The Peugeot Expert, especially with the 1.6 HDi engine, regularly suffers from serious starting problems that often stem from incorrect valve adjustment, loss of compression and cylinder head issues. With incorrectly closing valves in the cylinder head, also called cylinder head valving, the valves do not open or close at the right time or not fully. These faults lead to costly engine overhauls and long periods off the road. Find out why your engine will not start and what you can do about it.
Why won’t my Peugeot Expert start any more
Starting problems with the Peugeot Expert are often related to loss of compression in one or more cylinders. In diesel engines, sufficient compression is necessary for ignition, because the fuel is ignited by the heat generated when air is strongly compressed, rather than by a spark plug. If valves do not close properly or the valve timing is not exactly correct, the engine does not build up enough compression. As a result, the engine will turn over, but no combustion takes place.
This problem occurs especially often after work on the head gasket, cylinder head or timing. Real-world experience shows that after this kind of repair, owners regularly end up with an engine that keeps cranking for a long time without firing up. The cause usually lies in one or two cylinders where the valves do not close on time or fully. Measuring compression and checking the position of the camshaft in relation to the crankshaft are then the logical first diagnostic steps.
In addition to valve adjustment and compression issues, defective glow plugs can also cause starting problems. Remarkably, a glow plug can still test electrically “good”, but under load still not perform sufficiently. It also happens that fuel supply is not optimal because of clogged injectors or air in the system. For more information on common problems with this model, see the page about the Peugeot Expert.
What cylinder head valving means in practice
In practice, cylinder head valving means that the valves in the cylinder head do not open or close correctly. This can be caused by too little or too much clearance between the valve and camshaft or rocker arm (the valve clearance), incorrect timing, sticking valves or assembly errors after overhaul work. In a diesel engine such as the 1.6 HDi, this has a direct effect on compression and therefore on the starting ability of the engine.
When valves do not operate properly, a range of problems can arise:
- Poor compression in one or more cylinders
- Difficult starting, especially with a cold engine
- Rough or unstable idling
- Loss of power while driving
- Engine that turns over but does not fire up
Owners report that these symptoms often only appear after maintenance or repair to the cylinder head. It then turns out afterwards that the valves were not adjusted according to the correct specifications or that the camshaft position no longer corresponds exactly to the factory setting. Even a small difference in timing can lead to severe starting problems.
Known engine problems with the 1.6 HDi
The 1.6 HDi engine in the Peugeot Expert is known for several engine problems compared with the 2.0 HDi version. In addition to starting problems caused by valve adjustment and loss of compression, head gasket leaks, defective injectors and turbo problems are also common. This engine is often used in vans that do many cold starts and short trips, which increases its vulnerability.
Common causes of starting problems are:
- Valves that are not correctly adjusted or do not close fully
- Camshaft or valve timing that is incorrect after work has been carried out
- Loss of compression due to a leaking head gasket or warped cylinder head
- Injectors or fuel supply that do not provide good combustion
- Glow plugs that perform insufficiently under load
Owners also report that after a head gasket problem the cylinder head can be slightly warped, causing the cylinder head and block not to seal well enough against each other and allowing compression to escape. In that case, simply replacing the head gasket will not help; the head then needs to be skimmed or replaced to restore full sealing.
Useful checks for starting problems
With a Peugeot Expert that will not start, a logical order of checks is necessary to find the cause. Start with the most basic points before you intervene more deeply in the engine. Many problems turn out afterwards to be simple to solve if you work through things systematically.
Follow this sequence of checks:
- Check the battery voltage and starting current, especially with diesel engines that need a lot of power to start
- Measure the compression per cylinder if the engine turns over but does not start
- Check valve timing and camshaft position after work on the head or timing belt/chain
- Adjust the valves in the correct sequence if the engine design allows this
- Check glow plugs and fuel supply in case of cold starting problems
Measuring compression is an objective way to distinguish problems with internal engine components, such as valves, pistons or head gasket, from fuel or ignition issues. In a healthy diesel engine, compression per cylinder should be around 25 to 30 bar. If there is a difference of more than 10 per cent between cylinders, this points to a mechanical problem such as leaking valves, a defective head gasket or worn piston rings.
What you may notice as a driver
Problems with valves or the cylinder head manifest themselves in various ways in everyday use. Often the symptoms start subtly and gradually get worse. Pay close attention to unusual engine behaviour, especially after servicing or repairs.
Common signs are:
- Prolonged cranking without the engine firing
- Unstable idle or occasionally stalling
- White or incomplete smoke when starting the diesel
- Lack of pulling power during acceleration
- Tapping or unusual engine noise
- Engine that only starts after several attempts or only in cold conditions
For vans such as the Peugeot Expert, even a small adjustment error is particularly annoying, because the engine often does many cold starts and short journeys. As a result, starting problems become apparent more quickly and issues with valves, glow system and compression are more likely to be noticed than with a car that mainly does long trips. If you are unsure about the condition of your engine, have a compression test and valve check carried out in good time.
How expensive is an engine overhaul
An engine overhaul for the Peugeot Expert is an expensive affair. Depending on the severity of the damage and the chosen solution, costs vary considerably. In the case of light damage, replacing the head gasket and adjusting the valves may be sufficient, which can cost between €1,500 and €2,500. If the cylinder head is damaged or warped, it has to be skimmed or replaced, which pushes the costs up further.
With serious engine damage due to prolonged starting problems or insufficient compression, a full engine overhaul may be necessary. This means that the engine is removed from the vehicle and major components such as pistons, con rods, bearings and valves are replaced or reconditioned. The costs for this range between €3,500 and €6,000, depending on the engine type and the labour hours of the workshop.
In some cases, replacing the engine with a reconditioned or used unit is more economical than an overhaul. A reconditioned 1.6 HDi engine, including installation, costs between €4,000 and €5,500. A used engine with warranty can be cheaper, but offers less certainty about its condition and remaining life. Always compare several options before making a decision.
Practical tips for car enthusiasts
Prevent costly repairs by being alert to signs of valve or compression problems. Pay extra attention after repairs to the head gasket, cylinder head or timing system, because this is exactly when assembly or adjustment errors can occur. Check whether the cylinder head and block are flat enough, because even a slightly warped head after a failed head gasket can cause ongoing sealing problems.
Do not rely blindly on just a resistance test of glow plugs. Under real-world load a plug may still perform poorly, causing the engine not to start properly. Use compression tests as an objective diagnosis to distinguish between fuel, ignition and internal engine problems, such as issues with valves, pistons or head gasket. Adjust valves carefully according to the engine configuration, because a correct sequence and cam position are essential for good compression and timing.
Ensure regular maintenance of the fuel and glow systems, especially with vans that do many short trips. Dirty injectors or weak glow plugs worsen starting problems in an engine that is already struggling with loss of compression. If in doubt, always have a professional diagnosis carried out before you start working on the engine yourself.
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Frequently asked questions
Primary indicators are noticeable loss of compression (for example, the engine turns over easily but does not fire up, or clear differences between cylinders during a compression test) and prolonged or repeated cranking without firing, especially after recent work on the head or head gasket. Rough idle, loss of power or an engine that only fires after a lot of throttle also point to valves that are not closing properly or are incorrectly adjusted. An unusual tapping valve noise or an engine that suddenly starts badly after work on the timing or head further increases the likelihood that cylinder head valving is the main cause.
Regular maintenance on performance-oriented engines ensures that valve clearance, camshaft timing and the condition of the cylinder head are checked and corrected in good time, so that the valves close properly and compression remains at the correct level. This prevents the engine from starting poorly or not at all due to loss of compression or incorrectly adjusted valves. In addition, maintenance includes testing auxiliary components such as glow plugs and the fuel system, which means emerging issues are detected before they lead to real starting problems. Thanks to this combination of mechanical and system checks, cylinder head valving issues and related starting problems are largely avoided in practice.
A car enthusiast can watch out for symptoms of poor compression, such as long cranking times, rough or unstable idle and clear loss of power while driving. Also check oil and coolant levels and look under the caps for contamination or a “mayonnaise”-like deposit, which may indicate head gasket or head problems. When the engine is running, listen for unusual ticking or valve noises that point to incorrect valve clearance or valves that are not closing properly. Note down all observations (cranking time, smoke, noises) so that the mechanic can more accurately check for cylinder head valving and valve timing issues.
Yes, specific engine tuning and intensive track use can increase the risk of cylinder head valving. Higher revs, more power and greater thermal loads place additional stress on valves, valve seats and cylinder head, which means valves are more likely not to close properly. This can lead to loss of compression and thus to unexpected engine starting problems. Regular checks of valve clearance, timing and the cooling system are then even more important.
Persistently ignoring early signs of cylinder head valving often leads to increasing loss of compression, an engine that starts poorly or not at all and noticeable loss of power. The engine will run more and more unevenly, fuel consumption and emissions increase and the risk of overheating or damage to valves, pistons and head gasket grows. In the long run, reliability is greatly reduced, with more frequent breakdowns, higher maintenance costs and possibly the need for a complete head overhaul or engine replacement. As a result, both everyday usability and the overall performance of the engine are significantly reduced.
