Have you run a scan? Also check your PCV line by the intake manifold and make sure it's securely fastened. It's easy to forget to clip those black in place after an induction service. It will also make that popping sound when not connected right.

 

Well... I don't have to wonder about what I was experiencing anymore... now I just need to find the reason! Today there were way more of those pops, enough to trigger the CEL. And lo and behold;

P030400 - Cylinder 4 misfire detected

So my initial suspicion that I was noticing a misfire is detected. And apparently worsened by the cold weather. Spark plugs changed this summer (same Denso plugs Volvo uses, just without the Volvo logo, which is obviously being used against me now!).

 

What year is it? I would do a compression test first and then go from there.

 

A.. drum roll 2015.5! So I think I know exactly what you're thinking... Dealership wants to check spark plugs and coils first, though.. which could make sense. I replaced them on my own, and I could very well have screwed up the gap or it could even be a faulty plug. Plug and coil can simply be tested by swapping around, so it makes sense to start checking the cheapest.

But would an incorrect gap potentially start misfiring like crazy in the cold? It could if it's too large, I suppose? (Allthough the plugs did come pre-gapped and I did to the best of my knowledge correctly confirm that the gap was indeed correct).

 

I mean.. ya 😬

No you are right they are usually pre gapped unless there is a manufacturing error. The only times I have seen a new plug misfire was when it was a defective plug, and there was some sort of internal issue with it. I have had that happen before but it's rare.

It could also be fuel injectors too. Those can go on these and many other DI engines too.

 

I mean.. ya 😬

No you are right they are usually pre gapped unless there is a manufacturing error. The only times I have seen a new plug misfire was when it was a defective plug, and there was some sort of internal issue with it. I have had that happen before but it's rare.

It could also be fuel injectors too. Those can go on these and many other DI engines too.

Yeah, so you think it may be a symptom of this dreaded piston ring fault? If this is indeed what is going on, that's actually good news for me since I'm still covered by a 3rd party warranty that includes engine. So it would actually be a blessing if this was the issue so I could have it fixed now rather than experiencing it later.. but I'm never that lucky so I wouldn't count on it!

But I have not been noticing any oil being burned, at least not an excessive amount as it's never told me to add oil. Could it still be that if not experiencing a massive consumption? Car has done 87300 km (or 54200 miles if you will), also been serviced annually at Volvo. I bought this car a year ago.

I think also fuel injectors is covered on my warranty, but will have to check that. Just recently put the papers away after getting OK-ed a replacement of the blower fan which is taking place tomorrow! Unfortunatly they had no time to investigate my cylinder misfire tomorrow, so will have to just drive car home again and park it until I can have it checked out further Thought a recent-ish Volvo with low miles was going to give me less problems..

 

Here's a video of the exhaust of the car while idling today... doesn't sound too happy!

https://colaku.com/~tomsk/V60_misfire/v60_misfire.mp4

Edit: updated link to a more compatible video file.

 

Oh wait nm I forgot your car has lower mileage, forget that last part.. I would be curious what the intervals are though if you have them.

 

Service intervals here is 365 days or 25000km, whatever comes first. So well within the recommended intervals this one. The service manual is in my car right now so I don't have the specifics, but you can easily calculate the average since it's been served every year. Let's round up for simplicity.. 88000km / 8 = 11000km a year, or 6800 miles. Meaning if this thing is burning oil, it may still burn a lot without it being noticed because it's getting a refill every ~6800 miles.

What is this induction service you're talking about, though?

So, it's in your opinion too not likely that it is the pistons just yet? But yeah, dealership did mention that they had never seen a petrol car with the piston fault here, but some diesels... which is why they're certain this is something less severe. Time will tell, but it better not take too long because I do need the car to be working!

 

What is this induction service you're talking about, though?

The induction service is where you spray intake valve cleaner into the manifold where that pipe is when the car is running and it will help prevent build up on the valves and clean light amounts. That service can also trigger a misfire in a diag scan. I am just trying to list everything that it might be because it could be a lot of different things and the sound was very similar.

So, it's in your opinion too not likely that it is the pistons just yet? But yeah, dealership did mention that they had never seen a petrol car with the piston fault here, but some diesels... which is why they're certain this is something less severe. Time will tell, but it better not take too long because I do need the car to be working!

It could still be the pistons. Sometimes the sensor on the earlier cars can be a bit off too. The only way to be sure of that is to do an actual oil consumption test. They should be able to do that at the dealership if you ask them about it. It's tough to say. That's why I like to do a compression test before I do anything else because throwing parts at it can cost people a lot of money. I admit, I have done it before too but it's not a good habit.

Has the car ever overheated or anything such as that?

 

I also forgot to mention o2 sensors! Those can go on these too and if out of range enough can also cause a misfire. CC's can also be a cause but they don't seem quite as common as the o2 sensor. It's usually the front one.

 

It could still be the pistons. Sometimes the sensor on the earlier cars can be a bit off too. The only way to be sure of that is to do an actual oil consumption test. They should be able to do that at the dealership if you ask them about it. It's tough to say. That's why I like to do a compression test before I do anything else because throwing parts at it can cost people a lot of money. I admit, I have done it before too but it's not a good habit.

Has the car ever overheated or anything such as that?

It has not, but it did have a faulty thermostat that was caught by coincidence while I had my windshield replaced this autumn. Not sure if that ever lead to any actual overheating, though.

I guess I should mention why I also replaced the spark plugs to begin with, because as mentioned the car hasn't really had that many kilometers on it. When the engine was cold, I would sometimes get vibrations in the car until it warmed up. They were very subtle, but I could feel them and it felt as if something slightly stalled the engine. I changed the spark plugs but this did not change. I did not think any more of it until last week, then I experienced what prompted me to write the initial post here. I'm almost certain that it was the same symptom, just slightly stronger. Then today, it just went all-in and really threw a fit and just confirmed my suspicion.

I've also a handful times experienced the car surging right before it reached its operating temperature, as if someone was pumping the gas pedal. I've blamed this on the transmission earlier, but I'm now wondering if I can link it to this experience. It's not happened a lot, but it happened both prior to and after changing the spark plugs. So I'd say that the spark plugs seemingly did not change anything for better or for worse.

After having checked out the coils and spark plugs as Volvo suggests I begin with, I'll have to discuss with my mechanic and the warranty provider. Most stuff that's related to the engine is covered, but spark plugs is not. I will then mention the compression test and hear what they think of that, though.

 

As an additional note, on my way up to the dealer to leave the car for them to fix my blower fan tomorrow, it did not recover from the misfires during that trip. So whatever it is seems to be a bit permanent, it's also in limp mode because of the CEL.

 

It has not, but it did have a faulty thermostat that was caught by coincidence while I had my windshield replaced this autumn. Not sure if that ever lead to any actual overheating, though.

Most thermostats SHOULD stick open and not closed but sometimes weird stuff can happen. How is the coolant level?

I've also a handful times experienced the car surging right before it reached its operating temperature, as if someone was pumping the gas pedal. I've blamed this on the transmission earlier, but I'm now wondering if I can link it to this experience. It's not happened a lot, but it happened both prior to and after changing the spark plugs. So I'd say that the spark plugs seemingly did not change anything for better or for worse.

Surging can be sign of a fuel problem. A bad o2 sensor can cause more fuel to be added all kinds of stuff can cause an engine to run more rich. I would be more inclined to say that surging would be caused by a fuel injector but there are many other factors. I have seen where the seals dry up near the throttle body on some cars and unmetered air goes in and causes lunging like that. Scary stuff.

Do you notice any rattling when driving up hills etc?


Ya though I would start with the compression test, if it passes, move on to swapping the coils and plugs (even though the plugs are new, just to rule it out), if that passes I would then look at the o2 sensors and make sure that they are in range and check the CC isn't clogged up, they may need to run some cleaner possibly, that can work. Also check for any frayed wiring by the coils too. Not super common on that but check just in case. Check the exhaust manifold studs on the back of engine and torque them if needed. Swap the injectors and see if the misfire jumps and ya that will usually get to your problem. In most cases.

 

Most thermostats SHOULD stick open and not closed but sometimes weird stuff can happen. How is the coolant level?


Surging can be sign of a fuel problem. A bad o2 sensor can cause more fuel to be added all kinds of stuff can cause an engine to run more rich. I would be more inclined to say that surging would be caused by a fuel injector but there are many other factors. I have seen where the seals dry up near the throttle body on some cars and unmetered air goes in and causes lunging like that. Scary stuff.

Do you notice any rattling when driving up hills etc?


Ya though I would start with the compression test, if it passes, move on to swapping the coils and plugs (even though the plugs are new, just to rule it out), if that passes I would then look at the o2 sensors and make sure that they are in range and check the CC isn't clogged up, they may need to run some cleaner possibly, that can work. Also check for any frayed wiring by the coils too. Not super common on that but check just in case. Check the exhaust manifold studs on the back of engine and torque them if needed. Swap the injectors and see if the misfire jumps and ya that will usually get to your problem. In most cases.

Coolant level is OK. The thermostat is also changed btw. How long time does the compression test take? If it's quickly done I may ask to have that included in the check I'll have to set up an appointment for before they do the spark plugs and coils.

It did rattle a bit while driving today, but it's excused for that.. it was only driving on three cylinders after all

But normally, it behaved just perfectly. No rattling in hills, no loss of power, etc. I just hope whatever the fault is now is permanent so it can be easily located.

 

The compression test shouldn't take very long, maybe 20-30 minutes if that. They might even be able to do it on VIDA tbh.

I think it may be a fuel injector because it was intermitant before and they go on those. It's tricky to say though.

 

What year is your car? Thermostat in VEA engines up to 18th week 2016 may brick the expensive engine control module ECM (without CEL or any other warning). When you get CEL on dash, it is too late:

https://static.nhtsa.gov/odi/tsbs/2016/SB-10088748-5448.pdf

 

Thermostat was replaced a few weeks. CEL and engine misfire came up yesterday, so it's not related.

 

Which model year? Faulty VEA thermostat may take months to destroy the ECM (without any warnings on dash).

 

2015.5, but if it was the thermostat that was to blame (and it was not broken for a long time before it was replaced), that failure would have happened BEFORE it was replaced. It wouldn't happen weeks AFTER. The failure would eventually happen because of ignoring the faulty thermostat as it would in some cases actualy burn out the heater circuits on the ECM. It would also primarily just burn off the heater circuits as that circuit is unprotected against high power consumption. Rest of the ECM would usually be fine.

 

Well, this is just getting weirder. Volvo did not observe any misfiring at all and the CEL was not on anymore. And when I picked up the car, that was indeed gone. So not sure what to think, but going to be interesting to see if the problem returns when the temperature drops again... starting to have a really bad feeling about this.