Breaking in new engine

Undertowww · July 30th, 2010, 11:03 PM

Open to any suggestions on what to do with a rebuilt engine (91 GT):

Ie. break in time, how to drive it, when to do first oil change, regular vs premium gas, regular vs synthetic oil, stuff like that. This is my first time doing it, so any suggestions are much appreciated.

Thanks.

Sam

tahoe · July 31st, 2010, 10:48 AM

http://www.mototuneusa.com/break_in_secrets.htm

matt89glturbo · July 31st, 2010, 10:10 PM

gas doesn't matter, use cheap oil for break in, I change mine the first time at 500 miles, but everyone does it different, then follow the link he posted

I switched to synthetic at about 6k or so, don't have a speedo, so not sure exactly...

Undertowww · August 1st, 2010, 01:27 PM

Ok, thanks for the info. This one site here says to break it in hard, but I've read elsewhere to just vary the rpm's alot, without revving too high (< 3000). I'm starting it tonight, but I don't know if I should drive it easy or hard? And do I drive it in short spurts, or is it ok to drive it for say a half hour at first? Thanks.

sam

HotRodTom · August 4th, 2010, 12:20 PM

Glad to hear its started up OK!! Congrats on the rebuild!

How did the machine shop say to do it? Mine said that once I got the engine up to operating temp, shut it down, let it cool, and change the oil right away. Then he said to drive it normally- but no long cross-country trips, and I should keep the RPM's varied (example = not driving down to the beach in 5th gear at 2000 RPM for 2 hours). I didn't have an owners manual yet so I wasn't able to read about how the factory wanted me to break in the engine. (And a year later I discovered the hidden drawer under the passenger seat- and found an owners manual!)

And then (from October 22, 2008):

Quote:

Originally Posted by HotRodTom

The engine pulls nice & strong- I think it broke in rather well. I did a mix of "hard driving" (accelerate/de-accelerate with high RPMs) and relaxed driving (highway, low RPMs, but playing with the gas pedal so the RPMs didn't sit in one place for too long) for the first 500-1000 miles, and then just "normal" driving since then. So far I'm calling the job a success! After a few more miles & oil changes I'm going to move to synthetic oil.

My hard driving w/deceleration was using 2nd gear on my manual trans; I'd do that at night from stoplights when nobody was around. I still haven't moved to synthetic; it's been 25,000 miles already. I've got a slight oil pan leak and I'd rather leak dino juice then expen$ive $ynthetic!

But I did do a "0 mile" oil change, then changed it again at 500 miles, and then again at 2000 miles. For "fun" I ran a magnet thru the used oil and was glad to see that I didn't pick up any metal filings. After the 2000 mile oil change, I started "normal" oil changes (every 3000 miles) after that.

Undertowww · August 7th, 2010, 01:16 PM

Thanks man. The Haynes manual had a break in procedure that correlated with what I had read online (hard driving at first, then varying rpm, etc.). I think I'll just stick with reg oil. The engine runs well, but I have a few little problems that I need to fix. There's some rubbing noise near the pulleys, but the rebuilder is gonna look at it for free (plus I'm pissed cause he put the p/s pulley on backwards and I didn't notice till the engine was in the car), my cooling fan won't turn on, and my rotor seems to be rubbing on something (though not really engine related haha). Other than that, things went well, and hoping to get a long life to come from the car.

July 30th, 2010, 11:03 PM	#1
Undertowww Donating Member Join Date: May 2007 Posts: 184	Breaking in new engine Open to any suggestions on what to do with a rebuilt engine (91 GT): Ie. break in time, how to drive it, when to do first oil change, regular vs premium gas, regular vs synthetic oil, stuff like that. This is my first time doing it, so any suggestions are much appreciated. Thanks. Sam

July 31st, 2010, 10:48 AM	#2
tahoe ________________________ Join Date: Oct 2002 Location: wine country in northern california Posts: 1,702	http://www.mototuneusa.com/break_in_secrets.htm

July 31st, 2010, 10:10 PM	#3
matt89glturbo Turbo Member Join Date: Aug 2000 Posts: 1,608	gas doesn't matter, use cheap oil for break in, I change mine the first time at 500 miles, but everyone does it different, then follow the link he posted I switched to synthetic at about 6k or so, don't have a speedo, so not sure exactly...

August 1st, 2010, 01:27 PM	#4
Undertowww Donating Member Join Date: May 2007 Posts: 184	Ok, thanks for the info. This one site here says to break it in hard, but I've read elsewhere to just vary the rpm's alot, without revving too high (< 3000). I'm starting it tonight, but I don't know if I should drive it easy or hard? And do I drive it in short spurts, or is it ok to drive it for say a half hour at first? Thanks. sam

August 7th, 2010, 01:16 PM	#6
Undertowww Donating Member Join Date: May 2007 Posts: 184	Thanks man. The Haynes manual had a break in procedure that correlated with what I had read online (hard driving at first, then varying rpm, etc.). I think I'll just stick with reg oil. The engine runs well, but I have a few little problems that I need to fix. There's some rubbing noise near the pulleys, but the rebuilder is gonna look at it for free (plus I'm pissed cause he put the p/s pulley on backwards and I didn't notice till the engine was in the car), my cooling fan won't turn on, and my rotor seems to be rubbing on something (though not really engine related haha). Other than that, things went well, and hoping to get a long life to come from the car.