changing the engine oil

[ross]

Hi all, this is by way of an observation, which has frustrated and annoyed me. When I bought my turbo diesel grand espace, comming up for 6 years ago now, I contacted the garage that had carried out all the servicing for the previous owner, from new, and they very kindly told me what oil they had used and the process they had taken at every oil chage interval. This process involved the addition of an engine flush additive, running the engine on a fast idle for 20 minutes, and then draining the oil, removing and replacing the oil filter, before refilling the engine with a quality oil. I followed this practice and assumed I was giving my engine the best of treatment, until very recently. I had some problems with the cam shaft and needed to drop the engine to do the work. This is when I realised that the oil cooler will not empty of oil when the rest of the engine is drained due to the way the flexible pipes loop up before attaching to the manifold on the engine. This means that when I put nice new clean oil into my engine there is a reservoir of old diluted oil, in the oil cooler, that will immediately mix with my new oil and contaminate it. I am not sure how much oil is retained in the oil cooler but it is too much for my peace of mind. I cannot think of a realistic way of removing the old oil from the oil cooler at every oil change, so it seems to me that evey engine will always be running with a mixture of old mucky oil, even after an expensive oil change. I have had a look at the task of removing one of the flexible pipes from the oil cooler but it seems to be more trouble than it is worth.
Has anyone any observations on this matter, or do we need to forget it and carry on the best we can.
Regards
Ross

[BrianM]

Buy a cheap oil & use it as a second flush before using your quality oil.

[jack daniels]

this is common on most engines to a degree. A bit of old oil mixed in with new is no problem at all.
Engine flush however is different. That will thin out your new oil a bit.
  Frequent oil changes are the best protection for your motor, especially a diesel. The particles in your motor oil have to be physicly removed from the engine and the only way to do that is by draining those little blighters out thru the drain hole. Sure, the filter should intern the most dangerous particles up to a point, but that's probably about 50 micron pore size at best. Letting those little particles circulate around in there for a couple of thousand miles longer in an even more expensive oil is probably of no advantage.
 If the oil is drained often, before the detergent properties of the oil deteriorate then your motor should be spotless on the inside.
    These days engine flush is probably only necessary say if you buy a used car without a history and you want to start off clean or if you want to try fixing tapping noises and such.
     Even a cheap oil will hold an engine clean for a while, so its probably best to change a half price oil twice as often, than a doubly dear oil half as often.

[Anders Dinsen]

I wouldn't worry.

And I would'nt bother trying to flush the old oil out with cheap oil. It's better to use good quality fully synthetic oil and do yearly changes draining as much off as possible. Old synthetic oil is a bit thinner and darker due to the way it absorbs carbon, whereas mineral oil generates sludge.

/Anders

[ross]

Many thanks to all who took the time to reply to my little story.

I will stop the practice of flushing the engine with a flushing oil additive, as I agree that a bit of old engine oil mixed with the new oil is far better than a mixture of new oil and flushing additive.

I always change my oil at yearly intervals, even though I don't do an excessive mileage.

I did once remove the sump during an oil change, and was amazed at how clean it was inside.

I'm off to do this years oil change, so goodbye and many thanks.

regards

Ross

[jack daniels]

As long as the oil viscosity is correct for your car according to the user manual, and the oil has the correct diesel specification it will be fine.
I guess you'll need API CF or ACEA B3-B4.

I buy only brand name synthetic oil when it's on special and then stockpile a few litres at home