May 13

2012 Volvo XC90 Blinking Check Engine Light



Mark: Hi, it's Mark Bossert. I'm here with Bernie Pawlik. Pawlik Automotive in Vancouver. Vancouver's best auto service experience. 25 times voted best auto repair in Vancouver by their customers and we're talking cars. How you doing, Bernie? 

Bernie: Doing very well. 

Mark: So today's victim is a 2012 Volvo XC90. What was going on with this vehicle?

Bernie: So this vehicle was brought to our shop with the complaint of the check engine light on, blinking sometimes and the engine running rough. 

Mark: So what's does the blinking light mean? 

Bernie: The blinking check engine light means that the engine is misfiring and can possibly damage the catalytic converter. It's basically the definition is a catalyst damaging engine misfire.

So it's something to take extremely seriously. I'd say statistically based on my experience in the business, 99% of the time, when you have a blinking check engine light, if you don't fix it, like immediately you're going to be replacing your catalytic converters at some point in time.

And they're expensive. And sometimes it might only blink a little bit for a while. And then a month later, two months later, six months, you'll get codes for a cat inefficiency. So it's very, very, very important with a blinking check engine light to fix it. If the check engine light is just on solid and the engine runs fine. You've got some more time. You should get it fixed and diagnosed, but it's blinking. Fix it. 

Mark: Bad, bad stuff. Yeah. Right. So let's take a look at this vehicle right now. Here's our Volvo. So what'd you do to go ahead and start diagnosing this? 

2012 Volvo XC90 Blinking Check Engine Light

Bernie: So, so our first step was to drive the vehicle to verify the client's concern, which we did. Found the engine was running extremely rough, clearly misfiring. The check engine light was on.

2012 Volvo XC90 Blinking Check Engine Light

And then from there we connect the scan tool to the vehicle computers. We do a full vehicle system scan. And from there we found a number of trouble codes. So this gives us our first direction of diagnosis. I'll just bust the myth right now. This doesn't tell us what's wrong with the vehicle. It just tells us where the problem is.

2012 Volvo XC90 Blinking Check Engine Light

And you can see where the yellow arrow is pointing. We had a misfire in cylinder one, two, three, and six, plus a random misfire code, which is just something that if the vehicle picks up a misfire, sometimes it'll set that. Plus two catalytic converter efficiency codes, which means the two catalytic converters are most likely damaged beyond repair.

Well, repair is replacement, really. So the first step in this diagnosis is to figure out what's causing the misfire. And sometimes one cylinder will cause a number of cylinders to set misfire codes. So from there, the codes are cleared. And the next step is to, we can actually run the engine and monitor the misfires.

Most engines we can do this. You can on a Volvo and see which cylinder is misfiring. This is a six cylinder engine. And from running the engine, it's pretty clear that number two cylinder was misfiring pretty well continuously. That means that misfire means it's not actually firing. It's not working properly.

2012 Volvo XC90 Blinking Check Engine Light

So from there, you know, usually what happens is ignition coils go bad. If you can just look at the picture in the next one, Mark of the engine. We look at the top of the engine, there are six ignition coils here. You've got five of them covered, but anyways, number one's the yeah, there you go. We got them all. Most of the time of an ignition coil will go bad and cause a misfire. And we have a tester or we might actually swap coils from one cylinder to the other.

2012 Volvo XC90 Blinking Check Engine Light

And I always like to pull a spark plugs out to see what the condition of that is. So went to number two cylinder right away. Pulled the coil out, pulled the spark plug and found our problem right away. That spark plug on the left, that's from number two cylinder. 

2012 Volvo XC90 Blinking Check Engine Light

We'll just, if you want to look at the spark plug on the right, that's an old spark plug, but still in pretty good shape. That sort of curved thing on the top, that's called the ground electrode. It's got a slight bit of deposit on it, but not abnormal. These are quite likely original spark plugs. But when you look at the one in the centre, you can see a lot of deposit on the ground electrode and the actual centre electrode is a piece of porcelain that's cracked and broken.

So that's a very bad thing. That'll cause a misfire for sure. That's number three cylinder plug. But if you look to the left, that's number two, that's actually black, basically covered in oil and you can see that the combustion process of the spark plugs is much different.

Mark, go to the other picture of the spark plugs. This is you know, a good tool for reading the health of an engine. Just take a moment to look at these spark plugs. You can see that the fourth one from the left is actually pretty good. You know, that one's actually a fairly healthy old spark plug, but you can see the ones on the left side, unfortunately, the picture a little blurry, but even number one cylinder plug is not very good.

2012 Volvo XC90 Blinking Check Engine Light

Two and three are not good. And number six. And interestingly enough, there's misfire codes for all of those cylinders. So you know, the misfire counter is pretty accurate. It found the issues.

So, okay, what do we do from here? Do we just put a set of spark plugs in? No. You know, there's a reason why these spark plugs are looking so bad. Most likely there's too much oil getting into the engine from somewhere. It's burning it and causing the spark plugs to foul. So the next step of course, is to do a compression test on the engine.

And this, this checks the pressures of each cylinders, they should be 175, 200 pounds, maybe a tiny bit less might be okay. So we did the compression test and found that number two cylinder was at five PSI, which is basically dead. Number six was down at 75. The rest of them were, were pretty good in spite of the oil fouling on some of them, but we basically come to the conclusion, the engine needs to be replaced.

It's just that simple. So either repaired, replaced, rebuilt. Replaced with a used engine, there are many different options, and we're still working with the client on that. But also, at the end of the day, the catalytic converters, those codes will not likely be gone once we get the engine running. So will it run fine with the bad converters? Possibly. But you know, there'll be a check engine light on and your exhaust emissions will be higher than usual. 

Mark: So a difficult discussion and decision for the owner, because this is not an inexpensive repair for a 2012 vehicle. 

Bernie: No, it's not. And I'll say, the other thing I found interesting about this particular diagnosis is this, these fouled spark plugs, very unusual for a Volvo. I mean, we work on a lot of Volvos in our shop, never ever see spark plugs like this. I mean, you know, I actually did the diagnosis myself on this and I've been working on cars for, I don't know how long, 40 years or something. 

And I mean, this takes me back like 20 years or longer when you get engines in like mid eighties and seventies, GMs or any brand. I don't know, pick up, you know, you pull a spark plug and it's all oil fouled. And this is not something we see very often in a modern engine, let alone a Volvo. So I don't know why this occurred like this, but you know, nonetheless it needs to be fixed now.

Mark: Wouldn't the owner have noticed that the vehicle was needing to have a lot of oil put into the engine? Or wouldn't you see that there's blue smoke coming out of the back with it burning so much oil? 

Bernie: Yeah, good questions. I didn't talk to the owner myself and, and there wasn't any mention in the initial complaint of, Hey, I have to add a lot of oil to the engine. So I don't know about that, but the blue smoke, you would think it would be blowing blue smoke, but in this case it wasn't. Engines are interesting. Sometimes you can go through oil or you can have this kind of fouling problem without actually consuming a lot of oil.

It's just getting into the wrong spot a little too often, but you would think that you'd have to be adding a fair bit of oil or you would see smoke, but it doesn't always happen. So, you know, the key in this one is the blinking check engine light. And at that point, I mean, the engine was probably already done, but there may have been some earlier symptoms.

We had worked on this vehicle in the past and never noticed any problems with it. So sometimes things can come up quickly and damage can happen fast, for sort of no reason. 

Mark: So there you go. If you're looking for service for your Volvo in Vancouver, the guys to see are Pawlik Automotive. You can book your appointment online at Or you can call them at (604) 327-7112 to book your appointment. You have to book ahead. They're always busy. Pawlik Automotive in Vancouver, BC, Canada. Thanks so much for watching and listening. Thanks Bernie. 

Bernie: Thank you, Mark. And thanks for watching.

About the author 

Bernie Pawlik

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