TIMING BELTS SERVICE OR REPLACE

Subaru Timing Belt Replacement

The timing belt is a critical component in your Subaru engine, and because it rarely gives any indications of imminent failure, it is easy to neglect it, with disastrous results. If your timing belt breaks while the engine is running, serious damage to the engine will result. For that reason, replacement of belts is recommended at fixed mileage or time intervals, as well as inspections during routine services. When buying a used Subaru, unless you have reliable up-to-date service records indicating recent replacement, you can't be sure when the timing belt was last replaced. We recommend fitting a new belt and tensioner bearings to all second hand vehicles or recently purchased used engines.

"Subaru timing belt replacement is not for the novice. Variable valve timing is complex and critical. We at All Drive Subaroo have the equipment and know-how to get it right."

Warning: Subaru EJ series engines are "interference" engines, meaning that if the timing belt breaks it will result in contact between valves and pistons. This nearly always damages valves and pistons, necessitating a replacement engine. FYI, if you own a Subaru with a six cylinder EZ series engine you don't have to worry about timing belts. These models, as well as newly released FA or FB engines all now run timing chains.

Timing belt recommended service intervals

All Subaru EJ series engines from 1991 to current model shapes use a high quality rubber timing belt that is not only durable but efficient as well, and Subaru have recently adjusted their timing belt service mileage upward. However, timing belt tensioner bearings have proven to be less reliable and are the cause of most timing belt failures. Failure occurs for two reasons: either the bearing wears prematurely, or it had been incorrectly fitted. While Subaru recommends inspection and report on the bearings, we recommend replacing them along with the belt to minimise risks of future failure. In this case there is no such thing as over servicing. Bluntly speaking, a failed timing belt, idler bearing or tensioner will result in an expensive engine overhaul, costing much more than a timing belt change, so we think it's best to err on the side of caution.

Warning: the Subaru logbook does not mention service intervals for the tensioner bearings, despite the fact that these fail more commonly than the belts. They recommend inspection and report only. Inspection of these units can only be external, and does not guarantee that the bearings will remain serviceable until the next belt change interval. We recommend therefore that the tensioner bearing be changed at the same time as the belt. Timing belt repair and replacement work is routine at All Drive Subaroo for all Subaru models. During our regular inspection services we can inspect your timing belt and bearings to see they need replacement.

We offer 3 types of Subaru timing belt repairs with or without the bearing kit and tensioner:

Option 1: Genuine Subaru timing belt. Designed and manufactured specifically for your Subaru.

Option 2: Genuine Subaru parts designed for everyday motoring and mild motorsport applications.

Option 3: Cosworth Kevlar performance timing belts are 300% stronger than original equipment. Made from durable nylon fibre combined with Kevlar backing that improves wear resistance and strength

Subaru Timing Belt Tensioners

The Subaru timing belt tensioner serves two purposes: it maintains correct belt tension as the belt ages, and it reduces noise while ensuring smooth engine operation. If the tensioner is not replaced at the same time as the belt, the bearing or tensioner could ultimately seize, resulting in the valves misaligning with the crankshaft position causing the valves to strike the pistons resulting in catastrophic engine failure. Subaru boxer engines are particularly prone to this type of damage because of the fine tolerances employed in engine construction.

Indications of timing belt tensioner wear:

• Squealing sounds
• Knocking or rattling on start up
• Belt flapping sounds
• Visible signs of physical deterioration from aging

All Drive Subaroo recommend replacing the tensioner and bearing at the same time as the timing belt to avoid future problems. We use and recommend genuine Subaru timing belts and tensioners as they are high quality components, made in Japan and designed specifically for the vehicles. Cheaper Chinese aftermarket parts are available but these are of poor quality and we cannot guarantee longevity. We have seen numerous failures of Chinese sourced timing belt tensioners leaving the customer with no recourse but to pay the full cost of a new repair. We keep a large number of Subaru tensioners in stock so the replacement of your Subaru timing belt replacement will be timely and convenient for you.

Traps for the unwary installer:

The Subaru EJ engine has always been a relatively easy engine to swap out the timing belt in. The SOHC cam engine has had no technical changes up until now, other than the introduction of VVL that has no bearing on the timing belt. With the advent of the quad cam engine, from 1991 to 2001, it was still a straightforward repair despite the two extra camshafts. However in 2002 with the intro of AVCS on the inlet cam, installation become trickier for technicians, and mistakes were sometimes made with the variable timing resulting sometimes in expensive damage to engines. On some higher-end models AVCS was introduced on the exhaust cam also, leading to better driveability but still more complexity. We have assisted many mechanical workshops who have run into trouble with timing while changing belts in these models. Specialised tools and knowledge are required and repairs are best left to the experts.

"You can trust us to make an accurate and fair diagnosis of any problems your car might face. If you suspect timing belt problems in your Subaru, then it is time to see All Drive Subaroo at Peakhurst."