Engine and exhaust- knock knock!

2nd September 2007, 15:41

Right, don't know much about this, so advice would be greatly appreciated. My VTS's exhaust (standard) makes a knocking sound when I depress the clutch at lowish speed, mainly in first and second, sometimes third. Had the car up in the workshop, they can't fault the exhaust. They reckon its just the engine movements resonating through the exhaust, causing the knocking. So basically that means my frisky 1600 is moving about too much under there, right? They also told me that a 106 had a similar problem (runs in the family then) and to cure it they had to replace the engine mounts. My S has only done 37k from new. So is it likely I need new mounts? How much am I looking at spending then?? Thanks...

2nd September 2007, 16:49

Could be the lower gearbox mount.
Its like a bit of rubber in a circular metal frame.
Bolt goes through the rubber to another bracket and steadies the engine and stops it rocking.
This will cause the engine to rock near the exhaust if its gone.

I paid £30 for a powerflex one (just the rubber insert, but its easy enough to fit)

Could be the main gearbox mount - Under the battery tray is another mount - 2 Bolts hold it down, and then 1 goes through to support the gearbox end.

Sometimes the metal bush inside the rubber goes, and eventually wears the rubber out, and can cause knocking - Shouldn't be expensive, £20 - £30?

Also, there's the top left one - Chances are this hasn't gone, especially with that low mileage.

If its an engine mount, check out the lower one (in the middle next to the exhaust), or the higher gearbox one on the right.
Also check the exhaust rubbers - If they're moving too much, they can make the centre box hit the heat shield.

Hope this was of some help.
David

2nd September 2007, 20:17

Quote:

Originally Posted by DavidKent

Could be the lower gearbox mount.
Its like a bit of rubber in a circular metal frame.
Bolt goes through the rubber to another bracket and steadies the engine and stops it rocking.
This will cause the engine to rock near the exhaust if its gone.

I paid £30 for a powerflex one (just the rubber insert, but its easy enough to fit)

Could be the main gearbox mount - Under the battery tray is another mount - 2 Bolts hold it down, and then 1 goes through to support the gearbox end.

Sometimes the metal bush inside the rubber goes, and eventually wears the rubber out, and can cause knocking - Shouldn't be expensive, £20 - £30?

Also, there's the top left one - Chances are this hasn't gone, especially with that low mileage.

If its an engine mount, check out the lower one (in the middle next to the exhaust), or the higher gearbox one on the right.
Also check the exhaust rubbers - If they're moving too much, they can make the centre box hit the heat shield.

Hope this was of some help.
David

Thanks mate, big help!

2nd September 2007, 20:20

No probs mate!

2nd September 2007, 20:24

definately sounds like an engine mount.. if the main gearbox mount goes often you'll find it more difficult to get into gear

I'd start with the lower engine mount

2nd September 2007, 20:35

Cheers Kam, I'm agreeing with you and David. Knocking comes and goes, took it to the garage today and it had gone, they thought I was being paranoid. But when it comes it is quite loud, especially after long drives. Will certainly get the mounts looked over, I'm almost certain now thats where the problem lies. I'm just surprised that a car with only 37k miles is suffering these sorts of problems

2nd September 2007, 20:50

It might have 37k, but then its not been used so much, so could have perished etc etc... Doesn't always turn out to be just wear!

My exhaust used to knock slightly where it wasn't lined up..
Did it more so when hot and on bends etc.. the faster i was going the louder it was...
Usually that lower mount though!
David

2nd September 2007, 23:34

Cheers again David.
One more Q- I'm really busy next week so can't get the car sorted til the following week, but I need to cover some big motorway miles. Is it alright to drive at sustained motorway speed with the dodgy engine mounts? I mean, nothing other than the occassional knocking will happen, right?

3rd September 2007, 08:23

it was the gasket in between the cat and the exhaust where it is being pulled and springs in the gasket are worn it's right where the exhaust meets the cat takes to minutes to replace thats wat was wrong with mine anyway thought it might help

3rd September 2007, 13:33

I have the same problem, I've been wondering what the hell it is for a while. A mate of mine said it might be my CV joints, but i aint sure now after reading this???

Mine started doing it at about 37k too. I assume peoples advice is to get it looked at????

JACKO

3rd September 2007, 23:05

Yeah it should be ok for a short while, get it checked as soon as possible really to prevent further damage...
David