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I have a few of the R320's, one for ten years now, the other two more recently to keep one going...
Sorry to say they are not well understood except at really large Mercedes dealers. It took 4 dealerships to get my wheel alignment issue resolved (it was eating tires) as setting the ride height is essential to doing the wheel alignment...4 corner airmatic.
Be sure to change ALL the fluids, transfer case, drain the brake calipers and flush the brake fluid very well. They are one complicated vehicle to stay on top of, let alone deal with previous owners neglect-sometimes the transmission fluid needs a couple tries to get the fluid clean again if it is not serviced every 60k (not once as MB says), p/s racks generally have leak issues on the input shaft seal so keeping that fluid fresh never hurts.
Drive train issues can also be a big hurdle, driveshafts and axles on cars that were driven hard/aggressively.
For heater core issues do a citric acid flush and back flush with metered compressed air, VW/Audi products commonly have plugged heater cores and a lot of junk comes out using compressed air (not 125 psi, set it to 40 or 50 and experiment). If you not find anything coming out I doubt replacement is needed. Even vinegar would likely do the job, soak 15 min and flush.
The best scan tool I have found so far is the MBII iCarsoft on Amazon for $150, easy to use and reliable. I have an Autel unit that is useless (very basic one). I have not jumped into the Star stuff as most comment it crashes often or is not easy to use without computer tech knowledge to make it work.
Parts for these cars are pretty much impossible in Canada unless you consider dealer retail a fair price. They are never in stock either. I import everything I need from the US or use Exoparts.com in Toronto, oem with a discount when I cannot find it aftermarket.
Have a look at your brake rubber hoses, especially the front ones
Look at the control arm bushings especially the rear most ones on the front suspension, they tend to sag/split.
Never had a ball joint or tie rod replacement yet (300k on two them, 265 on other), they make great suspension parts considering the weight of these things.
Front sway bar mount bushings are usually worn and making noise, the end links go every 8-10 years.
Rust likes to hide around the jack points and inside the rear wheel wells (you might be fine being out west, but never hurts to peel parts off to look). I had severe rust hiding on one I recently bought, a foot of rocker panel missing/jack point structure and both inner rear wheel wells just a giant rust scab, and it had annual rust sprays done! Keeping the salt and sand out of the underbody and structure is a big task-the front wheel wells have some sand traps behind the struts, the back bumper area holds lots of junk, the rear subframe, jack points, rocker covers all love to hold lots of stuff and moisture. They were not well thought out, stuff gets in and is held there.
Then there is the floors, the actual floors that are a foot beneath the carpets. Usually moisture is down there from a poor carpet shampoo job (trapped, no drain) along with salt and whatever was spilled in the interior.
It always has stuff trapped and causing rust in the longitudinal channel of the floor structure, Mercedes did not put any wax flooding/undercoating down there so you will find rust. Seats out (both front rows), carpets out, under carpet panels out and voila, the hidden secrets of the underworld of the R class where all the electronics are stored and prone to flooding...the amount of damage varies with the treatment the vehicle had, lots of kids bring wet snow and gear, lots of moisture and rust, even some of the electronics, amps and brackets. Pair of professional adults and likely just a little damage. But you need to investigate. Once the rust is dealt with (I used Por15 3 step process) I flood it with rust chek or similar product. It is trapped down there and not going to rust again.
Keep your park brake cables in excellent shape, spray them with rust protection every year. The front cable is 10 hour to swap...it runs under everything (center console, carpets, seats) and a huge job.
There are also some upgrades coming out for them now, 722.9 + trans pan and blue fluid with 3 stage filter one of the more recent ones to be found.
I have a few of the R320's, one for ten years now, the other two more recently to keep one going...
Sorry to say they are not well understood except at really large Mercedes dealers. It took 4 dealerships to get my wheel alignment issue resolved (it was eating tires) as setting the ride height is essential to doing the wheel alignment...4 corner airmatic.
Be sure to change ALL the fluids, transfer case, drain the brake calipers and flush the brake fluid very well. They are one complicated vehicle to stay on top of, let alone deal with previous owners neglect-sometimes the transmission fluid needs a couple tries to get the fluid clean again if it is not serviced every 60k (not once as MB says), p/s racks generally have leak issues on the input shaft seal so keeping that fluid fresh never hurts.
Drive train issues can also be a big hurdle, driveshafts and axles on cars that were driven hard/aggressively.
For heater core issues do a citric acid flush and back flush with metered compressed air, VW/Audi products commonly have plugged heater cores and a lot of junk comes out using compressed air (not 125 psi, set it to 40 or 50 and experiment). If you not find anything coming out I doubt replacement is needed. Even vinegar would likely do the job, soak 15 min and flush.
The best scan tool I have found so far is the MBII iCarsoft on Amazon for $150, easy to use and reliable. I have an Autel unit that is useless (very basic one). I have not jumped into the Star stuff as most comment it crashes often or is not easy to use without computer tech knowledge to make it work.
Parts for these cars are pretty much impossible in Canada unless you consider dealer retail a fair price. They are never in stock either. I import everything I need from the US or use Exoparts.com in Toronto, oem with a discount when I cannot find it aftermarket.
Have a look at your brake rubber hoses, especially the front ones
Look at the control arm bushings especially the rear most ones on the front suspension, they tend to sag/split.
Never had a ball joint or tie rod replacement yet (300k on two them, 265 on other), they make great suspension parts considering the weight of these things.
Front sway bar mount bushings are usually worn and making noise, the end links go every 8-10 years.
Rust likes to hide around the jack points and inside the rear wheel wells (you might be fine being out west, but never hurts to peel parts off to look). I had severe rust hiding on one I recently bought, a foot of rocker panel missing/jack point structure and both inner rear wheel wells just a giant rust scab, and it had annual rust sprays done! Keeping the salt and sand out of the underbody and structure is a big task-the front wheel wells have some sand traps behind the struts, the back bumper area holds lots of junk, the rear subframe, jack points, rocker covers all love to hold lots of stuff and moisture. They were not well thought out, stuff gets in and is held there.
Then there is the floors, the actual floors that are a foot beneath the carpets. Usually moisture is down there from a poor carpet shampoo job (trapped, no drain) along with salt and whatever was spilled in the interior.
It always has stuff trapped and causing rust in the longitudinal channel of the floor structure, Mercedes did not put any wax flooding/undercoating down there so you will find rust. Seats out (both front rows), carpets out, under carpet panels out and voila, the hidden secrets of the underworld of the R class where all the electronics are stored and prone to flooding...the amount of damage varies with the treatment the vehicle had, lots of kids bring wet snow and gear, lots of moisture and rust, even some of the electronics, amps and brackets. Pair of professional adults and likely just a little damage. But you need to investigate. Once the rust is dealt with (I used Por15 3 step process) I flood it with rust chek or similar product. It is trapped down there and not going to rust again.
Keep your park brake cables in excellent shape, spray them with rust protection every year. The front cable is 10 hour to swap...it runs under everything (center console, carpets, seats) and a huge job.
There are also some upgrades coming out for them now, 722.9 + trans pan and blue fluid with 3 stage filter one of the more recent ones to be found.
I've been ordering parts from partsavatar.ca and pelicanparts.com
Plan on doing rust removal next year, it was going to be this year but I decided to tackle some mechanical issues first, thanks for the heads up regarding the suspension bushings and rust issues.
I figured if the heater core wasn't completely plugged there must be someway to clear it out as liquid can still pass through it, going to have it flushed out again to see what happens before I deal with replacement of it.
You can save a lot on parts with other sites, believe me and not suffer on quality. It does take some time to research/look around though. You do have a very unique model!
With the heater core if it is restricted with scale it can take several attempts, some VAG products we do every fall like clockwork.
Make sure you do the transfer case and that you use the upgraded fluid for the front diff. Transfer case is a 20 minute job. Ignore MB advice on trans, transfer case and diff fluids. Change them all regularly as well as coolant.
The C4 Star diagnostic came in a few days ago and I've been checking out DAS and here is what I've found regarding the heating
Looks like left footwell sensor is reading incorrectly and a diverter flap actuator motor is faulty?
While the vehicle is warmed up in the heated garage;
After driving around the block(-7'C outside)
After Check of adjustment range of positioning motors;
Not sure exactly what the diverter test is stating other than replacing the diverter motor or of theres an issue with the flap itself.
That left footwell sensor is reading high in my opinion though, not sure why it would be reading so much higher than the others.
Had the heater core flushed as well and they were able to remove a substantial amount of silica from the core, which means the silica bag inside the reservoir(?) ruptured sending this crap everywhere, we now have good heat coming from the vents but I intend on doing another flush next year or if it plugs up again.
EDIT: forgot to also mention that my wife was cut off by a minivan and ended up rearending them as she couldn't come to a stop in time due to the ice and crappy all seasons causing a decent amount of damage to the front grills, I managed to locate some nice looking GL/ML rims with almost new winter tires and what an improvement that is over the all seasons.
Bought and installed a new upper grill from a R350 at a wrecker and managed to order a new Sport/AMG lower grill for a reasonable price($115 shipped) from Alieexpress, dealer wanted $450~ for it. I found two part numbers for the lower grill A2518851053 and A2518850553 but the latter one is the one I used to order from Aliexpress
-Sounds like I may have a worn front driver side front wheel bearing, started out as a groan that only happened when turning the wheel a certain direction while driving, now its groaning whenever the vehicle is moving and is more audible at slower speeds regardless of what direction the wheels are turned, have researched it could also be the front differential wearing out, however the major symptom of front diff wear is a sound when decelerating/taking foot off gas and accel/decel makes no difference with regards to the sound.
-Rear DVD player will run the optic laser cleaning disc I have but whenever I insert a store bought DVD I get "Invalid DVD format or Disc error"
Still waiting on the MOST converter from Aliexpress so I can slam in an updated infotainment system I purchased a while ago.
-Sounds like I may have a worn front driver side front wheel bearing, started out as a groan that only happened when turning the wheel a certain direction while driving, now its groaning whenever the vehicle is moving and is more audible at slower speeds regardless of what direction the wheels are turned, have researched it could also be the front differential wearing out, however the major symptom of front diff wear is a sound when decelerating/taking foot off gas and accel/decel makes no difference with regards to the sound.
-Rear DVD player will run the optic laser cleaning disc I have but whenever I insert a store bought DVD I get "Invalid DVD format or Disc error"
Still waiting on the MOST converter from Aliexpress so I can slam in an updated infotainment system I purchased a while ago.
Nothing wrong with the wheel bearings or drivetrain lol, just noisy tires making the noise.
Have to replace the passenger rear airbag though as its leaking, ordered a new Arnott unit from rockauto for $194CAD shipped so I'm looking forward to slamming that in
Updated the front corner lights, new one on the passenger side, old one on the driver side, also updated the license plate lights but still get the error, ordered from superbrightled store.
No actually I will be replacing the driver side front air bag, I raised the ride height a bit over an inch in Xentry as the leak was on the fold of the bag and now at least it's stopped leaking, new bag arrived yesterday, going to be tackling it this weekend. Bag is an Arnott and was $390 shipped from Rockauto.
Also did the rear muffler delete, it's not overly loud and I have to say I do like the way the vehicle sounds now.
Just finished reading your thread. Was very happy to see you replaced the hideous rims that came with car. The new ones are perfect. And nice LED parking light bulbs. I'm going to order some now
10-30-2020, 12:47 AM
