Engine Mounts...

Diagro

Diagro

Diagro

Soldato
Joined
3 Jun 2012
Posts
11,250
Hey,

So... I sold my Mazda 3 MPS.. and am going to be using a family spare for a while.

it's a C-Max...

It really needed some new engine mounts, so we changed all three.
However, ever since the vibrations through into the cabin are pretty pronounced when above 2.5k RPM
Same sort of feeling from installing Proper firm mounts on a race car... however these mounts are basic replacements from AutoDoc...

Could faulty installation cause this additional vibration above 2.5k RPM?
 
SixTwoSix said:
Off topic but why?!? Such a well loved and cared for example :(
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It was time.

History:
I've been a victim of EON royally shafting my credit rating for no fault of my own. Which has made it impossible to get a bank loan below 15% for years.
My rating has finally breached into the Fair category, and I was approved for a decent loan @ 4.9% from Tesco. Pretty damn good considering the current times.

So... I now have the means to get myself into a more premium car and have repayments below £300 a month. Just needed the release the monies tied up in the MPS.
 
SixTwoSix said:
Well I guess congrats but also commiserations, still really missing mine 6 months on.
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Not gonna lie, I had tears in my eyes when i went outside today for the school run. And recalled I had sold it last night.
My son... well hes 4.. and LOVED my car. He was in floods of tears. I think mostly because he had covered it in Pokemon stickers which I left on the car for the new owner to enjoy.
 
What mounts did you exactly buy? Could be they aren't oem standard.

That said i know some engine mounts bed in after x miles? Not sure that applies to standard engine mounts though??
 
sja360 said:
What mounts did you exactly buy? Could be they aren't oem standard.

That said i know some engine mounts bed in after x miles? Not sure that applies to standard engine mounts though??
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Autodoc ones.
The big one was listed as a Hydro bearing one. And the other two just oem replacements.

I think something isn't aligned correctly.
 
On cars I’ve changed engine mounts on there has been no aligning, simply support engine, remove mount, fit new one and remove engine support.

However when it comes to anything that controls NVH I always only use genuine OEM parts, very important on engine and differentials.

Could just be that or they need time to settle and you adapting a bit to them.

Though it’s not fresh in my memory I don’t recall any alignment settings but I’d have simply taken note of how originals were installed and made sure new ones went back in the same.
 
Rubber bushes, of suspension, steering rack and engine mount type are some of the most highly developed parts on modern cars. Suspension bushes in particular.

Those innocuous looking bushes will have had vast resources thrown at them, compliance through voiding or none round housing shapes will change in various planes, their kinematics refined to the nth degree.. There are whole books written on modern automotive "rubber" bush technology. Fit some cheap aftermarket ones at your peril!

Same with engine mounts, NVH suppression versus control of engine and transmission movement is something that will have been meticulously developed and refined. I very much doubt Autodoc will have worried too much about elastomer viscosity and elasticity when cloning some engine mounts :)

As an aside, crankshaft dampers are something you should also ALWAYS purchase as OE items, again, the depth of science in them is belied by their outward simplicity.

Although that said Hispano-Suiza, (fabulous machines, fabulous engineering), did a very commendable job using mercury filled dampers on their engines.

An American company called Pittsburgh Powers plagiarised and resurrected this style of crank damper some years ago.
 
Chris Wilson said:
Rubber bushes, of suspension, steering rack and engine mount type are some of the most highly developed parts on modern cars. Suspension bushes in particular.

Those innocuous looking bushes will have had vast resources thrown at them, compliance through voiding or none round housing shapes will change in various planes, their kinematics refined to the nth degree.. There are whole books written on modern automotive "rubber" bush technology. Fit some cheap aftermarket ones at your peril!

Same with engine mounts, NVH suppression versus control of engine and transmission movement is something that will have been meticulously developed and refined. I very much doubt Autodoc will have worried too much about elastomer viscosity and elasticity when cloning some engine mounts :)

As an aside, crankshaft dampers are something you should also ALWAYS purchase as OE items, again, the depth of science in them is belied by their outward simplicity.
Although that said Hispano-Suiza, (fabulous machines, fabulous engineering), did a very commendable job using mercury filled dampers on their engines.

An American company called Pittsburgh Powers plagiarised and resurrected this style of crank damper some years ago.
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Chat gpt getting some use then.

Update to thread:

Top right engine mount was faulty.
 
Sounds like you got it sorted.

I changed the engine mounts on the Mrs Fiesta with ones I got off Euro cars parts, maybe even eBay not sure which and they were fine.
 
BUDFORCE said:
Sounds like you got it sorted.

I changed the engine mounts on the Mrs Fiesta with ones I got off Euro cars parts, maybe even eBay not sure which and they were fine.
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Yea, turns out the main mount which should be a hydro mount is actually solid rubber. Os that's the issue.
Not so much as a faulty mount than a crap one.

When it's disconnected and car revved, the vibration is gone.

We are waiting for a replacement to swap in.
 
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