3SGTE: Do I have a problem here?

[tadamany]

I hope it's nothing, but still wanted the advice of all you exerts. I have two questionable issues. I've got a '91 Turbo, all stock.

- My MR2 idles at about 1500-1800 RPM? Is this normal?

- I've never seen my engine temp gauge over 1/3 of the way. It's starts out at the very bottom, and as I drive for a while it gradually goes higher to about 1/3. The car runs great, so maybe it's just a sensor?

Any feedback is appeciated.

Thanks.

[masagsxr]

Seems ok... Regarding the idle, maybe the timing is a bit advanced. I believe N/A normal temp idles at 750rpm. Check the BGB for the turbo. I'm guessing its in the same range no more than 1K RPM. But yeah, if the timing is advanced then it can idle higher.

[MR210]

The car should idle at about that until it warms up. Once it's warm it should be barely over 1k or a little under.

[MR JAS]

Originally Posted by MR210

The car should idle at about that until it warms up. Once it's warm it should be barely over 1k or a little under.

thats what im thinking that combined with the temp never going up that far says to me the thermostat may be stuck open and the engine is over cooling hence keeping the choke on

[mr.ac]

for the idle I would check the vaccum lines, there may be some drit or gunk that is slightly clogging up the line.

as for the engine temp gage, I'm thinking its just a slow gage reading. could be the needle its self.

[MR210]

Originally Posted by MR JAS

thats what im thinking that combined with the temp never going up that far says to me the thermostat may be stuck open and the engine is over cooling hence keeping the choke on

I've seen it before. Had a friend take a car in because it was overheating in the summer. It was just a broken thermostat so they charged him parts and labor and just took the thermostat out. That winter he started to have these same symptoms.

I don't know the price on them, but I know for my kia beater it was only like 7 bucks for a new one, shouldn't be much more than that. cheap place to start looking anyway.

[MR JAS]

Originally Posted by MR210

I've seen it before. Had a friend take a car in because it was overheating in the summer. It was just a broken thermostat so they charged him parts and labor and just took the thermostat out. That winter he started to have these same symptoms.

I don't know the price on them, but I know for my kia beater it was only like 7 bucks for a new one, shouldn't be much more than that. cheap place to start looking anyway.

and for a cheap one for a vauxhall vectra its around$220 so they can vary but jap ones r cheap

[Gairloch]

Originally Posted by mr.ac

for the idle I would check the vaccum lines, there may be some drit or gunk that is slightly clogging up the line.

as for the engine temp gage, I'm thinking its just a slow gage reading. could be the needle its self.

Plugged vacuum lines will never cause high idle. If anything, they will cause the engine to idle too slowly or even stall.

If a temp gauge has failed then it will give no reading at all. If the needle moves then it's fine. A low coolant temperature reading is an indication that the thermostat is stuck in the open position and needs to be replaced. The cost of the part itself is usually less than $15 but the labor will be an hour or two because bleeding the MR2 coolant system is a bit of a pain.

[warhawk]

just FYI, according to the BGB the 3sgte normal operating temp idle speed is 800+ rpm.

[BishopTTU]

I was experiencing the same thing with the temperature gauge on my 93. After replacing the temperature sensor for the gauge the problem was solved.

I had Toyota do the work.

In my 91, I'm experiencing the same problem again. I have the OEM temperature sensor for the gauge and want to do the work myself. How does one bleed the coolant lines? Is there a sticky?

I didn't see in the BGB how to bleed. Only, how to drain and fill back up.

[warhawk]

Originally Posted by BishopTTU

I was experiencing the same thing with the temperature gauge on my 93. After replacing the temperature sensor for the gauge the problem was solved.

I had Toyota do the work.

In my 91, I'm experiencing the same problem again. I have the OEM temperature sensor for the gauge and want to do the work myself. How does one bleed the coolant lines? Is there a sticky?

I didn't see in the BGB how to bleed. Only, how to drain and fill back up.

This might help you out a bit. You're welcome

Bleeding Air out of the MR2 Cooling System

[tadamany]

Perhaps I'll take it to the Toyota Dealer to do this.

[Big Thurs]

thats what im thinking that combined with the temp never going up that far says to me the thermostat may be stuck open and the engine is over cooling hence keeping the choke on

This addresses both of the problems. Excessive flow through a stuck open t-stat prevents the coolant from getting up to operating temperature. When it stays cold, it stays in warmup enrichment which also means high idle to speed warmup. The gauge coolant temp sensor is also separate from the sensor for the ecu.
The other possible cause (although less likely) is the gauge sensor failing AND the idle needs to be manually adjusted. Is it building coolant pressure and does the coolant get hot?

[albertgunit101]

hows it going guys i just would like to add that i have the same problem with my 93 turbo. i drove the car on the freeway for about 1 hour and half continously and when i open the engine lid and touched the radiator cap it was not hot at all nor warm atleast. my temp gauge never moved since i started it.

do you guys think the problem is the temp gauge sensor or the thermostat stock open? but my idle was fine it was sitting a little below 1k.

does anybody knows where is this temp gauge sensor at and have any idea if they are expensive and difficult to replace. thanks

[MR JAS]

having a faulty temp gauge sensor wont keep the engine cold

its defiantly the thermostat

[tadamany]

So I changed the thermostat, flushed, refilled and bled the cooling system with a 50/50 mix of Toyota Red Stuff/distilled water. Ran the engine for 10 minutes at 3,000+ RPM. The Water Temp gauge still does not raise past the 3 tick mark on the dash.

The engine is getting hot, although I'm not sure how hot, but it's hot enough that you can feel the heat from a few feet away.

So unless the OEM thermostat I bought from Toytoa is bad, can I assume I have a bad temp sensor. Again, the temp gauge does move a little once it get's warmed up, but it doens't move up too far.

Also, there is a gasket around the theromstat. Should there also be a gasket where the water inlet piece meets the water pump? It's just metal on metal right now and I saw a couple drops of the Red fluid under that area this morning.

Thanks to everyone who's smarter than me about this.

[SVX92]

Reviving an old thread i'm having issues with slow warm up. Mine does get all the way to the halfway point but takes 10-15mins to happen. I also start up idle at 1500rpms. i have wondered if it's a stuck open t-stat as well.

The thing that makes me think it might be is if i put the heat on in the car the temp gauge drops quickly. It blows hot air but seems weird that the temp gauge drops.

This is on a na-to-3rd gen swap btw.

Any input is appreciated!

[BishopTTU]

The temp gauge sender seems to be out. The same thing you described would happen on my 93 -2 for about 6 months until I replaced the sender.

[RapMin]

do you know which one is the CTS to the Gauge? is it the black bladed one? or blue bladed one?