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Interefernce Engines

Is a 2000 Saturn SL2 1.9 liter DOHC engine an “INTERFERENCE” Engine? meaning if the timing chain goes will the engine be damaged?

Timing CHAINS seldom if ever break. They can wear and get loose enough to “Jump a tooth” and then the car will refuse to start or if it starts will run very poorly. On most OHC engines with a chain, there is a chain tensioner system that will compensate for wear for the life of the car…

Thanks; sounds good; finally something positive in car engine design

To answer your first question: no.

The Saturn DOHC engine is interference design.

I guess nobody told Gates.

http://www.gates.com/parts/locator/index.cfm?location_id=3598

Click on Automotive Aftermarket and then click on 'Part Locator & Interchange

I have worked on two different engines that had chains and interference engines that when the chain slipped it DESTROYED the engine. It is NOT difficult to destroy an interference engine if a chain slips a couple of teeth.

It won’t show up on the Gates site because Gates makes timing BELTS. The Saturn SL2, as previously mentioned, has a timing CHAIN. According to andrew j above, if the chain were to break, valves would be damaged. I suspect he’s right. He usually is.

Whenever interference engines are involved in Gates data on that site, it is noted as such.

The poster asked if the engine was an interference type, I said no. On Gates’ site there is NO note for it being an interference engine.

Gates Sells Belts

On belts:
Gates lists a timing belt for cars that have one. Obviously, they don’t list one for cars that don’t.

When one is listed, Gates tells whether or not that particular application is “interference” by noting that, following the belt information.

On chains:
Gates does not list timing chains, nor do they bother to specify whether or not a car with a chain is an “interference” design. They really have no interest in that. They don’t sell chains. Besides, most chains do not require periodic maintenance the way belts do.