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Old 11-03-2017, 09:37 AM   #1
turbopop23
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Default 2005 xc70 engine skipping

I am having issues with my 2005 xc70 with 170,000. When driving at steady speeds like holding at 40mph or 70mph, you feel a slight skip. You feel it in the seat of your pants. Not a major skip like I used to have. I have changed the plugs with Volvo plugs, changed all coil packs with Bosch coil packs. This made a major difference in how the car ran, but, I still have a slight skip, and its annoying. The pcv system and throttle body have been cleaned within the last year. About 6 months ago I had a check engine light that was for mass air flow sensor. My garage cleaned the maf and cleared the code and I have not had a check engine light since. Any ideas what could be causing my skip? Any help is really appreciated. I don't want to take it to Volvo to be checked, but it may come down to that.
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Old 11-03-2017, 10:14 AM   #2
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So there is no current Check Engine Light?

Could the "skipping" be coming from the driveline instead of the engine?
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Old 11-03-2017, 12:10 PM   #3
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What is meant by a skip? A Misfire? A surge?

Have the codes checked with a scanner that reads Volvo specific codes. Lack of a cel means nothing on these cars.
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Old 11-03-2017, 12:48 PM   #4
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I would hook up a high level scan tool and look for current or history codes, then go for a drive and watch the current misfire data.

At home, a $5 Bluetooth OBD reader and a smartphone app can't hurt.
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Old 11-03-2017, 02:35 PM   #5
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it feels like a older car with a bad plugwire. Seems to be a little worse when cold and damp. No there is no engine code either.
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Old 11-03-2017, 02:37 PM   #6
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Scan tool, bruh.

With the proper tool you can see exactly which cylinder is misfiring.

Also can look at fuel trims.
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Old 11-04-2017, 09:49 AM   #7
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OK, Thanks, looks like a trip to the dealer. $$$$$$$$$$
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Old 11-04-2017, 10:44 AM   #8
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Icarsoft and autel both make code readers that can read Volvo specific codes.
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Old 11-06-2017, 04:25 AM   #9
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Codes are the first step.

Visual for torn rubbers.
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Old 11-06-2017, 05:57 AM   #10
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I had a similar problem with a 940, which turned out to be the mass air flow sensor. If it is not reading correctly it will send a lean code to the computer which will cause this. Not sure cleaning is really enough.
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Old 11-07-2017, 03:50 PM   #11
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Thanks
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Old 11-07-2017, 08:38 PM   #12
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In my experiences with these cars a faulty MAF usually make itself known during the first cold start of the day.

Has the FPS (fuel pressure sensor) of this car ever been replaced? When my XC70 was sort of sputtering on the interstate it was due to a faulty FPS. There was no CEL but there was a fault code related to the FPS.
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Old 11-08-2017, 12:56 PM   #13
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Quote:
Originally Posted by ovlov760 View Post
In my experiences with these cars a faulty MAF usually make itself known during the first cold start of the day.

Has the FPS (fuel pressure sensor) of this car ever been replaced? When my XC70 was sort of sputtering on the interstate it was due to a faulty FPS. There was no CEL but there was a fault code related to the FPS.
Wasn't sure if that model has a FP sensor.

I have also heard of fuel pressure sensor being a common issue. One guy here bought a SCAN TOOL , and caught the glitch on the data stream.

As a pro, I would first pull codes and then check for TSB's relating to the codes and/or symptoms.. Do it!!!
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Old 11-08-2017, 03:58 PM   #14
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It's a common issue on p2 and even P1 cars. Easy to change on a p2. It's held in with one torx screw. Wiggle it out patiently and gently. Just beware the fuel will spill out even after the fuel rail is depressurized at the Schrader valve.

Last edited by ovlov760; 11-08-2017 at 06:34 PM..
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Old 11-08-2017, 04:11 PM   #15
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I think the fuel pressure sensor was replaced about 5-6 years ago. Probably with an aftermarket one. I don't know what you mean by "P1 and P2" cars? My garage has checked for codes and found none. Are fuel pressure sensors expensive on these cars?
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Old 11-08-2017, 04:37 PM   #16
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P is for platform? As in the different generations of Vo.

Man the parts cannon!!!!
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Old 11-08-2017, 06:21 PM   #17
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Thanks, I am ordering a Bosch from FCP right now.
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Old 11-08-2017, 08:39 PM   #18
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Order a SCAN TOOL instead!
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Old 11-14-2017, 02:34 PM   #19
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A friend had a known good MAF and FPS, put in MAF, drove the car, no difference, still skipped, changed FPS, drove car, still skipped. It only seems to skip between 1500-2000 rpms, runs fine before or above that. If throttle is held at those rpms on the road it skips/stutters.
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Old 11-15-2017, 08:51 AM   #20
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Your car has an ETM (electronic throttle module). These use carbon contact tracks that will gradually wear. (see pic) Your fault description (skipping at 1500-2000rpm) sure makes me think your carbon contact tracks inside the ETM are worn.

The stock Volvo/Magneti-Marelli ETM uses 2 TPS's , you can check the signals by hooking the car up to the VADIS software. Both TPS signals should overlap each other, if one does not and if it produces a weird spiked graph line you will know that TPS is worn. These spikes on the graph are what causes the 'skipping' while cruising.

https://xemodex.com/us/ has a permanent fix, they convert the ETM to use a single magnetic TPS.
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