First drive on rebuild

[napatiger]

The engine is running RICH.
Water vapor out of exhaust.

How long does it take for the engine to relearn?
I have driven it about 5 miles so far.
What is a normal break in period?.

Thanks.

[SappySE107]

THere are different opinions on breaking in a motor so I can't really tell you how to do it other than how I would do it.

Supposed to run it at 2000-2500 RPM for 20 minutes to break in the cam on pushrods but I don't think thats necessary for the DOHC since it doesn't rely on breakin in the cam/lifters to get them to spin.

Some say not to get over 3000 RPM for so many miles, then slowly go up on the allowed RPM. I say screw that too, though no red line. I would put it in first, and run it up to 5000 at decent acceleration. Not floored, not pussy footing about. Then let off and let it decel with the engine braking for you. This will increase pressure and push the rings against the cylinder walls to help break them in. Do this twice, every 300 or so miles for the first 1000 miles.

Change the oil often. Right away after initial start up and break in (that 20 min deal, so lets just call it 20 minutes anyway). Then again at 25 miles, then 100, then 300, then 1000, then 2000, then normal from there on out. No synthetics till at least 3000 though again, some will do it after 1000, and others wait longer.

Id give it more time for sure before I worry about the rich condition. Could just be blow by and shit burning off still. You did put a new O2 in there with the rebuild right?

[napatiger]

Yeah I put in a new O2 sensor; actually, that is why I pulled the engine the first time three years ago.

Notes on progress:

I pulled the synthetic oil out after initial breakin, kinda cloudy. Probably from all the assembly lube and what not.
I flushed the engine for a few minutes with Valvoline 5-30 dino and then changed the filter/oil again.
Pressure with synthetic: cold idle=25; hot idle 15; 3/4 throtle 50ish
Pressure with Dino oil raised about 5psi, guage isn't really that accurate.

Blew a bunch of fuses, fixed with 2 ga wire to starter.
Now the engine starts right up.

Still running rich, total 60 miles so far.
Idle has 150 rpm 'slight loop' at cold startup.

I have only brought it up to 5k twice.
I basically just gave it 3/4ish throttle for a while.

When should I change the trans fluid? It is new/reman as well.
I will add the new pan with temp sensor at first change.

I like having the oil pressure gauge, I am suprised there isn't one stock on the Z34.

I can' t believe that the radio still has my presets.

VERY happy with the rear disk brakes.
VERY happy with the springs and struts
Handles tight.

Once I have a 1000 miles on it I will not be so nervous about driving when/where/how I want.

I can't believe I did it. I never had any formal mechanics training or background for that matter.

Thank you to every one here at 60degreeV6.com.

[SappySE107]

You shouldn't do a break in with synthetic, as its too slippery to allow the rings to seal properly. Get that dyno oil back in there ASAP.

[Zboy]

Dexron/ Mercon ATF should be changed at between 15,000 to 20,000 miles. Now thats if you are granny driving in light traffic. There is very little chance a 3.4 DOHC is gonna get granny driven. If you hard drive the car I'd say changing ATF at 5,000 to 7,ooo is a good idea. 12,ooo to 15,000 for moderately hard driving. Of course if you are running a bigger trans cooler, synthetic fluid, deeper pan, etc., you should be able to increase your intervals. Ask your trans supplier or rebuilder what he recommends for a first service, Some builders say a full flush at 5,000, some say change the fluid when it gets dirty. Everybody has their own opinion on subjects like these. Hope this helps.

[napatiger]

I just flushed the new trannny at 150 miles and I am glad I did. It's kinda like a new motor, you want to get any shit out soon. Next I will change at 5000 then maybe 8000....

[napatiger]

Car now has 250 miles. All spark plugs look real good, tan.
Checked compression:
1,3 = 140 psi
2,4,5,6 = 150 psi

I guess that is pretty good.

Can anyone tell me if my trans fluid and motor oil would be about the same temp after everything is warmed up? I would assume that the oil will heat up faster, but the both should be about the same going throught the same radiator.

Slight lifter tick for 5 minutes on cold. then goes away, then comes back strong at 180 degrees. Interesting.

[Mach10]

Keep an eye on that. What I thought was lifter tick ended up being something totally different.

Loud when cold for about 15 seconds, then it'd quiet down. Then it'd start getting a bit louder at temperature, but only between 1500-2500rpm.

So I ignored it.

With interesting consequences.



Given the wear on the side of the bore, I'm assuing that I had a broken piston skirt that was causing the piston to cock in the bore. Never burnt oil, had good compression.

[napatiger]

Thanks for getting me nervous...

I think I remember someone saying that lifter tick went away with different type of oil.
I would also think that lifter tick could have more than one lifter ticking..
This only sounds like one thing. Maybe I should check it out. How could you have prevented that piston exploding?

[SappySE107]

What oil are you using now? I will be switching to 10W30 mobil as soon as all this amsoil is gone (probably a couple more weeks at the rate my motor goes through it). Its probably a lifter. The lighter ones tend to be a little noisier than the stockers.

[napatiger]

Oil is of the Dino variety, Valvaline 5-30W. Temps during the day are from 70-80 degrees F.

I am about to change for the 3rd time...500 miles so far.

How exactly does the lifter tick sound? Sounds like 'one' tick about 4-5 times per second at idle on my car.
800 rpm = 13 rps at the crank; right, then 6.5 rps on a single lifter is about right.

Would a stefascope (sp.) work for pinpointing the location of the tick? ?Block vs cam carrier.

[SappySE107]

Or a screwdriver will work. It sounds a lot like injectors really, only louder. I don't hear mine unless its over 90 degrees out and even then, its random and isn't there 99% of the time. I would keep using 5W30 dino oil for the time being since its still break in.

[napatiger]

Machine shop confirmed that it is lifter tick. He does not recommend storing lifters in oil prior to install, can trap air easier or something.

[napatiger]

changed the oil again, 800 miles.
4 qts of 5-30 Valvoline dino oil + 1.5 qts Mobile 1 synthetic.

Lifter tick is all but gone.

I wish the 95 had hood vents like the 93 lumina......