Starting a rebuilt 944 for the first time. Any advice?

[tryangles]

What kind of oil should I use? Anything I should know?

[Gary2397]

Try to stick with Mobile One Oil and OEM oil filter like Mahle.
Avoid driving hard until the car breaks in.

[944 boy]

For good instant oil pressure, if you have compressed air, blow some air into the dipstick tube with the filter off until oil bubbles up from the center hole. This worked amazingly well for me on my second motor, no lifter tap past 10 seconds and instant oil pressure. For a break in oil I would suggest good old castrol GTX. I talked with the engine shop I got machine work done at and they said that the new synthetics are not that good for breaking motors in with. That and its more expensive oil to run for only 500 miles. After the first 500 I would change the filter(mahle) and oil with Mobil1.

[white944cup]

If you have installed new rings, I've always heard that you should not put Mobil 1 in a new motor until it is broken in and the piston rings have seated. The reason being that Mobil 1 is too slick and it will prevent, or slow down the seating-in process. I've heard of rebuilt engines that had problems with the rings not seating, smoking, poor compression, lots of blow-by, etc. and would not seat until the Mobil 1 was replaced with standard dino oil. I usually break in an engine with a good multi-grade dino oil like Castrol 10W-30 or 10W-40, and then switch to Mobil 1 after the break-in period. If you haven't changed the rings, you probably don't need to worry about it. Just my $0.02 worth......I would be interested to hear other opinions and experiences.

[Razorback1980]

I disconnect the reference sensor which kills the spark and the injectors so you don't get gas in the cylinders which is important. Then remove the spark plugs and turn the engine over until you get oil pressure. Then reconnect the reference sensor and put the plugs back in and try to start it.

I also use break in oil on a new engine and I do like Castrol. Then I change it at 500 miles and I use Castrol synthetic in mine...but oil is a personal choice.

[924RACR]

+1 on what Razorback said, but isn't it easier to just remove the DME relay to kill spark and fuel? Definitely remove the plugs to ease the load on the starter.

It takes a LONG time at cranking speed to build pressure; the pump's designed to move oil, not air, so will take a long time to prime. That's why you put the engine together with assembly lube. You'll think you F'd something up, but it's just always like that.

Don't switch to synthetic so soon, gotta let those rings seat first or you'll get poor performance and mileage. I do agree with an oil change fairly early on, but I'd stick with the GTX for another oil change period first. I like Valvoline also, use their dino race oil VR1 in my race motor, NOT synthetic (after a struggle with rings not seating with M1), but GTX is great stuff too IMO.

I do agree, stick with good OEM filters like Mann or Mahle. I've been shocked by the garbage that cheaper filters like Fram let by.

As for break-in strategy, I'm in the camp of drive it like you stole it, work it hard like you plan to drive the car. For my race motors, I just do some minimal test-running at home to warm it up thoroughly, check for leaks and bleed the cooling system, then take it out and race it. This plan's been working very well for me for quite a few years now.

[John_AZ]

Here is additional information on doing the brake-in. Was written for motorcycles but applies to cars as well. http://www.mototuneusa.com/break_in_secrets.htm

John_AZ