Dear Abby,

I had the pox a while back but it seems to be cured now.

Mostly I am happy but sometimes when alone at night I worry that it may come back.

Should I answer Yes or No?

Yours etc,
Feeling Sticky

Quote:
Originally Posted by wilbydoughboy
How would I know if I have oil pressure issues. With a newish car under warranty I wouldnt think there would be such issues but unless told how would one know as I cannot see any oil spewing out anywhere or any smoke puffing.

I do not know anything about oil pressure issues, in fact I have never seen them mentioned anywhere (perhaps you could expand on this?).

The issue is in the title of the thread, Rising Oil Levels which you will notice everytime you check the oil level - assuming that you do.

Even under warranty you need to check the oil level since if it is low or high and damage occurs then the ensuing damage could be attributed to you as the maintainer and then the warranty would be void. You fill up the windscreen washers between services, you check the tyres, the need to check the oil level is in the same league as these items


I would have assumed that by having to much engine oil than the normal amount it would cause the oil pressure to rise. I remember once that I put in to much engine oil in my Ford Escort and the smoke that was belching out from the exhaust was very dense but this was a petrol engine so maybe with the diesel engine this wouldnt happen. I will keep an eye on the oil level but I havent been informed that I should check for rising oil level because I have put my trust in the Volvo brand and hope that their technicians would put the correct amount in at the service and inform me that this can rise. I dont feel that owners should take the blame for rising oil levels unless they are informed by Volvo and no blame should be put upon owners who would probably never have bought their cars if they knew that they had to keep an eye out for rising oil levels.

Excess oil will not cause the oil pressure to rise - it will cause the smoke you mention as the oil enters combustion chamber due to it splashing around excessively in the crankcase and usually being pushed up the crankcase breather into the air intake.

The effect on a petrol engine is to cause dense clouds of blue/black smoke, on a diesel it can cause runon, where the engine cannot be stopped.

Oil pressure is created by the oil pump which lifts the oil directly from the sump and is distributed to the bearings in the engine.

Your choice on whether to check the oil levels or not, I am not sure that I would put my trust in an oil level check that is done once per year at a service though :)

I've just posted a NO vote and hope I don't get punished by Sod's Law now...

I checked the oil level periodically using the dipstick from when I took delivery and after 3300 miles it has not budged; still on the maximum level.

I have seen what appears to be the DPF regeneration cycle several times now. The fuel consumption drops to almost half of what it normally is for the speed and road I'm on, and lasts around 10-20 minutes.

Average MPG so far is 36.4 on mixed roads with a careful but not OTT driving style, and ECC left on auto fulltime.

Could you explain what actually happens with the regeneration?

I'm certainly no DPF expert and there are quite a few detailed threads and links on this matter, but this is my basic understanding of how regeneration works:

The DPF consists of a fine ceramic mesh or membrane that collects soot particles in the exhaust gasses. As the filter becomes clogged with these particles over time, a back pressure builds up in the DPF. At a certain pressure level, the engine control unit injects diesel directly into the exhaust system before the DPF. This extra fuel ignites and raises the DPF temperature sufficiently to burn the soot particles and clean off the ceramic filter, thereby 'regenerating' it.

This is a highly simplified explanation and I'm sure the ECU factors in many other parameters too before deciding to initiate a regeneration cycle. Any experts, feel free to contribute...

So much for the theory. I understand problems arise when the exhaust system is not hot enough to fully ignite the injected diesel, some of which then finds its way into the sump. With normal diesel this would not be a problem as it will evaporate out of the sump, but apparently the plant oils in bio diesel do not evaporate and just collect in the sump, raising the oil level.

Thank you for the detailed reply nosmoking. :thumbs_up:

I have read the threads about the DPF, but what I really wanted to know is how did you know it was regenerating, in other words what signs were there? different engine noise, more sluggish, engine racing?
Sorry I didn't make it clear last time, hope it is this time. :)

I am in a similar situation, namely I am unable to tell when regeneration takes place and I can only assume that somewhere in the 10000 miles that my car has travelled that regeneration has taken place :)

I have never been aware that it has happened, and others have also indicated that they know when it is happening (though nothing definitive), perhaps I am missing the symptoms indicating that it is taking place (assuming it has :))?

Ah, gotcha! The few times I've noticed something I can only assume it was regeneration because of the increase in fuel consumption that I couldn't pin on anything else! I was on a motorway each time doing around 70 and didn't notice anything else, e.g. sluggishness or noise.

I could be totally wrong of course but I assumed that the additional injected diesel would have a direct hit on the instantaneous consumption, so this would be a fairly reliable indicator that regeneration was taking place.

Jus a post to pop this back up the list ... Sorry