2003 S60 T5 Seems to shudder/slip/skip under load/torque

HawleyTronics · Post by **HawleyTronics** » 23 Mar 2015, 10:09

Here's the story: My T5 has the 5-speed manual transmission and not too long ago the clutch slave cylinder failed and the pedal stuck to the floor, which is a common symptom of the issue. My mechanic installed a new Centric clutch kit I found on eBay for $200 and it shifts great again. I'm telling you this because I just want you to know the recent history in order to properly evaluate my problem...

One thing I noticed shortly BEFORE the slave cylinder failed is a slight hesitation/slip/jerk feeling when getting on the gas in 3rd and 4th gears, under heavy acceleration/torque. The T5 puts out some heavy torque to almost match the HP and I am wondering if the symptom is something to do with the clutch/transmission or if it is simply a fuel hesitation issue and not related to the tranny at all. I'm not getting any CEL indicators so I am not sure if maybe I need to clean/replace the fuel injectors or if anyone is familiar with this symptom in general and has a good idea of what is causing this what seems like a skip or hesitation. I only notice it when I first get into 3rd and 4th gears and it goes away once speed is picking up. I am almost thinking it is fuel system related rather than clutch/transmission related. Any ideas?

Post by **SuperHerman** » 23 Mar 2015, 21:29

I don't know much here, but it sounds like your tranny is slipping. What are your engine RPMs doing? Are they going up - sure sign of clutch slip or are they staying constant with the speed of the tranny - sign of another issue? What happens in the other gears? The engine does not really care what gear you are in - it just rotates per gas pedal input - the tranny does the power transfer work.

draser · Post by **draser** » 25 Mar 2015, 07:04

I'd check slave cyl fluid level and air in the system, it still may be clutch disc to pressure plate engagement at high torque. Not sure about Centric brand either, is that OEM?

Post by **chrism** » 25 Mar 2015, 09:56

You might want to consider the fuel pressure sensor as a possible cause of the miss/jerk. Our 2.5T S80 had a miss under heavy throttle for quite a while before we finally got a check engine light. In the case of our 2.4NA V70, I got a check engine light BEFORE I ever noticed a miss. In both cases it was a failing fuel pressure sensor which is a fairly common problem - common enough that Volvo issued a recall on some of the cars. You might want to call Volvo customer service and see if your VIN is included in the recall. If you call a dealer for this info, the answer will likely be "That VIN isn't included in the recall." Even if your VIN is included they will only cover a replacement once per car. And they do keep track.

If you have a fuel pressure gauge that you can connect to the injector rail and monitor the pressure as you drive, it may show an abnormal pressure fluctuation - at least in my case it did.

The turbos and NAs take a different sensor - one is black and one is gray, I just can't recall which is which. I don't have either car with me to look right now.

Good luck.

HawleyTronics · Post by **HawleyTronics** » 13 Apr 2015, 11:58

I read my codes recently with my DICE unit and the following codes were present:

CEM 1A56 - Communication with the driver information module (DIM). Signal missing (My DIM hasn't worked since I bought the car used. I have been trying to troubleshoot this ever since.)
CEM 5B01 - LH heating element. Signal faulty. Permanent fault (My seat heat hasn't worked since I bought the car used.)
CEM 8D02 - Stop lamps. Faulty signal (All brake lights work, but this code comes up anyway.)
DDM 0025 - Door mirror motor. Disconnected (The drivers door mirror casing was broken when I bought the car used, but the mirrors have always moved fine. Not sure about heating though.)
SRS 00D5 - SRS indicator lamp. Signal missing. Permanent fault (This I believe is DIM-related since it isn't able to display the SRS light if the DIM doesn't work.)
CEM 3A08 - Fuel pump (FP), Signal too high. Relay, leak diagnostic pump heating. Signal too low (This may indicate a faulty fuel pump?)

So a couple of problems I intend to solve:

The DIM not working could possibly be related to the seat heater not working as I believe the wiring/harness under the seat can also affect the DIM functionality from what I've read. Is that correct?

I am thinking that the fuel-pump related code could very well be telling me my fuel pump is on its way out. I think this to be true because since my DIM has not worked since I bought the car used, I have kept a small gas can full of gas in the trunk for when I run out of gas. When I run out of gas, I pour the gas can into the fuel tank (about 1.5 gallons) so that I can get to the nearest gas station to fill up. This may seem half-assed but it is the only way I can do it until I get my DIM (and fuel level gauge) working again. So running it empty often is probably sucking crud from the bottom of the tank, thus slowly destroying my fuel pump. Sound logical?