Engine shudder during acceleration

mikod4 · Post by **mikod4** » 20 Oct 2009, 13:16

Greetings,
I am new to this forum. I have a 2006 S60. When I slowly accelerate to 40 mph, the engine shudders for a second, then smooths out. I filled up my gas tank with a higher octane fuel, still shudders. What else would cause this. Plugs? Transmission?

rbodor3 · Post by **rbodor3** » 22 Oct 2009, 19:25

is it turbocharged?

Either way, check: spark plugs, upper engine mount for cracking, lower transmission mount (smaller bushing) for cracking, PCV for clogging. My bet is on spark plugs.

mikod4 · Post by **mikod4** » 23 Oct 2009, 06:59

It only happens between 35 and 40 mph and it last 2 seconds then smooths out. Otherwise it runs perfect no shudder.

rbodor3 · Post by **rbodor3** » 25 Oct 2009, 13:54

does it feel like a bad shift from the transmission?
Sounds like a bushing to me.

Check the upper engine mount (upper engine, driver's side, black rubber bushing). If that's not it then lift the front end, remove the plastic catch pan (12mm IIRC), and check the lower transmission mount. As soon as you drop the pan you will see a bushing similar to the picture. Both of these are common failures for the s60. Shudder would likely be worst in low gears and bad shifts with the transmission, and would vibrate at idle if the engine mount. Any sort of cracking, or breakage at all would mean new ones are needed.

: trans mount.jpg (119.22 KiB) Viewed 7853 times

mikod4 · Post by **mikod4** » 26 Oct 2009, 12:16

Thank you for the reply. Hopefully I can reach these mounts myself. The engine does seem to vibrate more when I put it in reverse.

mikod4 · Post by **mikod4** » 27 Oct 2009, 10:13

Checked mounting bolts and bushings..everything is fine: however when on road, car still shudders at low acceleration to 35 to 40 mph, only. When I'm on the open road or the highway, no problem. In the city or going slightly uphill, it seems like it is coming from transmission.

vorbosh · Post by **vorbosh** » 27 Oct 2009, 22:10

Unbelievable Coincidence but I just started having the same issue. s60 2005 2.5T

If I accelerate through 40 to maybe 45 quickly. No problem. If i go about 38 steady with the tachometer at 1500 then the car starts to shudder. I guess it feels like it is caught between shifts.

I will watch the post. I will also be taking the car to a repair place on Thursday. If I find out anything. I will post.

Good Luck.

mikod4 · Post by **mikod4** » 29 Oct 2009, 12:20

I received a message " Transmission Service Required". It's at a mech shop now. I'll post what he says the problem is. Before he mentioned a transmission relay not putting out enough pressure.

vorbosh · Post by **vorbosh** » 31 Oct 2009, 12:23

I used a friend's diagnostic tool and got the codes PO201 Injection circuit/Open Cylinder 1 and PO121 Throttle Pedal Position Sensor A Circuit Range/Performance.

Sounds like a similar problem but different cause.

Thanks for updating.

Craigd2599 · Post by **Craigd2599** » 31 Oct 2009, 13:50

do S60's have lock up torque converters? that sounds like a converter issue