8 replies to this topic

[craig 1010cc]

Afternoon all, I have a 1998 cooper Si which keeps blowing from the Y piece to link pipe joint (with the knuckle in it).

I've had all of the engine mounts and steady bushes checked and the specialist assures me that they are all fine and I would have though any slight engine rock should be dealt with by the knuckle joint? The manifold is less than a year old after the original Janspeed one split between 2 branches.

Also, any ideas on how to get the system to sit a bit higher? I run it very low, and even with the cat removed at best a have 1 1/2" ground clearance on the exhaust

Cheers

Craig

[SMP]

Where is it blowing from - is it where the downpipes come into the Y piece or is it where the Y piece joins the link pipe. Either way I'd have thought it needs some more cement in it.

If it does need more cement then something may have happened causing the joint to flex and crack the cement. Normally I would expect a cemented joint to last years. Perhaps the low ground clearance means you're always bashing the exhaust on the floor and that's why it's leaking.

Have you got the bracket to the downpipe from the gearbox fitted. Not sure how much difference it would make but it won't help if it's missing.

To get more clearance I would dis-assemble the exhaust - clean the joins up so that they can rotate a bit then hang it back on and find the best fit - rotating the pipes to get them as close to the underside of the car as possible. It will be easier to work out how much clearance is it possible using this method. Then pull the joints apart - apply cement and fit back to the position you found a few moments ago - and finally tighten up. Access to a garage ramp is best for this. You can use drive on ramps but it will be harder to judge the ground clearance.

Cheers
Steve

[Bungle]

do you have the bracket to the gear box ?

a spot of weld on each bit of the Y helps

just a spot you might want to remove it one day

[craig 1010cc]

Where is it blowing from - is it where the downpipes come into the Y piece or is it where the Y piece joins the link pipe. Either way I'd have thought it needs some more cement in it.

It's where the Y piece joins the the link pipe.

It very rarely grounds (i have learnt to choose my position on the road carefully) and as far as I know the gearbox bracket is still there. Might have to have a play with the system and see if i can gain an extra 1/2" or so, but the Y piece does seem low compared with the (non injection) LCB's i have fitted in the past

i have considered seam welding the link pipe to the Y piece, but I think that would just move the problem else where.

[SMP]

How much of a clonk do you get if you lift off the accelerator and then press down again? Mine doesn't really clonk at all but I recall in the past I have had some that clonked quite badly but the stabilisers looked fine and it was impossible to feel any movement at all by hand.

Your car is 10 years old now - have the stabiliser bushes been replaced? I'd be tempted to renew these anyway as the engine rocking back and forth certainly won't help that joint even with the knuckle. Does the knuckle look as though it does move - if it does there should be a tide mark where the rust has been rubbed away.

I know that this might sound daft but how symetrical is the y piece - does it matter if it has been fitted upside / down - is this even possible?

Cheers

[Sprocket]

The maniflow injection LCB does indeed tend to be a little low at that point, but not as low as you describe. Have you lowered the car, or is there wear in the knuckle joints or general sagging of the suspension cones?

Fix your leaky exhaust as if you get it MOT'd chances are it will fail emissions on high lambda.

Bin thos C**p steel band clips that maniflow supply, they are useless. Buy some Mikalor clips. You will fine them on Ebay for a very reasonable price, they are a high torque stainles steel band.

[craig 1010cc]

My sports pack is lowered quite a bit on hi-lo's (looking at this months minimag, my ride height is about the same as the min iwith hydrolics on the lowest setting they pictured )

I haven't got any record of the bushes being changed (I've only had it 18 months) and it doesn't clonk when i lift off. I am half thinking about poly bushing all of the steady bushes for good measure though. It just puzzles me that the knuckle isn't absorbing any movement there?

[Mini bullet]

ive had the same problem with mine.

when my brother and i removed all the pipes, we found the the manifold bolts to the back of the head had worked lose as well.

i now have a stright thru pipe with a silencer in it (ditched the cat). still scrapes on some bumps but is a lot better and gives a little more road cleance.

[miniboy1971]

I had problems with sealing the Y-piece on my MPi's LCB........

Try running your finger around the inside of each 'port' on the Y-piece and you'll probably feel a little lip where the steel has been rolled and seam welded. You need to file this down so its smooth and make sure you go down a good inch or two into the Y-piece so it will seal around the LCB or link pipe once you've pushed it together and done the clamps up...

You should only need the thinnest smear of exhaust paste around the mating surfaces to help seal it, if any....!!

My twopenneth anyway....good luck......I know this can be very frustrating.....