W210 E300 turbo Motor Mounts - PeachParts Mercedes-Benz Forum

jay_bob · #1 12-27-2016, 09:52 PM

Well for the last several months my car had been getting noticeably more vibration at stoplights, and a very un-Mercedes like shudder on shutdown. So I ordered up a pair of engine mounts from the forum sponsor. They got in right before Christmas so yesterday I was able to get to work changing them out.

I pulled out my trusty bootleg WIS and it told me I needed to remove the entire motor mount arm on the right side due to interference with the turbo. Unfortunately I found out that these motor mount arm to engine block bolts are stretch to yield and so are one use only, since the torque is 20 Nm plus 90 degrees.

It also calls for lifting the engine from above, well I don't have a sky hook in my garage, so it was a floor jack and a foot long piece of 2x10 for me.

So I got out to the car and studied the situation and it became apparent that if you remove the outlet flange exhaust piece from the turbo outlet you have clear access to the motor mount bolt. This is actually easy to remove, just undo the clamp at the turbo and then compress the spring clamp in front of the particulate filter, and the tube comes right off.

With the car up on ramps I pulled the exhaust tube and was pleasantly surprised that the bolt (16 mm) came loose easily. Note to self, that piece gets HOT even when just running the car for about a minute or two getting it positioned on the ramps.

I removed all 3 under body covers, it turns out you only need to remove the center piece, right under the engine block. The bottom engine mount bolts (13 mm) are accessed through holes in the lower sub frame.

So then I went to look at the drivers side. It was very difficult to get a wrench in from below so I pulled the intake manifold. Trust me, after pulling the intake manifold on an OM642 this is a cake walk. Once I had the manifold out of the way I could see the setup on this side. Unfortunately there is a support arm for the intercooler pipe that extends from one of the engine mount arm to block bolts. It is absolutely dead centered over the engine mount bolt, they could not have gotten it in any worse location. Fortunately with a u-joint and a couple extensions I was able to get the upper mount bolt loose. I didn't touch the support arm bolts since they are single use.

Then slid underneath and set up a floor jack and 2x10 block on the oil pan. I just pumped it up enough to make contact but not lift up at this point. I removed the two 13 mm bolts from below and the two 16 mm bolts from above.

Before pumping up the jack unclip the fan shroud and just let it hang. Otherwise the fan will crash into the shroud while you raise the engine.

I started pumping up the jack and at first saw the whole car lift up. I checked like 3 times to see what I was catching with the 2x10 and then realized since the car was still sitting on the suspension (since I was up on ramps) that the suspension was getting unloaded as the engine was getting lifted. If you use jack stands, the suspension will be unloaded already and the car body will not move as you pump up the jack.

I carefully checked for interferences all around the engine as I was pumping. It was probably a good thing to take out the exhaust elbow, as there is not a flexible joint between the turbo, the particle filter, and the exhaust pipe, and lifting the engine would have probably stressed out the exhaust mounts or even bent the exhaust pipe.

Once I got the engine high enough the mounts slipped out from above. That was a bonus, my wife was nervous about me getting under the car with the engine held up with a floor jack. I never had to get underneath until the mounts were sitting back in place with the engine resting on them to put in the bottom bolts.

You will get two mounts from Pelican in boxes that don't match the OEM part numbers (if you get the Corteco that is 1/3 the price of OE Mercedes). The mount with the rubber boot goes on the driver side. The unbooted mount goes under the heat shield below the turbo. Be sure the boot is completely seated on the mount head (the pin will stick out of the boot about 1/2 inch). And of course the pin has to go between the fork on the mount arm. Once you get the mounts seated, and the top bolts inserted snugly, you can let the engine back down onto the subframe.

Put your bottom bolts back in. Then go back and torque everything. Torque on the top bolts is 55 Nm and the bottom bolts is 35 Nm. Don't forget the heat shield under the turbo. I could not get my torque wrench on the driver side so I had to use an open end and my calibrated arm. I did notice blue loctite on the threads so I added more when I installed the bolts.

Once I saw the old mounts, it was amazing how much shorter they were, they were almost half the height of the new ones.

The only snag I ran into on reassembly was the exhaust clamp. It requires significant force to re-compress it enough to catch. And it wants to come apart on you as you are trying to get pliers on it to squeeze it in. So what you want to do is hook one side and then use a light duty clamp to hold the two rings in position while you line up with your vice-grips. Channel locks would not give me enough leverage to squeeze the halves tight enough to mate. Put the vice grips on the part and squeeze down to draw the two halves together close enough that you can re-seat the tab in the slot.

The difference was noticeable the first time I started the engine. Before I had a droning buzz in the car, that was gone, and at stop lights, you almost can't tell the engine is running now. It no longer vibrates on hard acceleration anymore.

This is probably the best $125 you can spend on your car, if you aren't sure how old your mounts are. It took me 4 hours total but I probably wasted an hour of that removing the forward and rearward under skirts that I didn't need to, and I spent probably an hour fighting with the exhaust clamp until I figured out the trick with the small clamp to keep everything from shifting around and giving up on trying to use channel locks. So if I had to do it all over again it would probably take more like 2 hours.

ROLLGUY · #2 12-27-2016, 11:07 PM

I did the mounts on my friends 99 E300 just about a month ago, and reading your thread made me think you were spying on me while I was doing the job! You explained the procedure almost exactly like I did it. I did not have as hard of time as you did getting the exhaust clamp back on. I remember just using a big Chanel-lock pliers, and squeezing the two pieces together till the tab clicked into place. I already had the manifold off for another job, so that made my job go a little faster than yours. I stressed out at first, but once I got into it, it wasn't that hard of a job in the end.....Rich

jay_bob · #3 12-28-2016, 02:47 PM

My biggest problem with the channel locks was trying to achieve enough leverage to pinch the halves together and then keep the halves close enough together to work the tab back in the slot. Using the vice grips kept the compression on the clamp while I grabbed the tab with needle nose pliers to park it correctly in the slot. Also there is not a lot of room behind the exhaust flange so it was tough to get my longer handled channel locks in there and be able to squeeze the handles sufficiently to pull the halves together.

Rick Miley · #4 12-30-2016, 11:05 AM

Every procedure under the hood of this car begins with "remove intake manifold."

Skid Row Joe · #5 12-30-2016, 08:55 PM

When I did my W210 '99 E300's engine mounts, I didn't have to remove any of what you did, beyond the drip pan(s). I was also advised to only change one at a time. I don't recall which was first, but I believe I changed the starboard first.

***When I did my 06 E320 CDI's engine mounts a couple years ago, again, I changed one side, then the other. I was also advised to lift the engine using the transmission housing = not the oil sump pan!

Been so many years since I did the E300, that I don't recall whether I lifted the engine utilizing the transmission housing, or the oil sump pan.

I distinctly remember lifting the W126 300SD's engine with the oil sump pan. My cautionary here is that the transmission housing may be safer. I dunno.

ESchwab · #6 12-30-2016, 09:11 PM

There is a Wiki paper for changing the motor mounts in the '97 e300, which does not have a turbo:

PeachPartsWiki: Engine Mount Replacement

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