Engine mount problems with ML270.

[oigle]

In the space of 5 years and 72000km, I have had the engine mounts replaced twice under warranty because of excessive NVH transmission. Each time, the problem was fixed but, within a year or so, it would gradually return. I now have the same problem and am out of warranty. So.............

Spent a few hours today playing with the drivers side (RH side) engine mount (the RH side one causes the most problems due to engine torque compressing it). A little bit of a fiddle getting it out. My diagnosis is that the mount rubbers are deliberately made quite soft to minimise the transmission of noise. This softness allows the rubbers to compress and distort somewhat with use, which in turn allows the bottom and top plates of the mount to touch under load (acceleration etc), These two plates have a thin strip of rubber, about 1/16th of an inch thick, on their surfaces to minimise the effect of the touching but still allows some harshness to transmit, which is what annoys us. The design fault, as I see it, is that the two plates are too close to each other. If they were spaced 3/16" further apart, the problem would go away. Some clever work with a press to reshape the two plates further apart would be the best solution. As a trial and stopgap, I have removed the layer of rubber from one of the surfaces - chiselled it off. This gave an extra 1/16" of clearance before contact. I was tempted to remove both layers but have resisted the temptation for now. The reduction of noise and harshness was very evident and was reminiscent of getting new mounts. Don't know how long this "fix" will last but good for now. If and when it fails again, I'll get a new mount and make endeavours to get it spread as I outlined above.
What would be really good would be to setup an additional set of mounts to reduce the load on the originals but that might take some engineering and I don't have a workshop anymore.
I'll let you know as time progresses how the modification works.

 

[toxic]

In the space of 5 years and 72000km, I have had the engine mounts replaced twice under warranty because of excessive NVH transmission. Each time, the problem was fixed but, within a year or so, it would gradually return. I now have the same problem and am out of warranty. So.............Spent a few hours today playing with the drivers side (RH side) engine mount (the RH side one causes the most problems due to engine torque compressing it). A little bit of a fiddle getting it out. My diagnosis is that the mount rubbers are deliberately made quite soft to minimise the transmission of noise. This softness allows the rubbers to compress and distort somewhat with use, which in turn allows the bottom and top plates of the mount to touch under load (acceleration etc), These two plates have a thin strip of rubber, about 1/16th of an inch thick, on their surfaces to minimise the effect of the touching but still allows some harshness to transmit, which is what annoys us. The design fault, as I see it, is that the two plates are too close to each other. If they were spaced 3/16" further apart, the problem would go away. Some clever work with a press to reshape the two plates further apart would be the best solution. As a trial and stopgap, I have removed the layer of rubber from one of the surfaces - chiselled it off. This gave an extra 1/16" of clearance before contact. I was tempted to remove both layers but have resisted the temptation for now. The reduction of noise and harshness was very evident and was reminiscent of getting new mounts. Don't know how long this "fix" will last but good for now. If and when it fails again, I'll get a new mount and make endeavours to get it spread as I outlined above.
What would be really good would be to setup an additional set of mounts to reduce the load on the originals but that might take some engineering and I don't have a workshop anymore.
I'll let you know as time progresses how the modification works.

Hi ask them to repair them after all 2 sets of engine mounts something's got to be eating them away,

regards Mark

 

[oigle]

Unfortunately Mark, this is not an uncommon problem. Merc service man admits to replacing many mounts with this problem. His explanation was that "the mounts were made soft to absorb vibration and thus are subject to sag. If they were made harder, there would have been more NVH all the time".
My observations are that the mount doesn't allow for enough sag before the two rubber covered metal plates come together and transmit excessive NVH. The design is not good. As I said, if I can get access to a press, I may be able to reshape the mount in such a way that it has more tolerance in that area. The rubber compound is probably quite OK - just the clearance and angle that the rubbers work at, are the problems. The rubbers do not carry the weight squarely and distort with load.
I'll wait until my temporary "fix" fails, as it probably will (1/16th of an inch of extra clearance won't last long, I don't think), and then have another go at modifying a new mount to provide extra clearance and better angle of compression.
I'll keep you posted with results as this is a very common problem for many people.

 

[stumo]

Gidday oigle, sorry to drag this old post up, but I think I may have the same problem.

I have an '02 ML270, and get a mild vibration for a second or so when I pull away from standstill. It only does it when the engine is hot, after say 20min city driving. It appears to be coming from the drivers side of the engine.

So I think that engine mount must be on its way out, and the heat from the turbo must be contributing to the softening of the rubber.

So it sounds like it was easy to replace, so I might give it a go. Do you have any tips? Where is the best place to get one from cheap (I'm in Melbourne)

Cheers.

 

[oigle]

Write to the Euro parts importers at the following address. They are dirt cheap - I think a mount was only around $30. Their delivery is quick and they sell genuine stuff. It will make a big difference to your vibration problem for about 20000km then it starts again!! Easy to do though on drivers side - other one is much harder. If you need any guidance, let me know. I'm travelling in SA at the moment but am connecting up most days. The Nullabor might present a challenge though!! The address is:-

mypartslocator@yahoo.com.au

They are working on a website currently.

 

[stumo]

Thanks oigle, I've seen them advertise ML brakes and stuff on eBay.

When you did it, did you use a lifting crane, or just a jack carefully under the engine?

I might just wait a while until it gets worse, since it is only for a second or so on take off. By then I might need new brakes at the same time!

 

[oigle]

Sounds like you don't need to do anything yet. How many km has the ML done? My first lot failed by about 30000km - fixed under warranty.
Did you buy new? If you bought it 2nd hand with mileage on it, you may not realise just how much improvement can be had with a new mount.
Re job - Remove the under tray under the front of the engine and using either a floor jack or an hydraulic jack, carefully support the engine under the sump using a wooden block. No need to jack it all - just support.
When you access the mount through the inner guard area, you can undo the bolts holding the engine mount to the bracket then undo the bolts holding the bracket to the engine block - there is an earth strap there too. Once undone (you will need star sockets for best results) you can then remove the bracket from the mount and lift out the old mount - reverse procedure to refit.
You may ned some new plastic screws to reattach the guard under the engine when you have finished - they butcher a bit getting them off.

Best of luck - it isn't hard.

 

[stumo]

thanks for the mini-howto oigle, good I was hoping it would be a simple procedure like that.

The ML is new to me, and has done 235kkm. (and yes it was very very cheap)

At the moment, I am just astounded by the difference fitting a set of new front bilsteins has made to the bump handling and ride! the old ones were rooted and I can only assume they were the factory fitted ones. I got the bilstiens from US ebay, and they were about half the price (incl shipping) of the same part locally.

I'd like to do the rear shocks next (which are a bit more involved than the bolt-on fronts), then maybe do the engine mount after that. I also seem to have some kind of leak at injectors 1 and 4, so that will need looking at too.

all in all though, I am extremely happy with our new ride. I really believe there is no safer family 7 seater on the market under AUD20k.

 

[oigle]

Doing rear shocks is quite involved - much harder than the fronts. I have already written about shockers on another thread. Have a look at my website that I did just for complaints on this vehicle and it might help you. http://members.optusnet.com.au/iananddesley/ Bilsteins are now much more affordable than they were when I did mine so they are a good reccommendation.The standard shocks on these cars are nothing short of woeful. Dangerous, in my opinion. The car can just bounce off the road in bad conditions. Good shocks are essential.
Let me know if I can help further.
I am at Ceduna now and about to embark on the Nullabor with my van.

 

[stumo]

ML rear shocks

I hope you made it through the desert in one piece oigle - 'cause I need your expertise again, since we are (now) on the subject of suspension.

I read with interest your tuning of the suspension on your ML270 and I can fully understand why you would go to such lengths. Mind you, one of the front shocks that came out of mine wasn't actually doing any absorbing whatsoever. Anyway, I count myself lucky that the Bilstiens are more readily available these days.

So my question is... What sort of spring/strut compressor will I need to use to get the spring off the old rear shocks? Would something like this be ok?..
http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=120318578822

I'm also interested from reading your notes about using 235 width tyres instead of the stock ones, allthough you say your stock tyres were 255, whereas mine came stock with 275's - currently in a tasty Pirelli Scorpion Zero flavour. I'm looking for ways to decrease the bump steer, apart from changing the front shocks, I also found that pumping the tyres up rock hard reduces it significantly, but obviously its not a good solution. I will be due new tyres in about 10k I reckon so your input would be great.

 

[oigle]

Made it to Fremantle and am here for a few days. Then up to Cervantes to check out the Pinnacles , then back to Perth for the Red Bull Air race on 1st/2nd Nov then we head back towards home. Good trip so far - UHF mike failed was only problem.
Re your car. Haven't used a compressor like that one but it looks OK. A standard type one that hooks on to the coils is rather hard to use on the ML, so maybe that would be a good bet. On the other hand, as you will probably only need to use it the one time, why not just remove the legs and take them with the new ones to a suspension place and get them to change them over - not a big job. Should only take an expert about 15 minutes to do both sides and shouldn't cost you much. Better than having a $150 gadget hanging around for years for no good purpose. Your choice. If you do it yourself, take care. If the spring escapes under tension, it can be quite dangerous.
Re tyres, my model - 2003 - came with 17" wheels. Yours has 16". I spent some time on the net working out what wall height ratio in 235 would equate to the original size so that my gearing didn't get stuffed up. I suggest you either spend some time on the net looking for the info or just go to your local tyre mob and ask them what 235 tyre would be the equivalent to your 275 in overall diameter. I found the narrower tyre to be a lot better. I have now done 51000km on them and still have probably 10K left - enough to get home I hope. You also have to make sure that the new tyre has the same or better load rating than the standard tyre for insurance reasons. The issue of wheel align ment is important too. I played around on a wheel alignment machine, using various front and rear end loads to see what changes occured to toe-in and camber. Eventaully settled on 6mm toe-in at the front and 3mm at the rear. The rear actually toes-in more with load. Those settings seemed to give the best result and the wear is acceptable. I reduced the camber to minimums too - think it was about -1/2 a degree.

Hope that helps.

Ian.

 

[stumo]

Thanks oigle. I did read somewhere that those hook type coil spring compressors were a pain to use on these struts. I think I would rather do it myself than take the struts in, I do like learning how stuff works etc. and at least you know you will do it right (have had some bad experiences with "professionals" in the past) but having said that, at the slightest hint of danger I will be taking them in.

On to the tyres... mine is the facelift model 02/2002 so it does have the 17's as standard. I have just re-checked the owners manual, and it says it came with either 255 or 275, mine must have come with 275 because it also has the nice looking optional light alloys. So I might just try 255s next time.

Thanks for the alignment specs, I will get that done when I get new tyres. I currently have one of my front tyres scrubbed quite badly on the inside edge, so I will need to get that seen to before then as well - maybe a balljoint?

 

[stumo]

Write to the Euro parts importers at the following address. They are dirt cheap - I think a mount was only around $30.

Oh by the way, they are $62.50 there now, still much cheaper than the stealer though. They also sell the MB "lifetime" ATF $5/l cheaper and also MB coolant about half the stealers prices too. So thanks for putting me on to them oigle.

 

[oigle]

Thanks oigle. I did read somewhere that those hook type coil spring compressors were a pain to use on these struts. I think I would rather do it myself than take the struts in, I do like learning how stuff works etc. and at least you know you will do it right (have had some bad experiences with "professionals" in the past) but having said that, at the slightest hint of danger I will be taking them in.

On to the tyres... mine is the facelift model 02/2002 so it does have the 17's as standard. I have just re-checked the owners manual, and it says it came with either 255 or 275, mine must have come with 275 because it also has the nice looking optional light alloys. So I might just try 255s next time.

Thanks for the alignment specs, I will get that done when I get new tyres. I currently have one of my front tyres scrubbed quite badly on the inside edge, so I will need to get that seen to before then as well - maybe a balljoint?

Thought the 17" only came in in late 2002/2003. Yours may have been optioned up. Your choice on tyres but I know 235's are better than 255's for ride and steering.
Have fun with the suspension.

 

[stumo]

Thought the 17" only came in in late 2002/2003.

All facelift W163's (available late 2001 in Oz) have to have 17" because they have bigger brakes and so you can't fit a 16" wheel on. There is a set of 17" ML wheels with 235's on (Michelin MX4) on eBay...http://cgi.ebay.com.au/17-ML-Merc-Rims-GENUINE-235-65-17-Michelin-MX4-90_W0QQitemZ150305280061QQcmdZViewItem?hash=item150305280061&_trkparms=39%3A1%7C66%3A2%7C65%3A1%7C240%3A1318&_trksid=p3286.c0.m14 Do you (or anyone) know if they are a good tyre for the ML? And what are the insurance implications of fitting a narrower tyre than stock (please correct me if I'm wrong, but I'm assuming 235's were never a factory option)?

 

[oigle]

All facelift W163's (available late 2001 in Oz) have to have 17" because they have bigger brakes and so you can't fit a 16" wheel on. There is a set of 17" ML wheels with 235's on (Michelin MX4) on eBay...http://cgi.ebay.com.au/17-ML-Merc-Rims-GENUINE-235-65-17-Michelin-MX4-90_W0QQitemZ150305280061QQcmdZViewItem?hash=item150305280061&_trkparms=39%3A1%7C66%3A2%7C65%3A1%7C240%3A1318&_trksid=p3286.c0.m14 Do you (or anyone) know if they are a good tyre for the ML? And what are the insurance implications of fitting a narrower tyre than stock (please correct me if I'm wrong, but I'm assuming 235's were never a factory option)?

Those rims and tyres are original equipment on the latest ML. Won't fit yours. The offset is insufficient and the wheel won't clear the brake calipers. I know - I tried them!! 235/65/17 is the standard size on the current ML.
Re insurance, provided the load rating and speed ratings are the same or better, there is no insurance problem. They would be hard up trying to say the current specs would not be good enough for the superseded model!! MB realised they were the better choice. The load rating especially is very important. The Yokohama tyres I used are correctly rated.
You can PM me if you wish.

 

[kebo57]

In the space of 5 years and 72000km, I have had the engine mounts replaced twice under warranty because of excessive NVH transmission. Each time, the problem was fixed but, within a year or so, it would gradually return. I now have the same problem and am out of warranty. So.............

Spent a few hours today playing with the drivers side (RH side) engine mount (the RH side one causes the most problems due to engine torque compressing it). A little bit of a fiddle getting it out. My diagnosis is that the mount rubbers are deliberately made quite soft to minimise the transmission of noise. This softness allows the rubbers to compress and distort somewhat with use, which in turn allows the bottom and top plates of the mount to touch under load (acceleration etc), These two plates have a thin strip of rubber, about 1/16th of an inch thick, on their surfaces to minimise the effect of the touching but still allows some harshness to transmit, which is what annoys us. The design fault, as I see it, is that the two plates are too close to each other. If they were spaced 3/16" further apart, the problem would go away. Some clever work with a press to reshape the two plates further apart would be the best solution. As a trial and stopgap, I have removed the layer of rubber from one of the surfaces - chiselled it off. This gave an extra 1/16" of clearance before contact. I was tempted to remove both layers but have resisted the temptation for now. The reduction of noise and harshness was very evident and was reminiscent of getting new mounts. Don't know how long this "fix" will last but good for now. If and when it fails again, I'll get a new mount and make endeavours to get it spread as I outlined above.
What would be really good would be to setup an additional set of mounts to reduce the load on the originals but that might take some engineering and I don't have a workshop anymore.
I'll let you know as time progresses how the modification works.

Hi oigle this thread as stuck on my mine for some time
I have modified an old engine mount and done a load test to obtain double the load before the top and bottom engine mount come together see pic's

1st pic modified E/M load reading
2nd pic close up of Modified E/M gap between top and bottom plates
3rd pic not modified E/M load reading
4th pic close up of not modified E/M gap between top and bottom plates

5th pic shows a comparison before and after the slight modification, the lower engine mount is the one with a simple flaring in the top plate

My press dial shows about 3/4 ton before & 1 & 3/4 ton after the mod the dial might not be reading correctly but that doesn't mater its only a comparison
I haven't tried this mod yet but I'm going to in the near future
I would like some input oigle if you are interested

Kevin

 

[oigle]

Hi oigle this thread as stuck on my mine for some time
I have modified an old engine mount and done a load test to obtain double the load before the top and bottom engine mount come together see pic's

1st pic modified E/M load reading
2nd pic close up of Modified E/M gap between top and bottom plates
3rd pic not modified E/M load reading
4th pic close up of not modified E/M gap between top and bottom plates

5th pic shows a comparison before and after the slight modification, the lower engine mount is the one with a simple flaring in the top plate

My press dial shows about 3/4 ton before & 1 & 3/4 ton after the mod the dial might not be reading correctly but that doesn't mater its only a comparison
I haven't tried this mod yet but I'm going to in the near future
I would like some input oigle if you are interested

Kevin

That is exactly what I wanted to do - increase the clearance between the plates. Unfortunately the workshop I used to have no longer is mine!!!! I would be very interested to know how the modified mount works for you. If you get a good result, I will make it my business to get one altered. Looks like you doubled the clearance which is what I wanted to do.
I have yet to scour the spare parts inventory of the Nissan and Toyota dealers to see if they have a suitable standard sandwich type mount that might fit the bill. Will keep you posted if I find one.

 

[Aussie Nick]

You could fix the problem right away by trading the ML in on A Cruiser or a Pajero...........No........ Not a Good idea.........Sorrrrrry!

 

[kebo57]

Unfortunately the workshop I used to have no longer is mine!!!! I would be very interested to know how the modified mount works for you. If you get a good result, I will make it my business to get one altered.

Hi oigle you would only need a vise, couple of blocks & plates, & a jemmy
to do the mod see picture

Kevin