Hi,
I have to get my 03 Mondeo TDCi (31000 miles) garage-serviced for a insurance-type warranty.
When I got the car home (4 miles) the oil was already black!
I've heard this happens quickly with diesels, but that quickly???
I have had little previous experience with diesels.
Could someone with greater knowledge help me to guess whether this is normal or should I do it again myself to be certain please?
Thanks
eljay
|
I have little to no experience with diesels but from what I gather reading on here, yes - it turning black that quick isn't out of the ordinary.
For the sake of your car, don't believe what I say - make sure a few people back me up first!
|
|
That is normal, the oil in a diesel picks up soot deposits and enough old oil is in the engine when drained for the new oil to look blackish after the engine has only been started for a minute or two. If the engine was flushed it would stay cleaner longer though not much longer. My TDCi is on 109k miles and has been as you describe following each service.
|
It makes you wonder what the hell it is, it stains cloth and driveways and even skin like ink!
Surely not just plain soot?
|
|
I noticed the same thing used to happen on my last car a 306 turbo diesel, after a hundred miles it looked like the oil needed changing again. It did make me wonder if the oil had been just topped up and not drained. In the last couple of years that I had the car, I disabled the EGR (exhaust gas recirculation) value and the oil used to stay clear for well over a 1,000 miles ?? I guess the engine didn?t like ingesting its own waste gas, I must get around to doing the same to my Leon.
|
|
On the Mondeo, the oil stays clear for about 30 seconds of running and then it's jet black.
|
Same experience here on all diesels except yaris where oil stays clear and only starts to darken after 1k miles.
A lot to do with engine tolerances and May be how long engine is left to drain when oil changed/how filter is changed. I leave diesels to drain for about 30 mins: seems to make no difference as oil dirties just as quickly.
With CRs of 20:1 , I imagine the slightest imperfection in piston ring tolerances mean lots of soot blown onto cylinder wlls and into sump.
madf
|
Indeed, back in the mid to late 80's, diesels typically would have oil filters of about twice the volume of the equivalent petrol engine - and only half of the service interval.
I suspect it is only advances in the oil formulation which has allowed us to progress to the point where diesels have similar filters and similar intervals to petrols.
To the OP - there's nothing to worry about, oil turning black quickly is normal behaviour for a diesel.
Number_Cruncher
|
without wishing to dredge up a recent thread where I was slated for stating that diesel oil worked harder than petrol oil inside the engine I think this thread and the comments on it bear out my comments.
When running a diesel car always use a good quality diesel oil of the viscosity required. Don't be tempted to use a good petrol oil, no names mentioned but one always appears to get mentioned, use the proper stuff!
|
|
if its the oil I'm thinking of, its equally suitable for diesel or petrol. The engine mfrs approvals need to be followed also.
|
OK it may be, but saying it is suitable for all petrol and diesels is incorrect.
Its like fleet user using one type of oil for all vehicles, its ok as in better than nothing, but its not good. Oil is the blood of the engine! The right sort, changed frequently will and does make a difference to the life of the engine.
Understand if you are selling the car before the engine is too old, some one else gets that problem, but the result is the same.
|
Look, Mobil and even VW rate oils for diesels and petrol. Try checking the mfrs site.
"Mercedes Benz 229.31, BMW LL-04, VW 504 / 507, API SM/CF, ACEA A3/B3/B4/C3" This is from the latest Mobil ESP oil spec and you will notice that it covers both petrol and diesel engines, in ACEA and mfr terms.
|
|
and covers the viscosity required too !
|
if its the oil I'm thinking of, its equally suitable for diesel or petrol. The engine mfrs approvals need to be followed also.
It is all to do with detergent quality. New synthetics can have sufficient detergent quality to meet the diesel spec. Older diesel engine oils had extra detergents added that were not used in the petrol versions. Also didn't older diesel fuel have more sulphur..? This I think maybe corrosive and maybe eeded neutralising.
Having black oil was always seen as a good thing.
|
|
It actually proves the oil is working! Holding the particles in suspension.
|
|
It makes you wonder what the hell it is, it stains cloth and driveways and even skin like ink! Surely not just plain soot?
>>
Yes it basically is, but in suspension in such small particlles it is a devil for staining every nook and cranny...
|
|
All the diesels I've had have done this !
|
Same with all the diesels I've ever owned.
The oil doesn't stay clear for 2 minutes.
Ken.
|
|
My Vectra oil stays clear for the first 1000 or so. It's done almost 20,000 miles, and I change the oil every 6000 to 7000.
|
The new Ford Focus uses the same semi-synthetic 5/30 oil for petrol and diesel engines. Oil & additives are so good these days it can't really be compared to oil used in older diesel engines. Some diesel lorries go 40k miles without an oil change, unthinkable a few years ago.
As far as changing oil is concerned, well petrol and diesel engines will need more frequent oil changes if lots of stop/start and/or short journeys are made. Considering the price of an oil & filter change can be done for under £30 by a Ford dealership then by all means change the oil sooner rather than later. It's not just a question of economics but to get the best life out of an engine ensuring it has a constant supply of fresh oil is the best thing you can do for your car and the environment.
Oh and yes, a diesel engine's oil does look/go black much sooner than a petrol engine oil.
|
|
According to my info they use different oils from petrol to to diesel engines as specified by ford. Same viscosity but diferent grades. !
|
What's your source of information ?
According to the new Ford Focus Ownes Manual (Copyright 2004) both petrol & diesel engines use the same oil.
Our Ford main dealer Rapid Fit staff confirm this to be the case, it all comes out of the same big oil drum, Formula E SAE 5W-30, semi-synthetic.
|
focus diesel moderate climate 5w/30 cf/b1-98
focus petrol moderate climate 5w/30 sj/a1-96
|
The petrol spec you quoted has now been superceded and the diesel uses the same spec as the petrol now.
SAE 5w-30, API SL, ILSAC GF-3, ACEA A1/B1
the API SJ spec was quoted for engines up to 2001 IIRC.
|
Ok
SJ spec is up to 2004 actually, but it means sj or higher spec may be used.
The oil may (may!) be the same, but check that the spec that the engine type needs is specified on the container. Not all do, believe me ( But I know from experience my information is disagreed with by people who are far better qualified and informed than me). Usually because they have read the advertising material of a certain oil!
I really dont care what oil people use, I just try to help point out the correct info for people who want it.
|
Oh, and the higher spec normally is only higher because it is suitable for higher mileage extended service intervals.
A discussion that has been held many times. But who wants to carry dirty engine oil around an engine longer? especially in a diesel?
|
|
Spot on rob, I'd rather and do change the oil more frequently than spec'd, nothing quiet like seeing clean oil on the dipstick from a diesel engine, well at least for 10 minutes or so (hehe).
|
|
|
|
Hi eljay,
oil in any diesel will turn black very quickly. But - because you see it's black you automatically assume it's not doing the job. This is not so. Back in the 80's i used to service trucks and they were fitted with what was called a 'cresco' filter. This meant that you didn't change the oil for a minimum of 100,000 miles - you just changed the filter at regular service intervals. Our Foreman was a suspicious person and actually had some oil removed from some trucks that had done 50,000 and 75,000 miles then sent them for analysis. I remember seeing his face when the lab report stated the oil properties were within limits and there was no degradation of the spec of the oil.
So, just because the oil is black - don't assume its no good.
I just changed the oil in my '02 Peugeot 406 with 45k on the clock and the oil was black within hours.
Hope this answers the question
--
These are the views of Robin the Technician with 35 years in the trade. I fix, therefore I am...
|
|
|
