AfterMarketNews Auto Care Pro AutoProJobs Auto-Video.com Brake&Frontend BodyShopBusiness Counterman EngineBuilder Fleet Equipment ImportCar Motorcycle & Powersports News Servicio Automotriz Shop Owner Tire Review Tech Shop Tomorrow's Tech Underhood Service

Battery Service and Diagnosis

A good battery with an adequate charge is absolutely essential for reliable cold starting. A weak battery, or one that is rundown, may not deliver enough amps to crank the engine when temperatures plunge and the oil thickens. Cold weather can be hard...

Read more...

Toughest Spark Plug Changes

We have all been there before: scratched arms, busted knuckles and an aching back caused by a difficult spark plug replacement job. If you think they are getting tougher every year, you are right. Every new engine design is putting the plugs deeper...

Read more...

Improving the Head Gaskets, Fasteners Relationship

The relationship between head gaskets and head bolts is an intimate one. The clamping load applied by the head bolts is what allows the head gasket to maintain its seal. For this marriage to last, there has to be constant tension – not too much,...

Read more...

The Problem With Living In The 'Now'

I once had a shop manager who concentrated on the “now.” Every day was a mad dash to complete the jobs at hand. He wanted to know who was working on what, where the parts were and when everything would be done. He was constantly reacting to a customer’s...

Read more...

ASE G1: Drive Belt Inspection, Replacement

The ASE G1 Certification test contains 55 scored questions, plus 10 unscored ­research questions, that cover a range of skills and knowledge related to maintenance and light repairs in engine systems, automatic transmission/transaxle, manual drivetrain...

Read more...

Amateurs and Hacks Provide Job Security For Automotive Service Professionals

Two cars pull up in front of my shop. The drivers didn’t come in, but I heard the commotion from my office window. The boyfriend opens the hood of his girlfriend’s car. They both stare at the engine; she tells the boyfriend that she was supposed...

Read more...

Wheel Bearings: Measurement and Torque

Wheel bearings are either of the ball or tapered roller variety. Front wheel bearing applications are an angular-type ball bearing, which will accept greater thrust loads than a Conrad-type bearing, and will accept a 100 percent load in the radial...

Read more...

Why Alignment Angles Change

An alignment angle doesn’t change randomly. There is a cause-and-effect relationship between external and ­internal forces that can alter the geometry of a vehicle’s suspension. Having the alignment reading for only one angle on one corner is just...

Read more...

Using Recalls, TSBs as Brake Job Tools

You are getting ready to perform a brake job on a vehicle. While checking the torque specifications on the vehicle, you decide to hit the tab with TSBs and recalls. All of a sudden you are staring at a screen of brake recall notices and TSBs for that...

Read more...

Analyzing the Cylinder Pressure Waveform from a Running Engine, Part 3

By Vasyl Postolovskyi and Olle Gladso Contributing Writers and Instructors at Riverland Technical and Community College in Albert Lea, MN   In Part 1 of this Maximizing Tools series, we discussed an alternative approach to diagnosing an engine...

Read more...

Mac Tools Is Wrenching for a Cure

In support of Breast Cancer Awareness month, Mac Tools is featuring a variety of Wrenching For A Cure products available for purchase in the Flyer 11 through Nov. 2. Featured pink products include clothing, accessories, flashlights, pint glasses, and...

Read more...

5 Tool Storage Tips

  As a technician, you likely own thousands of dollars worth of tools and equipment, and require tool storage capacity to hold them all, along with carts and accessories to help move those tools around your work area. Here are a few items...

Read more...

Home News Volvo: Sometimes You Learn the Hard Way: Fixing Volvo Oil Leaks Right...

Print Print Email Email

The customer’s Volvo has an oil leak. You think you do everything right. You add dye and see the rear main oil seal leaking. The repair goes smoothly, the customer is happy…for about two weeks. Then the rear main oil seal is leaking again, and he wants to know why.

This is not an isolated case. Saab has released several TSBs on upgrading its crankcase ventilation system. It was inadequate and the excess pressure caused oil leaks. VW and Audi recommend replacing the suction pump on some of its cars before leaks are repaired. Again, excess crankcase pressure can cause leaks. Repair an oil leak without eliminating the pressure, and the leak will surely return. We learned the hard way.

In the hope of saving you from the same aggravation, I’ll discuss some of the symptoms of a clogged oil trap; how to test crankcase pressure; and, if it’s necessary, the steps involved in replacing the oil trap and related hoses. The older Volvo 240 and 740 models and the newer s70 and s80 models had similar setups to the 850 model that I’ll be discussing in this article.

Finding the Problem:

A customer’s 850 turbo comes in and it looks like oil is leaking from just about everywhere, or the dipstick is popped out. (See Photo 1.) Both are signs of a severely plugged oil trap. If you’re doing routine maintenance and, while cleaning the throttle housing, you notice oil in the housing, there is a good chance the oil trap is plugged. This is one of the reasons for all the electronic throttle housing failures on 1999 and later Volvos. We’ve also seen uneven idles and check engine lights with fuel trim codes stored, caused by plugged crankcase ventilation systems. Other cars with minor oil leaks may have partially clogged breather assemblies and are much more difficult to diagnose.

Volvo has a couple of TSBs on diagnosing and cleaning some of the crankcase ventilation systems on newer s60, s70 and s80 cars. Its special tool, P/N 9997226, is attached to the dipstick tube and at idle they want to see -0.2 KPA or less. We use an exhaust backpressure gauge with a hose attached to measure crankcase pressure (See Photo 2.) On a good car, even when raising the idle, the gauge won’t move above 0 psi. Plugged boxes are easy to see. We’ve seen more than 4 psi on some cars, and a psi of 0.5 on others. Remember that even if we see no pressure, the box can be partially plugged and should be replaced. If the car has 100,000 miles on the odometer, the oil trap should be serviced. Ignoring the problem can lead to a plugged passage leading into the oil pan, which requires oil pan removal.

Replacing the Oil Trap:

So, we’ve determined that before any oil seals are replaced, we need to check and replace the oil trap. Let’s get started.

Note: Always disconnect the negative battery terminal before starting any major repair.

  1. The oil trap is located under the intake manifold, so the intake needs to be removed. Photo 1 also shows the intake oil leaks around the top of the engine.

  2. Disconnect the throttle cable (See Photo 3) and the hoses from the vacuum tree (See Photo 4) and intake housing. There were five vacuum hoses on our turbo model.

  3. Remove the lower hose from the IAC valve, then remove the turbo intercooler to throttle housing tube. Be sure to check and clean all the vacuum ports on the tree and at the other ends of the hoses where they go into the turbo duct by the turbo (See Photo 5). The hoses will also become clogged over time.

  4. The spark plug cover must be removed to access the hose that comes from the oil trap (See Photo 6). Oil all over the cam cover is a good indication that the oil fill cap gasket is leaking. This is also an indicator that the oil trap is plugged. (See Photo 7).

  5. On this model, the fuel rail does not have to be removed. Just relieve the pressure on the system and disconnect the feed and return lines. Unplug the injectors and be sure not to lose the plug gaskets (See Photo 8).

  6. While not necessary on some models, it’s easy to remove the cooling fan assembly, which gives you a lot more room to work.

  7. If equipped, the EGR tube and EGR temperature sensor will need to be disconnected. Also disconnect the throttle position sensor. (See Photo 9).

  8. Remove the upper intake bolts and loosen the lower intake bolts. The bottom bolt holes are slotted, so the bolts do not have to be removed. This makes assembly much easier.

  9. There is also a bracket under the intake that will need to be removed before the oil trap can be removed (See Photo 10).

  10. We are now ready to remove the two bolts that hold the oil trap to the block (See Photo 11).

  11. Disconnect the hoses and remove the oil trap. This one wasn’t the worst, but it was bad enough. The lower port was plugged only halfway. This is the passage that goes down into the oil pan (See Photo 12).

  12. If it’s plugged, the oil pan should be removed to properly clean the passage.

  13. Our car had 160,000 miles on it, and all the hoses were very hard and brittle. We replaced the oil trap and all the hoses and clamps going to it (See Photo 13). There’s nothing worse than having to go in and replace them later.

  14. You will need the engine serial number to order the correct parts. The serial number is located on the timing cover (See Photo 14).

  15. Clean the passages in the block, being careful not to push any debris into the engine block.

  16. Once the oil trap and related hoses are in place, the intake manifold can be replaced. Photo 15 shows the lower intake bolts holding the gasket in place to ease installation.

  17. Reconnect the EGR tube and temperature sensor. Install the cooling fan and reconnect the fuel rail.

  18. Once everything is back together, I recommend degreasing the engine and adding dye to check for any persistent gasket or seal leaks, which you can then repair.

The total cost for parts for this repair was about $150. Labor for the 850 and s70 models is between three and four hours, depending on whether it’s a turbo or not. The s80s are four to five hours depending on whether it’s a turbo or not. Not having to warranty leaking oil seals and gaskets? Priceless — for you and your customer.

The following two tabs change content below.

Bob Howlett

Bob Howlett joined the Swedish Solution crew in 1985 and bought the business 10 years ago. Bob is an ASE-certified Master Technician and is an L1 Advanced Level Specialist. The Swedish Solution specializes in Saab, Volvo, VW and Audi, but it employs four ASE Master Technicians who can service all makes and models.
Latest articles from our other sites:

Battery Service and Diagnosis

A good battery with an adequate charge is absolutely essential for reliable cold starting. A weak battery, or one that is rundown, may not deliver enough amps to crank the engine when temperatures...More

Chemical Gasketing: Cleaning the Surface

Service technicians can now use chemical gaskets where OEs had originally used formed-in-place or pre-cut gaskets during vehicle assembly. In addition to complying with OE specs, chemical gaskets are...More

Check Out The October Issue Of Brake & Front End Magazine

The digital version of the October issue of Brake & Front End magazine is available online. CLICK HERE to access the easy-to-view digital version that features articles on Rotor Failure, Independent...More

Arnott Introduces New Right And Left Front Air Struts For 2000-'06 E53 Chassis BMW X5 With 4-Corner Air Leveling

Arnott Air Suspension Products has announced the introduction of new Arnott-engineered aftermarket air suspension struts for the front of the 2000-'06 BMW X5 (E53 Chassis) with 4-corner air leveling. Arnott's...More

Wheel Bearings: Measurement and Torque

Wheel bearings are either of the ball or tapered roller variety. Front wheel bearing applications are an angular-type ball bearing, which will accept greater thrust loads than a Conrad-type bearing,...More

Why Alignment Angles Change

An alignment angle doesn’t change randomly. There is a cause-and-effect relationship between external and ­internal forces that can alter the geometry of a vehicle’s suspension. Having the alignment...More

New Snap-on Heavy Duty Catalog Offers Array Of Performance-Enhancing Tools And Equipment

The new Snap-on Heavy Duty Catalog showcases some of the most innovative tools and equipment around, including an assortment of hand tools, power tools, shop and tech equipment, tool storage units, mobile...More

Analyzing the Cylinder Pressure Waveform from a Running Engine, Part 3

By Vasyl Postolovskyi and Olle Gladso Contributing Writers and Instructors at Riverland Technical and Community College in Albert Lea, MN   In Part 1 of this Maximizing Tools series, we discussed...More