interference engines and timing belts

Interference Engines: …….. Advantageous advice by

An interference engine is an engine architecture that has been avoided by some manufacturers for able-bodied over 80 age. General Motors, Chrysler, etc., typically statement a metal chain-type timing girdle on push-rod engines (generally called a timing chain) to transmit torque from the engine crankshaft o the engine camshaft that opens the valves that admit air and fuel. (Note: on some advanced cars the fuel is admitted not buttoned up the valves but buttoned up injectors in the top of the cylinder. Rather than statement a steel timing chain, interference engines may statement a rubber timing girdle with its limited action, whereas steel timing belts typically last 150,000 to 200,000 miles or added.

Valves accessible further in an interference engine and project further into the combustion chamber than in a ‘chargeless-running’ engine. This allows outside air at atmospheric pressure flow faster into the combustion chamber buttoned up the larger valve opening. The engine can accordingly inhale added air, be a babyish smaller, and still actualize as much adeptness while reducing its manufactured cost and again guaranteeing approaching repair bag for its dealer. If a rubber timing girdle breaks by not being replaced soon enough, some of the valves stuck in their accessible position will collide with the top of the pistons, thereby breaking or irreversibly damaging one or the other or both. To accomplish matters worse, it is not possible to measure the wear on such a rubber girdle so that it could be replaced when there is some indication of impending failure. Failure in these belts is catastrophic, without warning. This will crave a entire advanced engine be installed. Woe to the owner. Finally, the rubber girdle may accept to be replaced continued before 60,000 miles solely due to its age. This is really playing a bad poker hand. Interference engines are according to a age bomb waiting to explode unless replacing the timing girdle at the recommended interval. Be aware of that guaranteed approaching expense before buying a advanced car, or especially a used car, ” with such an engine.

For details on this subject or for recommended mileage to replace rubber timing belts on interference engines, connect on the Internet to ©Gates Rubber Company, a worldwide manufacturer of such belts. When its interlacing site appears, click on Replacement parts/Automotive. Attending for ‘Timing girdle replacement Adviser’.

When buying a used car always insist on determining if the vehicle has a rubber timing-girdle. Be aware that about five age ago an International Oil Company did a chase up on 5,000 cars it had turned back after 3 year leases and traced them to their eventual private owners. All the cars had by then passed buttoned up wholesale auction markets and likely one or added retail dealers before being sold to a private owner. The survey disclosed that 50% of the cars had their odometers illegally turned back.

When buying a used car, supposedly with 40,000 miles for archetype, and determining it has a rubber timing girdle, insist on a written guarantee from the seller to guarantee in writing to replace the timing girdle at no charge if it fails within another 20,000 miles, a typical recommended total amount (call any Dealer to amuse the recommended amount for the particular accomplish of vehicle). After all, the vehicle may in actuality already accept 55,000 miles on it. If the seller will not accomplish that guarantee, then he is admitting that the mileage is probably not accurate and by implication may able-bodied accept been turned back. If the seller will not accomplish that guarantee, accede a compromise, such as $100 maximum cost. If not acceptable, airing away and attending elsewhere.”

Before buying any car, especially 4-cylinder foreign cars, or even 6-cyl. BMW’s, be aware of the unavoidable cost of $400-$800 to replace the timing girdle at anywhere from 50,000 to 70,000 miles if the car has an interference type of engine. The sales person will invariably not mention that an interference type engine powers the vehicle and may not even apperceive what one is. If a timing girdle on an interference engine is not replaced at recommended intervals, the repair cost when the girdle breaks (not gradually, but always catastrophically) could access to $3,000 to $5,000 due to engine failure as parts accept smashed into each other

If the sales person does not apperceive if the vehicle has an interference engine, airing out to the repair shop and buzz the ‘Service writer’, who is probably a former mechanic. Finally, since words are cheap, inscription on the purchase adjustment that the seller guarantees the engine is not a “interference engine” and will indemnify you 100% if it turns out that it is and the engine breaks when the rubber timing girdle breaks.

Copyright 2004 by Beacon Data LLC All rights reserved

About The Author

Ralph Hoffmann majored in Applied Mathematics at the Univ. of Wisconsin, but worked chiefly in appliance tool manufacturing. When he was 16 he replaced the rod bearings on a ’34 Pontiac, which involved melting out the aged ones and having advanced ones poured in abode, then hand scraped to fit. Got lots of oil pressure for sure. His Eeperience with cars based on bitter and expensive acquaintance.

Originall posted December 25, 2011