Cam Belt Tensioner


MG Rover recommend changing the Cam Belt every 60,000 miles ( or 5 years, which ever is greater ), but they do not make a similar recommendation for either the Cam Belt Tensioner or the Water Pump.

Click to enlarge Click to enlarge
One disintergrated tensioner = 16 bent valves = 1,250 !!!!!


Date: Jun 29, 2006, 12:00am

As some of you will know, Lynn and I should have just returned from Sweden and Norway after a 2 week trip that would have included the Swedish Annual MG meeting at Falkenberg. We didn't make it! In fact we only got as far as the Clacket Lane Service Station on the M25.

Stopping for a natural break, it was obvious something was wrong with the engine as we pulled into the carpark. At 10 mph it was possible to hear a dreadful whirring sound from the cam belt side of the engine, which then stuttered and cut out, just allowing us to coast into a parking slot.

In short, the tensioner had disintergrated, the belt jumped, and the valves crunched. We had driven the 90 miles from home in the rain, at 70 mph, fully loaded, hood up, case on the luggage rack, and with the wind noise, no obvious sign of anything amiss.

Nor had I heard anything over the previous days, though over time, unless there is a dramatic change at one go, slow changes in noise are not always obvious.

The Rover MG recommendation is to change the cam belt every 60,000 miles. The general concensus of opinion on the web and covering all makes of cars, (this of course is hindsight) is that tensioners, on average, last twice as long as cam belts. This of course means that some will not! They may go just before the 120,000 mile service. Mine is now at 93,000

When I had the 60,000 service done, I insisted that the water pump be changed as well. But not the tensioner. It only costs about 48 plus fitting.

Have a look at http://www.mgfcar.de/cam_belt/preventive_70345_E02.pdf"

Want to see the consequences of a tensioner failure ? See Don's engine pictures here: tensioner_failure.htm

Don't wait - get it done and save a new head!