Keeping a record of scheduled maintenance and service repairs is probably the best selling feature when the time comes to trade or sell a vehicle. You know the type: They baby their car, and their friends and family want first dibs when they decide to sell it.
In most cases, that level of upkeep is a large investment, but proper care means the vehicle will retain a higher value. Most Volvo owners keep their cars for much longer periods of the time than any other car in our repair facility. When a customer drops by for a simple oil and filter change in a 240 or even in a new series Volvo, we take the time and go over most major areas and point out potential problems that call for preventive maintenance. In this article, I will point out some driveability and service procedures for 1995 to 2000 Volvo models, describe some methods to simplify repairs and also explain all of the systems they contain.
MAINTENANCE IS CHEAPER THAN REPAIR
First, it is necessary to distinguish between repair and maintenance. Repair implies that something has broken or is not functioning properly. A needed repair is often caused by lack of maintenance. For example, draining and changing the engine oil and filter at specific mileage intervals is maintenance recommended by the manufacturer. Failure to do so can shorten engine life and potentially lead to very expensive repairs.
Fluid changes, with injection cleaning/carbon removal service, can be very profitable at routine intervals, as can cooling system flushes and brake fluid changes. Transmission and power steering fluid can only be properly changed with a fluid exchanger. Most of the time, with an automatic transmission, we flush 15 quarts of new fluid into the system at a normal service. The old method involved pulling off the drain plug and allowing just a few quarts of fluid to drain out. As a result, when the engine was run for a short period of time, the new fluid appeared dark when it mixed with the old.
Don’t forget to check for some driveability problems that can be easily overlooked, such as a small vacuum leak in the intake side, which causes erratic skipping and stalling problems. Some companies sell smoke-making machines to aid in locating such leaks with ease. Placing the smoke probe in the intake system port and watching for leaks is something impressive to see. In our repair shop, we use this equipment almost every day to diagnose problems ranging from EVAP trouble codes to various other leak problems.
ELECTRONIC ENGINE CONTROLS
The engine control module (ECM) performs many functions. It accepts information from many sensors and computes the required fuel flow rate to maintain the correct amount of air/fuel ratio throughout the entire operational range.
The oxygen sensor (HO2S) is a device that is always blamed for not producing the correct pulse for normal engine functions. Other sensors can lead to out-of-range inputs, including vacuum leaks that can cause rich or lean conditions.
The air idle control valve (AIC) that Volvo uses is incorporated into the intake system to set the correct air valve opening and constant idle speed. Some of the time this fault code will come up and cause erratic idle. Cleaning of the valve port and removing some sludge can correct this problem.
The engine coolant temperature sensor (ECT) identifies resistance changes in response to engine coolant temperature. If the connection is faulty, the ECM will not have the correct input, causing driveability problems. Some of the time we find loose wire connections or some corrosion on the terminals connecting the switch. Just repairing this simple problem could rectify the situation.
The camshaft position sensor (CMP) is located on the exhaust camshaft and determines which cylinder requires ignition. Some intermittent spark problems can result in a bad sensor. (You know the type – when the tow truck drops off the car at the repair shop, it starts and runs.)
The crank position sensor (CKP), sometimes called rpm impulse sensor, is used to determine engine speed and top dead center (TDC) with precise ignition timing. This sensor is located at the rear of the engine block above the flywheel in all Volvos. The engine won’t start without this signal. As with the CMP sensor, it tends to have intermittent problems.
FUEL DELIVERY SYSTEM
Checking the fuel pressure is one of the most important procedures in diagnosing driveability problems. Checking the fuel pump relay (see Fig. 1) for proper function could resolve many intermittent cut-out problems. A possible source of failure in some older Volvo models is the pre-pump in the fuel tank, which delivers fuel to the main pump. To test this pump, pull off the fuel line going to the main pump and crank over the engine to see if the fuel is being pumped out in a small stream.
Another problem I have encountered over the years in some front-wheel-drive Volvos is the right rear shock upper-mount failing to bring up the shock through the body and tearing off the fuel pump connections. This causes a short in the wire harness and the possible melting of wires.
Replacing the fuel pump in front-wheel-drive Volvos is quite simple with the aide of a factory tool (p/n 999-5485; see Fig. 2) to remove the pump retaining ring. After the retaining ring is removed, lift the pump out of the tank and drain out the fuel.
Always replace the fuel filter after the fuel pump has been changed since it may contain metal particles from the failed fuel pump.
Often I have seen a plugged exhaust system overlooked on cars with loss-in-power problems. Some of the best technicians get caught up in trying to locate the problem in other fuel delivery systems.
When a CAT converter or muffler is blocked, most of the time a code will show up stating the rear O2 sensor is not responding or is changing. Some later Volvos have this common problem and could be diagnosed with a hand-held laser temperature probe (see Fig. 3).
The exhaust system tends to last longer in the 850 and 70 series cars than in older models. It appears that the metal used has a type of coating inside and out for longer durability.
The cooling system has the most common problem that brings these cars to the shop for repairs. Many times the cooling fan and a host of other problem areas are overlooked when the car comes in for service.
A seeping water pump seal can result because of cooling system contamination. Flushing of the coolant when service is performed is very important. Using the correct coolant is a must! Some coolants gel when mixed with other types, so I recommend using factory coolant.
When a customer complains about coolant loss, and the level indicator light shows up on the dash, don’t overlook the cooling fan operation. Fluid can escape from the pressure cap without any notice, resulting in the engine temperature climbing. Some customers will not notice the temperature gauge rising in stop-and-go traffic. Always check the condition of all hose and thermostat function after flushing has been completed. The only problem I’ve seen because of coolant loss in 850 models is the radiator tank leaking, with the unit having to be replaced.
TIMING BELT REPLACEMENT
When any service is performed in our shop, we tend to look for timing belt replacement stickers under the hood area. Some repair shops forget to put the reminder stickers on or use some type of marker that washes off with time. In our shop, I’ve made up special timing belt replacement stickers. After it’s applied, we put on clear tape over the writing for protection (see Fig. 4).
Logging the mileage in the customer’s service book takes the guesswork out of future replacement of the timing and serpentine belts. The idler and tensioner pulleys should be checked and replaced at this time as well.
Any time a customer complains about noise or rattling when going over a bumpy road, the sway bar link arms are the most likely culprits. Check the boots for tears, which are telltale signs. Water and road debris can damage the joints (see Fig. 5). Ball joints, as well as tie-rod ends are non-serviceable since there are no grease fittings. If there is any play in these areas, the part should be replaced following a four-wheel alignment.
Also check the struts and upper mountings for wear; if worn, they can make a thumping sound when driven over the smallest bumps. Replacement of the upper strut mounts is carried out in the same manner as replacement of the strut cartridge: Use a strut spring compressor to relieve the pressure on the mount.
Pulling off the wheels for rotation when servicing gives a view of the brake pads and rotor surface. Before giving an estimate for the work to be performed, don’t forget to check the condition of the brake calipers for free float on the sliding pins and the piston/boot condition. When any repairs to the brake system are done, the ABS wheel sensors should be checked for cracked wire cables and corrosion in the connections. It’s necessary to clean off rust and debris from the sensors for a good contact reading.
Some 850 models come in with the ABS light on, and when pulling up fault codes, it gives you a code that the right wheel sensor is faulty. Check the connections and sensors for good readings; if they’re OK, it’s possible that the ABS control unit is faulty and must be replaced.
Many failures in the emission system are caused by small vacuum leaks and sticking control valves. Pulling up codes, tracing the faults and repairing the problem areas can be very profitable to the repair shop. On OBD II cars, the secondary air pumps have the tendency to seize up and set off the Check Engine light. The check valve in the exhaust manifold should be replaced at the same time as the pump. When this valve fails and is not operating properly, water and exhaust is directed into the air pump, possibly leading to irreversible damage to the pump and its replacement again.
EVAP codes are often set off because of leakage in the system, so checks should be carried out. Not to be overlooked are a simple loose gas cap, an intermittent purge valve problem or leaks in the hose coming from the tank up to the engine area.
MAINTENANCE MEANS PROFITS
Working on Volvos and performing the proper maintenance on all systems can be profitable for your shop. Parts are readily available, and the prices are reasonable for most repairs. The special factory tools needed are a small investment compared to the profits to be made. And regular maintenance will also result in satisfied – and repeat – customers, the backbone of any successful repair shop.