Mercedes Experts? Fixing/modifying E270Cdi

We have a problem with a delayed (big style) response from a 6 month old E270Cdi Mercedes. Following vid clip (1.9Mb) shows it nicely:

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After 1 second I nail the throttle, right foot flat on the floor, nice (exudes quality...) click sound.

Bog-all happens for the next second - it takes a full second for the revs to go from idle to 2000rpm; the car moves all of about 2 metres (chack signpost out the window). Then the car starts to move and finally 2 seconds after having pressed the throttle we get full boost and revs at torque converter stall speed, whereupon we have meaningful acceleration (camera moves backwards then forwards again).

That's a full second delay from nailing the throttle to anything happening and a 2 second delay between nailing the throttle and the car accelerating.

Either this car is broken (but it doesn't blink anything at you to say so, and I'd expect it to given the festive dashbaord warning lights and urgent sounding blings giving you a heart attack and letting you know the washer bottle is only half full); or Mercedes have been playing stupid games with the engine management system to clean up the emissions. (if they put a 'ramp up' curve on the throttle response, or introduce some more playdough between throttle and engine, then the diesel emissions won't be quite so bad?)

It takes a second for stuff to happen if you nail it. 'Ease' the throttle in traffic or on the open road, and it can take as long as three seconds. The temptation (instinct) is to apply even more throttle whilst waiting for things to happen, which means when they do the turbo goes wohooo autobox kicks down and you're away and having to back off again. Repeat for 3 hours and the gut feeling is not unlike seasickness....

Oddly cruise control seems to work without this delay, which makes me think the ECU responds to its own instructions but not the driver's.

It gets 25mpg around town and 38mpg at a constant 120km/h (70mph?); which is godawful for a diesel as slow as this one - the s-type Jag (3.0 petrol) it replaced also did 25mpg around town and 36mpg at constant 80mph, only it actually shifted some when so instructed.

The car is in SA, but is full RHD Euro spec (UK spec) with two exceptions - it doesn't carry a fire extinguisher because they're not mndatory, and there is no precious metals in the catalyst because emissions are not controlled here.

Is it broken, or have Mercedes been playing silly games? If silly games - can the engine management be remapped in any way such as to respond to the driver's instructions? Huge power hikes are not in order really - as at 6000ft and 35C ambient air temperature turbo engines have a habit of melting even at standard output. (newish Impreza turbos must be de-catted for example; else the ceramic in the cat melts when on-boost and goes through the tubocharger...)

Anybody got an E270Cdi, or better still experience of a remapped one, or know how to fix this one if it is actually broken?

And apologies in advance for such a poor choice in car - it ain't ours its dad's company motor out here in SA; and it was purchased on the basis its the biggest heaviest car (also with the most side airbags) dad could get on the company scheme. You'll understand why it was chosen on that basis the first time you drive in Johannesburg... Its the deisel instead of the petrol because the 2.4 normally aspirated petrol is limp at sea level and even more so when you knock 15% power/torque off due to altitude. The turbodiesel boosts such that manifold pressure is always the same whether at sea level or 6000ft, so doesn't suffer so much with the altitude. Logical, albeit boring!

Cheers

Reply to
marko
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You say this is a 6 mth old car? Urm, am I being stupid when I say "Take it back to the dealer"?

Reply to
Alex Jackson

  1. It's an auto - autos don't do standing starts
  2. It's a diesel, diesels don't do standing starts
  3. It's a turbo. Turbos don't do standing starts

So as an automatic turbo diesel driver you need to learn to live with these facts, those of us with turbo petrol cars at least have some reasonable power off boost.

Reply to
Tim S Kemp

Isnt it called turbo lag???

Chip the car that will sort some of it out

Reply to
Ron

Firstly if its 6 months old, go back to the dealer. Demand they look at it and give you a drive of a similar vehicle to prove that it isnt a trait of them. (it might be!) The symptoms you mention could be a result of a faulty throttle pedal position sensor where the first track has gone open circuit.

You are always going to have some soggyness off idle at that altitude with this type of engine, as the ECU does restrict fuelling to keep smoke at bay until the turbo has spooled up so I doubt very much you will solve the problem completely.

Tim..

Reply to
Tim (Remove NOSPAM. Registry corupted, reformated HD and l

????? Well all the fastest cars at the drag strip tend to be autos, from street cars up to top fuel........... So I don't know where you got that from!

You have never been in a quick diesel turbo have you?

Like a fast chipped 4x4 cosworth escort??? Or You mean like my turbo 270 nhp gsx1135cc suzuki? It did 171mph in 440 yds... and 8.1 secs.

Reply to
Burgerman

Ultimately, in a car with the TC set up for road use, there's a lot of slip to take up before you get thrust. I have owned autos and manuals, autos always exhibit some delay off the line.

BMW530? Merc E320? Volvo S60D5? No, never.

It's a diesel. Off boost it has no go. So in the scenario in the video it will be a while before the rush.

Correct.

To get the cossie off the standing start needs revs and a dumped clutch. Anti-lag helps as well. Oddly enough my S60 will only crack its factory

0-100k time with that kind of abuse, a "granny start" will only produce a 9.5-10s 0-100k time. Can do 7.5 with lots of revs and a carefully fed clutch. A diesel auto, held from a start and mashed onto the throttle pedal will suffer from waiting for the torque converter to react and then waiting for the turbo.
Reply to
Tim S Kemp

bullshit.... carry on dreaming...

Reply to
Theo

And theres lots MORE on a race converter! It allows the revs to be higher as you leave...

4000 rpm stall speed converters are common on race cars.

Should be practically instant as fast as the motor can pick up. And if you are after a fast standing start you put left foot on brake, right foot on gas, and take up all the "slack" and already be on boost, ready to leave. You need driving lessons.

Yep, me too. And thats bull. My V8 sierra first had an auto box, till it bust! It took off like a rat up a drainpipe... NO delay.

Later with 5 speed it was just the same.

As I said. They are standard cars... Slow...

Off boost it has LESS go

Not if the turbo is the correct size and you set off correctly as I mentioned above.

So zero to 170 plus in 8 secs is slow????? Zero to 60 in 2.?? something, Zero to 100 in 4 secs???????

You nhave no idea.

Well the fastest ever quarter mile cosworth escort had a HUGE turbo, and an AUTO box! (It was a mk 2 escort with a cosworth sierra motor, and nitrous. On slicks it ran a high 8 sec pass at york raceway... The guy came from malta and was extremely pleased...

He had an AUTO box. This means with the left foot on the brake he can hit full boost without moving! Then remove foot from brake. Autos HELP you get boost, and dont wast time shifting...

You dont need it in an auto. But nitrous works great!

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Thats complete bollocks. And measured how exactly?

Err right if you say so. Mine just lit up the tyres.

You will already have boost if you are at full throttle with a stalled torque converter. If you havent you have either the wrong torque converter or the turbo is oversized.

Reply to
Burgerman

Yea but, to be fair, that Merc doesn't have one of them...

And it is a standard car...

Reply to
Dan405

But he claimed that this was the "delay" ! Its the opposite. The more slip the better - Torque converters dont "slip" like a clutch they are torque "multipliers".

Exactly, diesels as standard are pretty slow, but theyt dont have to be, as he claimed. So he has no idea how fast a deisel can really be.

Reply to
Burgerman

Yea but they still smoke and sound like a tractor :)

Reply to
Dan405

And of course diesel motors don't pick up fast off boost, electronically controlled turbo motors don't boost until the engine is loaded and you don't generally do the left-foot-on-brake thing on the road, certainly in the OPs video he's not doing it either. Once on stream and the pushing torque rto

Your V8 sierra was not exactly standard now was it??? And it wasn't IIRC turbocharged either.

yes indeed - a lot less go. Driven a non-turbo diesel recently?

you are talking bikes. we are talking cars. Unmodified, turbo diesel, automatic barge style cars. I would say that the performance his video is showing is pretty typical and you've spent too much time at the drag strip to remember what a normal motor is like.

What's got up your arse so far today Burgerman?

When does an Essie Cossie cease to be an EssieCossie and become a built for purpose drag car?

indeed - nitrous is the ultimate anti-lag, works will in my mates RS4 - the most evil lag-free manual boxed standard looking estate car I've used. Ride's a bit harsh and the fuel consumption is hairy but they'll need a roadblock to stop you as they don't have anything that can catch you.

IF you have full throttle yes. If you just take your foot from the brake to the throttle it will wait for the revs to rise and the motor to load up before allowing any boost. Watch his video, that's what he does, that's what I'm commenting on.

Reply to
Tim S Kemp

Oh yes I do...

Reply to
Tim S Kemp

In article , snipped-for-privacy@yahoo.co.uk spouted forth into uk.rec.cars.modifications...

Not quick granted, but probably not slower than a lot of auto box TDs.

Does sound nice though, not a hint of tractor about it. Go complain, and see what they say. I hope you haven't been getting paranoid after listening to Clarkson lately that all Mercs need at least six months a year in the garage? makes them sound as bad as Alfas ;)

Reply to
MeatballTurbo

Well no... But it was a standard engine and autobox then.

I try not to...

Not you claimed turbod stuff didn't do standing starts! Well obviously they do. Some faster than others.

You can't spend too much time there!

Its Christmas! I HATE christmas.... Worst time of the year.

Cars are just cars... To prove my point he fitted the auto box because it made it run standing starts FASTER.

Well you cant blame the car if he doesent know how to drive it properly!

Reply to
Burgerman

Merc dealers are Merc dealers. There's nothing wrong with that car sir, it starts and moves and is a Mercedes, what more do you want?

They'll also hardly likely to give any advice about modifying it to work better.

With the Rovers you can download the dealer .pdfs over the next; run through a fault-finding sequence that even a complete monkey could understand; then turn up at the dealer and tll them that part 78239 on page 24b needs schanging/adjsuting; stand and watch over their shoulder to check they do the work properly and have the car back and working at your convenience. If you hand over the keys and just say 'its broken'; you will be given a 1.0 corsa courtesy car for the 3 days it takes them to look at the car and make those intake of breath noises before declaring there's nothing wrong with it...

The dealers are shut over xmas/new year too...

Aside from that, nothing stops it going to the dealer, and it will go to the dealer when they're open again in the new year; but we'd like some info on what's likely wrong first...

Reply to
marko

The last automatic turdodiseasel we had the displeasure of a journey in was an L-plate BMW 525Tds with over 200k miles on it.

The injectors, injection pump and turbo were all original, and fubar.

Despite this; if you prodded the throttle, it would drive just like it had 70bhp then like it had 140bhp once the turbo spooled up. What it did not do was drive like it had 3.5bhp until the ECU decided to respond to the throttle, then drive like it had 70bhp, then drive like it had 140bhp.

Prod the throttle and it did not take ONE SECOND to build 1000 rpm under no load - the revs rose as with any other petrol/diesel engine, albeit one with a large rotating mass.

The only annoying thing was the habit it had of dropping off boost at

75mph on the motorway, neccessitating a kickdown to 3rd and lots of boost to get to 80. Cruising at 90 (or german autobahn speeds) it didn't drop below boost threshold and was okay.

Even automatic turbodiesel land-rovers respond quicker than this thing; and I'm sure there are some tractors out there than can build up moer than 1000rpm a second under no load?

On the upside somebody has just posted me a vid clip of their E270Cdi doing a standign start. It "only" takes 0.5 seconds to build 1000rpm and start moving, not 1 full second. The vid and a couple of snapshots will help convince the dealer that there is something wrong with it, one point to the internet. :)

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Had to wind down the windows to hear the engine in the cabin. From the outside it sounds like a wierd Audi quattro 5-pot meets tractor hybrid.

Haven't watched any TV since about May. You can tell the quality is at best average though. Nice 'strong' (heavy anyway, what with leccy windows, airbags, soundproofing etc) doors; that make the b-pillars flex visibly when you close them for example. Benz have made the E class the same weight as the old one by adding toys soundproofing and such s**te whilst removing steel. Fit and finish is on par with any modern Ford with the exception of the Ka. Windscreen cracked within the first couple of months (fault from new), dealers didn't know how to refit the funny 3-link wiper system in the correct position so it sweeps the wrong part of the screen. Its just a car, they're just dealers; nothing out of the ordinary believe me...

Reply to
marko

Err yeah, like .2 of a second for engine revs to rise to torque converter stall speed and fluid pressure to reach all the nooks and crannies of the autobox, shouldnt' be a second before the car even moves - did you watch the clip?

Fuel type is completely irrelevant.

As to turbos - Why? I shouldn't imagine the benz runs any more than 1 bar boost. If I plant my right foor, I should INSTANTLY have a car that behaves as if it had 85bhp then later have a car that has 170bhp. Its not a large turbo and its a variable nozzle type so should spool very quickly. I shouldn't have a car with 3.5bhp that one full second later turns into something with 170bhp. You any idea just how long one second is? Or any idea just how big a turbo/heavy a flywheel you'd need to fit for the delay to be one second?

How about when you're driving and come to a hill? You apply a little more throttle. In this nothing will happen for two or three seconds. That's about 100m worth of distance on the open roads taking it easy. Then when it does it'll kickdown come on boost and shift some. TC slip isn't an issue on the move either. Fuel type is irrelevant and the turbo does not take 3 seconds to spool. Window down you can hear the thing - its not like its trying to spool up but taking forever, its not as if the engine nte/exhaust note changes in the slightest when you alter throttle position - it just does absolutely nothing for a while.

One second's worth? One *full* second? I'm not convinced I'm afraid, mainly 'cos I've seen dumb all mechanically controlled turdodiseasel autos step off the mark far quicker...

Will have a look for any sign of a throttle pot/position sensor mind, thanks to the other post by Tim.

Doesn't seem to be anybody out there with a chipped one though. :(

Reply to
marko

Picks up at the rate of a whole 1000rpm every second....

And leave it does; traction control light blinking away at you until about 20mph. Its impractical for day-day driving though. Sometimes you just want to be able to follow the car in front, not instantly put a merc shaped dent in the back of it or wait a second then dent the back of it.

Slow is not a problem for me - I drive a Series landrover too don't forget. 0-60 in 30 seconds is fine, provided it does it when I tell it to and behaves predictably. Slow ain't a problem for dad either, no need for speed in the city.

When the turbo spools it chirps the rear tyres then moves. Locked in first gear and rolling; provided you're over the 1800rpm boost threshold you can back off, nail it, and I'd class the response as 'instant', or a barely preceptible delay. Turbo lag is not an issue here?

Reply to
marko

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