I am experiencing an intermittent loss of power in the form of a stutter under certain driving conditions. It almost always happens while driving at about 40-50 mph on the highway and applying mild pressure to accelerator to go up a hill or pass a car. It only happens if the transmission is in 5th gear showing approx 1700-1800 rpm on the tach. If I accelerate hard enough, the transmission will downshift to 4th gear, rpm will increase to around 3000 rpm and everything functions normally. The stutter only happens under light acceleration (usually up a slight grade) when the car is in 5th gear at low rpm (under 2000).

This is a 2004 Volvo S60 2.5T AWD (automatic trans) with approximately 110k miles. Most of the my driving is on the highway.

No check engine light or anything like that. Dealer ran their diagnostics and didn't come up with any codes. They felt the issue but didn't know what it could be without the codes. We changed the transmission fluid because it was just about due, but the problem still exists.

Does anyone know what this could be?

 

In an automatic car when you put your foot down to accelerate your cars ecu realizes that to get enough power to do what you want it needs to downshift. The "stutter" you experience is normal in automatics when driving relatively slow and in a high gear. This is because the car is in the process of downshifting which takes a full seccond or more sometimes. No power cAn make it to wheels when between gears.

 

Hello all... new to the site...

This is EXACTLY the behavior I have in my 2004 S60, however, I've a manual transmission. I can reproduce it, at will. Notably, however, I experience this as follows:

Slow for stop sign (not complete stop), so no downshift to 1st gear or neutral. With car in motion, 2nd gear, apply light throttle to accelerate away, and experience the 'stutter' -- almost feels like a misfire (had very similar experience 6 months ago with bad spark plug and misfire engine codes).

As noted by OP, no engine codes. Under SAME driving behaviors, I did not have this problem greater than 6 months ago. After replacing spark plugs (replaced all) this problem did not occur for perhaps 4 months afterwards...

Taking this to a dealer at $133/hr for diagnosis (which could run hours with no result) seems like writing a blank check -- not willing to do.

Thoughts?


Edit:
Just found this thread which leads me to believe cleaning of MAF and ETS may aid... any ideas on how to do this?
https://volvoforums.com/forum/volvo-...-idling-69436/

 

Wow Im having the exact same problem as the original poster. Any updates? I have a 2005 s60 2.5t

 

experienced something like that on another car - turned out to be sparkplug wires carbon had degraded.

check your coilpacks and sparkplugs

 

Have a look if the torque rod is not worn as well. Could be part of the problem.

 

I replaced the trq rod and sparkplugs 3 months ago with genuine volvo parts.

 

Just a stone in the bush but have a look at the fuel pressure regulator. I have all sort of funny symptoms with my s60 2.4t and i suspect that sucker. I am no fuel pressure fundi but you never know.

 

I'm experiencing the exact same problem as the OP with my '04 XC90 2.5T automatic. I have replaced the engine mounts and the torque mount and it didn't help with this specific issue. There are no CEL or codes present so I guess I'll go ahead and replace the spark plugs and maybe the fuel pressure sensor. I hate to throw money at random parts so if anyone got to the bottom of this please post an update.

Cheers!

 

It's the fuel pressure sensor. It fixed my problem.

 

u need to isolate the problem first. is it a loss of power or just shutter? if just loss of power u need to look at the engine side, if just shutter then it could b the tranny

 

I wish I could tell. Honestly I'm not sure if it's the engine or tranny at this point. At first I thought the tranny was going back and forth between the 5th and 4th gears in a super quick fashion. But then it also feels like the engine is cutting out and engaging again. And there are no codes or anything thrown.


I'll try putting the tranny in tiptronic and see if I can reproduce it in 5th gear. Not sure if it'd prove anything as the tranny can still override the selected gear afaik. Any other suggestions to narrow it down - I'm all ears.


BTW, it seems my 2.5T doesn't have a fuel pressure sensor at the end of the fuel rail. The release valve is there on the driver's side of the rail and there's nothing at the other end of the rail. Anybody know if all the 2.5Ts have that sensor for sure?


Thanks.

 

Mu 2005 2.5t has a fuel pressure sensor. I replaced it myself which solved my problem. It is a common issue. The same part is cheaper if you buy it from Land Rover dealer since they use the same bosh fuel sensor.

 

how ironic, Land Rover parts got cheaper than Volvo

indeed, fps is known all over the world to mess up in a way or another.

other than that I would look at ignition problem such as spark plugs.

 

It is a bad coil almost always. Mine was doing this and what i found was that on one of the coils the plug on the coil had broken apart and the actual plug itself was barely making contact and when you put torque on the motor it would shift just enough to break the connection. Replaced the coil and problem resolved. I would recommend replacing all 5 coils and all 5 plugs. The other thing it could be is the sensor on the end of the fuel rail. The fuel pressure sensor.

 

It's a bad coil/coils. Replace all plugs and coils and that should fix your problem. Just went through it.