2000 V70 GLT - Oil passages in head and Cyl#5 overheating?

AngrySquid · Post by **AngrySquid** » 11 Aug 2015, 20:26

My 150K mile Volvo picked up a stumble recently and after reading the code I was lead to a Cylinder #5 misfire.

During my investigation I found the #5 spark plug well had a fair amount of oil in it which I'm guessing shorted out the wire to plug connection.

Since the other plug wells looked clean and I didn't see any obvious oil build up on the top of the cam cover near #5 I assumed that I had a leak between the Cam cover and the head.

Now that I have the cam cover off I've found a couple interesting things.

1) I see four small holes surrounding each cylinder, some of these had some gunk in them which I tried to pick out. Prodding around with a toothpick these holes aren't very deep, just a few mm. I can't tell if they are clogged or if there is a sharp angle to the passage. Are they supposed to supply oil? If so what's the best way to clean them?

2) I notice there is a lot more oil tarnish on the Cylinder #5 side of the head. Is this normal for these engines, or do I have a coolant problem?

Picture below. I have a toothpick standing in one of the holes referenced in my first issue.

Post by **rspi** » 12 Aug 2015, 04:16

I'm pretty sure those ports lead to the lifters, they do in the pre '99 heads.

Not sure why there is more tarnish near #5. I have several photos & videos of heads open that you can look at to compare.

Why did you pull the cam cover? Was oil on top of the spark plug and on the wire?

Post by **abscate** » 12 Aug 2015, 04:24

You should do a compression test to see if you have a gasket problem. You'll need to put it together first, of course. Do cam seals while you have it apart. Did you test the ignition coil my moving cylinder 5 to cylinder 1 to see if that was misfiring? That could be the whole trouble.