Engine Temp Problem

[david-b]

Ok, so this is how it breaks down.

It was 50 degrees outside while driving. This was coming home. I don't remember what the coolant temp was at start up. While driving for a while (around normal temp), it was chilling at ~135. While driving, it would go up to ~160, and eventually hit ~180.

Going to work the coolant did hit ~198, but it didn't do it until I got to work. Car being on for about 20 minutes, kinda speeding.

That 135 seems really really low. This was on the logger. Needle didn't move at all. I pushed it down and it never came back up. Thermistate?

[Mikelb]

Yeah, with the coolant staying that low for that long... I would believe that your thermostat is frozen in the open position...
Allowing the coolant to constantly flow through the radiator, running the car cooler than optimal temp...
I would think you're car would lose a slight amount of performance as well as gas mileage (not running at normal temp, exhaust gases aren't being pushed out the exhaust as fast b/c they're not hot enough)... I might think that you're also more liable to run rich

[david-b]

That does explain a lot. My EGR valve is bad too, which causes the car to idle bad at times. It actually got really rough the last couple days. Both working together... or not working together... has been bogging the car down some. Gas mileage has sucked ass for the many months now.

I have to change my coolant tank and flushing the radiator then, so I might as well get a thermostate then too. How much am I looking at price wise for one of them?

[gthompson97]

A thermostat? I think they're like ~$5 or so. Haven't bought one in awhile but they're cheap.

[david-b]

Sweet. I have to find my Haynes manual on how to replace it. At least it's cheap and I can get one new. Just going to wait for my coolant tank to come in and then do everything all at once. ALl in the same area.

[Mikelb]

yeah, FYI, while you're in there... take off the EGR housing... Take a tin can (I used MD, Do The Dew) and make two flat strips of aluminum, lay the EGR on them and cut them to the size of the EGR... then use some scissors to punch holes for the bolts (one strip at a time)... and then bolt the EGR back up there... and WALA... no more EGR problems...

Of course, the instructions above are for informational purposes only, no car operated on a public roadway can legally have the EGR tampered with...

and the Thermostat shouldn't be hard... but I would suggest doing it all at once, it should allow you to properly flush the system and be much easier than going into it twice...

[eclipsed at 3am]

yeah really easy, thank you mitsubishi. iirc, its just two bolts and its located just under the radiator cap(which actually isnt on the radiator, so i guess just the "coolant cap"). dont forget to get a new termostat gasket while you got it opened up. dont use the liquid sealer-gasket stuff, it sucks and gets everywhere and never seals good. get the regular hard gasket. oh and make sure you dont drop any bolts down in that hole. trust me its a bitch. good luck.

ive actually taken my thermostat out. someone told me that it isnt really needed, seeing as how this is super hot florida and all. is that true? I notice that w/o the thermostat, i can drive about 3-4 miles at about 45mph in medium traffic and it never heats up all the way. is this dangerous?

[Mikelb]

Originally Posted by eclipsed at 3am

yeah really easy, thank you mitsubishi. iirc, its just two bolts and its located just under the radiator cap(which actually isnt on the radiator, so i guess just the "coolant cap"). dont forget to get a new termostat gasket while you got it opened up. dont use the liquid sealer-gasket stuff, it sucks and gets everywhere and never seals good. get the regular hard gasket. oh and make sure you dont drop any bolts down in that hole. trust me its a bitch. good luck.

ive actually taken my thermostat out. someone told me that it isnt really needed, seeing as how this is super hot florida and all. is that true? I notice that w/o the thermostat, i can drive about 3-4 miles at about 45mph in medium traffic and it never heats up all the way. is this dangerous?

Remember he has the 420a (NT 2G)... his will probably be a little different than the 4g63... I don't remember what the thermostat on the 420 looked like, that's why I didn't include instructions...

A/b removing the thermostat... I wouldn't think that it would necessarily be "dangerous"... like causing the car to blow up or overheat or anything...

I think that worst-case scenario... The car would use more gas, be more inefficient, cause the plugs to foul, car to run rich, overheat the cat and plug it shut(by melting the honeycomb together)... a good reason to replace it with a high-flow cat (though I wouldn't suggest trying this just to get the high-flow, as it could possibly cause damage)...

I also wouldn't suggest the E-bay "speed chip" as it is a resistor causing the car to run rich possibly causing the above problem...

I have also heard that running a car rich for too long kills the motor, by destroying the piston rings... I don't know if that's true, nor do I wish to find out...

To sum up all the jargon I just said... I suggest running the thermostat, and periodically replacing it...

[dmblover4136]

Mine did the same thing now it wont move from the bottom, did work fine 1 day it quit and I didnt even worry about it till now any thoughts.

[SLoe]

Read the sticky... I put the thermostat info in there IIRC. If it's stuck open or removed then you reach operating temperature as quickly. You will suffer from poor fuel mileage due to running rich, and the engine will operate at a different temperature than what the ecu expects. So performance could suffer without an air/fuel controller or some sort of management. It shouldn't cause you to overheat though, I ran a car for years without a thermostat.

[david-b]

Yeah, I'm definitely going to change it when I get all my goodies in this week. I hope my new resivoir comes in tomorrow or saturday. Then going to flush everything too.

I can't block off the EGR, I have emmissions here in IL. I actually have an EGR blockoff kit, but I'm not going to use it. Anyone interested in buying it?

[Mikelb]

Originally Posted by SLoe

Read the sticky... I put the thermostat info in there IIRC. If it's stuck open or removed then you reach operating temperature as quickly. You will suffer from poor fuel mileage due to running rich, and the engine will operate at a different temperature than what the ecu expects. So performance could suffer without an air/fuel controller or some sort of management. It shouldn't cause you to overheat though, I ran a car for years without a thermostat.

like you said it would run poorly... I don't think you would overheat (without a thermostat), but your cat could suffer, as the car would most likely run rich, causing the catalyst to burn hotter than normal operating temp to burn off the extra gas... that's why I suggested the high-flow (it's really just a resonator, with a straight flow, no honeycombs or catalyst)

[david-b]

Finally got around to buying my thermostat today. Also got my new resivior in the mail, so I was pretty happy too. lol.

Anyways, I opened the radiator cap and right away I seen the problem. The old one look like it blew up. The little metal pieces sticking towards the front of the car broke off. The spring was half way down inside the neck, and the middle piece that moves was wedged sideways.

I took off the front of the housing and took all pieces out. Slipped the new one in and everything went back together. It actually took longer cause I had to move the power steering tank over a little to fit the new one in, so I had to drain it and all, but all in all, it all went good. I have to make a mount for the new tank, but it's sturdy for now.

I didn't have antifreeze so I just reused the stuff that was in there. Have to buy some this week for the flush. So I used water for now. Tried out the car and it warmed up quickly and went to 201, 203, then back to 201 and sat there (idle). So it's all good. Thing warmed up quick as hell! Idle was smoothe too. I wanted to take a pic of the brokem thermo, but i forgot, so I'll do later.

The temp gauge still doesn't work though at all. It's gone. LOL.

THANKS EVERYONE WHO HELPED!!

[david-b]

Just got home from being out all night. There is a huge difference with the car now. For example, when I throw the car to neutral, the rpms would drop and then shoot up to 2k rpm then float back down. Now when the car is warm, I pop to neutral and the rpms fall to idle. Idle surge was a problem too. I always thought it was the EGR valve. Apparently maybe not. It's running great.

I did over fill quite a bit apparently. Overflow tank, well, over flowed pretty good all over my g/fs driveway after I got there. But it's about 80/20 mix of water and coolant right now. Got to fix that this week. Will also help lower the temp a little bit too.

[gthompson97]

Originally Posted by eclipsed at 3am

ive actually taken my thermostat out. someone told me that it isnt really needed, seeing as how this is super hot florida and all. is that true? I notice that w/o the thermostat, i can drive about 3-4 miles at about 45mph in medium traffic and it never heats up all the way. is this dangerous?

The only problem that I see with not running the thermostat at all (even in a warm area) is that the car will not get up to its optimum temp. range, or it will take much longer to get there. That's all the thermostat is really used for. If you don't want to run it, then don't, but I don't see why you wouldn't. It's not like it takes away power or anything, it's more of a "convenience" part for your engine.