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Iv got a few problems with my 1994 1.5 coupe and was wondering if anyone could help me out.
Not knowing alot about cars, some of these problems may sound stupid but im just want to make sure everythings ok.

1. I know its pretty normal for smoke to come out of the exhaust when its cold but i was a bit worried tonight after i drove home because i stopped off at my house for a few minutes then went back out and when i started the car, there was a big cloud of white smoke which then went as soon as the engine had been fully warm for 10 minutes or so. Its probably normal seen as though my other civic done it but i heard it had something to do with your head gasket if smoke came from the exhaust :-

2. When my engines fully warm, i get a really annoying noise coming from the engine, like one of the belts turning. Iv checked them and they seem to be ok but my dad reckons its dry bearings in the alternator. Also when im driving along, i get this whining noise (best way i can think of to describe it) from the engine also which gets louder the higher i have the revs. So im guessing these are the same problem.

3. I fitted a non standard backbox to my car a few weeks ago and when the engine was cold, it made a rattling noise in 1st and 2nd gear as if it was hitting off something but after checking it, the backbox wasnt really close to anything that it could hit against. So i took it off and fitted the standard one back on which never made a noise at all when i drove it :- Any ideas?? i was wondering maybe because i dont have a gasket where the backbox is, that could be making a noise somehow :- im not sure. Iv bought a gasket but dont want to attempt fitting it if i know the exhaust is going to make that rattling again.

thanks
 

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Hi Claire

The exhaust could be "rattling" because in lower gears/revs the low revs create a slower sound wave with more space between the waves allowing the wave to bounce around the exhaust causing the exhaust to move and rattle. However at higher revs the sound waves are a lot tighter packed and this is because the sound is traveling faster and has less time to bounce around in the exhaust.

Your other problems: wont be anything to worry about as i think as you say it goes away after ten minutes which is enough time for the engine and exhaust to fully heat up. By any chance do you keep your car outside at night, if so try keeping it garaged for a few nights this will keep the car a little warmer at nights as the cold air is not penetrating the car for hours before its next used. If you don't have a garage you could try a car cover, this can also help keep the car that few deg's warmer than normal.

Not sure about your other problem tho, sorry.

Chris
 

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Discussion Starter #3
Thanks for your reply back.

Handy info there. So theres nothing i can do to stop the exhaust rattling as it is a bit loud and i dont understand why it only does it with the non standard backbox. Oh well :)

Yeah i keep my car outside at night so thats where im going wrong. Problem is my garages and the drive are taken up by my dads stuff so my car gets parked on the grass outside my house and if i put a cover over the car, someone will probably nick it but aslong as the cars ok then im fine with it smoking a little bit.

Still not sure what my other problem is either :-
 

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coupe_claire said:
Thanks for your reply back.

Handy info there. So theres nothing i can do to stop the exhaust rattling as it is a bit loud and i dont understand why it only does it with the non standard backbox. Oh well :)

Yeah i keep my car outside at night so thats where im going wrong. Problem is my garages and the drive are taken up by my dads stuff so my car gets parked on the grass outside my house and if i put a cover over the car, someone will probably nick it but aslong as the cars ok then im fine with it smoking a little bit.

Still not sure what my other problem is either :-
Well the reason for that is the standard box is designed for "normal drivers" and is full of dampening fibers to soak up noise and exhaust gases. But since aftermarket back box's have little to no dampening in them they create far more noise. And it is because of the lack of dampening that low RPM sound can bounce around causing the exhaust to move and rattle a bit. If it gets worse i would take it into the garage as it could be more than just noise vibration.

BTW: What type of back box is it?

Its not that your going wrong or anything its just chemistry. Oh, technically its not smoke, its more like steam or condinsation (spelling?). When you next start your car from cold put your hand over the exhaust and you will feel cool air coming from the exhaust. Because the engine was cold before your started it the heat of the engine/exhaust gases are causing condinsation to happen on the inside of the pipe work further up the exhaust. And it is this condinsation that causes the " white smoke" that you see.

Parking your car on grass is another cause for the pre-longed "smoke". I know I'm starting to sound very sad at this moment but its very true. Take race cars for example, they are never parked on grass as grass/soil takes a lot longer to heat up from the sun then tarmac does. Because grass has a high consintration of water in it the water cause's the grass to cool/freeze faster than tarmac. And since your car is sitting over/out in what is natures version of a freezer the car will cool down a few more degrees than if it were garaged at night. And at night if there is a sudden drop in temperature this can cause ice crystals to form on the metal work of the exhaust and the engine causing the "white smoke" effect to last longer...

Chris
 

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so im ruining my car parking it on the grass? i'd rather it be where it is than it be on the road. its only june-sep that its parked there at night.

i regularly drive my car and never get any smoke etc. the car is working perfectly in my eyes.
 

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coupe_claire said:
1. I know its pretty normal for smoke to come out of the exhaust when its cold but i was a bit worried tonight after i drove home because i stopped off at my house for a few minutes then went back out and when i started the car, there was a big cloud of white smoke which then went as soon as the engine had been fully warm for 10 minutes or so. Its probably normal seen as though my other civic done it but i heard it had something to do with your head gasket if smoke came from the exhaust :- RIGHT I WOULD NOT WORRY ABOUT THIS WHEN THE EXHAUST IS COLD ONLY WORRY ABOUT WHITE SMOKE WHEN IT CONTINUOUS IT OBVIOUSLY POINTS TO A HEAD GASKET BUT IF IT GOES DONT WORRY , A CAR ACTUALLY PRODUCES 1 GALLON OF WATER FOR EVERY GALLON OF FUEL SO WHEN THE EXHAUST IS COLD THATS WHERE YOUR STEAM COMES FROM

2. When my engines fully warm, i get a really annoying noise coming from the engine, like one of the belts turning. Iv checked them and they seem to be ok but my dad reckons its dry bearings in the alternator. Also when im driving along, i get this whining noise (best way i can think of to describe it) from the engine also which gets louder the higher i have the revs. So im guessing these are the same problem. HAVE YOU TRYED SPRAYING WD40 ON THE ALT BELT IF THE NOISE GOES PROBLEM SOLVED.

3. I fitted a non standard backbox to my car a few weeks ago and when the engine was cold, it made a rattling noise in 1st and 2nd gear as if it was hitting off something but after checking it, the backbox wasnt really close to anything that it could hit against. So i took it off and fitted the standard one back on which never made a noise at all when i drove it :- Any ideas?? i was wondering maybe because i dont have a gasket where the backbox is, that could be making a noise somehow :- im not sure. Iv bought a gasket but dont want to attempt fitting it if i know the exhaust is going to make that rattling again. YOU WONT GET A RATTLING NOISE BECAUSE OF AN AFTER MARKET BOX IT MAYBE A FAULTY BAFFLE INSIDE

thanks
 

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Discussion Starter #8
Iv tried spraying WD40 on the belt but the noise is still there so im not sure what else it points to.

I fitted the backbox yesterday and i havent had any rattling coming from it so im not sure what i done different but it worked. There is a faulty baffle inside... well i think it is a faulty baffle because when i hold the backbox n shake it slightly, its as if theres a metal ball rolling about inside.
Im not sure what type of backbox it is, the person who i bought it off just described it as a 4.5" stainless steel.
 

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stug45 said:
so im ruining my car parking it on the grass? i'd rather it be where it is than it be on the road. its only june-sep that its parked there at night.

i regularly drive my car and never get any smoke etc. the car is working perfectly in my eyes.
Kinda, if you cool a sheet of metal then heat it up again, do this enough and the metal will develop cracks in the structure of the metal. Heating and cooling metal can make it stronger, but it can also have the reverse effect if its done outside a controlled area and will damage the structure of metal. This is one reason why rust develops on metal.
 

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ive gotta disagree with this in the case of an exhaust it spends its whole life being cooled and heated
parking in the grass will only result in a fire from a boiling hot cat at worst as most owners manuals will advice against parking on long grass because of this and only this
i dont say that heating and cooling steel has an effect on its molecular consruction it does but exhausts are designed to cop with this in there construction.
 

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True, sorry i kinda got carried away with the scientific side of metallurgy. Deal with it quite a lot at work so was looking at it from a metal fracturing point of view. :ugeek: :geek: :lol:
 

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i've thought that a hot cat will burn but only on dry grass. i've parked with a red hot manifold on grass and all its doing is evaporating the water from the grass and killing it. i park on grass all the time with my blue car. didnt once catch fire! lol
 

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hi, personally if the smokes white and quite bad until heat up then its fine id say the valve stem oil seals were away,as for the exhaust , mine creaks when cold but fine after a couple of mins.. :)
 

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So you got your problems fixed yet???
 
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