High Revs

[Golioth]

Hey guys.

I have a question for all the gurus out there.
I ZD30 engine recently grenade, so I put a reco'd ZD30 back in. I have noticed now that if it is started cold (haven't run it in 12+hours) that the revs sit higher for the first 10 minutes. Normally when cruising on the freeway at 100 my revs sit at about 2200, but in the first 10 minutes or so it now sits at about 2500-2600. I told my mechanic about it who had a look, but sure enough it didn't bloody do it when he looked. He said that it was probably just the tacho sticking. but I can audibly hear the change of revs when it drops from 2500 to 2200. it isn't a slow drop either, its instant.

Just need to know if this is something I need to be worried about. Last thing I want is to be forking out another $10k for another engine.

Any advise would be appreciated. cheers

[Rock Trol]

Hi Goliath.
Is the Trol an auto or manual? If its an auto maybe overdrive is not being engaged until it warms up. That would explain the drop in revs.
If manual then I can't even try to explain it.

[Paule]

I take it that it's an auto, if so mine does the same, when the revs drop it your torque converter locking up. Which it won't do until it's warmed up

[4bye4]

I take it that it's an auto, if so mine does the same, when the revs drop it your torque converter locking up. Which it won't do until it's warmed up

Ditto on my ZD30 auto. Drops revs about 10 mins into my freeway run to work and again coming home.

[paulyg]

Thats normal for an auto, the torque converter wont lock up till it reaches operating temp.

[kevin07]

and again from me

[happygu]

Couldn't do it if it was a Manual ..... only if clutch as slipping when cold .... therefore it must be Auto

[Bush Ranger]

As above. I have a ZD30 with a manual in it and it sits around the 2500 rpm at 100 Ks or so.

[Winnie]

My Corolla does it too.... lol
When I bought the Corolla it had a dodgy thermostat in it so it would not get to temperature, the torque converter would not lock up at all on a 25 min drive to work, now it gets to temperature and about 3 mins it locks up.

[Golioth]

Thanks everyone. yeah its an auto. great to know that its nothing I need to worry about. you all have really put my mind at ease. thanks guys