Belt-Driven System/Accessory System

70,000 - 100,000 Miles

Inclusive of nearly everything you'd typically see on the front of your engine, your accessory system turns the kinetic energy of the engine's rotation into power for multiple other vital ancillaries. This typically includes coolant flow and circulation, electrical charging, and pressure for hydraulic systems.

Cooling System

Starting with the cooling system, the water pump will often be accessory built-driven (on some older models and also some unique cases, the water pump can be timing belt-driven or even timing chain-driven) and uses the engine's rotation to circulate coolant through the entire engine. This coolant's circulation is regulated by the thermostat, which can be fully mechanical, partially electronic, or on more modern cars, fully electronic, and coolant is transported between the pump, the radiator, and the expansion tank through coolant hoses or pipes.

The aging of cooling system components varies greatly by engine and make, with electronic water pumps on BMW N-series engines going as early as sub-100,000 miles and mechanical units on something like a Mercedes M113 as late as nearly 200,000 miles. The same is the case with hoses and plastic components - a rubber hose should remain soft and pliable, and plastic tanks becoming brittle are at risk of cracking under pressure. Any of the above have the potential to strand you, cause damage, or both - keep an eye on your components and inspect for any visual leaks or odors, signs of abnormal wear, or odd operating conditions.

Radiator

Arguably the most important part of the cooling system, the radiator is designed to pull heat from circulating coolant. Most radiators fail when the end tanks cracks or separates with old age inducing leaks, but higher-mileage radiators may also have missing or bent fins that affect function. These are often clogged with debris and cause overheating issues as the radiator cannot flow cool air through the fins effectively. If your radiator is in rough shape, we recommend replacing it - potentially even if it isn't leaking yet, as it can still affect vehicle reliability. We also highly recommend inspecting/replacing the upper and lower radiator hoses at that time, as it'll be easiest to replace those parts "while you're in there" and the coolant is drained from the circuit.

Periodically inspecting for leaks, cracks, or clogging is important for the longevity of your cooling system, minimizing the risk of overheating and possibly damaging crucial internal parts.

When replacing parts, be it a radiator, the thermostat, or a full cooling kit, bleeding the system will remove any air pockets that can impede the flow of coolant and induce excess pressure or heat - making it a vital part of your service process, any time the cooling system is opened and drained.

The cooling system bleed procedure will vary by vehicle, with some cars using a bleed screw on the coolant reservoir, some packing an electronic bleed procedure operated by a handheld scanner, and some having no bleed procedure other than simply running the vehicle - it's vital to research the best-practice for your car and engine's outlined procedure. Follow this manufacturer-specified procedure, top up the reservoir if low, and drive off into the sunset.

Popular Brands at FCP Euro:

• Nissens
• Mahle Behr
• Valeo
• CSF
• Do88

Water Pump

The water pump circulates coolant (a mix of antifreeze and water) from the radiator, through the engine, and back to the radiator to prevent the engine from overheating. The pump is typically run by the drive belt, chain, or gear. Maintaining a consistent flow of coolant through the engine block, cylinder heads, and radiator to regulate the engine’s temperature prevents overheating or freezing in extreme conditions. Never open the radiator/overflow cap if the car is hot; the coolant is still hot and under pressure, and if opened, it can eject dangerously-hot coolant and cause injury.

Symptoms of Elongated Service Intervals:

• Overheating engine: An ailing or failed water pump may cease to circulate coolant efficiently or entirely, causing a rapid spike in engine temperature. Cease driving as soon as possible, until the water pump can be replaced.

• Coolant leak through weep hole: A failing water pump will initially weep coolant, producing a sweet smell that can be hard to locate the source of. If you smell coolant and the leak isn't immediately apparent, locate the water pump's weep hole and check for liquid or residue.
  
• Bearing noise: A failing water pump bearing may rattle, wobble, or cause the pulley to shake, which is a clear indicator that the pump needs to be replaced.
  

Popular Brands at FCP Euro:

• Pierburg
• Graf
• Continental/VDO
• HEPU
  

Thermostat

Thermostats simply regulate the coolant flow through the engine. When coolant is cold, they stay closed to stop the coolant's flow and help the engine warm up faster. Once up to operating temperature, they'll regulate by opening and closing the coolant flow between the radiator and the engine to maintain proper engine temperature. 

If you find your car overheating or not meeting operating temperature, there is a chance your thermostat is either stuck or failing. 

Also worth noting is the shelf life of your coolant. Not only does it protect from freezing and overheating simultaneously, but it is also designed in accordance with the metals and materials used in your engine's construction - meaning its vital to use the correct coolant specified for your vehicle, and that deferred coolant maintenance can cause wear in your engine's internals. A good practice is to drain and replace the coolant in your car with your thermostat or water pump replacement (whichever comes first), as your coolant will likely be on a similar service interval.

Need a hand finding the right coolant for your European car? Let our experts help you out.

Symptoms of Elongated Service Intervals:

• Engine not reaching optimal running temperature

• Radiator fan not engaging

• Low coolant light on instrument cluster indicating a cooling system leak

• Thermostat stuck open (most common): Coolant will flow through the engine constantly from cold, preventing the engine from reaching operating temperature. Usually this means a rich mixture resulting in poor fuel mileage and potential catalytic converter damage.

Popular Brands at FCP Euro:

• Wahler
• Rein
• Mahle
• Borg Warner

Timing/Internal Components

75,000 - 200,000 Miles

Barring a couple of exceptions, engine timing will almost always be managed by either a timing belt or a timing chain. This is the physical system that links the "bottom end" rotation of the crankshaft to the "top end" rotation of the camshafts and valve timing.

Timing Chain

The timing chain serves the same purpose as the timing belt, opening and closing intake exhaust valves in accordance with crankshaft and piston position to ensure efficiency and that no contact is made. However, a chain-timed engine utilizes a metal chain instead of a rubber belt to synchronize the rotation of the crankshaft and camshafts. It ensures that the engine's valves open and close at the proper times during each cylinder's intake and exhaust strokes, maintaining optimal engine performance.

A common misnomer is that timing chains are designed to last for the life of the engine - while this is true in some instances, the introduction of chain-driven fuel pumps and vacuum pumps as well as highly-strung small displacement modern engines means that even chain-drive systems can wear out, become damaged, and stretch over time. Damaged or stretched chains can impact the timing of an engine and overwork the tensioner; failures in this system can cause catastrophic engine failure and costly repairs.

Symptoms of Elongated Service Intervals:

• Engine Code: P0016 Cam/Crank Correlation Code 

• Noise: A common symptom of a failing timing chain is a rattling or slapping noise coming from the engine, especially during startup or acceleration. This noise may be more pronounced at idle or startup

• Poor Engine Performance:  If the timing chain is stretched, it can lead to decreased power, acceleration problems, or sluggish performance.

Popular Brands at FCP Euro:

• Febi
• Schaeffler/INA
• Iwis
• Genuine

Chain Guides/Tensioner

The camshaft timing chain tensioner keeps tension on the timing chain guide to prevent the camshaft timing chain from coming out of timing. It preloads the timing chain, preventing slack in the system, as too much chain slack will result in derailment of the timing chain and engine failure. Engine timing chain tensioners are typically oil-fed, so verifying you have adequate oil volume and pressure is vital when troubleshooting the timing chain tensioner. 

The engine timing chain guide's primary role is to work alongside the timing chain tensioner and maintain the timing chain's proper alignment. The guide ensures that the timing chain follows the correct path around the crankshaft and camshaft sprockets to prevent misalignment and help minimize excessive movement or vibration of the timing chain. Proper tension is critical to prevent chain slack, which can affect engine performance or lead to damage.

Symptoms of Elongated Service Intervals:

• Rattling or Clanking Noise: One of the most common symptoms of a failing timing chain tensioner is a noticeable rattling, clanking, or ticking noise, especially on startup. This is because the tensioner may no longer be maintaining proper tension on the chain, causing it to become loose and hit surrounding components.

• Check Engine, Misfires: A worn or damaged timing chain guide can cause the timing chain to slip, leading to improper timing between the crankshaft and camshaft(s). This can result in engine misfires, where the fuel-air mixture in the cylinders is not ignited at the correct time.

Popular Brands at FCP Euro:

• IWIS
• Febi
• INA
• OE Supplier
• Genuine

Timing Belt / Tensioner

The timing belt serves the exact same purpose as the timing chain assembly, albeit in a slightly more traditional blueprint with a rubber belt instead of a metal chain. While some will argue that this setup is archaic compared to its chain-drive counterpart as a modern standard, timing belts are still regularly used (such as in the current VW Atlas V6) and typically offer an easier service than their engine-oil-lubricated, chain-drive alternative.

Serving the same role of timing valve movements in the cylinder head with the rotation of each individual piston, the timing belt is a component you're better off servicing preemptively. On "interference" engines, a timing belt snapping is generally a catastrophic failure - "interference" referencing the fact that pistons will meet the valves when the engine falls out of time, likely causing irreparable damage. "Non-interference" engines may survive a timing belt snapping without any serious damage, but they'll still leave you stranded on the side of the road.

Unlike a chain that may stretch or cause timing codes due to a slackening of tolerances, belts typically show signs of age cosmetically. Cracking, separating, or dry rotting are telltale signs that a timing belt is on its final rotations and warrants immediate replacement. A timing belt typically won't use guides to reduce slack, but will instead use idler and tensioner pullies to keep the belt taught.

Inspecting your timing belt is generally pretty easy, and is done by removing the timing cover while the vehicle isn't running. Typical safe practice is to do a timing belt every 70,000-90,000 miles, or along with your water pump replacement as many engines will use the two systems in close proximity. When servicing your timing belt, you'll also want to service your idler and tensioner pulleys to ensure tolerances are correct.

Symptoms of Elongated Service Intervals:

• Noise: Although it is harder to detect than chain timing issues, a worn timing belt may make excessive noise prior to failure due to the belt stiffening or beginning to fray.

• Poor Cosmetic Apperance:  An old timing belt may show signs of cracking, dryrot, or delamination.

Popular Brands at FCP Euro:

• Continental/Contitech Belts
• Gates
• Genuine

Mounting/Breathing/Sealing

80,000 - 150,000 Miles

As parts more or less tasked with holding the engine in-place or even together, these are no less important than some of these internal components we've discussed above - yet, they're perhaps the most-commonly neglected.

Gaskets

While gaskets come in all shapes, sizes, and materials, their importance is unchanged. Ultimately, gaskets fill the space between two surfaces to prevent leaks and relieve pressure. Whether for your oil filter or valve cover, their purpose is the same. Gaskets can be made from metal, rubber, Teflon, cork, liquid adhesive, or any mix of the above - but due to these materials, they can dry, crack, and warp to create small leaks or catastrophic repairs. Gaskets with major importance to inspect include your head gasket, valve cover gasket, and oil pan gasket.

Is your head gasket leaking coolant or pressure into the cooling system? Coolant mingling with engine oil reduces lubricity and can cause adverse wear on your rod bearings and other lubricated components, so it's worth tackling ASAP.

Alternatively, a valve cover gasket is typically a smelly and ugly annoyance best handled as soon as possible, but isn't necessarily a pressing danger to your drivetrain.

As all gaskets serve different processes, the failure window of a gasket won't necessarily be a fixed mileage window. Your best option for staying on top of gaskets is simply to be observant while driving. Check oil level and coolant level regularly, monitor for any odors with your nose while driving/idling, and inspect your engine for any visible leaks when you're under the hood. Simply being watchful will typically give you a good deal of warning ahead of a gasket's complete demise. For rubber gaskets like a valve cover gasket, replacement will typically be worthwhile in the 60,000-100,000 mile window barring some leaky exceptions.

Symptoms of Elongated Service Intervals:

• Overheating engine

• White smoke from exhaust

• White/milky engine oil

• Obvious Oil leaks: This can appear in several different ways, the most common of which is oil seepage or obvious leaks running down the cylinder head from the valve cover.

• Mysterious Oil Leaks: It is possible to have a “mystery” oil leak where oil residue and moisture gather in an unusual or unlikely spot. If you see this and have no other obvious causes, a quick degrease and careful monitoring could point you in the direction of a bad valve cover gasket.

Popular Brands at FCP Euro:

• Elring
• Victor Reinz
• Corteco
• Genuine

Engine Mounts

Engine mounts are designed to keep your engine and transmission supported and fixed to your vehicle’s frame or subframe. Common materials in various engine mounts include rubber, urethane, and metal, and mounts can be prone to deterioration, separation, and rust. Over time, this can result in extra engine noise, engine rocking, and a less-than-enjoyable driving experience. 

Cleaning dirt and grime from your engine mounts and checking for cracks or excessive buildup are recommended. When it comes time to replace, upgrading to performance polyurethane or higher-density rubber can decrease engine movement over OEM, improve shifting feel, reduce drivetrain play, and increase the longevity of your engine mounts, at the expense of added vibration and cabin noise.

Symptoms of Elongated Service Intervals:

• Engine/Drivetrain Vibration: If you suddenly or gradually begin to notice an increased presence of vibration in the cabin, there's a good chance one or several engine mounts are failing. Especially in cars sporting hydraulic mounts such as Mercedes or Audi, this is a byproduct of a mount having collapsed.

• Excessive engine movement: If you can feel driveline movement during acceleration, braking, or cornering, this is a good chance a mount has slipped out of tolerance. This can coincide with loud thumps and clunks over bumps in significant failure cases.

Popular Brands at FCP Euro:

• Lemforder
• Corteco
• Rein
• Vaico
• 034Motorsport
  
• Revshift

PCV (Positive Crankcase Ventilation)

To understand what a PCV (Positive Crankcase Ventilation) valve or "CCV" does, we must first understand what “blowby” is. While your engine goes through the combustion process, the piston rings cannot always hold 100% of the gasses. Vapors can escape through and consolidate in the crankcase, where PCV/CCV function allows ventilation. In excess, these vapors can indicate a bigger issue - excessive blowby can be tested by removing the oil fill cap as the engine is running and feeling for smoke or a significant amount of air escaping.

General cylinder head pressure is why our engines have a PCV valve, which is a one-way valve that works to remove these unwanted gasses from the crankcase. As combustion occurs, you'll naturally have an offset in pressure, and the explosions happening in the confined space will always create crankcase pressure. Your PCV valve will manage this pressure and redirect the gasses back into the engine (typically venting into the air intake circuit) rather than being expelled into the atmosphere or causing harm to critical engine components.

Symptoms of Elongated Service Intervals:

• Misfire: A severe air intake leak can cause rough running and an engine misfire, a common side effect of a bad engine crankcase breather hose or PCV Valve

• Broken Connectors: Plastic can become brittle over time, especially when exposed to heat and oil, and it’s easy to break one of the securing clips or connectors for a PCV hose, either during removal or during other services.

• Broken or Damaged Hose: Soft rubber or brittle plastic, depending on the material of the hose, can result in an obvious hole or split in an engine crankcase breather hose, usually accompanied by one of the other faults listed below.

• Check Engine Light: Excessive unmetered air from a failed engine crankcase breather hose can result in a CEL for an air intake leak fault or other airflow-related diagnostic trouble codes.'

• Oil Consumption, Noise: On some models (such as a lot of the Volvo 5-cylinders), a PCV failure is synonymous with a high-pitched whistling noise as the engine struggles to vent properly. In these instances, when either a vent valve is stuck open or closed, you'll often have oil consumption issues regardless of your make or model. Some vehicles will actually consume oil, due to the valve being stuck open and allowing vented oil vapors to enter the intake system in excess, while other cars will develop leaks around rubber seals due to the excess pressure of a vent valve stuck closed.

Popular Brands at FCP Euro:

• Vaico
• OE Supplier
• Genuine
• Febi
• VNE