front pipe knocking

[K611HDT]

Hi, new to the forum, have an annoying problem hope someone can help.

The front pipe on my Montego estate keeps knocking on the anti rollbar when I take up forward drive. It has always done this since buying it 2 years ago but only when I had to really pull away from junctions. However, about 6 weeks ago I had a new frontpipe fitted (non Rover) and everything seemed okay on the way home.

Next day, got 25 yards from home and heard a bang from underneath car. Stopped, nothing visible, but since then the frontpipe really bangs on the anti rollbar when in first and second gear.

I have changed the bottom engine mounting to no success. The front mounting is not of the snubber cup variety (my car's a 93). When drive is taken up the engine is pivoting about it's side mountings and allowing it to tip backwards towards the cabin, hence the banging.

Is it likely to be a side mounting failure or does the front mounting need some adjustment?

Any suggestions would be great as this is driving me mad as well as probably ruining mhy catalytic at the same time.

Thanks for any help you can offer.

[G Force]

Hello there, your problem is possibly due to the front pipe not inserted far enough into the intermediate pipe. Pushing the pipe further in results in lifting the pipe upwards away from the anti roll bar.

Regards gary.

[K611HDT]

Thanks gary. Will have it checked and see what happens.

Cheers, Lol.

[K611HDT]

gary, I had a look at the Haynes manual and the frontpipe connects directly to the manifold at one end with a flange so there is no provision to insert it. At the other end is the flange connection for the cat. Any other thoughts? Would loosening the front mounting through bolt (which passes through an elongated slot), raising the engine from the rear hence tipping it forward slightly, and then retightening the through bolt cause any stress to the other mountings?:banghead:

I don't mind spending the money(withinn reason) to fix a problem but just finding the reason on this one is being a real pain.

All thoughts and advice welcome.

Cheers, Lol

[derek mclean]

Alas, Haynes maunals are rather limited with common-sense advice.

I suggest you get underneath and attack the front pipe with a welding torch. If you don't have such facilities ask your local garage to do it. It shouldn't take long. What it needs is just enough heat to soften it so you can bend it slightly. And of couse it needs to be done with some care, and/or a handy fire extinguisher just in case.

In my experience few exhaust parts fit well these days. I had to spend about an hour making a front pipe fit on my recently-acquired Honda Accord. I struggled even to find a non-Honda part, and when I tried to fit it it was so far out I had to make several bends before it would go anywhere near. And it still rattles a bit.

Similarly, my M16 Montego. And there isn't a great deal of room for manoeuvre between the a-r bar and the tunnel, but with perseverance you can get it right. My M16 still rattles a bit on full-power take-offs, but I can live with it.

Derek.

[K611HDT]

Thanks for the reply Derek. From your post I take it that on your Montego your f/pipe vibrates on the anti-rollbar? If that's the case then perhaps I am loking for a fault on the engine mountings that just does not exist. Would I have any recourse do you think with the company that fitted the f/pipe?

Look forward to your reply,

cheers, Lol

[E_T_V]

If they fitted it incorrectly so it rattles they should at least correct it so that it doesn't rattle. Take it back and complain but watch them when they are correcting it so they don't do a bodge job.

[K611HDT]

The guy who fitted it is actually my next door neighbour. he's manager at a trye and exhaust depot and I watched him fit it. I think the problem lies with the f/pipe itself and a combination of perhaps more engine movement than usual. One solution I,ve thought of is putting some radiator hose n the a/r bar to cushion the effect. I tried it round the block with just a piece of rag and it was silent so i think this might be as god a fix as it gets. Anothe option is to get a f/pipe from a brekers and fit that and compare the diffrence.

Cheers, Lol

[Landcrab1800]

Hi,
Just had the fornt pipe on my MG Montego replaced by Kwik Fit (£42) and it does not rattle.

If your pipe has got worse since fitting then either:
1) It's fitted wrong
2) It's the wrong one or shape.
I have worked in the fast fit area and know how tricky things can be to fit, slightly mis-aligned and your in problem. Exhausts should be fitted from front to rear and if a section is being replaved ALL pipes to the rear of this should be loosened off and then the pipe retightened F - R

Take it back and get them to sort it.
I NEVER go where my friends or neighbours work so I CAN complain( I have fallen foul of this and it cost me a freinship and a couple hundred pounds).

If the rattle is when you set off it is probable your mountings aswell. Try setting of slowly and if this improves thing bingo your engine mounts. Remember the mounts work together, changing one relieves the problem but does not cure it.

Gordon;)

[K611HDT]

Cheers Gordon. Mine cost me £89 :censored: and that was the cheapest option I could find. I checked with Partco who supplied the grage and theyv'e supplied the right one acording to the part numbers on the invoice. I think it's the mounts but I really don't want to get into that at the minute. Pulling away slowly helps if I take up drive really getly by doing a bit of clutch slipping, but that increases the wear on the clutch! The joys of car ownership (are there any?)!

Cheers, Lol

[BIGLAD]

Originally posted by Landcrab1800
Hi,
Just had the fornt pipe on my MG Montego replaced by Kwik Fit (£42) and it does not rattle.

If your pipe has got worse since fitting then either:
1) It's fitted wrong
2) It's the wrong one or shape.
I have worked in the fast fit area and know how tricky things can be to fit, slightly mis-aligned and your in problem. Exhausts should be fitted from front to rear and if a section is being replaved ALL pipes to the rear of this should be loosened off and then the pipe retightened F - R

Take it back and get them to sort it.
I NEVER go where my friends or neighbours work so I CAN complain( I have fallen foul of this and it cost me a freinship and a couple hundred pounds).

If the rattle is when you set off it is probable your mountings aswell. Try setting of slowly and if this improves thing bingo your engine mounts. Remember the mounts work together, changing one relieves the problem but does not cure it.

Gordon;)


Hi,
I changed dozens of these under warranty in the early 90's.
The Knocking only occurs on 2000cc Petrol Efi WITH Cat, models. (Saloon or Estate)
We used to fit genuine/and or unipart ones but the knock was always there.Its the Anti-Roll bar touching the Front Pipe.
Rover Group (as were then) didnt seem to interested in the problem, ( i think because Monty was nearing end of production /and most people were buying the diesel?)
We used to take the fron pipe off, heat it up with the gas bottles till it was cherry red and bend it in the vice. Then refit.
I cant remember if there was ever an official Rover Bulletin/cure though...................
Biglad
:(

[K611HDT]

Cheers Biglad. Any thoughts on the mounting problem? As I said in my initial post we heard/felt a bang and only since then has it been really bad. Previous to this with the Rover part fitted it only gave a slight rumble, and none at all with the new part until the dreaded banh occurred. Could it be a mount collapsing, although there appears to be no discernible tilt on the engine in either directon when stood?


On another note, where did you bend the f/pipe? In the single section or in the twin pipe part?


Cheers, Lol

[E_T_V]

Check the anti-roll bar mountings. They aren't unknown to break and that might be the roll bar hitting the exhaust rather than the other way round. (Just a thought as you said it happened after one loud bang.

To check the engine movement you'll have to apply the brakes and try to pull off with the bonnet open and someone watching the amount of engine tilt. (they should stand at the side of the car obviouisly :D)

[BIGLAD]

Hi,
Heat up the single part of the front pipe, 4-6 inches where it passes over the Anti-Roll bar. Check the engine mount on the o/s, (near the expansion tank)sometimes the rubber moves in the alloy housing. A trick was to drill the alloy and screw a self-tapping screw in.
Thanks Biglad.

[K611HDT]

Cheers fella, soon as I get chance I,m onto the engine mounting.

Thanks, Lol

[K611HDT]

Yup, the frontpipe is still knocking! What with college, a lack of funds and no where to work i haven't had chance to sort it (will soon). However, it passed the MOT in January no probs (apart from 2 plates on the sill). What makes me curious about this problem is: if it was a mount problem wouldn't the MOT test pick up on that? Still unsure as to the best approach to this one.

Lol