Loss of power (2002 V40SD 102Bhp)

[Mark]

Help..
Can anyone help me on this problem.. When I'm in 4th and 5th with foot to the floor when the revs are between 2500 and 3000 I get a couple a "Blips" in the power. When I'm above 3000 revs the power delivery is fine with no problems. My V40 is fitted with the Renault oil burner (102bhp) and has done 73K now. I've no other problems and not using any oil between changes.. every 6k.

Please can any one help on this?

Cheers
Mark

I just happen to have the same exact problem for a couple of days now.
When rising above 2300RPM approx. i feel this "blip" momentarely, like if I was pressing the brakes for a millisecond and then releasing them, it goes on like this until I reach the 300RPM.
Today I looked at it more closely: while this was happening I looked at my back mirror and saw, every time there was a "blip" there was white/blueish smoke coming out of the exhaust pipe, like a (sorry for the word for it is the best description) fard.
I am thinking if it is the Air Mass Meter. I removed it and of course looks fine because there is no maintenance at all that can be done to it. I will do more research and let you know if I find something, hope you do the same.
Good luck.

Alex.

[Mark]

I've not seen the puff of smoke, but you have described it exactly.

Where is the air mass meter? Is it the device just after the air filter box?

All I have done so far is looked at the Air Pressure sensor that is fitted to the manifold intake duct after the intercoler top pipe. I removed it ? disconnected it and went fro a drive .. this device seems to control when the Turbo kicks in, as when I tried it the power was way down and the turbo didn't spin up. I sprayed some switch cleaner down the small hole as there was signs of oil on it and on the inside of the ducting? I dn't know where this has come from but I know the car isn't using any. Doing this dosn't have seen to have made any difference to the "blip" of power!

Mark

Yes, the air mass meter is the thing just after the air filter box.
Two Torx 25 screws and a clamp. To get it out the best is to take the connector away, loosen the big clamp, unclamp the air filter cover and then pull so the thing comes out together with the air filter cover, this way you have very easy access to the two screws.
I also think there is nothing involving turbo parts.

To me, not scientifically speaking, the engine cannot cope with all the diesel that gets in. I speak about having the problem up to 3000RPM but really honestly I think the problem continues but there is too much power output for us to fell this "blips".

I have been told by a car mechanic that the Air Mass Meter is used for elctronic scheduling of Diesel injection, could that be the responsible? The guy honestly did not know, he said to me I could try replacing it but it is a quite expensive item and I do not know where to get it from besides my official Volvo dealer.

If I discover something else I'll let you know.

Alex.

[Mark]

I'll have a look at that at the week end or Friday eve after work when I can pull my car into the factory as I haven't a garage.

That is very interesting about the the extra diesel thing as I've a PSI Power box fitted that keeps the injectors open for a fraction of a second longer.. giving bags more torque and power. I don't notice the problem in all gears upto 4th and 5th as when I put my foot down the car takes off very quickly and the revs go past the 2500/3000 point very quickly. To be honest, the blip is still there when I turn off the power box, but not as noticable.

Have you tried running the car with this device removed or un plugged?

I haven't felt any blips after 3000rpm close to red lining with my foot right down.. about 115mph. I haven't pushed my car to the point the rev limiter comes on and don't intend to.

Have you modded you car at all?

Mark

I found the problem.

I found it on the flexible line (pipe) of the intercooler between the radiator top part and the pressure sensor that you talked about removing, the line had a three centimeter long crack. It was on the bottom part that's why I couldn't see it. Went today to get a new pipe at my Volvo dealer and replaced it. My car runs smooth and nice again.

For your info: part number 30621196, catalog price: 78.50EUR + taxes.
This fixed my car, see if you can find this problem on your car.
Good luck,

Alex.

[Mark]

Alex,
I've removed the plastic tube and flexiable rubber tube between the plastic inlet manifold that has that butterfly valve device fitted and the top of the intercooler and had a good look. I've no cracks or splits, although yesterday after re fitting the tubes I had none of those "blips" in power??

When you removed the pipe work, was ther any oil in it? I have oil in mine and also if I feel in where the butterfly valve is there is oil there. Is it comming up from that, what looks like a flexiable stainless tube coming from the back of the engine? Does anyone know if this is normal and where does the stainless tube come from and what is it for?

Whilst I was working on the engine I also had a look at the mass air flow sensor that is fitted just after the air filter box... Hmmm, looks like there is a thermister and that srange device that looks like a couple of pieces of glass plate? What are they?

Mark

Mark,

Yes there was oil inside the pipes. A colleague told me it is not unusual to have a little bit. About this metallic flexible line, I honestly have no clue about it. But it looks like the oil is coming from there on my car too.

About the Air Mass Meter don't know much myself but I found this ultra-interesting website and now I understand a little bit more:
http://en.wikipedia.org/wiki/Mass_air_meter

Regards from Belgium,

Alex.

[Mark]

Afternoon Alex,

I'll have a look at that web site shortly.

I'm pleased that you have some oil from that area too and your colleague says it's not unusual. I've just enough oil seeping through the joint between the Ally inlet manifold and the plastic moulding where that butterfly is to attract the dust. Not enough to drip! My car has done over 73000 miles now and not using any oil between changes (I change the oil every 6k miles and filters every 12k).

I'm waiting for a copy of a service dvd to arrive. Hopefully I'll be able to identify what that s/steel tube is for and where it goes?

Cheers from Kent (UK)

Mark