Numerous Ml Faults

[currycowboy]

Bought myself an ML 270 2001 british registered car in spain for use getting out and around rough terrain. I live in a very hilly area (near Riogordo, Malaga) on a dry river bed, which undulates over rough shingle and rocky ground which i thought the ML would be great for. Its an old car that has covered 143k and hasn't been maintained very well if at all. Cars are extortionate in Spain and this is all my budget could suit at €1200, which i thought was cheap and am gambling the fixes are not going to double the price!!!
The dashboard lights are lit up like a christmas tree. ABS, water level/temp, sensor esp, airbag all lit. There is no kick down and on inpection the kick down switch seems to operate mechanically although I havent used a multimeter on it as I dont currently have tools out in Spain and will be taking them with me next time I go. There is a lot of float in the accelerator peddle left to right (seen fix for replacing plastic pin for bolt and will do that when i get out to spain in few weeks). Am on here predominantly to try and get info to fix it, so I can amass necessary parts in Uk which will be cheaper than spain and take them with me.
The car seems fairly gutless in drive, is better in Tip and in low range. When in Tip shifting down it does seem to emit more darker emissions but when revved in park doesn't seem to be excessive, usual diesel look and no major engine noises. In drive I am only reaching 40mph on inclines etc revving only to about 2500-3000rpm.
I bought the ML through a 3rd party and the owner states that Mercedes told him there is likely a valve issue on outlet on manifold that needs cleaning. Can anyone shed light on this also please and how easy/difficult a repair to diy fix, if indeed this is the likely reason for lack of power etc. I thought maybe it may have been MAF sensor prior to this revelation but am clutching at straws as have no knowledge whatsoever on Mercs, this being my first. .
The radiator fan is not working but temp seems to be stable around 80-85 coolant level is correct. I need to sort this though as I dont want anything to cook when its hot again, also would be nice for aircon improvement as o.k when moving but warm when stationary!!
Needs passenger mirror assembly has back casing only and needs drivers side casing only, aint they kin expensive!!!!!
Havent inspected gearbox whatsoever so wouldn't know about ATF drain top up if there is a stick or measured amounts so any info on that would also be greatly appreciated.
The car is surprisingly complete with only a few battle scars for a Spanish car (they are normally dented about all over, so would be nice to get sorted, being a 7 seater will be really handy to collect relatives from the airport or anyone on this forum who fancies flying out to fix it lol.
I have purchased oil, air and oil filter and intend changing (with my tools on my next trip out there). Where is filter housed on these (only had 5 minute look when i was there and couldn't see it).
First post and welcome sarcasm piss takes etc as well as some help which I am sure will be in abundance

 

[Bobby Dazzler]

I can't help on many of those points but for the cost (£60 and 15 minutes, or less) then I would change the MAF - could be the cause of both limited revs and lack of kick down.

Sounds like you already know about the pedal fix - I recall this is a scheduled service item, but if it doesn't visit a dealer it won't have been changed.

Lastly there's a known problem with the brake switch which causes the ABS light to illuminate. I recall they're about £15 and so worth changing to see if it takes out at least one light!

Even with the problems you mention it sounds like a cheap car - hopefully easy fixes.

 

[jay1983]

Welcome to the joys of ml ownership.

If I was you I'd go to mercedes and purchase a positive terminal battery fuse. Approx £5 and fits on the positive terminal with a large red plastic screw. This is a usual suspect for the low coolant level light and also runs the fan. For the cost it's worth changing to eliminate that possibility. I would also purchase a genuine maf for piece of mind.

The likely hood is your egr valve and inlet manifold will be full of crap. There are good write ups on here on how to clean them up and modify the manifold to make it run better. This would be a good start to see if it runs better.

Unless you can get it on a star diagnostics system in Spain you will be guessing and spending money trying to fix the issues. It might be an idea to bite the bullet and take it to a dealership over there to at least get an accurate diagnoses.

It will also benefit from a gearbox fluid change by the sounds of it.

All in all the ml is a very capable workhorse, but does need a bit of tlc. It should be good for twice that mileage.

 

[jay1983]

Btw air filter is on the left of the engine as you look at it, in a box secured by 3 star bolts and the fuel and oil filters are on the other side under the engine covers

 

[currycowboy]

Welcome to the joys of ml ownership.

If I was you I'd go to mercedes and purchase a positive terminal battery fuse. Approx £5 and fits on the positive terminal with a large red plastic screw. This is a usual suspect for the low coolant level light and also runs the fan. For the cost it's worth changing to eliminate that possibility. I would also purchase a genuine maf for piece of mind.

The likely hood is your egr valve and inlet manifold will be full of crap. There are good write ups on here on how to clean them up and modify the manifold to make it run better. This would be a good start to see if it runs better.

Unless you can get it on a star diagnostics system in Spain you will be guessing and spending money trying to fix the issues. It might be an idea to bite the bullet and take it to a dealership over there to at least get an accurate diagnoses.

It will also benefit from a gearbox fluid change by the sounds of it.

All in all the ml is a very capable workhorse, but does need a bit of tlc. It should be good for twice that mileage.

Thanks for those tips.
Is there an EGR blanking plate on the market, someone advised me that he has done this on a couple of cars and it solved the problem.
I know where the air filter is, thanks for telling me where oil and fuel is.
Will I get significant info from an OBDII reader or is star only route?

 

[John Jones Jr]

If I was you the first item to get is a decent code reader (which one I don't know), post the codes and parameters up here and I'm sure several on here will be able to assist.
Or as suggested use an M-B dealer for the same job. Regardless, I'd still get a new Bosch MAF.

 

[currycowboy]

Welcome to the joys of ml ownership.

If I was you I'd go to mercedes and purchase a positive terminal battery fuse. Approx £5 and fits on the positive terminal with a large red plastic screw. This is a usual suspect for the low coolant level light and also runs the fan. For the cost it's worth changing to eliminate that possibility. I would also purchase a genuine maf for piece of mind.

The likely hood is your egr valve and inlet manifold will be full of crap. There are good write ups on here on how to clean them up and modify the manifold to make it run better. This would be a good start to see if it runs better.

Unless you can get it on a star diagnostics system in Spain you will be guessing and spending money trying to fix the issues. It might be an idea to bite the bullet and take it to a dealership over there to at least get an accurate diagnoses.

It will also benefit from a gearbox fluid change by the sounds of it.

All in all the ml is a very capable workhorse, but does need a bit of tlc. It should be good for twice that mileage.

Had a good read of some mods etc removing egr valves and fooling maf sensor, so assume from your comments you are saying clean the inlet first get flaps freed up, clean egr and refit see how it runs? or it would be pointless buying new MAF if I am going to go the route of modding the manifold as it would be redundant?

 

[jay1983]

Had a good read of some mods etc removing egr valves and fooling maf sensor, so assume from your comments you are saying clean the inlet first get flaps freed up, clean egr and refit see how it runs? or it would be pointless buying new MAF if I am going to go the route of modding the manifold as it would be redundant?

I would personally do the manifold mod and change the maf. Purely so there are no potential faults sent to the ecu. I could be wrong but I believe the maf monitors air flow to regulate the air/fuel mixture and the inlet manifold works together with the egr to reduce emissions?

Either way a faulty maf will continue to operate regardless of the modification done to the manifold

 

[currycowboy]

I can't help on many of those points but for the cost (£60 and 15 minutes, or less) then I would change the MAF - could be the cause of both limited revs and lack of kick down.

Sounds like you already know about the pedal fix - I recall this is a scheduled service item, but if it doesn't visit a dealer it won't have been changed.

Lastly there's a known problem with the brake switch which causes the ABS light to illuminate. I recall they're about £15 and so worth changing to see if it takes out at least one light!

Even with the problems you mention it sounds like a cheap car - hopefully easy fixes.

The brake lights operate ok, so I would assume the switch works or is there something I am missing here? are the ones on fleabay any good or would you go genuine? same question regarding MAF?

 

[currycowboy]

I would personally do the manifold mod and change the maf. Purely so there are no potential faults sent to the ecu. I could be wrong but I believe the maf monitors air flow to regulate the air/fuel mixture and the inlet manifold works together with the egr to reduce emissions?

Either way a faulty maf will continue to operate regardless of the modification done to the manifold

From what I have read modding the manifold and removing flaps results in limp home mode if the MAF is left as is. It needs a little wire harness with couple of resistors to fool ECU, if I have interpreted things correctly?
I did disconnect the lead from the MAF sensor and the car drove exactly the same for a mile so I pulled over and reconnected.

 

[Howard]

The brake lights will work ok even with a defective switch , but a bad switch can throw up all sorts of errors

As an example , when mine failed on my CLK , i had ABS defective , BAS defective , ESP defective warnings come up. All cured with a £15 brake switch.

Get it from the dealer using your VIN , as they can vary from year to year even on the same model.

Once you've fitted it , you need to go lock to lock twice to reset the system.

The other thing that can throw up things like that is the steering angle sensor , but i'd try the brake light switch first as it's the cheapest option and the car will probably need one anyway at 143k

Good luck. We have an ML 430 as well , and its a very capable car.

 

[gIzzE]

The MAF on these go pretty often, but they are cheap, around £65 from a dealer with a bit of discount.
Don't buy anything but a proper one, people report getting them and them being faulty from the start, so that won't help your diagnosis.

When you sit in park does the car rev over 3000rpm.
Start car, don't put it in gear or move, just rev, if it doesn't go passed 3000rpm your maf 99% certainly.

 

[panason1c]

Sounds like a good price, even with the faults it came with.

These are very easy cars to work on and not overly expensive to repair.

Basically, the inside of the brake light switch is fitted with a twin set of contacts, one set works the brake lights, the other set is for multiple functions via the ecu, therefore, it is common for the brake light switch to be faulty even though the brake lights operate as normal. Cruise control might also not work with faulty BL switch. New switch costs around £10 and is a 5 minute job to fit.

As suggested, Best to replace the maf with a genuine part (NOT an ebay purchase), a faulty maf will cause the kickdown and turbo to be inoperative. About £70 from MB (UK) and 10 minutes to fit

The coolant light and non-working engine fan may be caused by a blown fuse which is located on the battery positive pole (square shaped fuse)....this fuse, when blown, will also cause the heated seats not to function properly. Fuse about £5 from MB and 5 minutes to fit. (or buy a 30amp fuse and holder and wire it in place of the MB one)

Any time you disconnect and then reconnect the battery you need to turn the steering from lock to lock a couple of times with the ignition turned on to extinguish the ets light on the dash

Airbag light on is usually caused by a faulty passenger seat sensor, check all underseat connections, including the rear seats. You will need a scanner (or similar) to reset the airbag light once the fault is rectified.

Almost tempted to take your offer of a free holiday if work commitments didnt get in the way. (-:

 

[currycowboy]

Sounds like a good price, even with the faults it came with.

These are very easy cars to work on and not overly expensive to repair.

Basically, the inside of the brake light switch is fitted with a twin set of contacts, one set works the brake lights, the other set is for multiple functions via the ecu, therefore, it is common for the brake light switch to be faulty even though the brake lights operate as normal. Cruise control might also not work with faulty BL switch. New switch costs around £10 and is a 5 minute job to fit.

As suggested, Best to replace the maf with a genuine part (NOT an ebay purchase), a faulty maf will cause the kickdown and turbo to be inoperative. About £70 from MB (UK) and 10 minutes to fit

The coolant light and non-working engine fan may be caused by a blown fuse which is located on the battery positive pole (square shaped fuse)....this fuse, when blown, will also cause the heated seats not to function properly. Fuse about £5 from MB and 5 minutes to fit. (or buy a 30amp fuse and holder and wire it in place of the MB one)

Any time you disconnect and then reconnect the battery you need to turn the steering from lock to lock a couple of times with the ignition turned on to extinguish the ets light on the dash

Airbag light on is usually caused by a faulty passenger seat sensor, check all underseat connections, including the rear seats. You will need a scanner (or similar) to reset the airbag light once the fault is rectified.

Almost tempted to take your offer of a free holiday if work commitments didnt get in the way. (-:

Thats helpful thanks. Will be going to local dealer tomorrow, to but those parts suggested.
Do you, or anyone else happen to have an answer to my question regarding gearbox fluid in original post above please?

 

[panason1c]

Thats helpful thanks. Will be going to local dealer tomorrow, to but those parts suggested.
Do you, or anyone else happen to have an answer to my question regarding gearbox fluid in original post above please?

Gearbox fluid is best bought from MB, the system holds about 7.5ltr but you will only need about 4ltr as the torque converter does not have a drain plug resulting in some fluid remaining in the system.

There isnt a dipstick for the tranny, you have to buy one and place it into the tube on the left, rear of the engine (as you look at the engine)

You will need 4ltr of fluid, a new rubber sump gasket and a oil filter to service the box.

Best to do a search on the forum as there is loads of info on servicing the gearbox.

 

[currycowboy]

The MAF on these go pretty often, but they are cheap, around £65 from a dealer with a bit of discount.
Don't buy anything but a proper one, people report getting them and them being faulty from the start, so that won't help your diagnosis.

When you sit in park does the car rev over 3000rpm.
Start car, don't put it in gear or move, just rev, if it doesn't go passed 3000rpm your maf 99% certainly.

Top man, 2800 is the max in park. One Pierburg MAF ordered from ECP

I'm liking this forum.

Thanks guys.

 

[gIzzE]

Is that the OEM one? I thought mine was Bosch?

See how you go with it, if it still doesn't rev higher I would return it and get one from Mercedes.

 

[currycowboy]

Is that the OEM one? I thought mine was Bosch?

See how you go with it, if it still doesn't rev higher I would return it and get one from Mercedes.

Its the one I found links from other members to on here, so I thought it was the prefered one. Maybe I dropped a clanger I didn't see anything in the thread I read to cast aspersions on the Pierburg, GSF quote it as being OEM but pass, maybe Bosch and Pierburg were used..... answers on a postcard

 

[panason1c]

Mine is OE direct from my MB dealer, and it is a Pierburg.. (-:

 

[Howard]

Will it rev past 3k in park / neutral ?

I didn't think they were meant to , regardless of if the MAF is working or not