Peugeot 406 with mileage: expensive overhaul of the box and engines no worse than Mercedes

Running gear

Braking system

PSA have saved money on brakes – probably they made a calculation for calm drivers. Anyway, the most part of cars with engines 1,6-1,8 up to 115 hp (both petrol and diesel) have drum brakes behind and discs of very small diameter in front. German competitors in D-class in those years did not have drums, and disks are steadily larger.

The good news: the technical solutions of the braking system are conservative and reliable. It is expected that the service life of front brakes on cars with motors up to 1,8 is less, than on cars with 2,0-2,2, but pads usually go 30-50 thousand even on cars with automatic transmission.

The handbrake on the copies with drums in the back is reliable, and if there are disks in the back, a bit capricious mechanism may be absent or be worn to the limit. The handbrake is made in the form of separate small drums – the non-specialized service centers are not familiar with this construction, and the stuffing inside the drum corrodes much. But there are no special complexities with overhaul, it is not “screw” rear calipers Lucas with eternally overgrown mechanism.

The great bulk of problems with brakes are breakages of ABS. The wiring harness on the control unit, wiring to sensors, sensors themselves, sometimes the block itself and sensors combs on the front wheels. And the wiring suffers in many respects because of the design: wires are not fixed as it should be and therefore are worn out in the most problem place, on a rack of suspension and directly on an output from the sensor. And the front wiring harness short-circuits because of vibrations and moisture, which gets into engine compartment from under left arch duster.  The ABS comb on the CVA just rots, but they are commercially available separately, you don’t have to replace the entire CVA.

The suspension is one of the strong points of the model. Unusually strong shock absorbers, good smooth running and at the same time steerability with a pleasant zest in the form of exact trajectory control in the turn with traction. It’s amazing, but even with the killed suspension on the Chinese components the car keeps quite good drivability and comfort.


The front suspension is more reliable than the rear. The struts could be considered eternal, if it were not for the weak support bearings. And the problem is constructive: a ring bearing (according to SS20 principle) gets moisture and dirt, and then its working surfaces corrode. All cars with such design have similar problems, on Opel Vectra C, for example. Lever and silentblocks are very hardy, can go for 100, and sometimes for 200 thousand miles. Stabilizer bars and bushings are an expendable item, but it’s not expensive.

Peugeot 406 with mileage: expensive overhaul of the box and engines no worse than Mercedes

The rear suspension is multilever and noticeably more expensive to maintain. And it doesn’t like dirt and overloading. All the silent blocks are replaceable, they are inexpensive and there are few of them, as on the Volvo you don’t have to suffer. Sometimes the longitudinal arm bushing gets stuck in the aluminum bracket, and then you can’t change it in the garage. Also the big support arm, the lower transverse arm, corrodes. Otherwise, everything else is done “for the people”. Big repairs, as a rule, are started by the figure “over 200” on the odometer, but the silents of the longitudinal arm and external silents of transverse can ask for replacement even at mileages three times less. Overloading, spring breakage (it happens) and dirt are strongly affecting the service life.

Rear hub bearings are not very reliable and they corrode inside.  It is recommended to listen to their work during test-drive, and if possible – to rotate disengaged wheel.


Steering with usual steering unit has several interesting nuances. First, the steering rack with external booster cylinder could be used in pre-2002 models.  It is attached to the rod and body via silent blocks, which can be worn out.  Such design can be repaired well, but the service life is less, because the reducer is more momentarily loaded and depends on the condition of the silent blocks. Besides, the force is uneven due to the play in the drive. However, the usual rears were installed also, even on the cars prior to restyling, it is just a matter of luck. But the rack with external cylinder, if you buy it in the version for 405 (they are interchangeable), can be much cheaper.

One more nuance is connected with a steering tube. The propshafts in it are not just backlashing, but sometimes even jammed, as a result the “old” rack strongly breaks the upper oil seal, and it quickly begins to leak. Check condition of cardan joints at any jamming. The rack is deeply hidden in a subframe, and it is impossible to get to it without removing it.

The steering pumps are used with variable capacity. However, unlike full-fledged servo from ZF, here is quite primitive scheme, when CPS pump capacity drops at high rpm (without taking into account speed!). Which causes a bunch of funny problems at once, when the pump runs at some rpm when the system wears out, and then there’s no pressure again. Usually the problem becomes acute by about 200 thousand miles

Peugeot 406 with mileage: expensive overhaul of the box and engines no worse than Mercedes

It is not too difficult and not too expensive to change the pump for normal, you can adapt ZF from Shniva (it seems that these pumps are sold many times more than made by the Shniva). Pressure at native pump – 100, which is higher than shnivskogo (87), but considering that the normal pump will not fall productivity when driving on the highway at high speeds, it is even useful.


General problems

Since the cars are front-wheel drive only, the list of possible problems on the transmission side is limited to wear of the CVT and outboard bearing. All these elements are very reliable, even on cars before restyling you can find the original parts. It is traditionally recommended to inspect joint covers at every service – they are not durable.

Manual Transmissions

Two series of boxes are used on the Peugeot 406, the five-speed BLM ML5T/ML5C and the six-speed ML6C, and the slightly weaker five-speed BE3R/BE4R series. The first are usually found in versions with gasoline engines 2.2-2.9 liters and powerful versions of diesel engines 2.0 / 2.2 liters, and the boxes of the second series can be found with both smaller gasoline engines and diesels up to 2.1 liters. The boxes of ML5T/ML6C series keep torque up to 350 Nm, and possibilities of the BE series are more modest – up to 300 Nm depending on the type of box.

The problems are similar in both families. First of all it is the wear of shifting mechanisms, sticking of cables, leaks. With runtimes more than 250 thousand more wear of bearings of a primary shaft and synchromesh clutches is added, and lovers of bumping may have problems with the differential – axles of satellites get stuck.

Cables and leaks in general are treated simply: new grease, new glands of axles, cleaning of breather, in extreme cases replacement of cables, only at first it is necessary to look, under what diameter couplings are cables, confusion is possible. Wear of rocker arm is not a problem either, there are bushings on sale. With wear of synchronizers usually just be reconciled: the box continues to work, though with difficulties or even crunch at fast shifts.

Peugeot 406 with mileage: expensive overhaul of the box and engines no worse than Mercedes

Serious problems are the wear and tear of the shift mechanism and the bearings of the boxes primary shaft. The play of the mechanism axle during operation on dusty roads can reach several millimeters, and the repair, to put it mildly, is difficult. It requires axle rebuilding, welding and machine work with rethreading and making new axles. Well, and replacement of bearings is usually a complete overhaul of the gearbox, replacement and making new distance washers, and for the ML5/ML6 series – also replacement of the pinion roller bearings. Here, by the way, inexpensive domestic SKs 202616 are suitable instead of the original two-levels.

In general, it is often cheaper to buy a contract gearbox than to repair your own, good thing these series MCP put for many years on the cars PSA and find it in working order is not so difficult. The price will make 15-20 thousand rubles, but there may be a surprise for the owner: some cars have boxes with non-standard gear ratios, and their bell jar is also different. By experience, the differences have the versions for diesel 2.1 and petrol 2.9, but the “non-standard” boxes are also found on other versions. However, in any case the problem can be solved by some kohozing.

Automatic transmissions

Automatic transmissions are of two types: either well-known AL4, aka DP0/DP8 on Renault cars, or ZF 4HP20 on trucks with a 2.9 engine or diesel 2.2.  The number of “automatic” cars is extremely small, which is not surprising. AL4 was just introduced on the 406, so it got the very first and most problematic series, and only put them with 2.0 engines before the restyling, and after that, even with 1.8 engines. ZF was used for top versions, which are few in principle. So the AL4s didn’t usually survive, they were replaced by manual transmission (they used to be expensive to repair), and the ZFs were originally few and far between. You can read more about these automatic transmissions in the material on the Citroen C5 I or Renault Megane II.

Peugeot 406 with mileage: expensive overhaul of the box and engines no worse than Mercedes


General problems

Peugeot 406 was created in the times when they believed that the car should be reliable. We cannot say that the French have got the most trouble-free car, but it is evident that everything is thoroughly done and the engineers tried their best to solve any problems simply. Well, except that the electric system was clearly made by Cossacks sent from the end of the 2000’s (details about it – in the first part of the review, but the fashion for quick disconnecting nozzles has struck the crankcase ventilation system of the majority of engines after the restyling.

The petrol engines of the XU line are the strongest family of the French, and the others are not pumped up. The only serious flaw is the quality of the electric fans and their control system. Often there are problems with the service life of electric motors, wiring to them and resistors of reduced speed. The coil burns out, the restoring fuse does not recover, or the deflector gets clogged with snow.

In a cold and damp climate, one more nuance of the layout becomes apparent: the air inlet of the majority of motors is very low, and it is easy to get a hydro strike when forcing water obstacles. However, now the air intake pipe is worn out and half torn off in most cars, so the engine sucks air from hot engine compartment. It will not give its full power in such a case, but one should not be afraid of hydroblow.

Well, don’t forget that under a hood wiring is unreliable, shorts in harnesses and simply rotten wires are a rule, rather than an exception. Damaged pads with broken plastic and oxidized contacts are also usual thing. Everything is complicated with underdeveloped dust caps.

In general, the car is obviously designed for dry and simply dusty roads, but not for constant mud. At purchase, an inspection of wiring in the engine compartment will allow avoiding a lot of troubles in the future. At least, directly run power wires should embarrass you. It’s also worth checking what kind of gas pump it is, or better to look at the bulb. Broken pipes, incorrectly assembled flask are sure signs of “kolhoza”. The gas pump itself is weak, when replacing a regular Bosch from VAZ with minimal alterations, but often it is assembled very poorly.

Gasoline engines

Prior to restyling, the main series of engines on the Peugeot 406 are XU5, XU7, XU10 in their later versions. These are very, very reliable motors, not only due to their simplicity, but also due to the hardness of the design. Their block is aluminum, and the liners are wet cast iron and replaceable. Timing belt drive, on the 406 mainly put 16-valve versions, but the motor XU10 is in the supercharged version and 8-valve cylinder head. The design is quite sensitive to build quality, but it has 500+ service life, thanks to the thick liner, lucky pistons, good power system, good oil pump and well tuned design.

The downsides are mainly due to oil leaks, a weak crankcase ventilation system, and a not-so-good mechanical throttle. It gets depressurized, and also has a weak position sensor and flow meter. Also in the Sagem 7 control unit, the idle control channel dies very often.

Peugeot 406 with mileage: expensive overhaul of the box and engines no worse than Mercedes

Pistons are very difficult to ruin. The engine starts to eat oil if you change the oil and air filter very seldom, overheat, run the engine into the cutoff and in general purposefully destroy the car. If it is serviced regularly and qualitatively, the motors of XU series amaze with their service life. A million kilometers without overhaul is quite a real bar.

We should separately note, that the cruise control here is realized by a separate block, which usually dies because of moisture in the engine compartment, and catalysts often crumble during 300+ miles. And in general the Peugeot exhaust is not very reliable, after 10 years it starts falling apart at the flanges, but repairs are not too expensive.

I have already considered motors of newer EW series in the reviews of Peugeot 407 and Citroen C5, you can read details by the links. In short, these are also reliable and strong motors, with an aluminum block and dry cast-iron liners. Service life is, of course, less than that of the XU, due to the lighter piston and thinner piston rings, the presence of EGR and the secondary air system. There is a chance to overhaul the engine at 500,000, but it is not very good, because the engine is much more sensitive to overheating and increased oil change interval. The oil appetite has progressed for most of the cars, the style of operation and maintenance of which is far from being perfect, even after 250K mileage.

Peugeot 406 with mileage: expensive overhaul of the box and engines no worse than Mercedes

Repair is complicated by the fact that normally there are no repair sizes of pistons, though the truth is clever: for the most popular motor EW7 1,8-liter pistons from Focus of the 2nd generation are suitable.

Fortunately, in most cases there is no need in replacement of pistons – the problem is solved by replacement of piston rings only, thanks to wear of liner and piston itself is minimal, and oil escapes because of coking. In the most successful cases it is possible to do without disassembly, with only chemical decontamination.

The crankcase ventilation system is a real headache. It is different not only in EW7 and EW12, but also in engines of the same type, but of different years. Its components such as plastic corrugated hoses and oil separator will be different and incompatible. And they require regular replacement: oil separator spouts break, hoses crack, and loose quick couplings cause leaks. All this costs a lot, so it is not surprising that crankcase ventilation for 406 is not a rarity.

Many good things can be said about ES9 series V6 engines with displacement of 2,9 liters, which the French like to designate as 3,0. It is more capricious and troublesome in maintenance (in comparison with in-line 4) engine, but with good service life. The problem is the layout, leaks, and unusual engineering. I’ve already addressed its problems in a piece about the Peugeot 407 and Citroen C5, and it’s vanishingly rare on the 406.

In addition to what has been said in other materials about this engine, I note that the timing gear in the cars before the restyling has no phasor regulators and is a bit cheaper than the postrestyling ones. You have to watch out for belt oiling – the front crankshaft oil seal turned out to be weak and leaks a lot if there are problems with ventilation.

Uneven idle is showing up due to air flow meter and blowoffs. Vibrations and ignition problems are due to triple coils and plugs on the pre-rest and individual coils on the restyling. Less commonly, the throttle and vacuum actuated cruise control. We can also mention the weird and expensive injectors, the pump on the restyling and the finicky thermostat. Also the split timing gears on the pre-restyling engines.

Diesel engines

In Russia, 406 diesel engines are unpopular, which is not the case in Belarus. The XUD series diesel engines before the restyling and DW after are some of the most successful passenger car diesels. Of course, they are far behind the much later N47/B47 from BMW in traction and consumption, but for their time they were successful solutions.

The XUD9SD/XUD9TE and XUD11BTE engines are a family of forked-chamber diesel engines, known since the 80’s, it was introduced on the predecessor of the 406, the Peugeot 405 with a mechanical HPF and vacuum advance injection. The 406 has the Bosch VE hydraulic/electric injection advance control injector, which is strong enough and inexpensive in service. The new one, of course, costs 140 thousand rubles, but it is quite reliable and maintainable, and the electronics, unlike VP44, does not contain, and all consumables are on sale.

The main problem with this engine, besides age and mileage is cylinder-head corrosion, loosening of the fork tubes, cylinder-head gasket and cracks in the cooling jacket. Valve clearance adjustments are relatively frequent and troublesome. It has a very strong piston group, the simplest fuel equipment, the simplest turbine, and therefore a very good service life. And the supercharged variants of diesels serve longer than the non-supercharged SD, because it is necessary to twist them much less. For comparison, the turbocharged 1.9 has a peak torque of 200 Nm, the 2.1 has 250 Nm, and the naturally aspirated 1.9 has only 120 Nm.

Peugeot 406 with mileage: expensive overhaul of the box and engines no worse than Mercedes

Among the specific problems of the 406 is the frequent breakdown of the fuel filter. The design is bad, and heated versions are also very expensive, and the engine cooling system is very picky, since the cylinder head is high, a drop in the antifreeze level at the first prolonged load manifests itself with a gasket breakdown.

The DW engines are much more reliable than its predecessors and have less problems. There are hydro-compensators in the valve train, but the main thing is Common Rail system with direct injection, which means a much finer control of the flow and very high efficiency under any load. And that means not only quick response on the gas pedal, but also availability of highly boosted variants.

The 90-110 hp versions of DW10 have a fantastic service life, the Bosch fuel system is very reliable, and if the engine is not overheated and oil and filters are changed in time, the chances of breakdowns are minimal. Even if the timing belt will be torn, the valves will not be bent. There is still a lot of troubles with belt breakage, first of all because it breaks rockers and overdrives the camshaft. Due to the 8-valve cylinder head the injectors are installed very well, copper washers don’t burn out at least 50-80 thousand kilometers, HPF is solid, EGR is vacuum and reliable enough.  It’s a pity, there are not so many for the 406, and the ones that are available are already at 350+ miles.

Should to buy or not to buy?

If you have not much tired 406 with still a decent body and without obvious signs of “kolhoz”, then with some provisos you can buy it. The choice of modification is a difficult question. A “million” resource of old motors is tempting, but if to estimate the situation soberly, it is obvious that in 20-25 years old the car will not be able to drive so many kilometers. Even if everything is excellent with the engine, everything else will fail by age. Therefore, it is necessary to estimate each instance separately, and it is quite probable, that on the totality of factors it will be easier to buy even more difficult, but a newer and less mileage copy.

Peugeot 406 with mileage: expensive overhaul of the box and engines no worse than Mercedes

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