Advice on low use diesel mercs
Discussion
Hi all
I currently have a 2004 Astra Diesel which I use for my daily commute to work. It's been a good car and now has 220k miles.
In a few months time I intend to buy my dream car which will be either a one year old 'C' or 'E' class coupe. The majority of models on sale are diesel engines.
I still intend to keep the Astra as the commute car and run it until it dies so really the Merc will just be used at weekends.
I realise that a petrol model would be better for my use but these appear to be scarce. I've also read all the horror storied about the dreaded DPF getting clogged up and the costs it can incur.
I've looked at cars in Merc Dealerships and they seem to think that you just need to get the engine up to temperature for a short while.
Does anyone have any experience of using diesel mercs in the same way without any issues or would I be better off holding out for a petrol model.
Cheers
Janski
I currently have a 2004 Astra Diesel which I use for my daily commute to work. It's been a good car and now has 220k miles.
In a few months time I intend to buy my dream car which will be either a one year old 'C' or 'E' class coupe. The majority of models on sale are diesel engines.
I still intend to keep the Astra as the commute car and run it until it dies so really the Merc will just be used at weekends.
I realise that a petrol model would be better for my use but these appear to be scarce. I've also read all the horror storied about the dreaded DPF getting clogged up and the costs it can incur.
I've looked at cars in Merc Dealerships and they seem to think that you just need to get the engine up to temperature for a short while.
Does anyone have any experience of using diesel mercs in the same way without any issues or would I be better off holding out for a petrol model.
Cheers
Janski
Hi there,
I can't answer your question but I wondered if you'd considered a 3-4 year old AMG if it's only a weekend thing? Yes, running costs will be higher but not cripplingly so when you're doing so few miles and you will have far less depreciation than a 1 year old E or C class which will sit in the garage shedding 50 quid notes.
I can't answer your question but I wondered if you'd considered a 3-4 year old AMG if it's only a weekend thing? Yes, running costs will be higher but not cripplingly so when you're doing so few miles and you will have far less depreciation than a 1 year old E or C class which will sit in the garage shedding 50 quid notes.
Janski said:
I've looked at cars in Merc Dealerships and they seem to think that you just need to get the engine up to temperature for a short while.
Are talking about getting the dpf up to temp, or the engine?I have an older diesel Merc (C270CDi) without dpf, and I reckon it takes 20 miles to get the car thoroughly warm. My wife's year old diesel VW Tiguan shows the oil temp in the cluster and in rolling A road driving takes 15 miles for the oil to get to temp (the pretend water temp gauge is at normal in 3 miles).
If they're talking about passively regenning the dpf, then I tend to think the idea of taking it for a run is b
ks these days - on the Tiguan it never passively regens, the dpf simply doesn't get hot enough. Maybe Mercedes do it in a different way, but I don't know why it would be so different. I found getting information about how VW system works very difficult and Mercedes tend to be even worse.
Sheepshanks said:
If they're talking about passively regenning the dpf, then I tend to think the idea of taking it for a run is bks these days - on the Tiguan it never passively regens, the dpf simply doesn't get hot enough.
Maybe Mercedes do it in a different way, but I don't know why it would be so different. I found getting information about how VW system works very difficult and Mercedes tend to be even worse.
My Mercedes dealership are very good re information etc. I only use my E class for shorter trips nowadays and they advise me to give it a 30 min dual carriageway run every 2 weeks or so to get everything up to temp and the DPF will regen if needed. This has worked for me ok for the last 2 years after 4 years of doing very high mileages.ks these days - on the Tiguan it never passively regens, the dpf simply doesn't get hot enough. Maybe Mercedes do it in a different way, but I don't know why it would be so different. I found getting information about how VW system works very difficult and Mercedes tend to be even worse.
They have also said the DPF can be cleaned if reqd, and the car can do a forced regen if necessary. They have no interest is selling me a replacement DPF.
Monkeylegend said:
My Mercedes dealership are very good re information etc. I only use my E class for shorter trips nowadays and they advise me to give it a 30 min dual carriageway run every 2 weeks or so to get everything up to temp and the DPF will regen if needed. This has worked for me ok for the last 2 years after 4 years of doing very high mileages.
They have also said the DPF can be cleaned if reqd, and the car can do a forced regen if necessary. They have no interest is selling me a replacement DPF.
Thank you all for your replies, especially MonkeyLegend, who was the most informative and seems to back up what I've discovered so far.They have also said the DPF can be cleaned if reqd, and the car can do a forced regen if necessary. They have no interest is selling me a replacement DPF.
I'm not really interested in classic cars so the w123/124 thing is out and also my pocket won't stretch to a brand new E200. I basically just want a one or two year old car to plod around in at the weekend which looks great without having the temptation to add points on my license. To this end just a basic 2.0 or 2.5 litre engine would be fine.
Having searched both this forum and the internet in general, with just one or two exceptions, MB's don't have dpf problems which is very encouraging.
I've still got a few months to think about this. In the end I'll probably play safe and go for a petrol model, especially as diesels are starting to get some really bad press now.
But, when the time comes, a diesel turn's up which is really low mileage and looks stunning I might just take the plunge.
Janski
Edited by Janski on Monday 9th January 09:54
One of the many problems I have had with my increasingly disappointing W204 C350 was DPF related. When I bought it I was doing 18k a year mostly motorway miles. More recently I tend to do shorter trips. My understanding of the system is :-
There is a Differential Pressure Sensor across the DPF which detects when it is getting clogged. Some software somewhere then chooses an appropriate time to force a regeneration, to do that the DPF temperature has to be raised significantly so the soot is burnt off. If the measured Exhaust gas temperature and engine temperature is sufficient, extra fuel is injected during the exhaust stroke which gets the DPF good and hot. You can tell when it is doing this in two ways. It will hold a lower gear than normal and generally keep the revs higher than usual and the exhaust will whiff of what smells like burnt rubber. I have never figured out if that is the exhaust mountings being less than up to the job or the actual gas. If you keep doing short trips and turn off mid regenerate it is not beneficial to the de-clogging process which is probably where the take it for a drive story comes from.
Beyond a certain amount of clogging the software will not regenerate. You can however force a regeneration via the OBD port. If it really is clogged and won't clear you can, so I am told remove it and wash a fair bit of the soot out. The problem with mine was the Differential Pressure Sensor not the DPF itself.
If you are buying a car you can check the clogged or not status of the DPF by reading the real time data from the the OBD port.
There is a Differential Pressure Sensor across the DPF which detects when it is getting clogged. Some software somewhere then chooses an appropriate time to force a regeneration, to do that the DPF temperature has to be raised significantly so the soot is burnt off. If the measured Exhaust gas temperature and engine temperature is sufficient, extra fuel is injected during the exhaust stroke which gets the DPF good and hot. You can tell when it is doing this in two ways. It will hold a lower gear than normal and generally keep the revs higher than usual and the exhaust will whiff of what smells like burnt rubber. I have never figured out if that is the exhaust mountings being less than up to the job or the actual gas. If you keep doing short trips and turn off mid regenerate it is not beneficial to the de-clogging process which is probably where the take it for a drive story comes from.
Beyond a certain amount of clogging the software will not regenerate. You can however force a regeneration via the OBD port. If it really is clogged and won't clear you can, so I am told remove it and wash a fair bit of the soot out. The problem with mine was the Differential Pressure Sensor not the DPF itself.
If you are buying a car you can check the clogged or not status of the DPF by reading the real time data from the the OBD port.
s70rmp said:
When I had a Saab 9-3 TTID you could tell when the DPF was doing its regen, but when I Had a W204 220 Coupe I couldnt tell and I've never noticed it in my C350 either.
Is there away of telling when it's actually doing it ?
On my W212 it smells like a tyre rubbing against the bodywork, a rubbery burning smell. I only notice it when stopped outside the car, never when I am driving.Is there away of telling when it's actually doing it ?
Janski said:
I basically just want a one or two year old car to plod around in at the weekend which looks great without having the temptation to add points on my license. To this end just a basic 2.0 or 2.5 litre engine would be fine.
Having searched both this forum and the internet in general, with just one or two exceptions, MB's don't have dpf problems which is very encouraging.
I've still got a few months to think about this. In the end I'll probably play safe and go for a petrol model, especially as diesels are starting to get some really bad press now.
I'd just add in that I'd recommend you drive a small engined turbo petrol model before buying.Having searched both this forum and the internet in general, with just one or two exceptions, MB's don't have dpf problems which is very encouraging.
I've still got a few months to think about this. In the end I'll probably play safe and go for a petrol model, especially as diesels are starting to get some really bad press now.
I've had both the petrol E200 CGI and diesel E220 CDI (current car) in recent years, I had the petrol for all of 6 months and hated it - I didn't drive it before buying which was a mistake. The performance statistics on paper suggest not much between those engines but I found the E200 sluggish and not really suited to the car - it also only returned 30mpg on average so if I was buying a petrol E Class again I'd have no less than 6 cylinders!
I've had the E220 for just over 2 years and go through periods of only doing lots of short journeys, and have had no issues at all with the DPF (edit: that I'm aware of!), I forget it actually has one.
Edited by anonymous-user on Monday 9th January 14:08
Edited by anonymous-user on Monday 9th January 14:08
Thats useful information. I always wondered about these being large cars and having only 4 cylinders on the petrol engine.
I once had a 4yr old BMW 325i and that was a straight 6 petrol engine. It was so smooth and powerful.
If it's petrol I go for then I'll certainly have a test drive.
I once had a 4yr old BMW 325i and that was a straight 6 petrol engine. It was so smooth and powerful.
If it's petrol I go for then I'll certainly have a test drive.
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