AfterMarketNews Brake&Frontend BodyShopBusiness Counterman EngineBuilder Fleet Equipment ImportCar Motorcycle & Powersports News Servicio Automotriz Shop Owner Tire Review Tech Shop Tomorrow's Tech Underhood Service Speedville

Preventive Maintenance Profits: Preferred Automotive, Jenkintown, PA

With the summer months heating up and cross-country road trips beginning, many people want to make sure their vehicles are prepped for the long haul. For the first-ever July edition of Maintenance Chronicles, we will focus on Preferred Automotive Specialists,...

Read more...

GM HVAC Door Actuator Motors: Operation And Calibration

GM Electrically Driven Actuator Motors Long gone are the cables and rods jutting out of the firewall to operate the heater control valve or a vacuum unit pulling a blend door open. These days, it’s electrically driven actuator motors (modules) accomplishing...

Read more...

Solving Carbon Deposits In Direct Fuel Injection Engines

Symptom: Misfire codes, stumbling and suspicious fuel trim numbers. On a scan tool, the engine may show a loss in volumetric efficiency. The driver may complain about a loss of power, poor fuel economy and hard starts. Cause: Carbon deposits on...

Read more...

Making Sense Of Steering Angle Sensor Input And Data

Measuring the­ ­position angle, rate of turn and force of the steering wheel is critical for Electronic Stability Control (ESC) systems. Scan tools call these Steering Angle Sensors (SAS) and typically display the information in degrees. The SAS...

Read more...

Rotor Failure: Why Rotors Crack And Make Noise

The prices of rotors seem to be dropping the past few years. Call just about any parts supplier and they can quote you a vast range of prices for the same application. And when you compare the rotors side-by-side, they may look the same, but the difference...

Read more...

Tire Tread Wear: Causes And Symptoms

Understanding Tire Tread Wear Tire tread wear can tell you a lot about a suspension. Most specifically, it can tell you if the angles, inflation and components are within specification. Here are the most common tread wear patterns and what causes them. Over-inflated...

Read more...

The Ins And Outs Of Sanders

Sanders are required tools in today’s collision repair shop. Body techs and painters rely upon them every day to achieve that perfect finish on your customers’ vehicles. Whether you’re prepping a panel for paint or removing imperfections before...

Read more...

Are You Regularly Maintaining Your Equipment?

Technicians who are idling because the welder won’t feed wire, the hydraulic ram won’t pull chains, the booth heater won’t heat or the air compressor won’t compress enough air is a costly mistake, as labor time is the most expensive thing in any...

Read more...

Celebrate 'Back To The Future' Day By Watching The Time Machine Get A 2015 Detail

    For many today is just another Wednesday, but for a lot of people it is more than just your average Wednesday, it is "Back to the Future" Day. It is a day that everyone who watched the cult classic trilogy Back to the Future recognizes...

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.

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.

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.

  •  

    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.

    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).

    Pages: 1 2Next page

    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 posts by Bob Howlett (see all)

    Latest articles from our other sites:

    Subaru Pulse-Width Modulated Fuel Pumps

    I think it might have been a 2003 Subaru WRX, but it was parked in front of my local Subaru specialist’s shop after going on its fourth fuel pump replacement from other shops in less than six months....More

    Don't Let "Not Me" Ruin Your Shop

    In the newspaper comics section, there is a strip called Family Circus. Either you hate the strip for its sappiness and blunt humor that cuts like a dull butter knife, or you love it for its simple wit....More

    Solving Brake Noise With the Right Brake Pad and Shim

    Where does brake noise originate from? When a brake pad makes contact with the rotor, it causes the brake pad and rotor to vibrate. This is “ground zero” for all brake noise. If the vibration is transmitted...More

    Cleaning Disc Pad and Brake Shoe Break-In (Burnish) Procedure

    An effective burnish cycle to seat the friction materials into the opposing rotor and drum surfaces requires approximately 200 stops. The 200 stops are consistent with the burnish procedure outlined in...More

    Handheld Digital Tire Inflator from AME International

    AME International announces the release of its Accu-Flate XL, a handheld digital tire inflator. The Accu-Flate XL measures, inflates and deflates tires with advanced precision and is for use in the...More

    AIRCAT Composite Stubby Impact Wrenches

    AIRCAT Pneumatic Tools, a division of Florida Pneumatic Manufacturing Corporation, announces the launch of its new composite versions of its Stubby impacts – the 1056-XL and 1076-XL 3/8”. With 550...More