What Speed Should I Drive

[allerston]

hi guys my engine was overhauled about 2 months now and i would like to know what speed should i drive my car would i damage the pistons, rings and bearings if i drive to fast what speed should i drive and for how long ?

bmw 525 1990 e34 (m20 engine)

thank you guys

[Blitzkrieg Bob]

As fast as you can...

[RockJock]

lol wut?

[allerston]

ha ha

[repenttokyo]

he's asking about engine break-in procedure.

[RockJock]

he's asking about engine break-in procedure.

haha, indeed...

1st 1,000km keep below 4,000 rpm
2nd 1,000km keep below 5,000 rpm

then go to town!

[BigKriss]

As slow as you can...

[Tiger]

You all all pretty much wrong. The right way to break in the car is fluctuating RPMs... not steady slow constant RPM. City driving is best. Highway driving is worse for breaking it in.

With slow constant RPM, the piston rings would never seat itself properly and can lead to oil consumption problem. Like Popular Science article said a owner of a Toyota I think... that his car is only 2 years old and it burns a quart every 1000 miles.... and the service rep said is acceptable because the factory spec called for 1 quart every 600 miles before they would warranty the engine.

[632 Regal]

blast and pass give it hell, the rings wont seat if you idle through traffic. Give it hell, pass the soccer moms doing 90 in the slow lane talking on their fuk#$@ cell phones, blast the horn as you do so.

siting around waiting for things to set dont do it.

replace the break in oil at 100 miles if you do the above
after 5000 miles and sure the rings seat then back to synthetic stuff

[Ross]

If you have been driving it for two months the point is moot.
Having said this the point is to avoid long idling, lugging the motor and extended high revs or full load operation for the first few thou. And as always never beat on a cold engine.
Don't baby it, just don't pound the crap out of it.