[bmw_solid]

Hi All,

Hope you are all well.

Just in the process of tracing a vibration/slight shake which occurs only at idle (P, R, N or D) when the engine is fully warmed up. (108k miles done so far, original mounts)

I know it could be a couple of things like injectors, MAF, dampener pully, EGR, etc but I would first like to eradicate the engine mount vacuum system.

(The engine mounts seem fine to me as there are no obvious symptoms like engine shaking a lot or a shudder/shake when the engine turns off, hence don't think the cause of this vibration at idle is due to the mounts.)

According to realoem.com, both engine mounts have a vacuum hose each leading to a T connector, which leads to the Pressure Control Valve (PCV) with part number: 11747810831.

Now, the confusion starts here for me...Apparently this PCV is located on the RHS near the glow plugs and when I google this part number, it comes up with EGR Exhaust Control Charge Pressure Regulator!!

So my question is... does this part supply vacuum to the EGR and the engine mounts together or does the engine have 2 of these identical parts, one for the EGR and one for the Mounts??

The reason I am asking this question is because if there is only 1 of these parts in the engine, then if there is a issue with the PCV, it will not be providing vacuum to both the engine mounts and EGR. So what would be the symptoms of this case in terms of the EGR? (My engine pulls fine and turbo kicks in as normal no smoke etc)

On the contrary, it could be that the PCV is working fine but there is a crack/leak in the hoses or connectors leading to the mounts. This case I can check it by getting under the car, pulling the hose off the mount and checking for vacuum by putting my finger over the hose.

If there are 2 of these parts in the engine (1 for the EGR and 1 for the mounts) then I know the engine mount PCV would be the culprit if there is no vacuum at the hoses (assuming no leaks in the hoses/connectors) and can ignore the EGR completely.

Let me know your thoughts.

[Bham]

Yes there are 3 . one is on the egr cooler and the one for the mounts is under the # 5 intake port right above the starter ! With a hand vacuum pump you can check them and the cars vacuum pump if necessary
At idle there shouldn’t be a vacuum to the mount so that they can absorb the vibrations then at 1500 rpm it opens to suck down the bellows in the mounts to make them stiffer ! I Might be off on numbers ! It’s from memory

[bmw_solid]

Originally Posted by Bham

Yes there are 3 . one is on the egr cooler and the one for the mounts is under the # 5 intake port right above the starter ! With a hand vacuum pump you can check them and the cars vacuum pump if necessary
At idle there shouldn’t be a vacuum to the mount so that they can absorb the vibrations then at 1500 rpm it opens to suck down the bellows in the mounts to make them stiffer ! I Might be off on numbers ! It’s from memory

Many thanks for providing this info, it is really handy. At least now I know that there is a individual pressure control valve for the engine mounts!

I was reading somewhere that depending on the model (E90, E70, E60 etc.) the engine mounts are by default in their hard or soft setting. For the E90, I think the default setting is soft (I may be wrong here).

So now I know where the valve is, I will first remove both vacuum hoses going to the mounts and check there is vacuum (with someone in the car to rev the engine if required) and put my thumb over the hoses to see if their is suction. If no suction, I will then check the T connectors and Elbow connectors for cracks (I have purchased these from BMW just in case) and the last thing I will check will be the valve it self.

Just a little confused however...at idle should the mounts have vacuum or not? If they should, then its worth me checking but if they shouldn't then its not worth me checking as that would mean something else is causing the vibrations at idle then?

[Bham]

German rubber sucks !! I’ve almost have replaced every rubber piece on the car ! Had a noise when turning. Thought it was wheel bearings so change them only to find it was my mounts metal on metal. I wouldn’t rule the mount out ! See if they hold a vacuum too! Mine was at 84k these cars tear themselves up 500ftlbs of torque on a 3500lbs car. At least the way I drive

[bmw_solid]

Thanks.

I'm hoping its not the mounts as they are expensive around £60-70 (Febi Bilstein) per piece and the subframe needs to be removed to replace them! Expensive job, around £100 labour, meaning £250 or under!

I can do a lot of the jobs my self as I have axle stands, trolley jack etc buy not very confident about removing a subframe whilst under the car with limit space!

[Bham]

It’s super easy dude !!!! Just need a engine support bar . The worst part was that the new ones are much taller so a pry bar helped get that extra little bit ! Take tires off and disconnect the aft lower control arm link and torsion bar links and headlight level link so it lowers and can get some more separation with the support bar by raising motor just a little watch hoses and ducts !!! Do tranny mounts. Too. I didn’t. But on my kids ‘02 325 had too because the new mounts made it sat high in the front and fan hit

[bmw_solid]

Originally Posted by Bham

It’s super easy dude !!!! Just need a engine support bar . The worst part was that the new ones are much taller so a pry bar helped get that extra little bit ! Take tires off and disconnect the aft lower control arm link and torsion bar links and headlight level link so it lowers and can get some more separation with the support bar by raising motor just a little watch hoses and ducts !!! Do tranny mounts. Too. I didn’t. But on my kids ‘02 325 had too because the new mounts made it sat high in the front and fan hit

I will debate whether to do it or not... Much easier when on the ramp!!