Vacuum Engine Isolator Purpose - 4.5 V8 Diesel (1VD)

[goexplore]

So, my engine mounts are shot.

My car is a G spec 200 with a 1VD and manual box. Bare bones, UN spec, but it seems this bring some challenges.

The engine mounts on my car are oil filled but have no vacuum tubing. These mounts are only specifically fitted to my spec of vehicle, which is rare as rocking horse excrement, especially here in the GCC.

My question, what is the purpose of the vacuum pipework on engine mounts? All other 1VD 200’s have the same mounts, but with a vacuum pipe coming from them?

I can get vacuum engine mounts easily, however the non-vacuum ones are special order from Japan and a 4 week lead time, followed by an inshallah.

 

[bloc]

Your post got me curious and I dug around in the parts system. Sure enough, vacuum lines going from both motor mounts to a control valve and the vacuum pump..

Now I've seen everything.

Sorry I can't help with whether it's important.. digging around online it seems vacuum controlled active engine mounts are somewhat common to reduce vibration.

 

[goexplore]

Your post got me curious and I dug around in the parts system. Sure enough, vacuum lines going from both motor mounts to a control valve and the vacuum pump..

Now I've seen everything.

Sorry I can't help with whether it's important.. I can't even imagine why they'd do that.. perhaps to make the mounts more rigid in times of extra torque?

Yeah, I’ve also been researching for the past week while trying to get my head around a four week lead time for new mounts without vacuum lines.

One possibility is that as the speed increases and vacuum pressure increases, it stiffens up the mounts to make them more rigid at higher speeds.

Next question is, if this is the case, would they operate as expected without the vacuum plumbing in place? Do we think they’re set softer than the ones without the vacuum tubing at standard, on the basis they possibly stiffen at speed?

 

[bloc]

Next question is, if this is the case, would they operate as expected without the vacuum plumbing in place? Do we think they’re set softer than the ones without the vacuum tubing at standard, on the basis they possibly stiffen at speed?

I would guess the mount is designed to isolate vibration when not activated, and to me that suggests it won't be as strong as a mount without that provision. Contrasted with your hydraulic mount being designed to handle all of the engine weight and torque with no assistance.

Personally I'd deal with the lead time just to be sure, and avoid having to buy two sets of mounts. How bad is engine movement while they are failed? Can your current mounts be modified with a welded-on chain for instance to prevent excess movement that could damage things?

 

[goexplore]

It’s undrivable at the moment with the broken mount. I’m in a hire car as the 200 is my daily driver.

I’ll have both mounts side by side tomorrow to check. The photos I have from the supplier look identical to the one that’s come off. Both oil filled/hydraulic.

 

[bloc]

It’s undrivable at the moment with the broken mount. I’m in a hire car as the 200 is my daily driver.

I’ll have both mounts side by side tomorrow to check. The photos I have from the supplier look identical to the one that’s come off. Both oil filled/hydraulic.

Yeah I'd bet they will bolt in place, but my suspicion is they won't last long without the vacuum assistance. That is total speculation on my part though.

 

[bjowett]

Here are the vacuum mounts.

 

[goexplore]

Here are the vacuum mounts.
View attachment 3530416

Thanks.

Still trying to work out whether it makes it more rigid at speed than the non-vacuum assisted one, and in turn softer when stationary.

 

[bjowett]

The mounts will be more rigid when installed in your vehicle. They need vacuum applied to soften.

 

[bloc]

That’s a more clever design than I had imagined. Thanks as usual bjowett

 

[goexplore]

The mounts will be more rigid when installed in your vehicle. They need vacuum applied to soften.

Thank you. That’s very useful information.

I guess now we look and see if the vacuum pump on my car is the same as the higher spec cars and if it’s possible to plumb the vacuum lines in.