270 CDI gearbox and other problems

[qasim]

Hello all, I have been reading the forum for a while and must say I am impressed with all the great knowledge out there. I hope some of you can help with my problem. I am good at what I do in my job which is office based but know little to nothing about about fixing Mercs.

Purchased the car, my first Merc a 2002 270CDI abut 18 months ago with about 90K on the clock, full MBSH and new turbo fitted before I handed the notes over. Now has 103K on the clock having recently been serviced by Andy Gale. Usual intermittant problems with brake and number plate bulbs over 18 months and recently head light bulb but loved the car untill recently.

Problem started with a chattering noise like a playing card on a bicycle wheel which got progressivly worse and louder to the extent where it is very loud and deeper and driving me to distraction.

About three weeks ago auto gearbox decided to stay locked in 2nd or 3rd gear. Stopped car, started it again and gear changes as normal. Started to happen more frequently untill locked perminantly in 2nd or third gear so having to rev up to 3000 rpm to achieve 30mph. Took it to recommended mechanic who put diagnostics on it and found nothing. Mechanic took it to gearbox specialist who managed to reset the box. Paid £40.00 total. However after 3 days back to being stuck in 2nd or 3rd. Also when it gets stuck, the S/W function stops. Last monday limped home to Birmingham from Coventry. Took it back last Tuesday and its still in the workshop. Mechanic has tried changing the MAF but no better. He fitted a new switch to the gearbox (apparantly there is such a thing) again no better. He thinks that I may need a replacement gearbox.

Also, since the problems started, there has been a burning oil? smell. Its not been possible for me to even look under the car for problems because of the plates fitted under the car. Oh, and the parking brake stopped makeing the rattchet noise when depressed, i have found bits of broken plastic but do not think this is major since the brake still works and to replace the plastic should not cost very much. Any suggestions (apart from giving it the John Cleese treatment) would be most welcome.

 

[television]

It is possible that you water in the oil in the gearbox, ask Andy Gayle to do the glycol test.
You do not say the model of the car though I suspect it is a 211, if it is a 211 if effects cars up to 30.09.03 the Valeo oil cooler/ radiator leaks.

Other cars effected are the 203 and 209 up to 30.09.03

malcolm

 

[qasim]

Thanks Malcolm, I will mention this to the mechanic when I see him in the morning, may have to get it to Andy Gale as you suggest. As I said previously, I do not know much about cars; all I know id it is 2002 CDi Aventgarde. Will let you know how I get on. Thanks again, Qaism.

 

[qasim]

Malcolm, you have just reminded me. I had the intercooler changed about 5 weeks ago because it had been leaking. I don't suppose there might be any connection?

 

[television]

Malcolm, you have just reminded me. I had the intercooler changed about 5 weeks ago because it had been leaking. I don't suppose there might be any connection?

Yes there could be, the first thing to do is to change all of the oil in the box,
What were the symptons when it went (inter cooler) I will post again with more details later in the day

malcolm

 

[qasim]

Thanks Malcolm, when the intercooler was diagnosed by Andy Gale, it was after I found oil on my drive and there had been a clicking noise (which I was told was the noise from oil leaking under pressure). I do not thrash the car so had not noticed any loss of power but Andy Gale told me that because of the intercooler leak I would find an increase in power after it was replaced. Apart from that the car ran absolutley fine.

 

[television]

Thanks Malcolm, when the intercooler was diagnosed by Andy Gale, it was after I found oil on my drive and there had been a clicking noise (which I was told was the noise from oil leaking under pressure). I do not thrash the car so had not noticed any loss of power but Andy Gale told me that because of the intercooler leak I would find an increase in power after it was replaced. Apart from that the car ran absolutley fine.

Sorry about my last post, it should have read no connection.

Malcolm

 

[liteuser]

when i lost power it was a lose 'turbo vacuum hose'. may be worth checking

 

[qasim]

Thanks guys, Mechanic drained the gearbox and had the fluid inspected by gearbox specialist. Apparantly because the fluid was a dirty/rusty brown colour I have been advised by the specialist that the gearbox is no good and needs to be replaced. Mechanic has sourced second hand replacement at a cost of £350.00 (recon apparantly costs 3 times that) and decided not to charge me for the work he has done so far, will charge me for fitting replacement box.

The noise has been diagnosed as a sticking fuel injector which cost £120 each! Apparantly the injectors on the CDi are badly designed, no room to get access to free it. Apparantly there is thick solidified tar like substance making the injecter stick which he has been trying to free up with WD40 over a few days but so far without sucsess. Only way to free these apparantly is to hit it with a hammer/chisel which can free it but more often than not end up with a scrap injector. Does anyone have any ideas on solvents or other methods to free it?

 

[liteuser]

try brake cleaner, cleans all sorts and evaporates after a couple of mins.

 

[qasim]

Thanks Liteuser
Mechanic tried sokeing it in brake fluid for some hours and that did not work. Problem is that it has solidified into a black rock like substance - like lava after it cools with a shiny appearance and the only way up to now (from his experience with diesal taxi's) has been to chip it away with a screwdriver or chisel and it breaks into little pieces. I have told him about your suggestion and he will give that a go in the morning failing which, unless someone else comes up with a suggestion, its look's like we will have to scrap it and fit a new one. Will let you know how we get on. thanks again.

 

[silverdreammachine]

my ml270 has started with same probs,had maf changed ok for a while then same again changed brake switch,same again.would reset with key but not now,anyone else with same and how do we solve?

 

[qasim]

Well, after about a week of soaking with various lubricants - duck oil, WD40, brake fluid and brake cleaner there was one other remedy to try to free up the injector. A new product on the market which comes in a small aerosol can at about £15.00. This freezes metal down to -40c in seconds. The idea being that if you spray this on one part, it contracts it thereby creating space tp free th injector. Howver before using this the mechanic made one last effort with his spanners and presto the injector was free so we never got to test the freezing spray.

After over 2 days with auto gearbox specialist, latest is that it is definately not the gearbox itself; its an electronic problem which they are still trying to pin point. Could be something as simple as the battery, could be alternator not charging battery or, may be the main ecu or the ESP unit. I was speaking to someone last night and these gearboxes are dependant on electrics. I had found the "ESP not available" warning coming on when this problem first started. My thoughts at present are that it is likely to turn out to be a faulty ESP unit because this receives information on spead from all four wheels and trys to work the best speed for the car to be at to avoid problems and send message to gearbox telling it which gear to be in. If this is malfunctioning, its not reading the correct spead and is sending wrong info to gearbox.

The gearbox specialist is working on it.

 

[Blobcat]

Well, after about a week of soaking with various lubricants - duck oil, WD40, brake fluid and brake cleaner there was one other remedy to try to free up the injector. A new product on the market which comes in a small aerosol can at about £15.00. This freezes metal down to -40c in seconds. The idea being that if you spray this on one part, it contracts it thereby creating space tp free th injector. Howver before using this the mechanic made one last effort with his spanners and presto the injector was free so we never got to test the freezing spray.

Freezer sprays have been used in electroincs for years, here are a few http://rswww.com/cgi-bin/bv/rswww/searchBrowseAction.do?N=4294729846&name=SiteStandard&in_dim_search=1&callingPage=/jsp/line/line.jsp&BV_SessionID=@@@@0162101506.1163946473@@@@&BV_EngineID=cccfaddjfjmkkjmcefeceeldgondhgi.0&cacheID=ukie&Nr=avl:uk

 

[television]

Some of the fault finfding does get very involved.. I think that if you had battery problems other things would have come to light. Simple test when parked, turn the headlamps on and measure the voltage across the battery,it should not be under 12 volt.

The gearbox ECU talks to the engine ECU, these in turn talk to the signal aquassion moduls and speed sensors scattered around the car via the Can busses. Has a fault code read out been done, one snag with the read outs is that often the piece at fault does not show up, as in Raj's 129 where there was a bad connection in the Gearbox ECU loads of implausable codes thrown up, but never the gear box.
Could this be a design fault in these systems,i have been in electronics long enough to know that with certain failures,the is no way that the faulty unit can give out fault codes. I can see that I am going to have to buy a code reader £2K but what the heck, as my older brother says that's nothing to spend on a hobby, and I have never had a hobby yet, apart from one,bless her.

Malcolm

 

[haydar]

Qasim

There are 3 things that can be causing the gearbox problem.

i. The torque convertor, if this starts to perform out of tolerance then the gearbox will go into fail-safe mode. Problems with Torque convertor are usually to do with the car jerking or juddering. This is an expensive part.
ii. The circuit plate. This sends the electric signals to the trottle body in which the gearbox accuators are located. This is a relatively cheap part and could well be causing the problem, especially if your car has suffered from coolant contamination.
iii. The throttle body. This holds the accuators which actually cause the car to change gear. If an accuator is faultly, it might not change gear properly and the car may revert to failsafe mode. This is an expensive part.

Try changing the circuit plate first and finger's crossed, it'll solve your problem.

 

[Uncle Benz]

Wise words from Malcolm. A fault code reader is only as good as the man operating it. Implausible or irrelevent codes occur a lot.

The problem you describe could indeed be ESP unit or wiring between.

I have also seen faults that provoke ESP not available and gearbox in safe mode caused by low fluid level.

If this is the case you will see a fault code reading something like 'ESP failure - input/output speed implausible' which happens basically because the low fluid level is causing the box to slip.

I'm not saying this is the problem you have, but a good fault reading session could give you the answers you need. Make sure the people you use have the gear and know how to use it. I would have thought Andy Gale should be able to do this, but personally I have no experience of him.

 

[silverdreammachine]

pain ml gearbox

Further to my last post.Qasim joged my memory when i read his post.My BAS/ESP light came on intermitantly about 12 months ago when brake pedal pressed resulting in no cruse control/speed limiter working but would reset on a restart.This was the start of my probs but did not link the two things,surely there must be more mls with this fault. 2000 270 62000 mls on clock.

 

[charlieB]

I think we might have the same problem

This is my thread of a month ago
I have a Mercedes C270 CDi Automatic. Year 2001
When I use the kickdown sometimes it defaults to 2nd gear. I have to stop the car switch off the engine it then resets itself. I put it into Mercedes they changed the gear selector this did not work. I took it to an automatic gearbox specialist he changed the valve body. This did not work. I have been told it may be the speed sensor the chap who changed the valve body has said he changed the speed sensor. Now I am being told it needs a new gearbox but the car runs fine if I do not use the kick down. Can anyone help

Sorry no remedy yet I will keep you posted

 

[qasim]

Well, the news today from the auto gearbox specialist is that it is definately NOT the gearbox itself. This is from Driver Transmissions, cheap Side, Digbeth in Birmingham who, I am told are amongst the best in the business and to whom the local MB steelerships send their auto gearbox probs. They have identified the problem as an electrical one but have not been able to pin point which. So next step is to see if Andy Gayle can help with his Star Diagnostic system. Will keep you all posted.