Alfa Romeo 166 (Type 936: 1998-2007)

Fragile suspension

Watch out for suspension noises (knocking and squeaking) when buying an Alfa Romeo 166. The suspension is relatively fragile in this car and other Alfa Romeos from that era. When it’s worn out or out of alignment, the car likes to eat the tyres quickly (tyre wear on the inner edge).

The suspension in the Alfa Romeo 166 will likely need refreshing every 50k miles or so. If you happen to drive on bad roads or use cheap suspension parts, take 50% off this number.

When buying an Alfa Romeo 166, take it for a test drive on some rough road and some speed bumps. Listen for any suspension noises. Also, check if the tyres are worn evenly.

V6 Busso – timing belt replacement interval

According to the manufacturer, the timing belt in this engine needs to be replaced every 72,000 miles or 5 years, whichever comes first.

In my opinion, this is too optimistic as there have been cases of the timing belt breaking earlier. I recommend getting it replaced not later than 60,000 miles.

Better safe than sorry.

2.0 Twin Spark – sensitive to poor maintenance

The Twin Spark is a dual ignition engine, which means that there are two spark plugs per cylinder (8 in total). The idea behind it is that igniting the air/fuel mixture in two places makes it burn quicker, thus improving efficiency and emissions. The dual ignition was dropped in later Alfa Romeo engines, probably because its benefits were too small.

Fun fact: dual ignition is still commonly used in aircraft engines for redundancy (the entire ignition system is duplicated, not just the spark plugs).

The Twin Spark engines are sensitive to poor maintenance.

Crankshaft bearings

First of all, a low oil level will kill the crankshaft bearings very quickly in these engines. For this reason, the oil needs to be changed regularly and oil level checked religiously to make sure it’s not low. Many old Twin Spark engines consume more engine oil than an average car. This usually isn’t a problem as long as the oil level is maintained.

The oil level in a Twin Spark engine should be checked monthly if not weekly (seriously).

Timing belt

Second, the timing belt in these engines isn’t very strong. It is very important to replace it every 36,000 miles or every three years, whichever comes first. This has to be done without fail as these belts are known to snap without warning. The belt replacement interval was only revised to 36k miles after many engines suffered timing belt failure (initially, the interval was 72k miles).

There are two timing belts in the 2.0 TS. One drives the valvetrain, while the second one turns two balance shafts. If any of the belts break, the results are catastrophic for the engine. Both belts need to be replaced at the same time.

Avoid engines that had the top end recently rebuilt after the timing belt had snapped. In this engine, a timing belt failure is sometimes followed by crankshaft bearings failure, which may get damaged when the valves hit the pistons when the timing belt breaks.

The bottom line is that these engines can be reliable as long as they are maintained well. Ideally, buy the car from an Alfa Romeo enthusiast.

2.0 Twin Spark – short-lived variators

All 16-valve Twin Spark engines (except the 105 PS 1.6L) are equipped with a device called the variator that adjusts the timing of the inlet camshaft (variable valve timing). The variator in the Twin Spark engines is not very durable and tends to wear out fairly quickly. A worn out variator makes the engine sound like a diesel.

Initially, the sound only appears after a cold start – before the oil gets pumped to the top of the engine. The clatter gradually gets more persistent. If your car sounds like a London taxi – get the variator replaced immediately.

The variator in the TS engines can fail as early as 40,000 miles. It makes sense to have it replaced with every timing belt job. The timing belt needs to be removed to replace the variator anyway.

2.4 JTD M-Jet 20v – timing belt & water pump

According to the manufacturer, the timing belt in this engine needs to be replaced every 72,000 miles or 5 years, whichever comes first. In my opinion, this is too optimistic. I recommend getting it replaced not later than 60,000 miles.

The water pump must be replaced at the same time as the timing belt, otherwise, it can seize and cause the timing belt to snap. It’s actually the water pump that is the weak point in the timing belt drive and the first part to fail.

The water pump in the 2.4 JTD MultiJet 20v is the same as in the 1.9 JTD MultiJet 16v, so both engines are affected.

2.4 JTD M-Jet 20v – swirl flaps

From mid-2005, these engines were fitted with swirl flaps in the intake manifold in order to improve emissions. There are two types of intake manifolds that were used on the JTD and MultiJet engines.

Luckily, the 2.4 JTD 20v has the safer aluminium manifold with plastic swirl flaps. These rarely fall off, unlike the metal ones that sometimes get detached and ingested by the engine.

In these engines, the swirl flap bearings wear out when the carbon build-up in the intake manifold becomes severe (it will eventually). Once the bearings are worn, they may develop air leaks, allowing the boost pressure to escape. Also, the flaps can simply get stuck before the bearings wear out.

Stuck or leaking swirl flaps manifest as rough engine running, reduced fuel economy and reduced power. The “Check engine” light may turn on as well.

The main cause of flap failure is increased friction in the flap mechanism from the carbon build-up in the intake manifold. Carbon build-up is a byproduct of the exhaust gas recirculation system (EGR) that feeds exhaust fumes back into the engine to improve emissions.

To fix the swirl flaps, a new intake manifold is required, which is fairly expensive. Another option is to remove the swirl flaps altogether, which has a minimal impact on the engine running. There are swirl flap removal kits available on the market.

Please be aware that removing the swirl flaps will increase emissions and is probably illegal – it depends on the country you live in.

2.4 JTD M-Jet 20v – worn drive shafts

The 20-valve JTD engine has an appetite for drive shafts. It seems that the General Motors drive shafts used in the 20-valve JTD cars are weaker than the Alfa Romeo ones used in the 10-valve JTD cars.

Make sure the drive shafts are in good condition in the car you are planning to buy, so you don’t get shafted. Look out for vibration when accelerating. It may be more noticeable in high gears at speeds above 50 mph.

Also, take the car to a parking lot or some other place where there is enough room to manoeuvre. Open both front windows, turn the steering wheel all the way to one direction, then do a circle. Listen for any noises coming from the CV joints.

Here’s what you don’t want to hear: