Replacing the timing belt/cambelt on an Alfa Romeo 166 at or before the recommended service interval is one of the most important pieces of maintenance you can do on one of these cars. Failure to do so opens you up to a much higher chance of belt or tensioner failure, which will result in a destroyed engine and a very expensive repair bill. In this quick guide we are going to tell you when to replace the timing belt on your 1999 to 2007 Alfa Romeo 166, along with some other timing belt related info as well.
Table of Contents
Does the Alfa Romeo 166 have a Timing Belt or Chain?
As you can see from the info below, all the engines fitted to the 1999 to 2007 Alfa 166 range are driven by a timing belt:
| Engine | Year Range | Timing Belt or Chain |
| 2.0 TS | 1999-2007 | Timing belt |
| 2.0 V6 TB | 1999-2003 | Timing belt |
| 2.5 V6 | 1999-2007 | Timing belt |
| 3.0 V6 24V | 1999-2007 | Timing belt |
| 3.2 V6 | 2003-2007 | Timing belt |
| 2.4 JTD | 1999-2007 | Timing belt |
| 2.4 JTD M-Jet | 2003-2007 | Timing belt |
When Does the Timing Belt Need to Be Replaced on an Alfa Romeo 166?
Alfa Romeo originally specified that the belt needed to be replaced every 116,000 km (72,000 miles) or every 6 years for all models. This was later changed to every 58,000 km (36,000 miles) or every 3 years for all petrol models, while diesel engines received a slight reduction to the time interval to 5 years. However, while the diesel interval didn’t officially change much it is now recommended by many owners and experts that you carry out replacements every 77,000 km (48,000 miles) or every 4 years, just to be safe.
The big interval reduction, especially for petrol models, was due to the high number of failures that these Alfa Romeo engines suffered from. The cause of the failure wasn’t often the belt, but actually the tensioner.
| Engine | Year Range | Recommended Change Interval (KM) | Recommended Change Interval (Miles) | Change Interval (Time) |
| 2.0 TS | 1999-2007 | 58,000km | 36,000mi | 3 years |
| 2.0 V6 TB | 1999-2003 | 58,000km | 36,000mi | 3 years |
| 2.5 V6 | 1999-2007 | 58,000km | 36,000mi | 3 years |
| 3.0 V6 24V | 1999-2007 | 58,000km | 36,000mi | 3 years |
| 3.2 V6 | 2003-2007 | 58,000km | 36,000mi | 3 years |
| 2.4 JTD | 1999-2007 | 77,000km | 48,000mi | 4 years recommended, 5 maximum |
| 2.4 JTD M-Jet | 2003-2007 | 77,000km | 48,000mi | 4 years recommended, 5 maximum |
What Happens if the Timing Belt Breaks on an Alfa 166?
All engines are interference engines, so if a belt breaks there is a very, very high probability that it will lead to severe engine damage as the pistons and valves smash together. To get a bit of an idea of health of both the belt and the tensioner, you can try to listen for any abnormal rubbing, squeaking, tapping, or ticking sounds originating from the timing belt area. The presence of such noises may signal that the belt and tensioner have surpassed their intended lifespan. However, if you want to get a good idea of the condition of the belt and tensioner they will need to be physically inspected (and then its probably better to just get them replaced).
What Else Should be Replaced with the Timing Belt?
You should replace the following components during a timing belt service on a 1999 to 2007 Alfa Romeo 166:
- Tensioner
- Idlers
- Aux belt
- Water pump – replacing with a metal pump is quite common on some models like the 3.2-litre V6 car. This is because metal pumps for these cars tend to have a sturdier impeller for enhanced durability, increasing their lifespan and reducing the risk of failure.
To Sum Up
All petrol models should have the timing belt replaced at or before 58,000 km (36,000 miles) or every 3 years. Diesel models have a slightly extended recommended service interval of 77,000 km (48,000 miles) or every 4/5 years. All engines in the Alfa 166 range are interference, so if a belt or tensioner fails catastrophic damage will almost certainly occur. Lastly, the belt should be replaced along with the tensioner, idlers, Aux belt, and water pump.
