Break-in and Warranty

Thank you for choosing JM Automotive for your engine build. Please read all of the information below to get the best understanding of your new engine and how to take care of it during the break-in miles and post tune.

On our engine building page, you will find our procedures for your engine while we were working on it here. This section is for when you get the car back. This will help explain how to take care of the new engine, break it in properly, and explain our warranty. As long as you follow all of the care information, you should not have any issues at all. We have built hundreds of engines with great success and many satisfied customers. All of our engines are blue print assembled and have a proven successful formula.

Picking your car up the first time:

By the time you are getting your car we have done vacuum pulls on the dyno to break in the piston rings, driven 300 miles on your engine, changed the oil, it has been tuned, and confirmed everything is ready for you to take it home. The vehicle will hit boost and be tuned if you full throttle. You will want to limit yourself to ZERO or little boost for those first 500 miles.

You will change the oil at the following mileage intervals:

100 miles on the new engine – We replaced your engine oil and oil filter. We used Motul break-in oil for the initial start up and put Motul break-in oil for this 100 mile oil change.
300 miles on the new engine – We changed the oil with break-in motor oil.
800 miles on the new engine – Change the oil and filter again with a good quality oil filter. We always use OEM Subaru oil filters. There are other good brands out there too. Just stay away from economy filters like “FRAM” and “NAPA Pro Select”. This time change the engine oil with Synthetic or racing motor oil. Most people with stock cams and stock rev limit use Motul 8100 X-Cess. More information on suggested oils is lower. Most name brand synthetic motor oils are good but never use “Mobil 1” or “Royal Purple”. These oils are known to burn up in these engines under certain conditions. Monitor your oil levels and if you start consuming excessive amounts with a different motor oil other than Motul, you will want to stop using it and change it right away.
1,800 miles on the new engine – Change the oil and filter again. Continue to use a good quality synthetic oil and good quality oil filter. After this interval you will want to make sure to change your engine oil regularly every 2,500-3,000 miles and monitor your oil level every 500 miles.

More information on oil change intervals below.

Couple rules of thumb and notes:

Built motors are much, much stronger than OEM – but they can also fail if not taken care of or driven properly.
5 Speed manual transmissions – Never WOT in 4th or 5th gear unless you have just redlined the gear prior. Your transmission 1:1 gear is in 3rd. 1st, 2nd, or 3rd gear you can full throttle at any RPM. But in 4th or 5th gear if you full throttle in a low RPM it will load up the engine, cause it to over boost, and can damage your pistons, bearings, or other engine components.
6 Speed manual transmissions – Never WOT in 5th or 6th gear unless you have just redlined the gear prior. Your transmission 1:1 gear is in 4th. 1st, 2nd, 3rd, or 4th gear you can full throttle at any RPM. But in 5th or 6th gear if you full throttle in a low RPM it will load up the engine, cause it to over boost, and can damage your pistons, bearings, or other engine components.
Never lug your engine. Do not drive in higher gears in lower RPMs (near 2000 RPMs). Lugging can damage your piston rings and bearings.
If you are going to track your car – Change your oil prior to going to the track and change your oil after you come back from the track. Check your oil repeatedly during the track session to make sure everything is going well and your breather system is working properly.
For built engines an IAG AOS is a must. We stock these, can help you choose the correct application, and can get one installed for you.
Always let your engine get up to operating temperature before any abuse (summer or winter).
Always let your engine get close to operating temperature before driving in extreme winter conditions.
If your engine sits for longer than 2 weeks, you want to prime your engine. Starting your engine can be harmful without priming it. You can disconnect the crank sensor or fuel pump to do this. Contact us if you are unsure.
If your car sits all winter and you have aftermarket injectors you will want to store them. Contact your injector manufacturer for storage instructions.
Make sure you are using the correct octane for your engine. Lower octane will cause detonation and will blow up a built engine. Stay away from non ethanol or non oxy fuel, it is very bad for our engines. Kwik Trip 91 fuel is non ethanol and very bad fuel for turbo engines.
If you are running E85 you will want to change your oil every 2500 or less if you have a stock turbo.
If you have 400 WHP or more you will want to change your oil more frequently than 2500-3000 miles. Depending on your HP and driving style will depend how frequently. Oil changes are the cheapest insurance for your engine. We suggest 1500 mile oil changes for most builds making 450 WHP+.
If you store your vehicle for the winter you will want to change the engine oil before and after.
If your car sits for extended periods of time, your oil still breaks down. Typically the rule is 3 months or 3,000 miles. If you do not drive it much, we do not suggest boosting on engine oil that is over 3 months old after it has been heated up inside the engine

Warranty:

The warranty begins the day the car is picked up.
Our warranty lasts for 1 year or 12,000 miles.
Any warranty repairs will not extend the warranty period.
Our warranty covers the short block and internal short block components. We also warranty our labor and other new parts too. If our labor or a new part is a cause of failure we warranty that too.
Our warranty covers leaks or issues related to our labor.
Our warranty covers labor to remove and repair the engine in the event of a failure or a problem.
Our warranty does not cover the gaskets, fluids, turbocharger, or other components damaged from a failure outside of the short block. You will have some out of pocket costs. Our engines are blue print assembled and proven to handle the HP they are rated for. As long as you take care of your engine and follow the information listed here you will not have any issues.
Our warranty only covers engines running our tunes. You must provide proof of the oil changes being done. We do not warranty neglect, improper care, or driver error. You cannot mechanically over rev the car, WOT in higher gears, leave engine oil dirty or low, or overheat the engine or the warranty will not cover your engine.
Our warranties are non-transferable without prior permission and inspection with all proof of maintenance.
Our warranty does not cover failure from a used part supplied by you or on the car prior, such as a fuel pump or injectors that go bad. If your car is not running correctly contact us right away to diagnose and repair it to prevent engine damage.

Oil Recommendations:

For 400 WHP and less we suggest Motul 5w40 8100 X-cess motor oil. This is great oil for all WHP levels, even stock.
For 400-550 WHP we suggest Motul 5w40 8100 POWER motor oil.
For 550 WHP or for track use we suggest Motul 5w40 300V motor oil.
5w40 is the recommended weight all year around for our engines. If you have higher hp it is good to change your oil more frequently than other normal vehicles. This will help prevent your engine from premature failure.

We stock All of these oils.