I have had a new rear silencer box fitted to my citroen C5 from my local exhaust center just over a week ago , It sound`s as if it is still blowing ( it`s not i had it re-checked and it is fitted ok ) I am also using more fuel than normal & rpm is different ( normally 70mph is 3000 rpm but since exhaust fitted 70 mph is now 3500rpm ) When I questioned the place that fitted it they said that the fuel & rpm have nothing to do with the exhaust system , and i have to give the box time to " carbon up " but i have done 1,200 miles since it was fitted , This is a none genuine exhaust but still cost £100 . Is the exhaust center correct about what they told me about the exhaust not being the cause of the extra fuel & rpm .This has only happend since i had it changed ..Many thank`s to all who reply .................................
2007-08-16 05:47:39 · 5 answers · asked by hayabusa999 1 in Cars & Transportation ➔ Maintenance & Repairs
no that's not all true,they may have put the wrong silencer on it,that would explain the loss in gas mileage,there not supposed to have to carbon back up to get better gas mileage,id take this one back to them,something happened to it that shouldn't have,the mileage should have not changed on it that all,take it back,they have messed up somewhere,good luck with it.
2007-08-16 05:58:16 · answer #1 · answered by dodge man 7 · 0⤊ 0⤋
The engine rpm should be the same. This is a matter of gearing and not the exhaust. However, the gas mileage could be affected by the exhaust system. The new muffler or silencer box, may have more restriction and will make the engine work harder and thus, use more gas. I don't know the type of muffler that was put on, but unless it was a glass pack then the mileage will stay the same as it is now. Good luck.
2007-08-16 13:02:32 · answer #2 · answered by Fordman 7 · 0⤊ 0⤋
Like everyone who have answered i dont think the rpm`s should of changed , but 100% yes the exhaust could cause the extra fuel consumption & the fact you mention it`s sound`s as if it is still blowing tell`s me that there is a definite problem with the silencer , sounds as if the exhaust gases are not flowing correctly it could have the wrong size baffles in it restricting / increasing the flow , take it back to the garage and tell them you have had the aa / rac look at it and they have told you it is the cause of your problem`s , 9 times out of 10 they will just replace it for you , If they refuse then you have a right to go to the trading standards agency as they have sold you good`s not of the required standard .
2007-08-16 14:40:44 · answer #3 · answered by charlotterobo 4 · 0⤊ 0⤋
The exhaust could cause an increase in fuel used but in your case I don't think so. If the rpm is higher than normal than I'd be checking for a transmission problem or if the engine isn't running properly it will effect the way the trans shifts. Take it to somebody that knows transmissions and preferably somebody that knows engines also.
2007-08-16 13:01:52 · answer #4 · answered by plymouthfurysport68 3 · 0⤊ 0⤋
Since you've not chanced gear ratios in the final drive (ring and pinion) or the transmission gearing you have a new problem. It's not an exhaust problem. I would suspect a transmission problem with the overdrive top gear. That's why you're seeing a different rpm @70 mph.
I'd certainly have the transmission fluid changed and make sure the technician is aware of your observed (very good) change in rpm.
2007-08-16 13:12:47 · answer #5 · answered by Country Boy 7 · 0⤊ 1⤋