Noisy exhaust bought on ebay (75 KV6 2.5 auto 1999)

[900xj]

In France, aplogize, using Google translation


Good afternoon,

I had a complete line assembled (mine was ok but was starting to be quite oxidized) taken from ebay. 150 € per line (doubled final exhaust was indicated and smaller but seemed well made).

Assembly, no problem but on the other hand at certain speeds (around 2,200 very/min) it is very noisy (at stabilized speed 90 / 110 / 130 is fine). Feels like you're driving a Mustang at times.

Have any of you had this problem and resolved it?

I quickly saw on the forum that some members had blocked one of the two pot outlets and that this did not pose a problem and apparently solved the problem, including one with a... sock, or to test, a potato. Others would have rolled it up and inserted (marine) fiberglass into it.

Well, I want to but I don't really see how to fix it without it coming out. Otherwise, a collar around an outlet and a piece of sheet metal or something else?

Another possible avenue also given the different shape of the pot, it may resonate in the bumper, I have to look more closely when the fleet will stop falling every 5 minutes here (west).

The previous owner had installed two chrome bits but there, if replaced, it touched the bumper. Risk of melting of the bumper? Otherwise, simpler, I block an outlet of the tip if I put it back.

(I went to the garage the next day to retrieve my old line in case I didn't get used to the noise or couldn't find a solution. It's not that damaged in the end. With a brush of wire, rustol if it can withstand the heat and black ht paint on the final exhaust + visible and not very clean - the previous owner had it replaced but with a second-hand one not very clean but not pierced, for the inspection - than the adaptable)

Thanks.

[xsport]

There are other back box options on ebay uk. The best one that i saw was the KLARIUS (clam shape) silencer. ( 170 Gbp )The original back box was very quiet , but no longer available. If your old one is reservicable try that again. Your problem mainly seems to be a result of very little silencer baffles on the aftermarket exhaust system that you have fitted. You may have to live with this noise now. The original twin tail pipes , were angled downwards to avoid plastic bumper heat, and others that were straight had a metal heat strip fitted inside the bumpers edge (190 180 )versions to avoid heat damage to the rear bumper .You could fit an extra silencer on to the main system along its length, but i still think that it will be noisy. Can i ask why the exhaust was changed ? The original rover exhaust was stainless steel,and should not have rusted through. Not ruling out damage ,it was better left alone !! If you went to an exhaust garage that fits made to measure stainless steel systems,they may be able to advise you what to do ....

[xsport]

Also , the chrome bent down exhaust tips were available to buy , to fix to the ends of the tail pipes, to avoid heat to the bumper plastic,if you do a search. Not sure if rimmer bros still have them available or not. good luck...

[900xj]

It's this model :


Told (translated) "
The silencers we sell are made of quality steel aluminized on both sides. In addition, they have another layer of sheet metal, so called "silent in silencer", to ensure a better lifespan!"


https://www.ebay.fr/itm/271774453076

Thanks. I'll have a look to see if i can improve.

Sender responsive but... in Poland.

[xsport]

Another thing to bear in mind , is that the diameter of the exhaust . 2.0 kv6 2.5 kv6 and 190 kv6 are all different diameter. Which can cause a problem to join to the back box .

[Costa Fortuna]

When I first got got my 1.8t it sounded awful, boomy and rough. Thanks to members on here who said how quiet the car should be I took the risk of buying a clamshell type which is what the OE spec looked like.

Super quiet now just as it should be - sorry can't remember the make, my local factor supplied it.

The original one fitted when I bought the car must have been a cheapy - it wasn't clamshell and I think half the guts were missing internally.

I think the op will have fun and games in France getting the right spec.

[900xj]

Well, test the sock on a ride, it actually no longer resonates like that, it becomes normal again, and rolls just as well. Except I lost a sacrificed sock on kick down. 😉 Well in any case that gives me the clue to try to solve it. It's a kind of resonance at some rounds per minute. Now find a collar and something to try to block an outing and see what happens when driving. I would have to find something flexible but rigid enough to be able to be put in place like that. Ideas ?

[900xj]

Well, it needs to be optimized and tested again but in the meantime I put some motorcycle exhaust refill (a sort of fireproof glass wool) in the right tube (I made a small tight roll of around fifteen of centimeters pushed in but removable if necessary), drilled two small holes in this outlet and passed an iron wire to make sure that the wool does not escape.

Apparently it doesn't move or at worst would be stopped. (200 km like that)

Result, well already visually without really leaning under the bumper and looking specifically there, it is not visible at all.

In use, the noise is now very pleasant, quiet and if I press you can still hear that it is a noble V6 which starts well. Perfect. Am I losing performance? That remains a bit mysterious. Not really the impression but with less noise it also plays on the unconscious and the placebo effect.

In any case in terms of driving comfort it's a joy (less noisy, almost silent at 90, light at 110, beyond that I didn't have much chance on my journey apart from a few kick down points to see if it was going well and that the wool remained in place).

I'm going to try to find a small, flexible and tight galvanized metal mesh to finalize all of this. I have some left over condenser protection and I tried but it is too stiff. Also, i'll try to make a small roll but not closed to still let the gases pass and see if that limits the volume just as well. That would be ideal if it was just a matter of resonance with certain regimes.