98 V70 non turbo - engine drones when accelerating

[Sommerfeldt]

no one mentioned this: are you driving in (n)ormal mode? switch that to sport! Makes a big difference once ECU learns your non granny driving style. I used to only drive on normal, and then made the switch to sport and never looked back

That's a good point. My T5 feels more comfortable, and actually gets better mileage in Sport (currently @ 28 - 32, no matter what I do).

- S

[mika]

Normal AKA granny mode. I cant believe I drove it like that for over a year. I thought I needed another p80 lol!

[jblackburn]

I can't stand Sport mode...

[98v70dad]

Funny. i just logged in to mention that the car is always in economy mode. I thought about it last night and I put it in sport mode this morning and it does seem a lot better but can anyone tell me what sport will do to my gas mileage? One guy said his would improve i noticed that in economy the car takes forever to shift out of first gear. When I notice its laboring on a hill and accelerating slowly and mash down the accelerator it will suddenly drop into second and get moving.

I also forgot to mention that the car has the original o2 sensors. I've been meaning to change them but its hard to find the time. That's my next project, hopefully in the next three weeks I'll get it done. I doubt old o2 sensors would contribute to lack of power but I suppose they could if the engine computer uses that data to determine the fuel delivery rate.

[98v70dad]

Oh. I forgot to mention that like jblackburn I also find sport mode annoying. Its like a teen aged boy who just learned to drive a stick trying to impress his date. To me its just as annoying as the gutless economy mode, but on the other end of the scale.

[mika]

In my opinion, don't worry about o2 sensors for now: they would give you a code if bad.

Sport mode should not decrease your mileage bad unless you ride the engine very hard. There are other things that would decrease your gas mileage more significantly if overlooked , like a seized handbrake drum, clogged PCV (which I know you did), spark plug gap, ect.

[Sommerfeldt]

Oh. I forgot to mention that like jblackburn I also find sport mode annoying. Its like a teen aged boy who just learned to drive a stick trying to impress his date. To me its just as annoying as the gutless economy mode, but on the other end of the scale.

I kind of get what you're talking about, but have you tried "teaching" the gearbox again before you start driving in Sport mode? It's the first thing I did when I got the car home 7 months ago. Never looked back.

As for the MPGs, like I said, my mileage is better in Sport than Eco. I get 28 - 32 consistently, and I don't drive my T5 carefully either. I love the sound of the turbo.
Eco is for people how live where there are no hills, and only straight roads. So... unless you're in the aussie outback, following road trains for hundreds of miles in a straight line, I think S is better than E.

- S

[98v70dad]

I appreciate everyone's comments. For now I'm going to give sport mode a try. It seemed to settle down after a day or two driving in that mode.

Everyone has lost sight of my original question though. I origionally asked about the droning noise on acceleration. For some reason the conversation has gotten stuck on lack of power. Does anyone have any further comments about the droning sound and what it might be? It seems as if sport mode makes the droning worse.

[erikv11]

I think the best answer was touched on in the first reply: likely it is the exhaust system. Could be at the manifold, flex pipe, or look just past the cat as it is very common for the exhaust to crack there.

[Sommerfeldt]

+1 on erikv11's reply there. Exhaust should at the very least be the first stop.

- S