If you’ve put time and money into modifying your car’s engine, you’ll want to make sure it’s properly looked after when it goes into storage. Modified engines have different requirements to standard setups, and getting the preparation wrong can mean corrosion, seized components or expensive damage that only shows up when you try to start the car again.
Read ahead to learn what you need to do before putting a modified car into storage, and what to look for in a facility that can handle it.
Why Modified Engines Need Extra Attention
A stock engine is designed to sit around for reasonable periods without much fuss. Modified engines are a different story. Aftermarket turbochargers, superchargers, uprated fuel systems and standalone ECUs all introduce components that need specific care when the car isn’t being driven for an extended period.
Forced induction systems rely on oil-fed bearings that can dry out during extended downtime. Aftermarket fuel injectors may be more sensitive to stale fuel than factory equivalents. And if you’ve fitted a standalone ECU or aftermarket wiring loom, parasitic battery drain can be higher than you’d expect. None of this means you can’t store a modified car safely, but you do need to prepare it with those differences in mind.
🚗You might also like this guide: Classic Car Care.
Fuel and Fluid Preparation
Start with the Fuel
If your car runs on standard pump petrol, fill the tank to around three quarters full before storage. A near-full tank reduces the air inside, which limits condensation. Add a fuel stabiliser too, especially if the car will be sitting for more than a couple of months. STA-BIL or Millers VSPe Power Plus will stop the fuel from breaking down and forming deposits in your injectors.
For cars running on E85 or high-ethanol blends, this is even more important. Ethanol absorbs moisture readily, and stale E85 can corrode fuel lines, seals and injectors. Drain the E85 and run the car on standard petrol with a stabiliser before storing it if you can.
Here’s more on this if you’re curious: Storing A Car With A Full Tank vs Empty Tank.
Oil Is Next
Change the oil before storage, not after. Old oil contains combustion byproducts and acids that will attack internal surfaces over time. Use the grade recommended for your setup, and if your engine builder specified a particular oil weight, stick with that.
Don’t Forget the Coolant
Make sure the mix is correct and the system is bled properly. Trapped air pockets and weak coolant can lead to localised corrosion in aluminium blocks and heads.
Battery and Electrical Considerations
Modified cars often have higher parasitic battery drain than standard models. Aftermarket ECUs, wideband sensors, alarm systems and auxiliary gauges all draw small amounts of current even with the ignition off. Over weeks or months, this will flatten the battery.
A smart trickle charger like a CTEK MXS 5.0 will monitor the battery and top it up as needed without overcharging. If the facility doesn’t offer mains power at each bay, ask whether they include battery conditioning as part of their service.
For cars with lightweight lithium batteries (common in track-prepped builds), the advice differs. Lithium cells don’t like sitting at full charge for long periods. Store them at around 60-70% state of charge and disconnect them entirely if the car won’t be on a charger.
Protecting the Engine Internals
If the car will be off the road for several months, it’s worth protecting the engine’s internals. A small amount of fogging oil squirted into each cylinder through the spark plug holes will coat the bores and prevent surface rust. This is particularly relevant for cars with cast iron liners or open-deck blocks.
Before you do this, turn the engine over by hand using a breaker bar on the crank pulley to distribute the oil. Don’t use the starter motor, as you want to avoid firing the engine with fogging oil on the pistons.
If you’ve got a dry-sump system, make sure the oil tank is filled to the correct level and run through the priming procedure before shutdown.
What to Look for in a Storage Facility
Not every storage facility is set up to handle modified or performance cars. There are a few things worth checking before you commit.
Climate Control Matters
Temperature swings and high humidity are the enemy of stored engines. Condensation inside the intake, exhaust and crankcase causes corrosion that’s invisible until you strip things down. A facility with stable, low-humidity conditions will reduce this risk significantly.
Security Is an Important Factor
Modified cars are often worth more than standard equivalents, and they attract attention. Look for a facility with CCTV, alarm systems, restricted access and on-site staff. Check whether the insurance covers aftermarket parts at full replacement value too, as some standard policies won’t.
Think About Access
You might want to check on your car periodically, run the engine or carry out seasonal maintenance. A good facility will offer flexible access without making it difficult.
Before You Collect the Car
When it’s time to bring the car out of storage, don’t just turn the key and drive off.
- Check the oil level and coolant first.
- Remove any fogging oil by cranking the engine with the spark plugs out before refitting them.
- Let the engine idle and come up to temperature slowly, checking for leaks or unusual noises.
- If the car has been sitting for more than six months, check rubber hoses, belts and any silicone couplers in the intake system. These can perish during extended storage, and you don’t want to discover a split boost hose at full throttle on the motorway.
A modified engine is a serious investment. Taking the time to store it properly will make sure it’s ready to perform whenever you are.
