The 5 Most Common Porsche 944 Problems

Released in 1982, the Porsche 944 is a front-engine coupe that survived in production until 1991. After 1991 the 944 was replaced with the Porsche 968. The Porsche 944 was produced in three different trims: a base model, a turbo model, and an ‘S’ model. The 944S was updated in 1989 and is common referred to as the ‘S2’.

Four different engines were used in the Porsche 944. The base model, 944S, and 944S2 were all naturally aspirated inline-4’s with 2.5L, 2.7L, or 3.0L engines. The 944 Turbo used a turbocharged version of the 2.5L.

When maintained properly, Porsche 944 reliability is actually quite good. However, as some of these cars are pushing past 40 years of age, there are a number of common problems that arise. This guide is going to focus on the most common Porsche 944 problems as well as discuss overall reliability and additional common maintenance items. Most of the problems discussed are applicable to all 944 trims and engines, but we’ll do our best to highlight problems where this isn’t the case.

If you own a 944 and are looking for some extra power, check out our Porsche 944 Performance Mods guide.

Common Porsche 944 Problems

• Timing Belt Failure
• Cam Chain Tensioner Failure
• DME Relay Failure
• Bad Water Pump
• Cruise Control Wiring Failure (must replace computer and servo both fail and are expensive to replace)

1) Porsche 944 Timing Belt Failure

All 944 engines are interference engines. On a non-interference engine the valves and pistons each have their own area or space to open and close. When the piston is at the top of the cylinder and the valve is fully open, they won’t touch. However, on an interference engines the valves and pistons have an overlapping space hence the name interference. If the piston is at the very top of its stroke and the valve is fully open, the valve and piston will collide.

The timing belt control the open and closing of the valves. The Porsche 944 timing belt is made of rubber and therefore is susceptible to normal wear and tear. Additionally, it can loosen over time or even completely snap if the rubber becomes torn, brittle, or excessively worn down.

Because the engine is an interference engine, when the 944 timing belt breaks it sends the valves and pistons colliding into each other. The end result is bent valves and potentially damaged pistons. Replacing valves and pistons will require the engine to be opened up which is labor intensive and therefore expensive.

Timing Belt Failure Symptoms

• Rough idling
• Cylinder misfires
• Bent valves
• Damaged pistons
• Timing belt squeak

If your timing belt completely fails, you’ll know it. The pistons and valves will collide likely creating a loud noise from the engine and the engine will eventually shut off. If the timing belt simply stretches a little bit then you’ll experience the symptoms above. However, since this is an interference engine, even a little bit of timing belt stretch can ruin the valves.

The downside to timing belt failure is that there isn’t usually much of a warning or heads up. This is why it’s important to inspect the timing belt frequently and also replace it frequently.

Porsche 944 Timing Belt Replacement

The timing belt on a 944 should be replaced every 30,000 miles. If you just purchased a 944 I’d recommend replacing the belt immediately unless you have detailed records of the last time it was replaced.

When replacing the timing belt it is also a good idea to replace the balance belt too, which is located right near the timing belt. Additionally, the water pump is driven off of the timing belt so it’s also recommended to replace this at the same time. And as you’ll notice below, water pump failure is also common.

The downside to Porsche 944’s is that they are expensive to maintain. A water pump and timing belt kit for the 944 costs about $500 just for the parts.

2) 944S and S2 Cam Chain Tensioner Failure

Specific to the S and S2 944 models is cam chain tensioner failure. One of the upgrades in both the 2.5L 944S and 3.0L 944S2 was a self-adjusting timing chain tensioner.

Compared to the base model 8-valve single-overhead cam engine, both the S and S2 engines are 16-valve engines with dual overhead cams. One camshaft drives the intake valves and the other drives the exhaust valves. The timing chain drives the exhaust camshaft. And then there is a chain between the intake and exhaust camshaft that allows the intake camshaft to move with the exhaust camshaft.

The chain connecting the two cams is self-adjusting and controlled via oil pressure. Over time the tensioner wears down and can fail which will cause the timing to be thrown off. Additionally, there are a few other components that can fail like the tensioner guide rails, or oil supply pipe which can also cause the whole system to fail. As aforementioned, timing being thrown off will crash the valves into the pistons.

On the S and S2, cam chain tensioner failure can also result in a cracked cylinder head.

Cam Chain Tensioner Replacement

The cam chain tensioner, guide rails, and pipe pads should be replaced every 100,000 miles to prevent failure. While this is a good mileage guide to follow also keep in mind how old the current parts on the car are. If these parts haven’t been replaced any time recently then we recommend replacing them all immediately. For DIY replacements, check out this guide here.

The tensioner, pads, guides and all can get quite expensive with an OEM tensioner running above $500 itself.

3) Porsche 944 DME Relay Failure

The Porsche 944 has a bad reputation for electrical problems. Fortunately, the majority of electrical problems that arise are caused by a bad DME relay. The DME is essentially the same thing as an ECU for the sake of keeping things simple.

The 944 DME relay controls both the engine computer and the fuel pump. The purpose of the relay is to shut off the fuel pump during an accident to prevent the car catching fire. When engine RPMs drop below 200 the relay shuts off the fuel pump.

The issue with the 944 DME is that it eventually begins to fail or become faulty over time. When this happens the car can randomly shut off while running or even not start at all. Additionally, since it is connected with the DME it can cause a bunch of random electrical type issues as well.

Fortunately, the DME relay is a $20 part and very easy to replace. It might be a good idea to buy two of these and leave one in your car due to the commonality of the problem.

944 DME Failure Symptoms

• Engine won’t start
• Engine shuts down while running
• Various random electrical issues

4) 944 Water Pump Failure

Water pumps circulate coolant through the engine. They are generally a pretty common maintenance item for all cars, however, they are known to fail a bit more frequently on the Porsche 944. The 944’s water pump is driven by the timing chain, which is also why we recommend replacing them at the same time. Water pumps naturally fail over time from wear and tear and old age.

The Porsche 944 water pump fails for a few different reasons. First, the internal bearing can go bad which will cause a “bearing” noise from the water pump. Secondly, the impeller can separate from the shaft or the shaft seal can go bad which will cause coolant leakage. Lastly, the pulley connecting the water pump to the timing chain can slip and cause failure.

The biggest concern of a failed water pump is the engine overheating. Heat kills all engines as it can warp internal components and so forth. Fortunately, 944 water pumps are a bit more cost friendly compared to other Porsche 944 problems with a pump running between $100-$200.

Porsche 944 Water Pump Failure Symptoms

• Engine overheating
• Coolant leaks from water pump housing or weep hole
• Low coolant light
• Noises from water pump

Since the water pump is part of the timing system it’s a good idea to replace the timing belt and balance belt at the same time if they haven’t been recently replaced.

5) Porsche 944 Cruise Control Problems

Cruise control was a luxury back in the 80’s, but this is Porsche so luxury is sort of expected. The cruise control system has a few different components: a cable that travels across the engine bay, a control module, and a servo motor. If you’re reading around the internet the control module is also frequently called the “brain”.

Cruise control issues arise primarily from the brain and the servo. However, there are quite a few owners who still continuously have cruise control problems after replacing both of these items. Our recommendation is honestly just to ignore the cruise control unit and not worry about it.

If you want to completely remove it you can unbolt the whole unit with the servo actuator, remove the control module, and then cap off the wiring harness. However, so long as the cruise control not working isn’t impacting any other systems then you can just ignore it.

Parts to replace the system aren’t too expensive but due to frequency of failure it doesn’t seem to be worth the money.

Porsche 944 Maintenance Items & Costs

I didn’t want to include this as a “problem” because it’s more of a heads-up. The Porsche 944 is very expensive to maintain. This is predominantly due to its age, the cost of replacement parts, and the cost of qualified labor to work on the car. As cars get older less replacement parts get manufactured which drives their costs up. And most general repair shops might not have the knowledge to properly diagnose and repair issues.

These cars are certainly less expensive when you have the DIY capabilities to handle all of these common problems yourselves. However, in addition to the problems listed above, there are a ton of maintenance repairs you’ll need to do if they’ve never been done before. Here is a list to name a few:

• All rubber lines such as vacuum lines, fuel lines, washer fluid lines
• Rubber hoses like coolant hoses
• Brake lines
• Motor mounts
• Clutch
• Power steering rack
• Ignition coils, spark plugs, etc.

In addition to these items the odometer fails easily and most are already broken. The dashboard cracks easily. The rear hatch window can become separated from the frame when new trunk struts are installed.

Overall, given the age of these cars there are a number of maintenance items that will need to be addressed. Additionally, the cost of replacing these items isn’t cheap making the Porsche 944 a pretty expensive car to own. Just keep this in mind when you find a 944 for a “really good deal” on the internet.

Porsche 944 Reliability

When properly maintained, the Porsche 944 is very reliable. None of the different models or engines really suffer from any catastrophic engine problems outside of potential damage caused by timing belt failure. So long as the timing belt and cam tensioners are replaced frequently there aren’t any big red flags with the 944.

However, while the engines themselves are reliable there are a lot of small items that will arise. Our list above is a good place to start if you just bought a new 944 and are looking to knock all of the typical maintenance items out. Absolutely replace the timing belt immediately after purchase, and the cam tensioner if you have an S or S2. Outside of these two items the majority of the other items can be addressed when they fail. However, it’s still a good idea to inspect all of these components frequently and replace them before they fail.

With the Porsche 944, maintenance is the key to reliability.