For those who love their Porsche 944, understanding and caring for its engine is a vital part of the experience. One crucial aspect of this care is timing belt maintenance. Neglecting your Porsche 944 timing belt can lead to severe engine damage, which is why regular inspection and replacement are essential for the longevity and performance of your Porsche 944.
In this guide, we will delve into the world of DIY Porsche 944 timing belt replacement. Whether you’re a seasoned DIYer or new to the game, this guide is designed to empower you with the knowledge and confidence to perform this critical task yourself. You’ll find that with the right tools, parts, and guidance, replacing your Porsche 944’s timing belt can be a rewarding and fulfilling project.
Stay tuned as we take you through each step of your Porsche 944’s timing belt replacement process, providing you with the knowledge and tips you need to master this task. Let’s embark on this DIY journey together and keep your Porsche 944 running smoothly and reliably.
Importance of Porsche 944’s Timing Belts Replacement
The timing belt is a crucial component that plays a vital role in synchronizing the engine’s camshaft and crankshaft rotations. By ensuring that the engine’s valves open and close at precisely the right times during each cylinder’s intake and exhaust strokes, the timing belt is integral to maintaining the engine’s rhythm and health.
But why is timing belt maintenance non-negotiable, especially for Porsche 944 owners? The answer lies in the design of the engine. The Porsche 944 is equipped with what is known as an interference engine. The clearance between the moving valves and the piston is minimal in interference engines. Therefore, if the timing belt fails, the valves and pistons can collide, leading to severe engine damage and a multitude of engine parts. Neglecting your Porsche 944’s timing belt replacement isn’t just risky; it’s an open invitation to significant mechanical troubles.
How often should you change the timing belt on a Porsche 944?
We and the Porsche 944 community recommend replacing the timing and balance shaft belts every 30,000 miles or 3 years. While you are at it, you need to replace the water pump as well to prevent any issues that may come with it if left unchecked.
Recognizing the signs of a worn or failing timing belt is vital to preemptive maintenance. Here are some indicators that your Porsche 944’s timing belt may need attention:
Engine Misfires — A worn-out timing belt can slip, leading to engine misfires where the camshaft timing is disrupted. This can cause the engine to stall or have difficulty starting.
Rough Idling or Trouble Starting the Car — If the belt’s teeth begin to wear out or if the belt has become loose, it can cause a rough idling engine or issues with starting the car.
Visual Signs of Wear — Regular inspections can reveal cracks, fraying, or excessive slack, all of which clearly indicate that the timing belt needs replacement.
Being proactive with timing belt maintenance is crucial for Porsche 944 owners. It’s not just about keeping your vehicle running smoothly; it’s about preventing catastrophic engine damage that can occur without warning.
Porsche 944 Timing belt inspection
Inspecting your Porsche 944’s timing belt is a critical step in maintaining the health and performance of your vehicle. Before diving into the inspection process, let’s go through some essential preliminary steps to ensure both your safety and the accuracy of your inspection.
Engine Cooled Down — Ensure that your Porsche 944’s engine is completely cool before starting any inspection. Working on a hot engine can lead to burns and other injuries.
Safety Measures — Disconnect the battery to avoid any electrical hazards. Wear appropriate safety gear, including gloves and protective eyewear.
Initial Engine Inspection — Begin with a general engine inspection. Look for any signs of oil or coolant leaks, as these could indicate other underlying issues that might affect your Porsche 944’s timing belt.
Once the preliminary steps are complete, proceed with your Porsche 944’s timing belt inspection:
Timing Belt Twist Test — A basic rule for checking your Porsche 944’s timing belt’s tension is the 90° twist test. Try to twist it on the longest side of the belt. The tension is likely good if you can twist it to 90 degrees with minimal force. However, this is just a general guideline, not a professional tension measurement substitute.
Check for Damages — Carefully examine your Porsche 944’s timing belt for any signs of wear and tear. This includes looking for cracks, fraying, side damage, or missing teeth. Any of these issues can be a precursor to belt failure and should be addressed immediately.
Inspect Belt Path and Pulleys — Ensure that the belt is correctly seated on the pulleys and that there is no misalignment. Misalignment can cause uneven wear and premature failure.
Check for Debris — Ensure that the belt and the surrounding area are free from debris. Foreign objects can get caught in the belt, leading to damage or disruption in belt function.
Tensioner and Idler Pulleys — Inspect the tensioner and idler pulleys for smooth operation. Any noise or roughness in movement can indicate wear and the need for replacement.
Pre-Game Steps for Replacing Your Porsche 944 Timing Belt
Before embarking on the journey of replacing your Porsche 944 timing belt, it’s crucial to prepare adequately. Aside from the earlier mentioned preliminary steps for timing belt inspection, these pre-game steps will ensure your safety and efficiency, helping you complete the job smoothly and safely.
Safety First
Create a Safe Work Environment — Ensure you have a clean, well-lit, and flat area to work in. Avoid clutter and ensure all necessary safety equipment, like fire extinguishers, are easily accessible.
Use Safety Gear — Always wear appropriate safety gear, including safety glasses, working gloves, and closed-toe shoes to protect against potential hazards.
Vehicle Stability — Make sure your Porsche 944 is securely parked and stabilized. Use wheel chocks and ensure the car is safely lifted and supported with jack stands if necessary.
Gathering Right Tools
A successful timing belt replacement hinges on having the right tools and parts at your disposal. Here’s a list of what you’ll need:
- Working gloves
- Safety goggles
- Disposable rags
- Masking tape
- Hydraulic jack rated 2-ton
- Jackstand rated 2-ton
- Mechanics creeper
- ⅜” ratchet and socket set
- Combination spanner set
- Allen key set
- Stubby flathead screwdriver
- Bright-colored paint marker
- Feeler gauge
- Torque wrench
- Porsche 944 timing tool
With all the necessary safety measures in place and our tools at the ready, let’s jump into replacing this troublemaker, shall we?
Porsche 944 Timing Belt Replacement
To kickstart our DIY Porsche 944 timing belt replacement, we must raise the Porsche 944 to a comfortable working height. We can use a car ramp or hydraulic jack and jack stand to accomplish this. Lift one side — start with either the left or right side of the Porsche 944 by placing the hydraulic jack under the lifting point on the running board marked with a diamond indent.
Once the side is raised, place the jack stands with rubber or wood block on the front lower control arm joint to the cross member for the front and rectangular reinforced supports placed in front of the rear wheel arch or the extended tubular mount of the torsion bar for the rear. Give the car a bit of a push to ensure that the vehicle is securely raised.
Oh, and if you still have those engine underneath covers, then you need to remove them too by unscrewing the six screws holding it in place. That’s it the fun part begins!
Battery Connection and Air Filter Box
Our first task is to disconnect the battery. To do that, just pop the hood and remove the cowl panel cover if you still have those. You will find the battery on the right side of the cowl area. Just disconnect the battery’s negative terminal using an open-end spanner and prevent it from reconnecting by covering it with disposable rags.
Then, you must remove the air filter box by removing three nuts on the front frame and two or four bolts at the rear frame. Disconnect the airflow meter sensor’s electrical connection and other ventilation pipes connected to the air filter box. The air filter box and airflow meter sensor will be removed as a complete unit.
Radiator Fan Assembly
To remove the radiator fan assembly, you will have to remove six screws mounting the assembly in its place. There will be three at the top and three at the bottom. Once all screw has been loosened up, disconnect the electrical connection, and the radiator assembly will be removed at the bottom of the car.
Starter Motor
Next up, we must remove the starter motor to fit our crankshaft locking tool later during our engine timing procedure. To do that, we have to disconnect the electrical wires connected to it. Unscrew the 8mm and 13mm nuts holding the T50 and T30 wires. Just ensure the battery has been disconnected first to avoid shorting your tools.
Once done, remove the bolts that hold the starter motor to the bell housing. There will be two 19mm bolts that need to be unscrewed on either side. The starter motor will then be pulled out of its mounting.
High-Tension Wires and Distributor Cap
Afterward, we will have to remove the distributor cap and the distributor rotor. Mark the high-tension wires using masking tape and marker to ensure they will be re-installed correctly later. Pull out the high-tension wires and remove the distributor cap by using a stubby flathead screwdriver. Push the locking hooks using the screwdriver and rotate it 90° clockwise to release it from its catch.
Next, remove the distributor rotor on the camshaft gear by using an Allen key to unscrew its mounting bolt.
Auxiliary Drive Belts
Up next is to remove the auxiliary drive belts. These belts drive your power steering pump, alternator, and air conditioning compressor. To remove the drive belt for your power steering pump, you will have to loosen up the 13mm pivot bolts on the front and rear of the steering pump. Once that is loose, you can now loosen its turn buckle tensioner by loosening the 13mm lock nut on both ends and rotating its body to loosen and remove the belt.
As for the drive belt of the alternator and air conditioning compressor, start by loosening the pivot bolts — 17mm at the front and 13mm at the rear of the air conditioning compressor. Once done, loosen the 17mm lock nut on its turn buckle and turn its body until the drive belt for the alternator and air compressor has enough slack and can be removed.
Timing Belt Covers
Afterward, we must remove the upper and lower plastic timing belt and aluminum camshaft gear cover. To start, we have to unscrew the 10mm screws holding the upper and lower plastic timing belt cover. Remove the upper and lower plastic timing belt cover. Then, we must remove the camshaft gear cover by unscrewing three 10mm bolts holding it in place.
Top Dead Center — TDC
Once your Porsche 944’s timing belt covers are removed, we can view the timing marks on the camshaft gear to ensure that the balance shaft and timing belt will be removed with the cylinder number one top dead center (TDC) compression stroke. Grab your paint marker and highlight those timing marks on the camshaft and cylinder head.
Note: To achieve TDC compression stroke on cylinder number one, we have to rotate the crankshaft clockwise to align the timing marks on both the camshaft gear and crankshaft. Always ensure that the transmission is neutral, and it will also help if the spark plugs are removed so that the cylinders won’t build up pressure.
The timing mark on the camshaft gear can be identified with a line marking on the edge of the camshaft gear to be aligned with the notch on the top right section of the cylinder head. As for the crankshaft, you can view its timing mark on the bottom center of the bell housing or at the square opening on the top bell housing located near the crankshaft speed sensor — the “OT” mark should be seen on the square opening.
Once both marks on the crankshaft and camshaft are aligned, you can now proceed to install your flywheel lock so it won’t move. Do this by installing one side first, then rotating the tool until the second bolt can be installed.
Balance Shaft Belt
Now comes the balance shaft belt. To remove this, we must loosen the balance shaft belt tensioner roller (A) near the lower balance shaft gear. Use your thin 24mm open-end spanner to hold the eccentric adjuster nut and loosen the 17mm lock nut, then rotate the eccentric adjuster nut counterclockwise to loosen the belt.
If you will replace your water pump as well, you will have to loosen the balance shaft belt idler roller (B) just above the lower balance shaft. Once the tensioner has been loosened, guide the balance shaft belt out of its routing. Note that if you are going to reuse it, mark its installation rotation.
Timing Belt
Depending on the year of your Porsche 944 model, its timing belt tensioner will vary. From 1983 to 1986, the Porsche 944 used an eccentric adjuster pulley, while the Porsche 944s from 1987 to 1991 used a spring-loaded automatic tensioner.
To loosen and remove the belt on the older version, locate your Porsche 944’s timing belt tensioner roller (C. OLD), then loosen its locking nut while countering it using a thin 24mm open-end spanner. Remove the timing belt idler puller (D) and the guide plate beside the water pump pulley by removing both 13mm nuts.
Disengage your Porsche 944’s timing belt out of the camshaft gear and guide it out of the crankshaft belt drive gear. Remember to mark the rotating direction of the timing belt if you must reuse it.
To remove the timing belt on the newer version, start by loosening the timing belt tensioner roller outer plate (C. NEW), 13mm lock nut, and bolt. Use the pin wrench included on your Porsche 944 timing belt tool set and loosen the tensioner by rotating it counterclockwise and tightening its lock nut and bolt again. Once done, remove your Porsche 944’s timing belt tensioner roller assembly by removing the three nuts at the back of the outer plate.
Remove the timing belt idler pulley (D) and the guide plate beside the water pump pulley by removing both 13mm nuts. Once done, guide the old timing belt out of the camshaft gear and guide it out of the crankshaft belt drive gear. That’s it! Your Porsche 944’s timing belt has been removed. You can now proceed with other repairs, such as water pump replacement, or you can just replace the timing belt.
Setting the Timing On the Timing Belt and Balance Shaft Belt
To ensure smooth engine operation after installation of the balance shaft and timing belts, we must ensure that the timing marks on the camshaft, crankshaft, and both balance shafts are aligned.
Porsche 944 Timing Belt Adjustment
Let’s start by installing your Porsche 944’s timing belt on the crankshaft belt drive gear and then routing it to the camshaft. Ensure that there will be no slack on the long side of the belt. An excellent way to ensure this is to turn the camshaft half a tooth forward and then seat the belt teeth from right to left. Once the belt is installed, reverse the crankshaft again so that the timing marks are aligned again, and there is no slack on the long side of the belt.
Install your Porsche 944’s timing belt idler puller (D), guide plate, and timing belt tensioner roller (C). Then, remove the flywheel lock, rotate the crankshaft 2 rotation clockwise, and ensure that the timing marks are still aligned.
Once the timing marks are confirmed to be aligned, rotate the crankshaft approximately 10° (1.5 teeth) counterclockwise to relieve the tension on your Porsche 944’s timing belt. Then, we can now adjust the timing belt’s tension. To do this, install your Porsche 944 belt tension checker and note its current tension. You can adjust or loosen the tension by turning the adjuster to achieve the specified tension. Always follow the instructions on the tools that you have. Once done, tighten all the bolts as per the specified torque.
Porsche 944 Balance Shaft Belt Adjustment
The balance shaft is incorporated into the engine design with Mitsubishi’s help. It is necessary for the Porsche 944’s engine so that it will run smoother and with less vibration. To ensure that the engine will continue running smoothly, we must ensure that the balance shaft belt is installed correctly.
With a paint marker, mark the timing notches on the upper (approximately 12 o’clock) and lower (approximately 7 o’clock) balance shaft gear and the corresponding marks on the inner plastic belt cover. Always ensure that they are aligned when installing the belt.
Start by installing the balance shaft belt on the crankshaft. Routing it to the upper balance shaft gear, above the balance shaft belt idler roller, then to its tensioner, and lastly to the lower balance shaft gear. Ensure the timing marks align with their corresponding marks before tightening and adjusting the balance shaft belt tensioner roller.
To adjust the balance shaft tension, use a thin 24mm open-end spanner and turn the eccentric adjuster until you achieve the specified tension. We must also take notice of the gap between the lower balance shaft gear and the balance shaft belt idler roller. There should be a 0.5mm gap between them, so use a feeler gauge to measure its gap and adjust it accordingly. Once both the balance shaft belt tensioner roller and idler roller are torqued to specification, we can now remove the flywheel lock and rotate the crankshaft two rotations clockwise, and check that the balance shaft marks are still aligned.
As for the drive belt on the power steering pump and air conditioning compressor/alternator, it also needs to be on the proper tension to prevent unnecessary force that could result in early wear on the drive belt and components. To ensure this, we must ensure that the drive belt for the power steering pump will have a defection of approximately 5mm and approximately 2mm deflection on the air conditioning compressor/alternator.
What happens if timing belt is set wrong?
Having an interference engine on your Porsche 944 can cause your engine to have catastrophic damage if the timing belt is set wrongly. Now, you can get away with it if we are just talking about half a tooth out of timing, and sometimes, it is also done deliberately to improve engine performance. But if the timing is out for a couple of tooths, those valves and pistons will collide and result in the inevitable death of your engine.
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