Diesel smell in cabin

[BobHUK]

Hello,

I've got an S210 diesel E220 CDi Estate automatic. I've had the car for around 2 1/2yrs, and last winter I had to replace all 4 glow plugs and no. 3 injector when the car became difficult to start from cold. Since then everything's been fine, but over the last couple of months I've noticed a smell of burnt diesel in the cabin, especially when stuck in traffic. To overcome the smell I've been using the air recirculation button on the dash to stop any nasty niffs from getting into the cab.

Today it was time to change the oil and filter, so I took the plastic engine covers off. When I did so it became obvious why I've been able to smell burnt diesel. Around injectors nos 1 and 4 there was a lot of black shiny stuff. I thought it was oil at first, but when I tried to wipe it away I found I couldn't.



It looked like oil, but it was hard and dry, like black plastic. However, I found that I could scrape it away with a screwdriver. So I spent the next few minutes carefully loosening and removing the black gloop from around the base of no. 1 injector so that I could try to find out where the leak was exactly.

With some difficulty and an injector removal slide hammer, I managed to get no. 1 injector out, after which I saw this sorry sight.



I managed to clean the mess away eventually, and remove the injector sealing washer from the bottom of the hole.

I've now got to do the same with the no. 4 injector, then I'm going to remove all the injectors and fit new sealing washers and securing bolts. With luck it will eventually look like this again.



Previously I'd had to replace no. 3 injector because it failed a leak-off test, and you can see the newly replaced injector in the picture above. You can also see that at that time all four injectors were clean and dry, and it's a bit of a worry to me that two other injectors have blown their seals 6,000 miles later. So when I do lift the injectors, fit new seals and mounting bolts, and refit them, I'll make sure to torque them all down to the correct tension, and in the correct order, as I've got a manual which states that the injectors have to torqued down in a particular order. According to the manual, for my four cylinder engine the sequence is 2-3-4-1.

 

[bes1110]

Does sound like an injector issue, I changed the faulty injector and seal on my s211 cured the problem.

 

[amazighman]

.Use Honda copper washers ... Make sure the injector face cap isnt worn, otherwise it will leak again

 

[Petrol Pete]

This is the world famous 'Black death' You have found it early, there are some stonking pictures on-line of engines where injector leaks been left for too long , pretty much destroying top of the engine.

Alex covers this on www.legitstreecars.com

Take a look, he does a very thorough job with a lot of hints and tips.

 

[BobHUK]

Thanks Petrol Pete, I'll take a look.

 

[BobHUK]

Just found another excellent site for hints and tips on what to do when you get the black death. It's on this link Mercedes Diesel Injector Seal Replacement – Notes

I read through the article, then read all the comments underneath, and very enlightening they were too. I must admit it makes me wary of buying another merc after reading the tales of woe I read there, but one positive that came out of it is that I will definitely be fitting the Honda Accord diesel injector washers, as they're not only thicker, but slightly softer as well, so will compress better to seal the injector. Luckily there's a Honda dealership near me, so I'll be going there later on today to see about getting a set of washers, then on to the local Merc dealership to get the new bolts. After that I'll be cutting a groove into an old retaining bolt and using that to clean the threads in the holes where the black goop has managed to accumulate.

 

[m80]

Make sure you plug the injector hole while cleaning, prefereably clean as you can prior to injector removal.
Having Henry help out is useful. I have a range of norrowing hoses to get into the nookw, and even a length of pipe to get down the injector hole.

Cleanliness is next to clitoris.

 

[BobHUK]

M80,

Thanks for the advice about plugging the hole. I've already removed no. 1 injector as you could see from the photos. I then put some paper towel into the injector hole while I scraped around the area with a screwdriver to remove the goop. After that I used my wet and dry vacuum cleaner, with a partly closed off pipe end (to allow for better suction in small spaces) and sucked all the goop away. I'll be adding a straw to the end of the pipe next time so that I can suck the goop out of the mounting bolt hole, as well as using a modified old bolt to clean the threads.

The plan is to lift all four injectors, clean the area thoroughly with oven cleaner (Mr Muscle?), then refit each one back into its own hole with a new sealing washer and the correct ceramic grease, then bolt them all down to 7 nm as the first stage, in the order 2-3-4-1 (as mentioned in my manual), then tighten by 90 degrees in the same order as the second stage, and finally another 90 degrees in the same order as the third and last stage.

After that I'll see about selling the car, as I'm getting fed up with fiddly expensive and time-consuming problems like this on what was supposed to be a prestige car, with legendary reliability. So far I've had to replace the following non-maintenance items, as well as normal wear and tear items such as tyres, wiper blades, bulbs, oil, filters, front discs, brake pads, etc;

1. The battery
2. The heater blower resistor
3. The water-cooled alternator (£300 and that was for a refurbed one!!)
4. The air con condenser (due to a stone puncture, and a bugger of a job to fit) and 1kg of AC gas
5. The radio (it refused to accept the correct code and finally died)
6. The front springs (both snapped, the driver's side one in two places!)
7. The front anti-roll bar drop arms
8. N/S fog light
9. Four glow plugs
10. One injector
11. The tubing for the fuel from the fuel filter to the high-pressure pump

And now I've got to replace the injector seals and mounting bolts. I've also found out that the oil sitting in the plastic under engine tray could be leaking from the auto gearbox, so that will need sorting as well. :-(

Not good is it? I bought the car in April 2017, with 169K on the clock and expected to get at least another 100K out of it before needing to replace it. It's now got 185K on the clock, so all this has gone wrong in 16K miles! I dread to think what'll go wrong next, so I'm going to rid myself of it and buy something that isn't Merc based for the future. Oh, and before anyone says the older cars had problems, but the newer ones have been sorted, I've noticed that on this forum people are complaining about quite newish ML270's having the same black death problems as my old heap, so Mercs haven't sorted the problem out yet.

 

[Deleted member 149005]

Prestige car with legendary reliability


You have my sympathy but It’s a myth.

 

[m80]

I'm not an MB nut who will defend MB for the sake of it, but.

Other makes suffer the black death also.
The ML270 finished in 2005, and it's reasonable to consider that to be an old motor. I'm driving a late 2006 and consider it to be old.
The engine you have, likely the OM611 is my guess, is arguably the best MB diesel for reliability. But guarantees for old motors are fanciful. After much considerstion I drive the same, well very similar, engine. A few changes over the years but pretty much same as yours.
The newer 2.1L 651 has issues MB should be embarrassed about, but it's a better engine for their revenues, and they're even putting Renault engines in now ffs.

It maybe that your renovations have created a more reliable motor for the next owner??
After driving a Merc for a several thousand miles you will likely find it difficult to adapt to different.
It is true that older motors can easily become beyond economical repair.
In your case rust was a major concern. MB improved, but didn't totally remove, the rust issue 2004 / 2005 (depending which model).

If yours looks likely to be costly in the foreseeable maybe you just run it till dead.
If your best guess is that it's near sorted then the future might be cheap and comfortable motoring.

 

[91dm]

I think you're being a bit hard on the car, a lot of the items on that list would be a problem with any car this age and mileage. You can be unlucky and buy a car just as all the common problems are about to arise. People only usually find out the common problems and what to look for after buying the model.

Black death on the injectors isn't a big problem, the problem is people let the leak develop for too long which becomes a major problem.

 

[amazighman]

I wouldn't worry about any mechanical issues as long as I can fix em, Rust is the main issue with W210s , thats why I got rid of mine

 

[Stratman]

.........................

The plan is to lift all four injectors, clean the area thoroughly with oven cleaner (Mr Muscle?),

...........................

Mr Muscle oven cleaner, in common with many others, contains sodium hydroxide (aka caustic soda) as an active ingredient. This dissolves aluminium, so if your cylinder head is made of it it's best avoided

 

[amazighman]

I have used UPVC solvent cleaner from toolstation and did the job very well.

Mr Muscle oven cleaner, in common with many others, contains sodium hydroxide (aka caustic soda) as an active ingredient. This dissolves aluminium, so if your cylinder head is made of it it's best avoided

 

[BobHUK]

I'm not an MB nut who will defend MB for the sake of it, but.

Other makes suffer the black death also.
The ML270 finished in 2005, and it's reasonable to consider that to be an old motor. I'm driving a late 2006 and consider it to be old.
The engine you have, likely the OM611 is my guess, is arguably the best MB diesel for reliability. But guarantees for old motors are fanciful. After much considerstion I drive the same, well very similar, engine. A few changes over the years but pretty much same as yours.
The newer 2.1L 651 has issues MB should be embarrassed about, but it's a better engine for their revenues, and they're even putting Renault engines in now ffs.

It maybe that your renovations have created a more reliable motor for the next owner??
After driving a Merc for a several thousand miles you will likely find it difficult to adapt to different.
It is true that older motors can easily become beyond economical repair.
In your case rust was a major concern. MB improved, but didn't totally remove, the rust issue 2004 / 2005 (depending which model).

If yours looks likely to be costly in the foreseeable maybe you just run it till dead.
If your best guess is that it's near sorted then the future might be cheap and comfortable motoring.

M80,

I agree with your comments about W210. I've had mine for 2 1/2 yrs, and in that time I've had to shell out on some expensive items. Today I finished lifting and reseating all four injectors, with Honda sealing washers, as they're thicker (2.4mm!). It took me over 2 hours to get no. 4 injector out this morning, and that was using the proper slide hammer to lift it! So now the engine runs without chuffing, and there's no nasty smell in the engine bay. However, it was getting dark by the time I finished getting it all back together, and just by chance I happened to let the torch light up the front of the engine. Oh dear! The alternator is now black with leaked oil. I'm not sure quite where it's coming from, but it looks like it's leaking from somewhere near the front of the exhaust manifold. I just hope this doesn't mean the head gasket is gone. If it is that'll definitely be the last straw.

Tomorrow I'll wash the front of the engine down and then run it to see if I can see where exactly the oil is coming from, after which I'll have a better idea of what needs doing next. Hopefully, it won't be too drastic, because I'm going to try and put it in as a part exchange for something that isn't a Merc, and the sooner the better I think, judging by the way the thing is trying to disintegrate on me.

 

[amazighman]

My alternator was soaking when the high pressure fuel pump and lines were leaking... Worth having a look...my cabin stank of raw diesel too.

 

[BobHUK]

amazighman,

Thanks for that, I'll take a look in the morning. The smell in my cabin was more like burnt diesel than raw diesel though, so I'm not sure that it's the high pressure pump or fuel lines. However, I did take the pump apart last winter to find out if it was worn. It wasn't, so I reassembled it, and it's worked flawlessly ever since. But, I wasn't pleased with the state of the fuel lines around the pump, so tomorrow I'll take a very close look at them to see if there's any chance it could be those that are leaking.

 

[BobHUK]

Hello again,

I had a very close look at the front of the engine this morning to find out where the oil is coming from that's soaked the front of the alternator. It looks like the seal behind the vacuum pump has gone. Last year when I was taking everything apart to find out why the engine wouldn't start from cold, I ended up removing the high-pressure pump among other things. Eventually someone on here suggested the problem was an injector, and he was right, it was. However, during my wild goose chase around the engine from the different diagnoses others had come up with, I took the vacuum pump off in order to get the high-pressure pump off. It seems that I've managed to cause the sealing ring to leak. From what I can remember it's a simple O ring type seal, so I'll take the pump off tomorrow and see if I can do a temporary job with silicone sealant till I can get a new rubber seal. I'll also see about washing down the front of the engine and the alternator, and clean the puddle of oil out of the undertray.

 

[amazighman]

Good you found the problem.

Just clean the alternator with some electric contact cleaner or similar.... W