We learned our lesson years ago. Before you fix any oil
leaks, make sure there isn’t excessive crankcase pressure. Many of the vehicles
we work on have crankcase breather systems that are much more involved than a
plain PCV valve. A few years back, we looked at the Volvo 850 system, saw how
it worked and what happens when it doesn’t. The newer cars with their extended
oil change intervals seem to be just as prone to clogged breather assemblies as
the older cars, and it’s even more so the case on the turbocharged cars.
Today, we’ll be looking at a 2004 Volvo XC70 that we
purchased from one of our customers. The car has high mileage, 198,123 miles to
be exact, but was maintained reasonably well, so I thought nothing of giving
her twice what the dealer offered on trade. It was a great deal for both of us.
It had a few small oil leaks and it looked like the oil trap was leaking, so I
planned on removing the intake manifold and replacing all the breather
components as soon as I took over the title.
I was amazed at just how bad it was. The passage into the
block that goes down into the oil pan was completely plugged, making it
necessary to remove the oil pan to properly clean all the passages. If we were
working on a customer’s car, we would have warned them before starting to
change the oil trap that, in some instances, the passage in the oil pan can be plugged
and the oil pan may also need to be removed. So let’s get started.
Replacing the Oil Trap:
1. Photo 1 provides a glimpse of the engine before we got
started. Remember to wait 15 minutes after shutting off the car before you
disconnect the battery.
2. Remove the bolts holding the power steering line to the
intake, as well as the dipstick tube, turbo duct and vacuum lines. See Photo 2.
3. The fuel rail can stay in the intake; just disconnect the
one fuel line going to the rail. We also put a rag in the turbo duct so nothing
would fall in. See Photo 3.
4. Removing the fitting on the bottom of the intake can be
challenging (see Photo 4). You don’t have to remove the power steering pump or
alternator. Just loosen the intake bolts and you should be able to move the
intake enough to remove the banjo bolt that holds it on.
5. Photo 5 shows the electronic throttle body cable. It goes
behind the starter so leave it attached and just set the intake off to the
6. Here is the oil trap and hoses ready to come out (see
Photo 6). The fitting that went into the bottom of the intake was completely
7. The long hose that goes from the oil trap around to the
turbo duct has a coolant passage and is trapped behind the bracket that the
upper torque mount is attached to (see Photo 7). Once the bracket and mount are
removed, you can finish removing the hose.
8. We finally have the oil trap box and hoses off, and we
can see that the lower passage in the oil trap and the passage into the block
are completely plugged. See Photos 8 and 9.
9. Usually we can clean out the passage going into the
block, but this one was plugged solid all the way down into the oil pan, and
the only way to properly clean it out was to remove the oil pan.
10. The oil pan is fairly easy to remove. Remove the oil
cooler (see Photo 10) and the 30 bolts that hold the oil pan to the block. The
pan will come off without jacking up the engine or moving the sub-frame.
11. Once the oil pan was off, we could see just how badly
the return passage was plugged in the block (see Photo 11) and how badly the
oil pan was plugged (see Photo 12).
12. Be sure to clean the oil passage in the pan from top to
bottom before getting the oil pan ready for reinstallation.
13. Photo 13 shows the oil pan clean and ready for
reinstallation. Be sure to replace the
O-rings for the oil pipe in the oil pan. They can get hard
and crack and cause a loss of oil pressure.
Volvo’s oil pan seal kit P/N
30750783 includes all the seals needed to do the job. The only parts that don’t
come with seal kit are for the oil cooler (see Photo 14
14. Photo 15 shows how the oil trap and hoses will look when
they are all put together and Photo 16 illustrates how it all looks installed
on the engine.
15. With the high mileage on this car, we replaced all the
oil trap-related hoses and clamps (Nothing fits better than the factory OE
parts and that includes the pinch clamps). It’s too much work to have to
replace any of the parts at a later time. The engine number on the timing cover
will ensure that you get the right parts for the car you’re working on.
16. The intake goes back on along with the vacuum hoses,
fuel line and turbo duct. Plug in your injectors. Finish the oil change, top up
the coolant and you’re ready to go (see Photo 17).
I think when cars start to reach higher mileage, customers
tend to neglect some of the regular service and extending oil change intervals
certainly contributes to these oil-related problems.
Volvo recommends oil changes every 7,500 miles, and if you
follow this recommendation there shouldn’t be any problems. It’s when the
customer is “too busy“ and they routinely extend the oil changes past the
recommendation that we see these types of problems. That’s why it’s important
that we educate our customers and stress the importance of regular maintenance.