The OFFICIAL let's make Erick's M30 stop overheating thread

[Erick]

Well, the thermostat and pump are brand new. And no, the car will heat up faster if I rev it out.

[bataangpinoy]

i know that your not supposed to do this, but try taking out your thermostat.
maybe its jammed shut?

[Erick]

Unlikely, since if it was jammed, it would never hold a temperature. The car holds temperature while on the highway at speeds (or cruising above 30-40mph).

If the radiator comes out (for whatever reason), I'll pull the thermostat out. With the little clearance I have now, to remove the T-Stat I need to pull the radiator completely out of the car.

[LowR3V'in]

I guess check the headgasket next? :(

One last question. Does the gauge needle move at all when you turn the fan on/off?
Mine would read alittle hotter once the fan was running because a shitty ground.

[Erick]

It's a brand new headgasket!! Just like the one I pulled was still in brand new shape. My overheating issues were never the headgasket to begin with.

I checked the head torque and everything checked out fine too.

As for the fan, I have been hesitant of running with it off. On the highway, I'll turn the fan off, and it'll seem to run just a bit cooler with the fan ON, but I'm still at around 190 while driving on the highway. (Mind you, that highway cruising temp will vary from 190-200 depending on the outside temperature)

I double checked my fan wiring at John's shop, and except for a loose connector (that I fixed into position properly so it wouldn't disconnect) all was good.

[Danny]

Cracked head/block?

[Erick]

I think that's what's its coming down to, even though the head is fine when they looked at it through the machine shop.

I am slowly thinking that somehow it is the block that is messed up, which sucks considering the amount of money I just dropped in it with head gasket, studs, machining costs, and a shitload of misc costs that added up MUCH higher than I expected

[ForcedFirebird]

Just for shit's and giggles, have you tried flushing the block? When you were here the other night, we back-flushed Brian's car, then regular flush, then back-flush etc etc for a couple hours before it would hold temp. You might just have debris/rust in a coolant passage like he did. Both of you run straight water and that corrodes the block exponentially faster than with coolant.

Yeah, Danny, that was my suggestion after we kept messing around with both cars that night.

[ForcedFirebird]

Well the car is trying to claim lives!!!!! Saw a hose clamp not quite right, and tried to adjust it and I got a face full of hot coolant :( Things we do for friends...

[ForcedFirebird]

We did this for educational purposes...

[bataangpinoy]

damn erick... im scared to start my car because of you guys.

my drifting buddy was taking off the alternator from my motor and i heard a loud crash. he put my engine on the ground but luckily it fell on some word, a distributor and a plastic box....

[Erick]

lol why is that? This is a personal battle between M30s and I.

Anywho, to give some insight on that video that John posted, we did a burnout to see how the car would react after the coolant flush in a "no-airflow" (drifting-like) scenario. The temperature went from about 195 to 210 in during the burnout. (About 15 seconds)

After the video was cut off, we let the car sit for about 10 minutes while still running and the temperature dropped to 205deg. So it seems like it's holding better now, but it's still taking way too long to cool it off.

After thinking for a long time, this will have to do for now. But future plans will either involve going back to an M20 on boost with a clutch fan, or doing a rear mount radiator setup on the M30. Either of those will happen in the near future hopefully, depending on what ends up sounding more cost effective.

- E

[ForcedFirebird]

I would start with a lower temp t-stat, or drilling a few holes in it. The new owner of Brian's car drilled his, and it's running tits now.

EDIT: BTW, the neck looks much better today!

[Erick]

Might as well just pull the t-stat out.

Glad to hear the neck is doing better!!

[FredK]

Are you using a stock M20 1.4 bar radiator cap? It'll let go earlier than the M30-appropriate cap, which is 2.0 bar. Lower pressure = less cooling capacity.

I also agree with ForcedFirebird, try a lower temp t-stat like an 80°C, and drill a little hole (like 1/8") where the arrow points to ease the bleeding process. 71°C and 75°C are also readily available and cheap, but generally, you want to keep the t-stat temperature high as possible without overheating to avoid prematurely wearing your engine and to promote good combustion.

With an 87°C thermostat, it's not surprising you're seeing 190°F water temps. The thermostat is attempting to make your engine run at 87°C, which is 188.6°F, so if anything, it's working as advertised.