W208 CLK 320 - Some engine issues

[mbenz1]

Steam from the exhaust in any car at this time of year is surely normal?....What do you mean by steam? Exhausts especially on bigger engine cars take a while to warm up. Mine will almost be filling the small car park I am in whilst trying to get some warmth to defrost all the windows in this weather (-4 now) especially if I blip the throttle to try and warm it quicker.

Neil

I mean white condensation gas but not white smoke.

In my car, the steam does not stop even after the engine has been fully warmed up. Lets say 20 minutes after fully warmed up I stop at idle, white steam starts to appear from exhaust about 3-4 seconds later.

 

[dan-mb]

i get that but there is a point when enoughs enough, for the money its costing you can easily get a less problematic/sorted car for similar money.

 

[dan-mb]

You are right there, it has been a money pit. We have spent nearly £1k of additional costs on this car but that has only led to getting the misfiring sorted.

I don't use the car in high miles so not in a rush to sell it but I would like to know where I stand.... Coolant leak in cylinder or vacuum leak? I know the plugs are good because they are only about 2 months old and injectors are okay because car pulls well throughout all loads.

Same here i only do about 4k miles a year in the CLK. But because there are a lot of second hand CLKs out there (some peaches and some lemons) if i were getting lots of problems/expenses with a car i would just sell it -as the cost of repairs will be similar if not more than the amount you would loose cutting your losses and selling it to get another CLK.

 

[dozypillock]

I mean white condensation gas but not white smoke.

In my car, the steam does not stop even after the engine has been fully warmed up. Lets say 20 minutes after fully warmed up I stop at idle, white steam starts to appear from exhaust about 3-4 seconds later.

Engine may be warmed up, but is the exhaust? When it is into -temperatures there is a lot of cold air flowing under car.
If you do the same again, and I hope with a few revs involved, when it starts steaming after you think it is fully warmed up, jump out and feel the exhaust tip/tips?
Be careful, as they may be red hot if you have "really" driven it, but I suspect they will still be fairly cool. I can drive round here for 20 minutes, and exhaust will not get that hot, as revs will probably not get above 1500, and lots of stop start. Engine will say its fully warm though.
A good motorway run for an hour, and I am sure all condensation etc will boil out of exhaust, and the problem (you think you have) will go away.
Modern exhausts have a lot of parts to heat up, clear through etc

If you drive like you stole it on every journey, then I am wrong, so ignore my thoughts.

Neil

 

[mbenz1]

Same here i only do about 4k miles a year in the CLK. But because there are a lot of second hand CLKs out there (some peaches and some lemons) if i were getting lots of problems/expenses with a car i would just sell it -as the cost of repairs will be similar if not more than the amount you would loose cutting your losses and selling it to get another CLK.

I understand what you are saying. If I decide to part exchange it (although circumstances don't really allow this) the new car may have other problems, require a service or replacement of general wear'n'tear items (which have been done in my car) so the costs will be added to what I've already spent (which I would.not like to do )

 

[mbenz1]

Engine may be warmed up, but is the exhaust? When it is into -temperatures there is a lot of cold air flowing under car.
If you do the same again, and I hope with a few revs involved, when it starts steaming after you think it is fully warmed up, jump out and feel the exhaust tip/tips?
Be careful, as they may be red hot if you have "really" driven it, but I suspect they will still be fairly cool. I can drive round here for 20 minutes, and exhaust will not get that hot, as revs will probably not get above 1500, and lots of stop start. Engine will say its fully warm though.
A good motorway run for an hour, and I am sure all condensation etc will boil out of exhaust, and the problem (you think you have) will go away.
Modern exhausts have a lot of parts to heat up, clear through etc

If you drive like you stole it on every journey, then I am wrong, so ignore my thoughts.

Neil

You have a really good point here, I never realised this.

The next time I will drive, I will feel the exhaust tip to see how warm it is. I drive with a light to (sometimes) medium foot also.

The reason why I think coolant leaks into cylinders is because my car has a problem with the engine temp. It fluctuates between 80 deg C to 100 deg C. When in stop/go traffic, it will gradually increase from 80C to 95-97C then gradually go back down to 80C after continuous driving. Therefore, I think that when the car was with the previous owner, he/she may have been stuck in a long traffic situation, where the car must have either overheated or engine temp must have stayed at ~100C for some time, resulting to corrosion of the metal surfaces in contact with coolant, hence allowing coolant to leal through ? I haven't been stuck in a traffic situation as such yet...

My dad has had many MB petrol cars and my brother previously had a W202 C200, which never gave off condensation/steam once warm.

But as you mentioned, the cold weather may be the cause of the steam. I will report back with my findings soon.

 

[mbenz1]

I finally remembered today to check how hot the exhaust tip was.

After a ~15 min journey (engine was at stable temperature before journey), I felt around the exhaust tip. It was hot but not boiling hot or fairly warm - I could only keep my hand on the surface for about 10 seconds. A bit similar to a medium-hot radiator in central heating system.

Im sure the exhaust is getting hot enough to a point where condensation should not be produced?

 

[mbzclk]

IIRC the Mercedes temp needle does not sit on dead 90 / middle of gauge like a BMW or Audi or others.

I thought there was something wrong when I first purchased my W208 6-7 years ago.

It used to sit on 80 and then rise up a slight bit then drop back down and so on, turns out it's totally normal and plenty of other Merc's also do this, did have a 2009 W204 that also did this...

Take it for a good run and then see how it behaves.

 

[markmifsud]

Mine normally gets to an indicated 80c (ish) and stays there.

 

[E270 Owner]

FFS

 

[mbenz1]

IIRC the Mercedes temp needle does not sit on dead 90 / middle of gauge like a BMW or Audi or others.

I thought there was something wrong when I first purchased my W208 6-7 years ago.

It used to sit on 80 and then rise up a slight bit then drop back down and so on, turns out it's totally normal and plenty of other Merc's also do this, did have a 2009 W204 that also did this...

Take it for a good run and then see how it behaves.

On a long run the car stays at 80C and doesn't change. I don't mind that the engine temperature needle fluctuates when the car is in a stop/start traffic situation or a long red light - the car has never overheated, which is the main thing.

My only concern is the condensation from the exhaust and the humming noise in the cabin - they both occur only at idle. Surely there must be a connection since both symptoms occur only at idle?

 

[dl94lopez]

Still got the car any news?

 

[mbenz1]

Still got the car any news?

I still have the car. I think the exhaust steam was due to exhaust temperature not getting high in winter, as suggested in this thread. I had no steam from exhaust over the summer period.

Engine still hasn't overheated so I guess all is well, although needle can reach near 100C mark and stay there when in serious traffic.

This thread has been resurrected after a long time

 

[dl94lopez]

Thanks for coming back. I thought this thread was already death. I did followed all this looooong conversation and founded really interesting.

I Just recently bought a W208 and gave my W203 C270 cdi tractor to my wife for now and then commutes. Got enough, thought I'll save £££ on the pump and spent all in repairs: Diesel pump, injector seals o'rings, fuel lines, starter motor,suspensions and still few issues to sorted out. Never got so deep with previous petrol Mecs. The good thing is that thanks to the tractor, I got really involve into mechanics, and now I love it. I really appreciate the talent of Mechanics, especially those specialists that even some of then spend hours in these forums helping others. A big thanks to them.

Anyway, my point in here is that I just bought a W208 320 V6 with 68K and after a few thousand miles the car start to behaive with the same symptoms as you described, maybe with no so much shaking as yours, with 95-100C on traffic, sometimes this annoying humming noise is present but not always, and delay in gears. But the car is absolutely lovely, -brought back the memories of my W202 230K. It was £47K new with all the extras and it feels strong and powerful.

I notice that when I use V Power from Shell the car is much sharper and shakes a bit. I use now Momentum 99 Ron from Tesco and the car is much smoother. Don't know why. Gears a bit duvitating, but not much, I think it just needs a gearbox oil change, a big high the oil level at moment. Other thing I noticed is when the car is on traffic the temperature goes till 100C but if putting on the heating, let's say position II, the temperature drops to a sensible numbers, around 90s.
The car at idle is always at 500rpm, is this normal? all my previous cars worked at 800rpm at idle, wierd.
I'll do a Start diagnostic at the same time gearbox oil change and keep it posted.

 

[mbenz1]

Thanks for coming back. I thought this thread was already death. I did followed all this looooong conversation and founded really interesting.

I Just recently bought a W208 and gave my W203 C270 cdi tractor to my wife for now and then commutes. Got enough, thought I'll save £££ on the pump and spent all in repairs: Diesel pump, injector seals o'rings, fuel lines, starter motor,suspensions and still few issues to sorted out. Never got so deep with previous petrol Mecs. The good thing is that thanks to the tractor, I got really involve into mechanics, and now I love it. I really appreciate the talent of Mechanics, especially those specialists that even some of then spend hours in these forums helping others. A big thanks to them.

Anyway, my point in here is that I just bought a W208 320 V6 with 68K and after a few thousand miles the car start to behaive with the same symptoms as you described, maybe with no so much shaking as yours, with 95-100C on traffic, sometimes this annoying humming noise is present but not always, and delay in gears. But the car is absolutely lovely, -brought back the memories of my W202 230K. It was £47K new with all the extras and it feels strong and powerful.

I notice that when I use V Power from Shell the car is much sharper and shakes a bit. I use now Momentum 99 Ron from Tesco and the car is much smoother. Don't know why. Gears a bit duvitating, but not much, I think it just needs a gearbox oil change, a big high the oil level at moment. Other thing I noticed is when the car is on traffic the temperature goes till 100C but if putting on the heating, let's say position II, the temperature drops to a sensible numbers, around 90s.
The car at idle is always at 500rpm, is this normal? all my previous cars worked at 800rpm at idle, wierd.
I'll do a Start diagnostic at the same time gearbox oil change and keep it posted.

Congrats on your purchase of what sounds to be a really fine CLK 320.

Yes the 270 CDI engine is claimed a very reliable engine but it still has its issues like you have mentioned. I'm sure you are enjoying the refinement of the 320 over the 270... Totally, the mechanics are clever people and I am also inspired by them. I also do some mechanical work on our cars now and then as as you have said, its really interesting.

Im guessing the humming noise is some sort of a resonance noise as this seems to be a really common issue in the M112 V6 engine. Some people have reported to cure this problem by changing either the plugs, leads, coil packs or a combination of the three items. I have changed all plugs and leads and one coil pack (Cylinder 4) which solved a slight misfire and shaking. Now the car has significantly reduced shaking (mainly noticeable when in P) but humming noise still remains. The W202 is also a fine car, my brother had a W202 C200 X Reg and even though I drove it once, it was a 'proper' MB with a timeless design. We still miss the old-school MB design of the W202, as the CLK is based on a trend-setting, modern design philosophy but still looks great even today.

We have used Shell V-Power in the 320 previously and noticed a good improvement in power response and quietness of the engine. Didn't really note the fuel economy as the car was mainly used in town.

I would recommend getting the gear box oil changed. These boxes came from the factory claiming itself as a 'sealed unit that requires no oil change. Many people have reported issues with this gearbox but after a oil change, most of which were resolved. Our 320 has some jolts when changing between P, R, N and D and also some jolts 'now and then' between gear changing. My local MB specialist recommended getting the gearbox oil changed at next service, its currently on 82,000 miles.

Im guessing that putting the heating on reduces the engine temp becuase the heat is took from the engine coolant. This would result to quicker heat loss from the coolant which would effectively lower the coolant temperature quicker therefore lower the temp needle position - this is my guess as I am not a mechanic.

The 320 also sits on 500rpm when in R and D. P and N has higher revs (between 700-800).

I would recommend a full STAR check as there can be many fault codes sleeping in blankets from previous years.

Enjoy your CLK and keep us posted, that's if I remember to check the thread!