how it drove before?!

The conditions were torrential, no scrap that, biblical rain!

Being logical I have the following thoughts:

• Exhaust rubber mount?
• Centre/driver-side seat of the car could be prop-shaft, but it's obviously not RWD so that's that eliminated.
• Wouldn't be a drive-shaft surely. Again, not with the noise and location of the noise.
• Gearbox, don't see how it could be that given the knocking noise and location of the noise. Happy to be corrected. Actually no, i'm not happy to be corrected because that sounds like it would be £££'s. Which I just cant afford right now.
• Gearbox mount?
• Can't think of anything else....

Recent work:

• J's 60RS fitted in last 2 weeks.
• Front engine mount replaced and Energy Insert fitted, again front only.

From a quick search of the forum I see people mentioning that it could be rain hitting a hot exhaust. Could it really be that with the noises i've described? I hope so but i'm keen for other peoples thoughts on this.

http://www.itr-dc5.com/forum/index.php?/topic/37017-knocking-and-vibrating-noise-when-wet/?hl=noise

All gears select fine and the engine runs fine as well. It's only on 46k (miles).

Going to call TGM tomorrow to see what Tom's thoughts are without actually seeing it until I can get it down there. Problem is i'm in London so that's a hell of a drive. I wan't to be sure something is going to implode on the motorway before I make that journey.

Thoughts?

 

[dave7368]

exhaust/heatshield.. they all do it in severe rainy conditions..

and it really is that loud.. i would think nothing to worry about, unless your engine is on the way out

the dyno day will finish that off :xlol:

 

[TonksyDC5]

Thanks for that Dave. I'm going to ignore the last part of your second line, and ALL of the third line!

I can't believe it makes that much knocking, banging, and other scary expensive sounding noises! All I saw was pound notes flashing in front of my eyes. They were obviously imaginary pound notes, it wasn't raining money unfortunately.

 

[Chewy]

Welcome to J's Racing 60RS ownership...The noise will be the B-pipe hitting the chassis.

 

[TonksyDC5]

Welcome to J's Racing 60RS ownership...The noise will be the B-pipe hitting the chassis.

I don't mind the exhaust making noises that scare pedestrians, but not the bloody driver!!

 

[Chewy]

I don't mind the exhaust making noises that scare pedestrians, but not the bloody driver!!

Haha, The noise they make is lovely, dispite being a little on the loud side, Very addictive...Just a shame the build quality appears to be slipping.

The fact that mine used to bouce off the bottom of the chassis was the reason I sent it back... The loud J's roar I could live with, the even louder clanging off the chassis rail is what I couldn't live with.

 

[TonksyDC5]

Fitment of mine and build quality seems ok to be honest (not seen older ones to compare though), once we (TGM) figured out how many J's and OEM rubber mounts should be used to get it sitting right that is. 2 x J's (1 x triangle and 1 x normal) and 1 x OEM. If we used all J's rubbers it would hug/touch the upper right hand-side of the exhaust hole section of the bumper.

Got it from Sumo Power.

If i'm honest I think the exhaust has bedded-in a bit now and has got louder. I love the sound!, on cold starts my neighbours not so much. It's a glorious noise though, love it to bits. Not sure if it would pass track db levels though?

I'm in the process of having to find a new place to live at the moment and have had to resort to putting in the silencer a few times, so not to put off any potential new land lord.

 

[WayneCivic]

Hey
Did you ever sort the knocking issue out? Mine has started doing the same thing 😔😢

 

[TonksyDC5]

No it's still there. Mine is only a weekend toy and sits in the garage mostly so it's pretty rare that I drive in heavy rain.

I can live with it.

Tom did take a look but said the only way he might, might be able to stop it would be to heat up the offending section of the exhaust and try adjust the angle with a hammer. Probably wasn't a hammer but you get the idea. Not sure how that would affect gas flow/performance though.


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[linh-ej9]

My exhaust on my civic knocks when im at high altitude.

 

[WayneCivic]

I only use mine on weekends aswell but the noise it made yesterday on the way to Jap fest was awful!

 

[TonksyDC5]

I know. It is bad but the noise it makes when it doesn't knock is amazing.

Two options if it's really bothering you.

1) Return it if it was recently purchased and new. Then look at something else, Spoon, TODA, Solid Fab, RM01 etc.

2) As mentioned above, bend/adjust the offending area. Not a guaranteed fix though.

The only other option is to shell out for the new range of 60RS. But these were around £1k, and that was before Brexit! God knows what the price is now due to the exchange rates being FUBAR. But these could also do it.


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[WayneCivic]

I know. It is bad but the noise it makes when it doesn't knock is amazing.

Two options if it's really bothering you.

1) Return it if it was recently purchased and new. Then look at something else, Spoon, TODA, Solid Fab, RM01 etc.

2) As mentioned above, bend/adjust the offending area. Not a guaranteed fix though.

The only other option is to shell out for the new range of 60RS. But these were around £1k, and that was before Brexit! God knows what the price is now due to the exchange rates being FUBAR. But these could also do it.


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Yeah they do sound amazing dude, I only bought it last month not even been on 1000miles yet.

Will have to get it on the ramp and see if there is anything I can do when I fitted it it looked like a really good fit not touching anything 😕

Is it more the front or the rear where it's touching do you know?

 

[TonksyDC5]

For me it is the very first bend, after the cat.

When it was on the ramp I couldn't see on the exhaust where it had been hitting, but you could see marks on the ridge/beam opposite the bend.

Here you go. Circled the area. The first bend and it hits on the ridge/beam immediately opposite, also in the circle.

Maybe do what Tom suggested and beat the area if its your daily.

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[linh-ej9]

Have you thought about wrapping it with exhaust wrap?

 

[TonksyDC5]

Would it be a good idea heat wrapping from the cat to the silencer? Quite a large section and exposed to the elements.

Would possibly solve the problem.


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[WayneCivic]

Thanks dude I will have a look a weekend, what manifold have you got?
Do you know why it only happens in the wet?

 

[TonksyDC5]

OEM manifold.

It happens due to the rain hitting the hot SS pipe apparently. If you take a look at the link in my first post there are more details.

I dont think it does it on all exhausts, but the J's stuff tends to be known for its lovely noise and hit and miss fitment.


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[Darren4]

When I was getting my exhaust made up, he explained that they need at least 1" clearance from the underside of the body for this exact reason. Guess most exhausts expand when it gets hot and it's raining bad.

I've heard j's exhaust are not great for firmest but great for noise lol

 

[Liam]

Heard this was an issue with the full 60RS system. Instead, my brother went for a 60R backbox (fits an OEM centre pipe) and an M2 Motorsport B pipe (available from SPD automotive) - no issues with fitting.

Just an option to consider if you're looking to go down the route of returning the exhaust.