My V70 2.4T has very little power. It feels like the car has a very little throttle being used. There are no codes, Gas mileage is 1/2, no visible hoses broken. Can someone give me a tip about where to look to start diagnosing this problem?
Thx,
Joel

 

You might want to have them check the MAF. I had an issue with this, and once they replaced it, the car was running as good as new again.

 

Here is something to try but do it at your own risk

My 01 V70 T5 had sluggish performance when I was battling a intermittent failing ETM prior to Volvo's new ETM software. I would get performance reduced message and a CEL on one drive cycle, but then it would go away like nothing is wrong. However, engine ran sluggish from that point on.

I finally figured out that the ECU went into a lower performance mode because of the ETM fault detection. I reset the ECU and all the power came back. I have experienced a couple of other instances where the ECU runs the car in a reduced performance mode. It seems to do that at the slightest suggestion of problem from the sensors. Now keep in mind I have no ability to know exactly how the ECU software works. Just observations over time.

So how do you reset the ECU. Here is a another bit of a mystery and you can consider doing it at your risk. You just disconnect the negative terminal of the battery for a period of time. But here is the disclaimer:

I've heard the warning that this may not be good for the engine as ECU may not setting optimal operational parameters to protect the engine. I kind of figured that the design shouldn't allow a power interruption do any harm to the car (after all, changing battery is a real maintenance event) So I went ahead and did this.

- Now, how do you dis/reconnect the battery? It isn't simple as usual. I've heard people frying their ECCs doing this. Here is what I do
- Turn off everything on the ECC
- Shut down the car
- Wait 10min (ECC seems to still runs awhile after the key is out)
- Disconnect the negative terminal on the battery
- Wait 15 min
- Set key to position II (volvo recommends reconnect power with key in this mode, see this the last step in this link
http://www.volvoxc.com/resources/how...le_removal.pdf
- Reconnect the battery

Sometimes the sunroof/homelink won't work after this because the electronics reinitialized incorrectly. Lock and unlock your door and everything will work again. And also need to setup your clock again.

Anyway, think about it and see if you want to do this. Just a warning that other's have fried their ECC. Read the *IMPORTANT* section of the following link for more info

http://www.freewebs.com/howardsvolvo...de75kmiles.htm