Hi I had just replaced tcv whilst trying to eliminate the boost fluctuations and hunting.
Regards Paul
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Ok. Another source of issues eliminated then. ;)
Basically, Unmetered air (after the MAF) has not been processed by the ECM. The ECM is 'expecting' a value of X but is presented with Y by the O2 sensor. Therefore, the ECM stores an O2 fault code because it has not been given the correct 'Expected' value.
So YOU think...."Ah, my O2 sensor is f@@ked"..... when in actual fact, it's not. You just have an air leak.
It's not just the fault code you get, but precisely what it says! You could still have an O2 sensor fault code, for example, that might say....."O2 sensor (bank 1, sensor 1) short to B+"..... In that example, yes, you may well have a knackered O2 sensor. You would need to corroborate that with live readings to see if that sensor was actually reading a voltage and if it was reacting when you accelerate. If the voltage stays still then it backs up the fault code and you replace the sensor. Get it?? :confused:
:smileypul Jesus that was hard to explain but I think i got it right.
Back on the issue of the plume of burnt oil smoke. Just been reading an old thread and it threw up another thought on the burnt oil after overrun, I may be barking up the wrong tree but its just a thought, on the thread I read about the grade of oil used, I have always used W5-30 Magnatec on my car after reading some sales info from Volvo a number of years ago stating that was the grade to use, however I noted on the thread that I think the person who had written the thread had been using a particular grade of oil and Tim Williams advised him in the thread that this would cause engine issues. Following that I read some other threads that suggested using a W10-30 grade oil what are your thoughts?
If you are due a oil change try 10w40 .
I've used 10-40 Valvoline Max Life in my S60 2.0T. 8k miles service interval from 120k miles till I sold it at 193K miles. Never had any issues, never had to to up. The Max life is developed for engines over 100k Km. It's a blended oil. Before the Valvoline, Castrol and Mobil. Both required to up before the end of the service interval.
http://valvoline-eu.lubricantadvisor....aspx?lang=eng
I just bought 12 litres of Shell Helix Ultra 5w-40 from Opie oils for £50 :)
I currently use Castrol EDGE Titanium FST 0W-30 but fancy a change. I'll be flushing out the engine on the next change too.
I had very similar issues to this on my 02 s60 t5 but with higher consumption of a litre in 600- 1000 miles on a good day and only with 90k on the clock. PCV replaced and sump removed to clean the little port which drops down into it which often blocks, turbo reconditioned, however still used a lot of oil yet never smoked on start up or driving really, only really when running down hills. In the end decided to bite the bullet and strip the engine and in doing so I replaced my valvestem seals and reground my valves but sadly found my bores were extremely worn and have lost all of the honing marks. Couldn't afford to rebuild the bottom end so rebuilt the engine and it has made little difference so my problem it seems is rings. I really hope your problem isn't this as valvestem seals are much easier and cheaper to do.
I would suggest doing what the other guys have suggested, take the PCV system apart and clean it or replace it paying special attention to the lower drain port that turns 90 degrees and drops into the sump (it's only about 1cm square once inside) and do a compression test if you haven't already and go from there. Good luck :)
http://youtu.be/m47XU_iVZtg
Years ago I made a little video as it hardly smoked but used loads of oil. This is all the smoking I got revving up after idling other than whiter steam when cold but turned out to be rings of this helps. I now a few years later can see some smoke when driving but only foot to the floor at high revs and only really noticeable in the dark in the lights of another car following. It is very subtle for the amount of oil being lost
Hate to say it but that video shows nothing other than excess fuel being burnt or unburnt. Excess fuel always exits the exhaust as a thin dark cloud. If it were burning oil then it would be a blueish/light grey cloud of smoke.
In my professional opinion it does not look to me like your car is burning oil in that video.
Also, the car was not under load, therefore, you're unlikely to see burning oil IF it has a burning oil issue!
OP, may I suggest that you inspect the PCV hose at the Intake pipe end. Check to make sure that the Intake hose PCV nipple is not blocked and/or that there is not excessive accumulation of oil in that area.
When replacing the PCV pipework properly, not cleaning (which does not work and is ill effective), it is necessary to remove and inspect the MAF to turbo hose. You need to check that the turbo end is not brittle or cracked, if so, fit a new hose as it will leak at the turbo end and cause MAF/Air leak related fault codes. You will not be able to check to see if the PCV pipe is blocked as it will be too brittle to bend or try to shove anything inside.
Note
If ALL the PCV pipework and related parts are not replaced when carrying out a PCV change, then it will affect the running of the car and of course this includes the crankcase breathing system. A partially blocked or fully blocked PCV will make the car idle poorly, consume more oil than is normal, contaminate the MAF with oil vapor and generally lead to an engine that doesn't flow or breath as it should. M.E.7.0.1 is very clever at masking issues because of it's ability to adapt. it will therefore often mask other underlying issues.
The biggest single enhancement I noticed to my engine, once I'd replaced all the PCV components, was the exhaust note!! It was noticeably different and seemed more throaty. Now some will argue there may be a placebo affect going on here, but none the less, the PCV system is often overlooked and easily misdiagnosed as they're are so many parts to it. This is why Volvo include replacing the PCV at a particular mileage interval on the service schedule.
Is your car mapped??
Hi Lee,
No cars not mapped as I have held off from mapping it until all issues are resolved.
The intake pipe is ok as it is an alloy and silicone set up (GWE) so no splits or cracking there.
Car has now been stood for 2 weeks as I now have the C70 Cabriolet to use whilst I get the V70 sorted, at the weekend I started it up for the first time in 2 weeks and ran it until thoroughly warmed through before moving it into my spare garage which I had cleared out, started but ran rough on 4 pots and gave a rather large plum of blue/ white burnt oil smoke, after a moment or so it settled down and ran smoothly and no further smoke.
I'm guessing from my limited knowledge that must have been oil seepage through the valve stem oil seals into the chambers. I will get round to doing a compression test to see if its just valve issues or whether rings are also worn.
Interestingly, I asked Murray Volvo in Edinburgh for a quote for the 100k service plus replacing my PCV system. Not only did they want a stupid amount for the service (but hey, we wash the car too!) But they quoted 30 quid for the PCV as "typically they just need to be cleaned out".
I declined their offer. Confidence lost.
If it clears pretty quickly after being laid up for a while without actually driving it , it sounds very like valve stem seals, the oil that has seeped in while it was standing idle will give you a rough start
After owning Volvos for about 30yrs Volvo seemed to only recommend 5W 30 oil when they started using the VVT system ?
Before that they only said 10W 40 so i always used the thicker oil. Of course earlier T5`s no VVT.
The thicker oil is no friend to the VVT system and can over time make it malfunction.