Diesel bottom engine mount & knocking sound

sln8458 · 6th November 2019, 09:05

Background:

I have had a knocking sound for a little while, happens generally when I go over speed bumps & if/when I lift off the gas in low gears.

The mechanic I use was unable to trace it when the car was in for service/mot (March). His suggestion was to leave it until it gets more noticeable and then have another look.

It did get worse so, Me being me, I decided to replace the bottom engine mount. Not a difficult task and would rule out that item. Note mileage is 145K. I fitted the mount for the 2.5V6 as recommended.

The noise/knock is far less noticeable since fitting the new mount. The old one had cracks in 2 places.

So to my question.
Where could the knock be coming from?

When driving the noise does sound like it's coming from near/under the drivers feet.

If replacing the lower mount has reduced the noise, could it be that the engine is still moving on the mounts (as it should, hence why they are rubber) and the exhaust is the item that is actually knocking?

Weather permitting I hope to get under the car at the weekend to check the exhaust mounts.

SteveN

6th November 2019, 09:05	#1
sln8458 Gets stuck in Rover 75 Contemporary SE 2.0 Diesel Auto 2005 Facelift Join Date: Dec 2010 Location: Norwich Posts: 589 Thanks: 90 Thanked 67 Times in 47 Posts	Diesel bottom engine mount & knocking sound Background: I have had a knocking sound for a little while, happens generally when I go over speed bumps & if/when I lift off the gas in low gears. The mechanic I use was unable to trace it when the car was in for service/mot (March). His suggestion was to leave it until it gets more noticeable and then have another look. It did get worse so, Me being me, I decided to replace the bottom engine mount. Not a difficult task and would rule out that item. Note mileage is 145K. I fitted the mount for the 2.5V6 as recommended. The noise/knock is far less noticeable since fitting the new mount. The old one had cracks in 2 places. So to my question. Where could the knock be coming from? When driving the noise does sound like it's coming from near/under the drivers feet. If replacing the lower mount has reduced the noise, could it be that the engine is still moving on the mounts (as it should, hence why they are rubber) and the exhaust is the item that is actually knocking? Weather permitting I hope to get under the car at the weekend to check the exhaust mounts. SteveN __________________ Mods Fitted: Cruise Control; FBH with GSM (was FrenchMike's Remote) & dash button; Rear Blind; In-line Thermostat; wired in front & rear cameras; Mercedes DRL +DRL2; twin horns, twin usb power outlets, digital coolant temperature readout, Real Walnut dash, Walnut & black leather steering wheel, Walnut Handbrake grip, Towbar with full Rover harness. Rear seat cup holders. Wanted: Walnut auto gear stick handle Mods to do: all done , need to come up with some more.