occasional limp mode and leaking injectors

[kmn]

Hi guys - I am in need of your sage advice! apologies for the long intro to my problems...

I recently bought an x reg w210 320 cdi estate. I got it cheap off a friend as the suspension needed fixing which is done. I have since had the following problems:

1) occasionally it goes into limp mode (max 2000 rpm). This happens a few times a week and tends to happen when going up steep hills. I have changed the MAF sensor which has made the performance better, but unfortunately it still limps occasionally. As soon as I turn the car off and restart - all is well again. Apparently no codes are showing and there are no malfunctions.

2) The car must have had leaking injectors for some time before I got it as there was the usual thick layer of black stuff all across the top of the rocker cover. I took it to my local independent (INAUTOS, Sussex) and they cleaned up the injectors and claimed they were fixed. A month later, and not only are at least two injectors blowing, but there is now liquid diesel sloshing about on the top of the rocker cover around the injectors.

My questions to you learned folk are therfore:
1) any ideas as to what may be causing the limp mode
2) is it usual for injectors to go again so quickly after apparently being repaired - should I have faith in the same garage again?

Any advice would be most welcome


p.s. almost forgot - ABS, BAS EPS lights occasionally come on symultaneously - I changed the break light switch but it still happens. Systems work inc break light even when warning lights are on. Not too worried about this.

 

[kmn]

update: Took it back to INAUTOS and they were great. Tightened up the bolts on the injectors and the metal feed pipes which stopped the diesel leak and injector pressure leak. So far so good on the injector front.

Limp mode problem is still not solved, but they are going to try and clean up the EGR valve and see if that helps as well as check the pipes to and from the intercooler as apparently STAR is showing a problem with turbo pressure boost......

 

[BlackC55]

Tightening the bolts won't help in the long term. The injector seats need re-cutting. I have a tool that I hire for this aplication. Let me know If I can help.

 

[kmn]

update

injectors seem to be ok for now, but I can't get to the bottom of the limp mode cutting in on steep hills.
The garage hooked it up to their machine which said 'low boost pressure'. They checked all pipes for leaks but there were none. They then removed the EGR valve which needed cleaning, but alas I got the car back and the problem is still happening.

So, its had a new MAF sensor, cleaned EGR valve, there are no leaks....what else could be causing it to go into limp mode on steep hills? Could the turbo be failing?

Help.....please.....

 

[proser]

Hi KMN

what did the MAF cost and was it genuine ??

 

[kmn]

Hi Mark - MAF was bought at great expense from Mercedes Benz of Gatwick. Could they have given me a dud?

Cheers

Karoly

 

[BlackC55]

The inlet port shut off could be sticking.

 

[kmn]

Thanks for the suggestion BlackC55. Is that something a novice such as myself could check or would I be better off getting it looked at professionally.
Do you know of anywhere I can acquire a workshop manual for my car or at least a diagram of the 320 cdi endine? I have no idea where the inlet port shutoff valve is..

Thanks for the suggestion and the earlier offer of tools - much appreciated.

 

[kmn]

took it back to the garage for more investigation. The only fault codes are low pressure boost. Tested the inlet port shut off valve which seemed to open and close on demand via STAR. All the pressures were tested and all worked perfectly. The mechanic is going to drive my car for a few days to see whether he can deduce what is going on.
The service I have got from INAUTOS has been exceptional even though they haven't solved the problem yet they are giving me lots of time and effort basically free!
They have my recommendation..

 

[sms78]

had trouble with my w210 320 cdi that kept going into limp mode plus lost about 10mpg and it turned out to be a non genuine maf sensor that i got from a certain french & german parts supplier . Ones they sell also fit volkswagens and they arn't quite right as i have found out by testing two of them . Ones from mercedes even though they looked exactly the same and had pierburg on them worked fine every time . But i have had a dud maf before from mercedes and took quite a bit of fuss for them to change it as they wanted the whole car in to test it !

 

[kmn]

Thanks sms78. I picked up a genuine MAF from Mercedes Benz of Gatwick so presume its ok.

An update: We are still stumped as to what the problem could be, but I discovered something new that could be connected to the limping up hills problem.
Our driveway is on a slope and if the car is parked over night facing uphill, it is difficult to start in the morning. It fires, then dies. It then turns over for quite a long time before eventually starting and even then wont rev up fully straight away.
Could the fact that it wont start when parked overnight facing uphill and that it is limited to 2000 rpm occasionally when going uphill, be connected?
Sounds like fuel starvation to me, but where should I start investigating? I have heard talk of delivery valves and 'O' rings....

 

[hygt2]

Thanks sms78. I picked up a genuine MAF from Mercedes Benz of Gatwick so presume its ok.

An update: We are still stumped as to what the problem could be, but I discovered something new that could be connected to the limping up hills problem.
Our driveway is on a slope and if the car is parked over night facing uphill, it is difficult to start in the morning. It fires, then dies. It then turns over for quite a long time before eventually starting and even then wont rev up fully straight away.
Could the fact that it wont start when parked overnight facing uphill and that it is limited to 2000 rpm occasionally when going uphill, be connected?
Sounds like fuel starvation to me, but where should I start investigating? I have heard talk of delivery valves and 'O' rings....

Blocked fuel filter?

 

[AndyPCD]

The poor starting in the mornings could be some of the plastic fuel pipes not being air tight and allowing fuel to return thus causing an airlock in the fuel system.

This could also cause the lack of power as it will draw in air when it is under load.

There is about four or five plastic pipes on the engine so would start there.

What area are you in

 

[kmn]

Thanks for the advice - will have my garage check the fuel lines and filters next week. It does make sense that the problems are connected and erratic.

East Grinstead is my nearest town

 

[hygt2]

Thanks for the advice - will have my garage check the fuel lines and filters next week. It does make sense that the problems are connected and erratic.

East Grinstead is my nearest town

You can change the fuel filter yourself first and see if it helps.

Only a 15 minutes job and it's well under £20 and it's a consumable anyway.

 

[proser]

Had a similar thing with fuel pipes letting air in and difficult to start in the morning, as described by KMN. When running you could see the air getting into the pipe that runs out of the filter to the pump. Replaced pipe and haven't had the same problem since.

HTH

 

[alexander patie]

if you try parking it facing downhill it may start ok!! as others say air is being drawn in with engine off, allowing fuel to drain back to tank.

this however will NOT be the cause of your limp home mode.

common causes of low boost are: heavily soiled air filter, leaking hoses and INTERCOOLER, sticking egr, blown egr diaphragm, leaking or jammed port flaps, blocked cat/s, and turbo vacuum supply issues (blocked/leaking pipes or faulty vacuum modulator). this assumes a 210 e320cdi. NOTE, jamming port flaps will generate their own specific code.

 

[kmn]

oh no! I was hoping a fixed fuel pipe or two would solve all my problems...seems I cant get my hopes up too high just yet.
All the pressures/vacuums have been checked, the egr has been cleaned and checked. The inlet port shut off has also been roughly checked with STAR and seems to work fine.....which I guess leaves air filter, fuel filter, and cat/s as well as the fuel line checks. All seem cheap to do except the cat which is probably horrifically expensive?
The car only has 117,000 miles - does that eliminate any of the possibilities? I guess after about 80,000 any part is fair game to fail.

 

[alexander patie]

the cat problem is caused by the front cat coming loose in its housing and causing enough debris to block the second cat. if you remove the front to check it make sure it cannot be moved to-and-fro in its housing, also check that both ends of the monolith are perfectly square. easy to check and free.

 

[kmn]

will do - thanks for the advice.
btw should one replace cats as a matter of course after x number of miles.....do they naturally deteriorate and affect performance?