2006 XC70 loses power at half tank Topic is solved

bleubistro · Post by **bleubistro** » 01 Jun 2019, 07:34

Volvo guru's, please help!

Whenever the fuel level falls below half tank, my 2006 XC70 has episodes where it loses all power, fluctuates, and sometimes dies altogether. Sometimes the car recovers and roars back to life within a few seconds, sometimes it dies and I have to roll to a stop at the shoulder. So far it has always restarted fine immediately afterwards.

It seems to happen most often when going around a sharp right hand turn. Also, it happens more frequently as the fuel level drops. One time I let it get below 1/4 tank, and it was happening every 2-3 minutes. Once I filled the gas tank, it stopped entirely until fuel level fell back below half.

I had my local auto parts store read the codes, see below. Based on advice from my local mechanic, we replaced the fuel pressure sensor on the top of the engine and the fuel filter near the rear passenger wheel. I also got another used fuel pump control unit/PEM from a salvage yard and tried that...nothing has made any difference to the issue.

The only other lead I have at this point is the following comment from someone else online: "I’m pretty sure it’s the in-tank pump and level sender that’s your problem. It’s plastic. If it gets a crack in the pickup it starts sucking in air when the fuel level drops below it."

Codes:
P0089 - Fuel Pressure Regulator Performance
P0027 - Exhaust Valve Control Solenoid Circuit Range/Performance (Bank 1)
P0420 - Catalyst System Efficiency Below Threshold (Bank 1)
P0087 - Fuel Rail/System Pressure - Too Low

Any help is appreciated!

Post by **Rattnalle** » 01 Jun 2019, 09:48

There's a contraption inside the tank that isn't really a pump but that moves fuel from one half of the saddle to the other. It's been known to break. The car will work normally when the tank is full since the pump itself is fine. Sort of sounds like your issue. Also it's not something you can get an error code for since it's a mechanical and not an electronic malfunction.

Post by **abscate** » 01 Jun 2019, 12:11

If anyone had has been in the tank for any reason it’s easy to link the lines and give funky running

Monitor furl pressure at rail to confirm

bleubistro · Post by **bleubistro** » 02 Jun 2019, 08:50

Thanks for the ideas. Sounds like the issue is likely inside the tank. I'm assuming this will be an expensive repair no matter what the actual issue is...and there will be some on-the-fly diagnosis necessary once you get into the tank.

How difficult is this repair? Should I consider tackling this myself, or is this just a dealer or Volvo shop repair?

Post by **abscate** » 02 Jun 2019, 11:15

I think there are plates you can get into the tank without dropping it, so paying $135 an hour for unskillled labor isn’t my cup of tea.

goldxc70 · Post by **goldxc70** » 05 Jun 2019, 22:13

Sounds like a problem I had last year. Once fuel level dropped to a certain level, engine would stutter and recover, or stutter and cut out. It turned out to be the fuel pump assembly. XC70 essentially has two interconnected fuel tanks, one on each side of the propshaft/exhaust hump. The pump is on the passenger side and there is a pickup unit that runs from the pump to the other side of the tank. It is an easy enough repair as long as you have the correct tool (I made my own) for removing the pump and pickup. I've done as have others and it's pretty well written up on this and other forums. Happy to answer any questions you may have.

goldxc70 · Post by **goldxc70** » 06 Jun 2019, 14:20

bleubistro wrote: ↑02 Jun 2019, 08:50 Thanks for the ideas. Sounds like the issue is likely inside the tank. I'm assuming this will be an expensive repair no matter what the actual issue is...and there will be some on-the-fly diagnosis necessary once you get into the tank.

How difficult is this repair? Should I consider tackling this myself, or is this just a dealer or Volvo shop repair?

Not difficult at all. You will have to pull the rear seatback behind the passenger seat to get at the pump coverplate. You don't need to remove the seatback behind the driver to get at the other coverplate.

Only trick is remembering to attach a cord to the pickup tube on the driver side before removing it and using that to pull in the replacement pickup tube. As others have reported, it's practically impossible to feed the pickup tube through without doing this.

Also, it's a good idea if the car is low on gas when you start the job. Make sure to open all doors and windows to ventilate any gas fumes.

bleubistro · Post by **bleubistro** » 06 Jun 2019, 17:32

Thanks so much! I'm feeling better about this situation after reading your comments. I plan to do some research on this repair this weekend, but if you have a link to a good step-by-step guide, that would sure be appreciated!

goldxc70 · Post by **goldxc70** » 10 Jun 2019, 11:55

bleubistro wrote: ↑06 Jun 2019, 17:32 Thanks so much! I'm feeling better about this situation after reading your comments. I plan to do some research on this repair this weekend, but if you have a link to a good step-by-step guide, that would sure be appreciated!

I used a step-by-step guide that I found on some forum. I'll try to track it down. Also, the locking ring on the pump (passenger side) and the sender unit (driver side) needs a special tool to remove it. Rather than buying it, I made one out of ABS pipe and would be happy to share details if you're interested.

UPDATE: This is the step-by-step I followed. It appears that the pictures are gone but I think it's still good.

viewtopic.php?f=9&t=67480

bleubistro · Post by **bleubistro** » 07 Jul 2019, 09:12

The step-by-step linked above by goldxc70 solved my issue!