[Edit: Completely forgot to mention this is a 2005 Volvo S40 2.4i]

So starting this off with this is my first time working on a Volvo and im not very well understanding of its common issues. This is the 2.4 NA 5 cylinder with 120k miles on the clock and its had this weird shutter almost like its stalling and coming back its barely noticable unless you are letting the car roll very slowly in idle. Regardless the car has done this since we bought it nearly 3 years ago and as of lately its been getting worse and now has stalled for its first time. I checked the codes and i had a P0026 intake valve control solenoid, P0300 random multiple misfire, and P0455 large evap leak this one likely was caused from replacing the fuel pump it commonly switches from large to small evap leak depending on the fuel caps tightness. Today i pulled the intake valve solenoid and gave it a nice clean with some brake cleaner let it dry and put it back in. The car didnt stall anymore but still had a pretty rough idle that shakes the entire car. I checked misfire data and it seems the main culprit would be cylinder 1 with the vehicle running for roughly 15 minutes i gathered this misfire data set:

Cylinder #1: 165
cylinder #2: 56
cylinder #3: 11
cylinder #4: 23
cylinder #5: 30

I repeated this test again and got roughly the same numbers give or take about 5. Tomorrow i plan to swap the cylinder 1 and 3 coils and possibly change the plugs even though they dont have more than 10k miles on them. On top of that ill do a compression test if i can find my kit and get a number on those if possible. If anyone can provide any ideas as to what it could be that would be very appreciated.

PS a few weird things i noticed upon start up when warm but its been sitting for a bit i get this vibration sorta like a rattle sound from the valve area but after rpms come down its gone. I do have a clip of it if someone can tell me how to share it. Also the intake cam gear has a slight imbalance compared to the non vvt exhaust gear. I hope this helps thanks in advance everyone!

 

I'm not trusting the compression test results - I really don't see how an engine would run with those low numbers for 3-5. if you can get the car to start and run, try doing the compression test on a warm engine. I'd also rent or borrow a guage with a correct fitting just to be sure you didn't blow by the seal. Did you try a wet test (drop a tablespoon or two of motor oil in the spark plug hole before the wet test. With that said, assuming the numbers show 4 of 5 cylinders as low - I'd check the valve timing next to see if it jumped a couple notches. Any signs of a head gasket leak like pressure in the cooling system, HCs in the coolant, coolant/oil milkshakes? Any signs of valve damage? You can try an inspection camera or do a leak down test to check.

 

havent tried all that but i did want to note the data i provided were the misfire counts within about a 15 minute window not the compression. I have reason to believe cylinder 1 is failing and the car may have a bad cam phaser based on the fact it doesnt look aligned. Belt is definitely old and is about due for replacement but i dont think it jumped timing ill put the motor at TDC and give the timing marks a look. I swapped the coils and there was a slight change for the worse so the coil is bad but there is still another issue present seeing as cylinder 3 started misfiring rising the count from 11 to 33

 

A youtube link to the video its the only way i knew how to share the sound

 

ah that explains the numbers! my bad - I tend to speed read posts while moderating :-) So with the focus on misfire counts, you may still want to check compression (but less of a concern now) but I'd also look at fuel pressure and any OBD run time data you can get regarding fuel trim. I don't think the VVT solenoid issue would cause misfires so I'd discount that for now. For the spark/coil question, did you inspect the wiring harness / connectors to the coil? Also, you may want to try swapping fuel injectors (say between #1 and #3). Last is you may want to check for air leaks/ dirty MAF etc. A quick spray of some CRC MAF cleaner may help.

 

im glad you brought that up so when i look at run time data the fuel system says its stuck in open loop no matter how warm the car gets. I didnt mention because i felt it wasnt as important but both my O2 sensors arent registering as plugged in when they are they have both been replaced and the same issue is present. Fuel trim data is set at 0 at almost all times, spark advance is all over the place at idle but holds steady with throttle, and the fuel pressure sits at about 55-60 psi average with a brand new pump.

 

interesting. open loop means the CPU isn't listening to the lambda feedback loop signal from the front O2 sensor (the rear sensor measures cat efficiency by looking at the O2 post cat and comparing to 02 pre cat) so it seems like next step is to see what signals are coming from the front o2 sensor. its a 4 wire sensor - two wires for the heater circuit, two wires for the sensor. Should be something on line or on Youtube for tips on testing the sensor at the connector. I'd expect a CEL to be thrown in the O2 sensor was open circuit so I'm wondering if something else like a wonky ECT sensor may be keeping the car in open loop. I'd also google or search a more techy site like Matthews to see if there's any posts describing how to test

 

FWIW, I used the (excellent and cheap) Torque Pro app on my 'droid phone, and a cheap Bluetooth OBD "dongle" to monitor things like the O2 sensor outputs (and fuel pressure, and temperatures, etc.). A total investment of about $20 and probably better than the F1 guys were using 20 years ago. ;-)

 

After consideration and investigation it seems the car jumped timing by 2 teeth on the intake cam. Additionally the coils seem original to the car all of them in fact so they are due to be changed along with plugs. The VVT solenoid is bad aswell but that was to be expected. In total we decided to just run the car till it cant go anymore. I reseated the timing belt and it runs a little better but to repair everything isnt worth it considering the other issues the car has so we decided to put as little money into it as possible. Thanks everyone for the help but im gonna have to abandon this repair sadly.

 

Thanks for the report. FWIW, unless the car is in really rough shape, it sure seems like it's worth a new timing belt! And FWIW, there's NO reason to replace all the coil packs - they just don't fail, and if they do, replace one with an OEM or used coil and call it a day.

I know that the timing belt job on these cars is a little fiddly (and I freely admit I never had to do it on any of my Volvos) but consider just getting / borrowing the tools to do the job, which will cost about 10% as much as having a garage do it. With that, I'd expect that car to run another 200,000 miles (my Volvos were very reliable).

 

This is true however i personally do a lot of preventative maintenance so when i see two torn coil packs i just go ahead and replace em all because the others may not be far behind. The rest of the car is in about the same shape as the motor it can be fixed but when there is this much wrong its an expensive job. The interior is falling apart there is a lot of water damage from previous leaks and current leaks, the transmission slips and kicks, and well you know how the motor is doing. Its very fixable but its not something im willing to fix, not on my budget atleast. But thanks for the help though!

 

It does sound like that is the kind of car that could be picked up for chump change on craigslist, especially with water leaks. FWIW, most transmission issues aren't fatal.

I bought a 2005 V50 (same as S40 but a wagon) for chump change because of a funky downshift and the fabric on the door cards was drooping (common in Arizona). Spent a couple hundred and a few hours, and it was a great car for years. But it never saw a water leak, either (hey, I live in the desert!).