Kaput exhaust

emuzeg

emuzeg

I think I have a hole in my exhaust. When revving it makes noises of different pitches. My question is though, can this cause poor performance? I only ask because recently I drove to Scotland and on the ups it would not go above 30mph. Would a dollop of high temp sealant do the trick?

(Also, is it illegal to drive with a damaged exhaust?)
 
Where is the hole?

Cant see it affecting performance much, if at all.

It is illegal, but nothing you'll get in trouble for. Worst case is you'll be pulled and told to fix it.

I'd weld it, but replacing might be easier depending where the hole is.
 
Cheers for the reply. Hmm I don't know where the hole is. How can I tell? Slid under the car and get someone to rev and then listen for where it might be?

How much do you reckon for a replacement exhaust for a K11, and also for just a welding shut of the hole? (I guess it would fail it's MOT like this..?)
 
stick your palm over the tailpipe when the car is idleing... you will hear a "fluffing/air escaping sound from any holes...

Best to do this from cold tho, or have a dam cloth in your hand so you dont get burnt (probably wouldnt be that hot to be honest!
 
if you have a hole anywhere in your exhaust sysem you would lose back pressure so you would prob lose a bit of low down power, but if its before the o2 sensor then it could make it run like crap as it would throw the fueling way out.
 
Hmm interesting, I'll give that a go.

Is it expected for a 1 litre automatic micra with 4 people and a suitcase to only manage 30 up a steep hill in the Scottish countryside?
 
flipside said:
if you have a hole anywhere in your exhaust sysem you would lose back pressure so you would prob lose a bit of low down power, but if its before the o2 sensor then it could make it run like crap as it would throw the fueling way out.
Click to expand...
I have had a brief check and the odd sound is coming from the back part of the exhaust, near the pipe. Is this near to o2 sensor?

Are there putties I can use to fix it, and would that be ok to pass the mot?
 
The o2 sensor is on the manifold which is right at the front of the car, but having 4 people in my 1 litre micra going up a steep hill is how i killed my clutch the first time so that was probably your problem lol, but you might scrape through MOT with a small hole, I have done before, but depending on size you might be able to gum it up.
 
as smc92 said the o2 sensor is on the exhaust manifold (the cast iron part coming off the engine) if thats ok before the o2 sensor it shouldnt fail on emmission's providing the sensor is in good working order , if its blowing anywhere else in the system it may get a high oxygen reading on the gas analyser due to drawing in air, but that would'nt be a fail

i wouldnt worry about it too much m8 , a fully ladened 1.0 automatic and a hill, its going to struggle a bit
 
Cheers for the replies, put my mind at rest then. I'll have a closer look when I have some time then and see if I can gum it up.

I soldered my heater card a while back and it fixed it, but it's broken again, so that and fixing a dodgy speaker in the right door is my priority then.

By the way, since changing the oil and filter I have done about 700 miles. The oil is getting blacky again already, should I change it again or not bother?

And my final thing, sometimes after multiple starts the engine struggles to keep running at the very start of it firing up, and other times it seem to run into higher revs right after turning the key, as though I was pressing the gas a bit. Is something sticking and causing the idle to be off when turning the key?
 
Mine seems to rev high when i start up the car and sometimes when im just idling, i think its my throttle cable spring thing. im just going spray wd40 on it and see if stops sticking, and personally i wouldnt change the oil yet, it will go black because its constantly re circulating around your engine, the haynes manual recommends 3000 miles i think, but i guess its on how you drive it really and how much driving you do, but yeah i wouldnt change it if you only did it 700 miles ago
 
on that subject of oil changing im changing my oil tommorrow wheres the sump cap on a k11 and has anyone got any tips of not getting coverd in oil :)
 
The sump drain plug is on the sump under the car, quite easy to find, and just undo and have a bucket ready to place under it
 
i change my oil every six months regardless , 5-30 in winter 10-40 in summer. smc if your revs stay high and idles lumpy it will most likely be your iacv (idle air control valve) when you close the throttle it redirect's the air into the engine to prevent stalling it get's gummed up with carbon and does'nt shut properly. if you use the search the site you will find more info on how to clean it up. don't mess about with your throttle cable
 
ill have a go at that then, i replaced throttle body, ages ago because it was constantly stalling and its run fine since, like i say the only issue is that sometimes it sticks around 2k RPM
 
what does 'L' stand for on the auto stick? Read that usually it is S for sport but I have a separate button for that
 
Micra.com.au doesn't have any instructions to clean the IACV for the coilpack engine which mine is, only the earlier types. I can't find any how-to's anywhere!!
 
Well I have found the hole, more of a crack. It it between the pipe coming from the engine where it meets up with the muffler at the back of the car. Ran my fingers round it and it all flaked off. The bit of metal at the top is holding the pipe to the muffler strong for now. See below. So, can I get some sort of putty to seal that with and will that be okay? Pass it's MOT? Or does it need to be cut out and replaced and welded?

p1100046n.jpg


p1100047x.jpg


p1100048x.jpg
 
Okay, but will I need to weld it on? I want something I can do myself without having to take it to a garage. I thought I would go to B&Q and get some metal epoxy putty?
 
I believe that's the one, just two bolts.
Not sure if the prefacelift and facelift ones are different mind you!

Probably best to use some exhaust putty too
 
Thanks. I got some gun gum from B&Q and that seems to have sealed it up really well. Great stuff to play with too and washes straight off with water. I ran the engine gently and no gases are escaping from the hole, so after a night's curing it will be good to go I hope. But, does anyone know the ins and outs of the MOT and if a putty filling a hole like mine will or will not pass?

If this doesn't last I'll get a new backbox.
 
Thanks! This morning part of my repair had gone all runny, like it was watery and it dripped off into my hands. The rest is okay and has hardened, but not fully, and after a brief drive a tiny hole has opened up in the putty where the exhaust comes through again. I guess once it has fully hardened I can just plug that hole up again.
 
I think the repair has not lasted.. I re-did it but it seems to be making a noise again. Looking at the photos below, there is a grey area along the line where the crack/hole was. How come it doesn't hold!?

What are your thoughts, should I try the strips of exhaust patch stuff, or get a new back box?

p1100083g.jpg


p1100082y.jpg
 
tomwest said:
stop torturing yourself with gungum! buy a back box. its a spanners job if the cars not too rusty underneath!
Click to expand...
Ok! I got a new back box for 29.95 and free shipping from ebay. Looks good and seems well made. Should I coat it with something (cheap) before putting it on or it'll just rust soon right?

Also at which end does the gasket go?

p1100242.jpg


p1100243i.jpg
 
Damn, I have only managed to get one of the bolts off. The other seemed to move but it's stuck so hard. I can ask to borrow a socket and wrench but will that even fit? Can anyone tell me if a socket works in this instance or if it's only a short spanner that there's enough clearance for?

Cheers.
 
emuzeg said:
Damn, I have only managed to get one of the bolts off. The other seemed to move but it's stuck so hard. I can ask to borrow a socket and wrench but will that even fit? Can anyone tell me if a socket works in this instance or if it's only a short spanner that there's enough clearance for?

Cheers.
Click to expand...

grind off, new nut and bolt?
 
From what i remember i used a spanner to hold the head and socket at the bottom. Where are you located mate?
 
some different makes of exhaust have different threads, iirc the factory one has metric fine captive nuts, and aftermarket ones have m10 threads.
have you busted the rotten backbox off ? (so that you can lower the pipe down for better access)
 
Oh that's an idea, didn't think of forcing the back box off to get better access. I'll try with a socket then I'll get off a friend, I have just the spanner, but using that and a pair of pliers nearly made me strain my shoulder muscles with all the pulling!

I'm located in York, SuluR.

The heater card I repaired a few months back with solder has broken again :( We might have to move and sell the car in a few months anyway, so when we sell it it'll be in darn better shape that when we got it - new oil, filter, plugs, windscreen, wipers, alternator and if I fix the heater card again, that too. Will I realise any extra cash for that all do you reckon if I provide paperwork etc?
 
emuzeg said:
Oh that's an idea, didn't think of forcing the back box off to get better access. I'll try with a socket then I'll get off a friend, I have just the spanner, but using that and a pair of pliers nearly made me strain my shoulder muscles with all the pulling!

I'm located in York, SuluR.

The heater card I repaired a few months back with solder has broken again :( We might have to move and sell the car in a few months anyway, so when we sell it it'll be in darn better shape that when we got it - new oil, filter, plugs, windscreen, wipers, alternator and if I fix the heater card again, that too. Will I realise any extra cash for that all do you reckon if I provide paperwork etc?
Click to expand...

Ah darn, could have come helped you out. hmm. if your still stuck could take a pic and show what your working with
 
I have replaced it now, looks good and sounds perfect. What do you think? I am worried about the level of rust under here though, does it look like it's on the borderline of MOT failure? Notice rust hole at back of photo, it's all really crusty.

p1100256b.jpg
 

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