last I checked coolers from GTM and stillen come with thermostatic plates. However, it looks like while the plate doesn't fully open until 180+ it never fully closes either. I think I read on here that it closes up to about 90%. I recently installed the GTM 25 row oil cooler and yes I will say that it is probably way to big for New York fall and winters. I bought it because I didn't want to have an insufficient cooler for when I went to the track, the HD just wasn't big enough.

Before the cooler I saw the temp up to 250ish when I really got on it. Most of the time a little bit of spirited driving had me sitting between 220-240+ all day and that really pissed me off.

Get a cooler, the Z needs one, the size of the cooler will depend on your intended use of the car. I'm sure eventually either GTM or a fellow member can construct a shroud for you.

BTW: what temperature is considered overcooling?

Below 160* or 170* is way too cold to be romping on it hard -- insufficient lubrication, although it's probably less of an issue with a good synthetic, which may have a wider heat range, hot and cold. I'd say 180* is the bare minimum and 200* is probably ideal.

Anything north of 250* for extended periods is iffy, but a good synthetic will still provide protection, for short bursts anyway, well over that.

Looks like a lot of folks on here like redline -- I'll probably go for that.

I've seen those inline thermostats and stayed away. If you order through racerpartswholesale.com you can have them special order the Mocal Sandwich adapter with a 200F thermostat built in rather than the 180F thermostat which they have in stock. If you do an inline thermostat like in that link, you just add four more points for potential leakage or hose blowout in your system.

I've been very happy with my Redline oil. Ever since the car has been over 3,000mi and on Redline, my temps have been better than my first summer with the car using NEO. I would routinely hit 240F in traffic last summer. Today I was testing it and only got to 225F sitting in traffic in 80F weather. That being said, a cooler is still mandatory for track days, hence my decision to install one now.

Hmm -- yikes! Thanks for the tip! When I get around to this, I'll go for the sandwich adapter you recommended :tup:

Hey how does this "rep" thing work? I owe ya point for the good advice :D

Nevermind -- figured it out... poor slow newbie :icon17:

One guy went into limp mode, he hit over 260.

That is a bit on the hot side. Anything over 250* isn't generally good... Does the limp mode self-clear or require an ECU reset?

Thanks for the rep :).

Limp mode self-clears when the temps drop. It may require an engine on/off cycle but there is no need for a code reader.

I'm putting in the cooler because I swear the engine loses power when the temps go over 230F.

Is their a relationship between needing a new short block and my high oil temps often 240+with low ambient temp. 258* was max when I put it into my own induced limp mode and dropped the revs down to 2500.
I am hoping I will not need oil an cooler after new short block. Keep hope alive.

first the too are not related, and If you are going to be doing some spirited driving?
It's highly recommended.

Meaning you just had a new short block installed and the oil temps are high?

That makes me wonder if you have a poor cooling... like maybe they resused the old head gasket when the engine was assembled.

Does the oil look milky? Any evidence of low coolant?

Sorry. I have just been prescribed a short block arriving next week. The coolant has remained at proper level. The oil looks milk free.

I just got back from 1600km long distance travel and during the whole time I was monitoring my oil temp... It always stayed below 210F even with more than occasional spirited driving :)

Break-in was done properly and synthetic oil thereafter. (mobile 1)

So oil temps are high but you don't have the new block installed.

Sounds to me like they figure something is amiss with the pistons and rings, so yeah, trashed shortblocks are potentially related to higher oil temps.

I'm not exactly sure why tho'... WarmAndSCSI, or someone else with lots of engine building experieicne, may be able to elucidate...

I hate you.... Mine is almost always above 230 :ugh2:

Reading all the oil cooler threads now...

It's not a break-in or oil type issue. More important to report would be your ambient temps, cruising speed and RPM, altitude, and A/C on or off.

Before my oil cooler, I could easily highway drive in the Midwest with temps at 210F even on an 80F day. But then immediately stop in traffic and that illusion quickly disappeared as airflow into the engine compartment became stagnant.