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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 100 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 900 miles.

You will change the oil at the following mileage intervals:

  • 100 miles on new engineWe 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.
  • 500 miles on new engine – Change the oil with conventional oil or break in motor oil. Change the oil filter too 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 filter like “FRAM” and “NAPA Pro Select”.
  • 1000 miles on new engine – Change the oil and filter again. This time change the engine oil with Synthetic or racing motor oil. most people with stock cams and stock rev limit use 5w-40 Rotella T6 motor oil. Most name brand synthetic motor oils are good but never use “Mobil 1” or “Royal Purple”. Monitor your oil levels and if you start consuming an excessive amounts with a different motor oil other than Rotella T6, you will want to stop using it and change it right away.
  • 2000 miles on 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.

Couple rules of thumb and notes:

  • Built motors are much, much stronger than OEM – but they can also blow up 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. If you do any track racing, then 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 then 2 weeks, you want to prime your engine. Dry starting your engine can be harmful. You can disconnect the knock 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.

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 handled 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 cover 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 350 WHP and less we suggest Rotella T6 5w40 motor oil.
  • For 350 WHP to 600 WHP we suggest Motul 5w40 8100 X-cess motor oil.
  • For 600 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 then other normal vehicles. This will help prevent your engine from pre-mature failure.

We stock both Motul motor oil options. Rotella T6 can be purchased at most retail locations (Napa, Walmart, Fleet Farm, etc).