Hi all.
I just wanted to relate this - might save someone else some unnecessary expense.

Two weeks ago I struck problems with my 200,000km 2000 S60 T5.
Local gas station was out of 95 octane so I kept driving to my work intending to fuel up on the way home. Low fuel light had been on for some time.
At an intermediate stop the car began lurching forward and back at idle - even in park it was rocking quite vigorously with the tacho flicking between about 500 and 1500rpm.
I drove on to the gas station and filled it. Problem continued.
I drove home and inspected everything I could. I wondered if I might have got some air in the fuel rail so I bled it using the valve at the end - just a quick escape of fuel as the pressure subsided.
I had no option but to keep using the car - only around town - and had to put it into neutral at intersections and rev it continually to prevent it stalling. An engine fault light came up with an "emission system service required" text on the dash.
I searched this forum and came up with reports of similar symptoms related to both the throttle body and the mass airflow sensor.
I removed the airflow sensor and cleaned it with the correct cleaner. It seemed to make matters slightly worse. That made me favour the sensor as being the likely problem, so I began searching for a replacement.
Local prices varied from NZ$500 down to NZ$250. I could get one from the USA for NZ$200. Then I found one in China for NZ$46 so I ordered it. I have had great success using cheap parts from China on other vehicles - but that is another story.
The following day I bled the fuel rail for the second time. The car seemed to be running smoother.
The day after that the car was running seemingly ok and the engine light went out all by itself.
That was last week. The car continues to run perfectly despite the fact that I have not replaced anything at all.

So.
My suspicion is that I either sucked some rubbish from the very low fuel tank - or some water - or I managed to get an airlock somewhere in the fuel line/rail by sucking air briefly.
Whichever of those it may have been - the problem is cured although my bleeding of the fuel rail or cleaning of the airflow sensor can not be dismissed as possibly having played a part.
I know for a fact that the engine fault codes are only a generalized message and often are not entirely accurate as to the real nature of the problem.
Having read many accounts of people replacing throttle bodies and airflow sensors I can only suspect that they may not have all been necessary - seeing as how their symptoms were exactly the same as mine.

I feel that I should drain the fuel tank just to make sure it has no contaminants, and maybe replace the fuel filter as a matter of its age - I do not know if it ever has been replaced in the past.

Do not be too hasty in ordering expensive parts - you may find your problem has a much more simple explanation.!

Anyone want a cheap airflow sensor..?

Go well.

P.S - It gets used...

 

I can tell you that "bleeding" the fuel rail did nothing at all. You likely have an intermittent problem that will return.

 

Regardless of whether it does or does not - the fact is - such a problem can go away by itself - even if for a short while.

To me that indicates that a permanent failure has not occurred.

I will be sure to update this post should there be new developments.

Cheers.

 

I would change the fuel filter anyway. Recommended is every 105,000 mis / 168,000 km. It's $21 USD, well worth it.
Generally speaking, one should change every 100k mi/ 150k km per the Volvo recommended service interval BUT when a tank is sucked that low should be done immediately after filling. The 'spooge' as I call it will plug the filter causing the symptoms you state.

On pump-in-tank cars (majority on the road now), the fuel itself cools the pump, as the pump is submerged in the fuel. Sort of like a can of soda in a cooler. If one keeps the tank above 1/2 most of it's life, the pump will last substantially longer and you'll have less chance of CREATING or sucking up condensate (water).

When I was a school bus dispatcher, the shop manager found that after 5 yrs of not keeping the buses topped off daily that the heat/cold would cause moisture condensation in the fuel tanks (diesel). We had buses with *15 GALLONS* of water in the bottom of the tanks. They spent several weeks over the 200+ buses draining the water and then created the mandate that they were to be topped off at night before parking. Water issues (and the ensuing gelling/freezeups it caused) ceased.

There are several points I made, but they all tie together. What I'm saying is to not go below 1/2 a tank a lot. 1/4 tank is bare minimum. Keep it filled and change the fuel filter per the interval. The filters are cheap enough to change every other oil change. In your case, I'd change the filter and then again in a month or so.... then follow change interval.

I changed the filter on my car because I bought it with 148k mi with no service history. Sure enough... it was the original filter on the car. Performance increased and when back draining filter there was a ton of 'spooge' it had trapped over the years.

 

I have an 04 S60 that did the same thing, I checked an earlier forum answer to the problem that said to clean the inside of the throttle body. Its easy to remove but have a replacement gasket to use in case you crack the old one. They are cheap and available at an car parts store. Remove (or just get access to ) the throttle body interior and spray carb cleaner in it and scrub around with a soft wire brush. Once you get it clean put the hose connections back together and it should run smooth immediately.

 

I have reason to suspect that the sensor on my throttle body may not be reporting it's position as well as it could. Has anyone opened it up and cleaned or repaired it.? The sensor that is..