Hi PM, As you know benzine is one of the problems with petrol particulates and one of the components that makes it so carcinogenic. The particulate matter from petrol engines has been found to contain left over saturates of benzine with a cocktail of other chemicals too. We all breath them in.

Yes... the comment was meant to point out that whilst diesel emissions can often be seen and have issues which is pointed out all the time by the anti diesel brigade, petrol isn't a "clean" fuel either even though they seem to think it is... Benzine being one prime example of some rather nasty emissions...

Benzine is a good point certainly (didn't it come in with unleaded?). For the record, I currently drive a diesel btw.

Hi Greenstripe,

I appreciate you may already know this but...there are several different types of DPF and even newer types in the pipeline. They all work ok but some in my opinion are better than others. I like the VAG type best as there is nothing to do to them to maintain them, unlike Peugeot which requires a DPF fluid to burn it clean and if you run out of this fluid your DPF may be history. The Ford coated type is also very good but not quite as efficient I understand.

When DPF's first started to be fitted to diesel cars back in 2004 (Toyota) I was sceptical as to how well they would last. Same when VAG started to fit them. But actually, with few exceptions they don't seem to give any trouble. My sisters CR1.6 Fabia estate has one and she only does 5-6 miles per day during the week and she has no trouble at all. She hardly gets over 45mph and mostly it's 30mph. However, at weekends she does cover more miles and some of that is on the dual carriage way. Her car is one year old now and she has never had a DPF warning light and never detects a regen. Many of my neighbours have Fabia's with the DPF and all do low mileages. None of them have any problems. Most don't even need to do a special run to burn them clean either.

There is nothing secret about the VAG DPF technology. It's a filter that traps the particulate matter. This is then burned clean from the filter (it's reduced to very very fine ash) and blown harmlessly out the exhaust. If the level of particulate matter in the DPF reaches a certain level where it is too high to be burned away with the heat from normal driving, then some small amount of extra fuel and air is injected into the exhaust to raise the temperature of the DPF. This burns it clean. It's very simple and effective. New common rail engines are designed to be used with DPF's. The ecu monitors the particulate level being passed to the DPF and the estimated and actual amount in the DPF, and takes appropriate action if it needs an extra clean (a regen). The Greenline 1 system is a little less sophisticated than the Greenline 2 but both work very well and don't give any problems. I think sales people put less emphasis on talking about DPF's now than when they first came out as we now know that DPF's are doing much better in the field than everyone thought, plus manufacturers have refined the software that looks after them to a higher level. Oil rise is not new and is still a rare thing actually but yes it can happen especially if the car is used on short runs all the time. But don't worry about your DPF, it'll be fine.

Hi Estateman,you say oil rise is rare and caused by short runs,I do over 100 miles per week some on motorway at 60 to 65 mph have never had the regen light come on and yet I have oil rise,must I continue having my oil changed whenever this happens,this will be very expensive using synthetic oil. The car is still under warranty , and fuel in the oil causes viscosity loss in the oil resulting in possible damage to engine. What should I do, can the dealer fix this problem. I bought this car as my last ever car for my retirement,hoping it would last ten years at least. With this problem will it?

Amastra, that's unfortunate if you have oil rise again. But is it actually fuel contamination or is it condensation? How many miles has your car covered? Was it run in correctly? It could and usually is fuel and condensation too on cars used for shorter trips. Although you are doing 100 miles a week it isn't very much and especially in cooler weather you need to do trips of 30 to 40 miles or more (depending on the level of contamination) at a good pace to remove all oil contaminates such as condensation and fuel. You need to get the oil up to maximum working temperature and keep it there for some time for evaporation to occur. On a 12 mile trip for example, your engine and oil will be at normal temperature but not for long enough to remove contaminates. So if you take an extended trip now and again your normal 100 miles per week should be fine to keep it clear. Petrol engines also suffer oil rise from fuel but mainly condensation but slightly less so especially if used on longer runs.

There are some things you can do that will help to avoid oil rise such as not letting your engine idle from cold (to try to warm it up) before driving off. Drive off after 30 seconds or so to reduce the amount of fuel bypassing the piston rings and entering the oil. Under load the engine warms up fast, the piston rings are pushed out against the cylinder bore walls reducing bypass, and the amount of fuel air ratio is reduced to normal much faster. Don't continually labour the engine at low revs in high gears. This increases fuel/air ratio until the ecu regains control. It causes too much fuel to be used and floods the cylinders with fuel for longer than necessary. As mentioned, once in a while take her for a good long run. This can be an extension of a normal run you make and will do the oil good.

It's very difficult for a diesel engine to be harmed, they are very very robust. But oil contamination by fuel isn't good. Some of the fuel contamination always remains in the engine especially with the newer diesel fuels which don't evaporate easily. So if you suspect large amounts of diesel in the oil (you can smell it usually) then changing the oil is a good bet. Some diesel in the oil is normal just as some petrol in the oil of petrol engined cars in normal (if used on shorter trips all the time). I think too you should speak to your dealer in detail about this as there are software changes I believe than can be made they may improve the situation. One or two others on this site have had a problem with the 1.6cr and it has been cured with software changes. Keep posting and let us all know how you get on with this issue.

Edited 21 November, 201114 yr by Estate Man

Amastra, that's unfortunate if you have oil rise again. But is it actually fuel contamination or is it condensation? How many miles has your car covered? Was it run in correctly? It could and usually is fuel and condensation too on cars used for shorter trips. Although you are doing 100 miles a week it isn't very much and especially in cooler weather you need to do trips of 30 to 40 miles or more (depending on the level of contamination) at a good pace to remove all oil contaminates such as condensation and fuel. You need to get the oil up to maximum working temperature and keep it there for some time for evaporation to occur. On a 12 mile trip for example, your engine and oil will be at normal temperature but not for long enough to remove contaminates.

It depends on route and driving style but did some trials last winter, at 0 degrees 2.0CR TDi Passat was taking 10 miles to reach it's normal operating temperature of 90degrees, oil temp to 80degrees was 15 miles. Oil temp is usually around 90 degrees but 80 to 90 degrees in freezing conditions takes ages.

Our old 1.9TDi Fabia on the same route took 15 miles to get to normal water temp. I couldn't monitor oil temp on the old Fabia.

In Feb of last year I had a TSi manual with maxidot. On the same route around freezing the TSi got to normal water temp in 5 miles and the oil was upto 80 degrees in 8 miles.

This was the main reason my wife wanted to look at Petrol this time, the 1.9TDi never got warm on her 2 to 3 miles to her mums/shops/school. She was driving with hat, scarf and big coat on. Having the TSi for a few days last winter opened her eyes, whithin the first mile it was chucking hot air into the cabin.

I know the CR's warm up quicker than the PD's but someone over on vwaudi forums graphed a 1.6CR TDi Golf warm up cycle and basically at idle or trailing throttle little to no increase in water temerature is detected, on light throttle the gain is very gentle and on boost the temperature rises pretty quickly. I think that's pretty much what my 2.0CR does and probably what the 1.2CR does. I run 40mph single carraigeway for the first 5 miles from my house and the temp hardly moves, I then get a uphill stretch and see the temp shoot up only to level out again on the next slow level section.

So looks like you can take it steady during warm up but you may never get it upto temperature or boot it a bit from cold but cold oil through cold engine and turbo?

Again just something for people to consider depending on their car useage.

Cheers

Lee

Edited 21 November, 201114 yr by logiclee

Lee, I reckon your stat was dodgy if it took 15 miles to get to normal engine coolant temp. Probably not closing properly. Not uncommon, it only needs to stick by just the tiniest bit for poor warm up performance. Even on a freezing day it should hit normal temp much much quicker than 15 miles. Although, the 1.9pd does take longer than the 1422cc pd to warm up (I guess the 3 pot motor works harder) I've noticed. My little diesel pumps out loads of hot air after 5 mins...honestly!

Lee, I reckon your stat was dodgy if it took 15 miles to get to normal engine coolant temp. Probably not closing properly.

Had it replaced because I thought that myself.

My run to work though is at 4.45am and on clear 40-50mph flat roads for the first 10 miles so a diesel is straight into top gear and tickle the throttle. In the Passat I set cruise control at 40mph within 200 yards of my house, there is no need or no oppurtunity to give it some. I said the Passat takes 10 miles on my drive to work to reach temperature at zero degrees but setting out for a drive during the day and going through town it can be upto temp in 2 miles at the same ambient temp. All depends on driving style and roads but a least on my run to work I can take traffic out of the equation. My old Mondeo TDCi 130 used to be the same as my Passat, 9.5 miles upto the motorway would still leave me someway off normal temp but as soon as I accelerated upto 70+ for the motorway then the temp would fly upto normal.

Currently my Passat is just upto water temp when I'm approaching the motorway 9.5miles at 7 degrees air temp.

My previous Mondy got upto water temp within 2 miles, but that was a 3.0V6 petrol that did 24mpg.

I think the reason the little petrols warm up so quick besides petrol wasting more of it's energy through heat is because they have so little oil and water to begin with. Our old diesel had 4.3 litres of oil, the little 1.2 only 2.8 litres. Coolant for diesel 8.4litres, 3 pot 1.2 5.5 litres although most should be shut off in the rad until the stat opens. And of course a little alloy engine block will take less heating through than a big old cast iron block.

Edited to add I'll check in the morning how many miles until oil temp reaches 90 degrees. I'm a chartered engineer myself and spend a large proportion of my time looking through diagnostics and analyzing ghaphs and trends. Mostly electric motor driven machinery upt 4000KW on 11kV but we also have eight 100 litre V20 turbo lpg 1.8mega watt generators.

Cheers

Lee

Edited 21 November, 201114 yr by logiclee

My old Mk1 vRS would not get to temperature on my commute of about 7 miles. It was just getting warm when it got switched off in the car park. :(

Yeah...some of my old Ford work diesels were like that. They've come some way since then Mike, and is yet another reason for the smaller engined diesel revolution.

Amastra, that's unfortunate if you have oil rise again. But is it actually fuel contamination or is it condensation? How many miles has your car covered? Was it run in correctly? It could and usually is fuel and condensation too on cars used for shorter trips. Although you are doing 100 miles a week it isn't very much and especially in cooler weather you need to do trips of 30 to 40 miles or more (depending on the level of contamination) at a good pace to remove all oil contaminates such as condensation and fuel. You need to get the oil up to maximum working temperature and keep it there for some time for evaporation to occur. On a 12 mile trip for example, your engine and oil will be at normal temperature but not for long enough to remove contaminates. So if you take an extended trip now and again your normal 100 miles per week should be fine to keep it clear. Petrol engines also suffer oil rise from fuel but mainly condensation but slightly less so especially if used on longer runs.

There are some things you can do that will help to avoid oil rise such as not letting your engine idle from cold (to try to warm it up) before driving off. Drive off after 30 seconds or so to reduce the amount of fuel bypassing the piston rings and entering the oil. Under load the engine warms up fast, the piston rings are pushed out against the cylinder bore walls reducing bypass, and the amount of fuel air ratio is reduced to normal much faster. Don't continually labour the engine at low revs in high gears. This increases fuel/air ratio until the ecu regains control. It causes too much fuel to be used and floods the cylinders with fuel for longer than necessary. As mentioned, once in a while take her for a good long run. This can be an extension of a normal run you make and will do the oil good.

It's very difficult for a diesel engine to be harmed, they are very very robust. But oil contamination by fuel isn't good. Some of the fuel contamination always remains in the engine especially with the newer diesel fuels which don't evaporate easily. So if you suspect large amounts of diesel in the oil (you can smell it usually) then changing the oil is a good bet. Some diesel in the oil is normal just as some petrol in the oil of petrol engined cars in normal (if used on shorter trips all the time). I think too you should speak to your dealer in detail about this as there are software changes I believe than can be made they may improve the situation. One or two others on this site have had a problem with the 1.6cr and it has been cured with software changes. Keep posting and let us all know how you get on with this issue.

Thanks Estateman as usual your information is much valued. I am still studying all that you have said and will keep all informed about it.On all my trips the engine always gets up to 90 dgs ,but I will get back to the dealer soon.Thanks again.

OK then some warm up times because I'm sad and anal.

All taken from VW Highline MFD (Maxidot). Latest generation MY2011 VAG 2.0CR with DSG but without stop/start or regen alternator.

To work 9.2 miles 40-50mph A road then motorway. Cruise set at 75mph indicated on motorway. Cabin climate set to 22 degrees

4.45am, outside air temperature 9 degrees.

Journey Distance 28 miles

Journey Time 36 minutes

Economy for journey 60.6mpg

Distance for engine to reach normal 90 degrees water temp - 10.4 miles

Distance for engine to reach 80 degrees oil temp - 15.2 miles

Distance for engine to reach 90 degrees oil temp - 20.7 miles

Coming home 3 miles through town centre then motorway. Keeping up with outside lane traffic on motorway. Cabin climate set to 22 degrees

2.30pm, outside air temperature 12.5 degrees.

Journey Distance 28 miles

Journey Time 41 minutes

Economy for journey 52.7mpg

Distance for engine to reach normal 90 degrees water temp 6.1 miles

Distance for engine to reach 80 degrees oil temp - 10.8 miles

Distance for engine to reach 90 degrees oil temp - 15.1 miles

Obviously if we were in freezing temperatures then the warm up time would be longer. The Passat does give warm air into the cabin very quickly though and I also have heated seats so pretty toasty quickly. But from the point of view of looking at what sort of miles you need to do to get water and oil fully upto temperarure it may be far longer than you thought.

The 1.6TDi would be pretty similar in my experience, I have used my uncles 1.6TDi DSG Golf on several occassions and the warm up times seem about the same.

I hate the non-maxidot display on the Mk2 Fabia, at what temperature does the blue light go out? anyone know?

The 2.8CRD engine that Jeep use has a unique feature. It has a unit that houses two viscous discs that drag and create 1.2kW of heat, the engine coolant is circulated around this unit and the heater matrix. The unit is belt driven off the engine and can be engaged or disengaged by the ecu. So if the engine is cold and the air temp is cold then you engage an instant 1.2kW heater that heats the engine and cabin up far more quickly than normal. I had one and it was the fastest warming up diesel I've ever had. Certainly as effective as the webasto type cabin heaters and less hassle.

Cheers

Lee

The 2.8CRD engine that Jeep use has a unique feature. It has a unit that houses two viscous discs that drag and create 1.2kW of heat, the engine coolant is circulated around this unit and the heater matrix. The unit is belt driven off the engine and can be engaged or disengaged by the ecu. So if the engine is cold and the air temp is cold then you engage an instant 1.2kW heater that heats the engine and cabin up far more quickly than normal. I had one and it was the fastest warming up diesel I've ever had. Certainly as effective as the webasto type cabin heaters and less hassle.

So, the Jeep had a design feature to deliberately introduce friction into the engine to improve heating?

Only american engineers could come up with such a solution!

I remember Fiat planning to install a paraffin heater in the electric version of the 500. Seems more sensible.

So, the Jeep had a design feature to deliberately introduce friction into the engine to improve heating?

Only american engineers could come up with such a solution!

I remember Fiat planning to install a paraffin heater in the electric version of the 500. Seems more sensible.

The engine Jeep use is made by Italian firm VM Motori. The viscous unit is external to the engine and belt driven exactly like the aircon compressor, the unit heats up and transfers heat to the engine coolant. The unit is only driven when required, the load it puts on the engine uses extra fuel but is partly offset by the faster warm up time. If the engine is warm or the outside air temp is warm then the unit is not engaged. The same system is used in some Toyota's although not in the UK.

The system allows Jeep to sell the diesel in Canada although an optional electric block heater can also be specified.

Cheers

Lee

Interesting stuff. Citroen have a solution to the warm up periods in their C4 Picasso range (1.6HDi), and probably elsewhere, which is to pass the air on its way in over the exhaust near the turbo. You can really feel the effect by 'giving it a bit' when cold, as the c/c increases the blower speed when there is heat available.

Obviously those following this thread will take a different view from it..., for me it's just another good reason not to bother with derv.

I hate the non-maxidot display on the Mk2 Fabia, at what temperature does the blue light go out? anyone know?

Lee

Don't actually know what the temp is when the light goes out but the engine isn't fully warmed up when it does of course. The coolant is well on it's way to warm, but oil is still pretty cold. My blue light goes out within 250 yards in summer (the distance to the end of my road), but it's variable in winter depending on how cold it is. It can be out in a third of a mile or it might be on until 3/4 of a mile. Depends on traffic of course, if sitting in traffic from cold it takes a bit longer. The main thing is that warm air is available (luke warm in winter) early on usually by the time I get to the end of my road, not like the diesels from a few years back when you had to go ages before warm air was there. Petrols do have the advantage here, but small diesels are much better now than they used to be. By the way...I too didn't get where I am today by not being 'sad and anal'...if you see what I mean!

The main thing is that warm air is available (luke warm in winter) early on usually by the time I get to the end of my road, not like the diesels from a few years back when you had to go ages before warm air was there.

I get warm air almost instantly from the Passat but as shown it can be 20miles + before the oil is upto temp.

Cheers

Lee

I watched my coolant and oil temperatures carefully today ...

The coolant was up to temperature in about 5 miles both ways while the oil reached 82 C at the end if 11.5 miles.

I didn't watch this morning how far before the oil reached the minimum displayed temperature of 50 C but tonight it was just over 2 miles.

If I remember I'll look what the oil temperature is just as the coolant is up to temperature.

I have noticed the warm air starts sooner than on my previous 1.9TDI PD Audi.

I wonder why they don't insulate the engine blocks with sprayed on foam, like hot-water cylinders.

I watched oil temperature today and have just looked at distances on Google Maps.

Both ways actually about 3 miles when the oil reached 50 C and coolant up to temperature in just under 5 miles at which point the oil temperature was 57-58 C.

The end oil temperature this morning was 83 C and 84 C tonight so virtually the same as yesterday.

I had a regen today and only about 200 miles since the last one rather than the recent intervals of around 300miles.

Given my journey pattern has not changed, although a couple of times longer morning queues due to amount of traffic for some reason, I can only assume due to the colder weather and now filling up with winter diesel.