I have a 2002 Buick Regal with 174,000 miles. I have been the only owner and most of the miles have been on long interstate trips of 250 limes or more. I am not a hard driver (translation = slow). The car is quiet and runs great. My mechanic “highly recommends” I change the timing chain soon at a cost of a grand.
He said if it braks it’s like throwing a handful of bearings in the engine and it will be ruined. I don’t pretend to be a mechanic but this sounds fishy. Does anyone have experience or knowledge you are willing to share?
thanks.
Look in your owner’s manual, it will say when to change it. Keep in mind it will say 123 miles OR 123 months, whichever occurs first. What your mechanic is talking about is an “interference” engine where the pistons can hit the valves at the top of their stroke if the timing gets screwed up i.e. if the belt breaks. So to answer your question, you need to do this @ the manufacturer prescribed intervals, to keep bad things from happening.
This vehicle has a timing chain not a belt. The manual does not make any comments regarding the timing chain in the scheduled maintenance section (which goes to 150,000 miles). I understand timing belts need changing but I thought chains were permanent unless they made a lot of noise.
Wait till it gets noisy. Timing chains thankfully very rarely break without warning(audible). They can cause a lot of damage breaking.
You are correct. When a timing chain stretches past a certain point, it will cause noise and driveability problems. These are easy to diagnose, and you shouldn’t need to worry about it until the problems appear. Timing chains rarely break, but, after time, will stretch to the point were it may jump a tooth.
Back in the days of distributors, it was easy to check the slop of the timing chain by rotating the crankshaft back and forth, and measuring the angle of lag-time between the corresponding rotor rotation. If the rotor didn’t move for 3 to 5 degrees of crank rotation when the rotation was reversed, the chain was too sloppy. Today’s DIS systems took that simple test away. Now, you gotta pull a valve cover and observe the lifters or camshaft.
Thanks for the info. The car is very quiet now but if the chain begins to fail will the noise be obvious? What kind of noise should I be listening for?
A streched timing chain will make a rattling sound that varies with engine speed. Sometimes a streched chain will break a tooth on a timing gear and then all heck will break loose in your engine when the little bits of metal start to get into some bad places such as oil channels. The tendancy is to put in something to quite the noise, such as motor honey or stp, but that won’t fix the chain. If the chain gets streched, it may jump time and then the car will stop dead and you will scratch your head wondering why. with this many miles, I would try to find a reputable mechanic who can do this job for around 300 or 350 bucks. Parts are cheap and labor is expensive, but a grand is a bit much for this job. Oh, and if you change the chain, you ought to change out the gears and the tensioner at the same time, and check the cam bearing wear while you are at it just for chuckles.
Great advise. Right now it is quiet at all speeds even at 70 mph on Interstate 10. I will keep my ear open and save your advise.
thanks