Billy Penley

I jus finished rebuilding my 2000 XJ 4.0 engine and considering starting the engine before I put the remaining parts on like radiator; fan; serpentine belt; etc.
Everything else is in place, and I have hand turned the engine over a few times and also with the starter, and appears the oil pressure gauge did rise about 1/8 inch
while turning it over with the starter. I have filled crankcase with Valvoline 10w30 ZR1 high zinc. Would it be Ok to start engine for a minute or so...just to be sure
I haven't got a problem? Also appears linkage is off on the shift lever...had to use neutral to start. any suggestions on where to start to adjust that would be good.
any additional suggestions on start up be appreciated.

Bugout4x4

It's a wise practice to NOT do that. lol

Billy Penley

Ok...Thanks...was thinking same thing....

Bugout4x4

When you start a fresh engine you will want to let it idle for quite awhile as the the rings first start to break in. So you want everything all together and ready to rock and roll.

investinwaffles

I don't think there is any harm in starting the motor and idling it for ~5 seconds to make sure it will fire up.

But when going for the first real start-up, I would at least have the water pump running and filled with coolant. Fill it from the heater hoses, they are the highest point on the motor I think. You want to avoid air pockets, and cavitation which could cause hot-spots in the motor. Possibly run it without a radiator cap to purge air, or get one of those "no-spill" funnels which will help bleed the system quickly. You will need the alternator and fan hooked up as well, so you will need all the front end accessories mounted up.

Make sure the battery terminals are loose incase you run into any wiring issues (you can just yank the battery terminal off quickly if so).

Prime the fuel system, then I would manually prime the oil pump but not sure how to do that if you don't have a distributor (coil pack I think came on the 00/01 XJ's).

Ask 10 people and I am sure you will get 10 different engine break-in answers.

Generally, you should run the motor at ~2000 RPM at no load (neutral) for about 15 minutes to run in the camshaft. Stop and cool for a while, until you can touch the header comfortably. Repeat for another 15 minutes and let it cool again.

Then, I drive it normally varying the RPM's quite a bit for about 30 minutes. No highway, only city driving. Keep the speeds down and try to avoid too much load on the motor. Stop and cool completely (several hours). Then I drive it again for about 30 minutes, and do 3-5 medium throttle pulls to 3500 RPM.

Then, drive it for about 500 miles varying the RPM (no long highway drives), and right before I change the oil I do several hard pulls, usually all the way to redline.


But that is just me, and i've only run in one rebuilt motor so I am not an expert or anything

Billy Penley

Thank you...good info...It's been a journey..I can see the end and don't want to mess up now!!!

investinwaffles

Make sure you use some magnets on the filter too - I gutted a few old hard drives I had laying around, but you can also buy some N42SH high heat magnets (300*F rated) and stick them to the oil filter, or get a magnetic drain plug.

Drain plug is best because it will catch stuff before sending it through the oil filter, but I use both for better filtration capability.

EDIT:
I might buy a set of these actually, since they are curved and would have better surface contact than what I am using currently

https://www.ebay.com/itm/CMS-Magneti...frqeWcFpn7TsxQ