The internal combustion engine is comprised of many valves and it is important to check if these valves open and close at the same time. The timing belt is the part of that engine and as the name implies, it helps in keeping check of the time of suction and exhaust valve’s opening and closing. Timeline coordinate between crankshaft and camshaft, so during fuel intake and removal of gas in cylinders, engine valves open and close at the same time.
Some people don’t understand the difference between a timing belt and a timing chain. Though same in function, the timing belt is low in manufacturing cost and needs replacement. The timing chain endures much longer than the timing belt and in fact known for no need for replacement as long as the vehicle runs. But you don’t have to worry about the performance difference between these two, as there are none.
Additionally, the Serpentine belt is different from drive belt.
The only reason for the timing belt desirability is its cheaper manufacturing and it’s smooth quite running in the engine.
Working of Timing Belt
So how does a timing belt works? As stated earlier, the timing belt keeps the timing of valves accurate through synchronization between crankshaft and camshaft. Correct valve timing is necessary for the smooth running of the engine. There are four strokes in an engine namely intake, compression, combustion, and exhaust stroke.
In intake stroke, air and fuel mixture enters the cylinder when the valve opens ups and pistons go down while the exhaust stroke is still closed. When the piston moves upward and there is compression of fuel and air mixture, this is the compression stroke. In this stroke, all valves remain closed. Again when the piston goes down and ignites the air mixture and fuel burns to give power to the vehicle, this stroke is called combustion stroke. The last stroke of the engine is the exhaust stroke in which air and gas due to burning to fuel exude from the cylinder. In the fourth stroke, the intake valve stays open.
During this operation, the timing belt makes sure that the camshaft and the crankshaft rotate in synchronization. This synchronization is significant in the working of the engine which otherwise can have a devastating effect on this whole operation. Once damaged, it becomes vital to replace the timing belt.
Symptoms of Bad Timing Belt
How do you know when the timing belt becomes faulty? There are some obvious symptoms that can tell you if the drive belt in your vehicle is faulty or not, which we can list as follows;
- Timing belt is quiet in a running engine so any noise is a red signal to notice immediately
- There comes decline in oil pressure and oil may leak from the cover of timing belt
- Valves get damaged and belt may slip on camshaft which results in the opening and closing of valves during cylindrical rotation earlier than the usual time
- Engine default is one of the clearer sign which can divert your attention to the need of replacement of timing belt. When you turn on the key, the engine does not ignite which in many cases means a red flag .
Cost of Replacement of Timing Belt BMW
Here take an example of BMW and let’s see how much it will cost you to replace the timing belt.
| BMW Model | Replacement Cost | Labor Cost | Parts Price |
| BMW 525i | $286-345 | $220-278 | $66-67 |
| BMW 325i | $347-415 | $189-240 | $158-175 |
| 1989 BMW 325i
L6-2.5L | Timing Belt Replacement | $559.54 | $721.37 – $1039.37 |
| 1992 BMW 325i
L6-2.5L | Timing Belt Replacement | $531.58 | $670.58 – $952.34 |
| 1990 BMW 325i
L6-2.5L | Timing Belt Replacement | $589.54 | $750.06 – $1067.07 |
| 1988 BMW 325i
L6-2.5L | Timing Belt Replacement | $559.54 | $730.51 – $1055.35 |
| 1991 BMW 325i
L6-2.5L | Timing Belt Replacement | $559.54 | $715.27 – $1028.68 |
| 1993 BMW 325i
L6-2.5L | Timing Belt Replacement | $504.58 | $635.85 – $911.82 |
| 1987 BMW 325i
L6-2.5L | Timing Belt Replacement | $559.54 | $718.34 – $1034.06 |
To stay on the safe side, replace your belt at manufacturer advised interval and keep checking the timing belt after every 6,000 to 9,000 miles of coverage as the last thing which could be on your mind is the rebuilding of engine. Check Dayco reviews as it may help in taking right decisions.
Being first timer, you can replace belt yourself or find reliable mechanic.
|
| Min $ | Max $ |
BMW 1 series |
346 |
1585 |
BMW 2 series |
664 |
739 |
BMW 3 series |
171 |
1879 |
BMW 4 series |
449 |
1520 |
BMW 5 series |
418 |
1865 |
BMW 6 series |
627 |
760 |
BMW 7series |
422 |
1480 |
BMW X1 |
976 |
1626 |
BMW X 3 |
361 |
2050 |
BMW X5 |
390 |
2235 |
BMW X6 |
637 |
1255 |
BMW Z3 |
364 |
893 |
BMW Z4 |
545 |
610 |
