Shuddering on My 04 XC70 120k

[Voldog]

As I was driving on the freeway this evening I started noticing the car shuddering intermittently. The car has been driving fine all this time. The Check Engine light flashed a few times while it was shuddering. I took over ownership a year ago and its been running fine. All I I've done is change oil.

I arrived at my destination 15 minutes later. After getting back in the car it starts fine and engine is idling fine. Check Engine light stayed on this time. The intermittent shuddering continued till I got home.

About 2 weeks ago the CEL came on with a P0101 MAF error. I resetted the CEL by disconnecting the battery. I also tested the MAF by disconnecting it while the car was running and the engine sputtered so I figured the MAF sensor was fine. Now am wondering if the MAF sensor actually was on its way to going bad and now it is and is causing the symptoms tonight.

Any thoughts?

[goldxc70]

Did you try cleaning the MAF?

[Xfingers]

If you decide to clean it, use a special cleaner for the MAF available at most auto parts stores ($10). Check the youtube videos on the procedure. Also, to remove the MAF you need a special security torx bit you can find on eBay for $10. There are 5-sided and 6-sided security torx bits so make sure you check the bolts (2) you need to remove before you order. (I ordered the wrong type.) On my 2002 which had 130k miles on it, there was a noticeable performance improvement after I cleaned the MAF, even though it wasn't throwing a code at the time.

[gary g]

Does the shuddering happen when you accelerate or go up a hill on the highway? If so, it could be a coil. That causes the CEL to blink, indicating a misfire.
Before I figured out what the problem was on my car years ago, I would downshift to 4th gear until I got up the hill.

[Voldog]

Does the shuddering happen when you accelerate or go up a hill on the highway? If so, it could be a coil. That causes the CEL to blink, indicating a misfire.
Before I figured out what the problem was on my car years ago, I would downshift to 4th gear until I got up the hill.

Yes it shudders when accelerating and the CEL blinked. Now its just on. I ordered a Bosch MAF sensor which will come tomorrow.

What did you do about the coil? And which coil?

[gary g]

The code might tell you if u have an obd scan tool or get it read at autozone. Might tell you”misfire cyl2” for example.
I got lucky on mine. I pulled the plugs and one plug was different. I figured precious owner tried to fix it w new plug so i replaced all the plugs and the coil on that cylinder.

[Voldog]

I'll try some trouble shooting today with the coils. But I'll have obd scanned first. Looked at an FCP video last night about possible causes of coil packs going bad. One is oil spill from oil fill which happened on the last oil change. Thanks for the input. When the xc acts up I always think about my 2 Accords that are absolutely trouble free.

[Voldog]

Looks like misfire on Cyl #3 per OBD. Car has 120k. What is the average life of these coils??!!! I check past records and looks like its never been done.

Should I replace all of them including the plugs?

[Voldog]

So, replaced all the plugs with Bosch FR7DPP platinums. The old plugs must be the originals (Volvo R6) because they look kinda foul and also failing at 120k. I also cleaned all the oil trapped on the cavities on the top end by covering the spark plug openings with paper towel and sprayed the area with brake cleaner. Let it sit for a minute to break down oil and blew it off with pressurized air. Repeated the process twice more to make sure everything is dried out. Before replacing spark plugs, I also blew pressurized air into the plug holes while old plugs where still in place to blow out any debris. Took car out for a ride and no more shudder. So I hope that was it.

[Voldog]

Forgot to mention that I tested all paks and they were good. Started with #3. Disconnected it and rpm went down. Reconnected and rpm went up. All the rest did the same. and the car is running fine now.