31 replies to this topic

[yorkshirechris]

Hey all.

I've got a '72 848cc mini, and it's been smelling of petrol since i got it the other week. today whilst spraying the plugs and having a general clean in the bonnet I found a pipe leading to nowhere! it's coming out of a tubular (almost exhaust box-like but a lot smaller) thing to the right hand side, and it was just shoved down the side next to the passenger side wing. Whilst looking around to see where it is supposed to go I found some weird looking bodge coming out of what I believe to be the piston jet thing, near the windscreen. It's silver, and I know the needle goes in the top of it, and there's an outlet (or inlet?!) coming out to the left of it, which has a bit of scrap bendy pipe on the end with a big bolt sticking in the end of it!

Being curious I took the bolt and scrap pipe off, and connected on the random pipe I found dangling (approx the right length + right size) and when i started it and revved up, the exhaust sprayed quite a lot of black poo out onto my lovely block paved drive.

I've put everything back as it was before I started messing about with it and I'm planning to go to the local garage when it re-opens on Wednesday but does anyone have any idea why it's been bodged like this, what it's for exactly, and if I should connect it on?

Sorry to be vague but I'm no mechanic...

P.S there's a hole on the box on my exhaust which isn't massive, will an exhaust bandage fix it adequately if it'll go on okay? Or should I get it sorted properly before the rust eats the whole thing?

Chris

[biggav]

pics may help.... if you have a smell of petrol inside your car, it coud be the breather pipe on the top of the tank in the boot

[minislapper]

Whilst looking around to see where it is supposed to go I found some weird looking bodge coming out of what I believe to be the piston jet thing, near the windscreen. It's silver, and I know the needle goes in the top of it, and there's an outlet (or inlet?!) coming out to the left of it, which has a bit of scrap bendy pipe on the end with a big bolt sticking in the end of it!

Silver thing where the needle goes in the top? Carb?

Fuel overflow pipe which has been blocked off? Not necessarily a bodge. Some carbs have an overflow pipe fitted, some have it blocked off.

A picture would be most helpful

Exhaust bandage would probably fix the leak for the time being. I'm presuming it's a standard exhaust? Last time I had a full standard system fitted it cost me less then £40 including fitting so it's not really worth patching them up for the long term.

Edited by minislapper, 16 April 2007 - 06:13 PM.

[yorkshirechris]

pics may help.... if you have a smell of petrol inside your car, it coud be the breather pipe on the top of the tank in the boot

Will get some pics on around 8ish, just nipping out.

[vasi]

Sounds like you are talking about the timing cover crankcase breather, and the breather connection on the carb. Mini's as per many old engine designs use negative crankcase breathing for emission control. ie the vacuum created in the intake manifold draws the blowby (exhaust gasses slipping past the piston rings on the compression stroke) back into the intake. It is a very crude system.

Although you are "supposed" to connect the breather back up to the carb, the real question is why would you want to pump that sh!t back into your engine.

Leaving it disconnected and dangling will do no harm, but the breather connection on the carb must be blocked off.

[Dan]

AHA, I think Vasi may have cracked what you are talking about. Some pictures will still help though. Sounds like someone has disconnected the POSITIVE crankcase ventilation system in your engine in order to stop this black crud coming out of the exhaust instead of actually fixing the poblem. When the vent pipe is removed from the carb it is required that the port it was connected to is blocked up or the engine will run dangerously lean. That sounds like the bodge you found but is a pretty normal way of sealing the port up. You need to find out why the PCV system is doing this. It is probably because the breathers and hoses have never been cleaned through in all the years it was working. Take the hose off and clean it out, refit it and fit a brand new oil cap (it is part of the system) and then try again. It is likely it will only blow black junk for a few minutes as the system clears itself. If it keeps blowing crud then you may have to remove the breather from the engine and clean it out too (fitting a new one is often easier ) or it could indicate a proper engine problem.

Oh, and it is far better for the engine to have the system connected than to not have. It is better to have the junk burned off than leave it in the bottom end of the engine where all the delicate and sensitive bits are kept.

Edited by Dan, 17 April 2007 - 04:12 PM.

[yorkshirechris]

AHA, I think Vasi may have cracked what you are talking about. Some pictures will still help though. Sounds like someone has disconnected the POSITIVE crankcase ventilation system in your engine in order to stop this black crud coming out of the exhaust instead of actually fixing the poblem. When the vent pipe is removed from the carb it is required that the port it was connected to is blocked up or the engine will run dangerously lean. That sounds like the bodge you found but is a pretty normal way of sealing the port up. You need to find out why the PCV system is doing this. It is probably because the breathers and hoses have never been cleaned through in all the years it was working. Take the hose off and clean it out, refit it and fit a brand new oil cap (it is part of the system) and then try again. It is likely it will only blow black junk for a few minutes as the system clears itself. If it keeps blowing crud then you may have to remove the breather from the engine and clean it out too (fitting a new one is often easier ) or it could indicate a proper engine problem.

Oh, and it is far better for the engine to have the system connected than to not have. It is better to have the junk burned off than leave it in the bottom end of the engine where all the delicate and sensitive bits are kept.

Yeah, I was pretty sure that's where the pipe had been taken off and thought I'd experiment and see what happened. When I saw all the poo come out of the exhaust I thought it had been removed to stop it, but didn't know whether it should be fixed properly or not.

I'll try get some pics up later this week, pretty busy at the moment. Off to the mini garage anyway tomorrow night so he might be able to tell me more.

Cheers guys!

[vasi]

Please explain how it is a positive system when it does not employ a check valve.

[Dan]

Don't get what you mean? It's just called a PCV system, I think it refers to it being an active system powered by the engine rather than a passive one.

[Jimmyarm]

Dont the breathers also effect the oil circulation, you need to have the crankcase pressure for it to work properly ?

[Dan]

The crankcase needs to be slightly evacuated ideally but tends to be slightly pressurised if the PCV is disconnected. Racers use a passive, catch tank system because PCV costs about 1 BHP in use but they can get away with it because they only drive properly warmed engines, they don't drive very far, they rebuild or inspect regularly and don't really mind how much oil they use.

[yorkshirechris]

Took the car to Minifixit today, turns out it's a shed.

The guy there (Steve?) had a look at the rust and said it shouldn't have passed it's MOT, and he told me to take it to the Ministry! He said he'd never seen anything like it and it'll cost about a grand, absolute minimum without even looking at it properly, to get it sorted out!

So on Saturday I'm off to the place where I bought it and trying my best to get a refund... either a refund or a long drawn out compensation claim through Trading Standards!

I've been well and truly "done" and in future I'll make sure I check things properly before I hand over a lot of money for them...

The bad parts of the car according to Steve are:

Holes around the bottom of both driver & passenger door
Hole in bottom of boot
rusty, corroded mounts for suspension (just behind wheel under wheel arches) - there's not even any evidence they've been probed at he MOT to check for this
Rusty sub-mounts
Rusty crack where the mounting bar for the passenger seat meets the floor, almost the full width of the seat!

He said that it's basically being held together by body filler... and in a crash i'd cause some serious damage to myself as well as the car.

Chris isn't happy and is going with backup on Saturday to get a refund!

In the meantime I'm looking at buying another (better!) mini around 1200£ - cheaper if possible - I've already seen Joe's yellow one (and please no-one else buy it - I really want it!) but if anyone knows of one not needing any work which is fairly old (cheap insurance for me) let me know!

Chris

[yorkshirechris]

Oh there's a hole in the bloody exhaust box too!

[Sammy D]

It's a breather!

Think it's been answered above anyway

Theres a place to connect it to your carb somewhere..

[minislapper]

Sorry to hear about the car, Chris. Steve is a good bloke. He knows what he's talking about.

Good luck with the refund. You've got a very limited time to contest an MOT decision (unless things have changed).

If you need to go and look at one that's reasonably local, shout up.