MitsuJDM

iTrader: (6)

I searched. This is weird. It's about 66 degrees tonight. I'm driving along waiting for the car to warm up. After awhile the car was not getting warm. The needle was barley over the bottom line. I pull out onto an empty bridge and go full throttle. The car warmed right up. I then noticed after a few minutes. The temperature dropped again. It's not keeping operating temps.

I was thinking maybe a bad thermostat. Usually a bad thermostat makes a car overheat but I can't think as to what would keep the car from keeping operating temps

Help?

ActofDuty

iTrader: (1)

Your thermostat could be stuck open

sho669

iTrader: (34)

+1 It's a lot better than sticking closed

MitsuJDM

iTrader: (6)

Yeah that's what I was thinking. It dark and I just got home I'll check it out tomorrow. The car is driving 100% and I do have heat in the cabin. I rested my hand on the radiator end tank and while it was hot, it wasn't as hot as it normally is.

Maybe I'll just pop a thermostat in and see if that fixes it. Still open to other opinions

mifesto

iTrader: (58)

it may not be a big deal now but once winter hits, you'll take a big hit on MPG as your engine wont warm up quickly... ya get a new thermostat soon

barneyb

Place both the thermostat out of the car and a new one in a sauce pan and cover with water. Now, slowly bring the water to a boil. I think you will find that the old one opens sooner than the new one. There doesn't have to be a lot of difference to make the heater inoperative.

Jim in Tucson

iTrader: (3)

Had the same symptoms when the fan controller was stuck on. Rad fan was running all the time and my VIII never warmed up completely.

MitsuJDM

iTrader: (6)

I was also thinking it could be a fan issue, it makes perfect sense. I'll look into that as well. What did you do to fix it?

Running cold is better than running hot, but this is seriously like right above the bottom line. The needle is moving around a lot. If I dip into boost, like 15psi at part throttle , the needle will go up to normal temps. But after driving at normal speeds in vaccum, it drops right back down to the cold line. So, the fan issue would totally make sense.

Man, my dad would love to have this problem with his Eclipse. He can't get the thing to run cool to save his life. Now my car is running TOO cool, haha.

lan_evo_mr9

iTrader: (10)

The fans will be on all the time if that's the issue... If they're not on all the time, then it's the TStat.

sho669

iTrader: (34)

I'm pretty sure I've read about the fan controllers going bad before. I don't think it's a totally uncommon thing, easy to diag as well then you just replace the "box" on your fan.

MitsuJDM

iTrader: (6)

Yeah I figured I'd just take the car for a short drive to get some temperature and then park it and see if the fans ever turn off.

Also, if there is a leak, the system can't build pressure and in turn can't build any heat. I've always had a very, very small coolant leak at the front water line into the turbo. Once in a great while, like maybe once every 2 months, I get a small hint of coolant smell while driving. I'm going to check out that leak too, maybe it finally needs fixed, haha.

Thanks guys, I'll go take a look at it shortly and hopefully come up with a very fast diagnosis.

Jim in Tucson

iTrader: (3)

If your temps are that cool, then the fan should never run at all. I'm thinking this is your T-stat stuck wide open. Or you could have more than one issue.

Easy to tell. Fans should not come on at all until engine warms up. So, if your engine is not warming up, then fans should not even come on at all.

However, to prove the fan controller is working or not, you may need to heat up the motor to the point where the fans come on in order to see if they do shut off properly, or if the controller sticks in the on position.

MitsuJDM

iTrader: (6)

I just went and checked a few things. I drove the car enough to put temperature into it. Did the same stuff, under boost, temp rises then falls right back down after normal driving. The fans are not coming on at all, which leads me to believe it is in fact the thermostat. The system IS building pressure so that's not a problem.

EDIT:

Hahaha, didn't read Jim's post before I posted. Pretty much right on

I'll buy a thermostat today or later this week and throw it in along with a collant flush. We'll see what happen's. Good thing I have a badass '98 malibu as a DD!

MitsuJDM

iTrader: (6)

AGGHH!!

Ordered an OEM thermostat kit. It's on a 5-day backorder

I guess I'll just take short trips and baby it to get my Evo "fix" for the next week or two. And, atleast it's not overheating The Malibu is a great DD, but to be stuck with it as my only car SUCKS!

MitsuJDM

iTrader: (6)

Ok, a little bump here.

I drained the coolant, did the thermostat, and then refilled and bled the cooling system. Everything seemed to be just fine for about a month. Today I was driving the car, it's pretty cool today, low 50's. I noticed the temp gauge hanging out JUST below where operating temps should be. It was about 1/3 from the C line. Usually operating temp is JUST below half way.

So I keep an eye on it and it starts to fluctuate randomly betwen about a 1/4 way from C, to operating temp. Before it was dropping below the C line, to "full cold" and staying there until I boosted the car. Now it's staying warm, just not consistently.

I did a pressure test and the system held 15psi for awhile. After about 10 minutes it dropped to about 14. So I know there is a leak. There always has been that I've been aware of. But the car isn't really losing much coolant. I didn't need to add any.

So I'm at a loss what the issue could be. The fans don't seem to be sticking on, because every time I open the hood to check, they're not running. Thermostat is new. I just bled the system. only thing I could think of would be a faulty sensor, but I'm not sure how to diagnose that without some sort of scanner that has a "data list" of engine sensors like I do at work for Honda's.

Any ideas? I did most of the easy stuff.