[Mk2] [Turbo] Is my Temperature gauge ok?

[joemacmr2]

Ever since I bought my turbo, the temperature gauge has never went to half way. Last night after an hr run it only went up to just over a quarter. Do they normally sit half when warned up. It has never been half way ever. Is my green temp sensor bad? If so is the usual problem low mpg?

[Ryan S]

Ever since I bought my turbo, the temperature gauge has never went to half way. Last night after an hr run it only went up to just over a quarter. Do they normally sit half when warned up. It has never been half way ever. Is my green temp sensor bad? If so is the usual problem low mpg?

sounds normal matey, i've had 4 mr2's and none of them have went to the halfway point, one of them actually sat at about a quarter all the time, you might have a sticking thermostat.

[joemacmr2]

What are the implications of sticking thermostat?

[Ryan S]

What are the implications of sticking thermostat?

If it sticks open, car will take longer than usual to get up to temperature, if it sticks closed the car will overheat, change it, it's a 2 minute job and a new thermo is pennies. Or take the current one out and run without one.

[laze]

Run without one? Is that commonplace?

[bobhatton]

Run without one? Is that commonplace?

No it is not and should never be done

[Ryan S]

There's no problem running without one, the car will take longer to warm up, i've seen a couple of the big builds on here actually remove the thermostat to reduce the risk of a cracked block. However, it's such an easy job that you should really just replace it.

[mrfil13]

Its not a case of taking longer to warm up, without one it will never get to the full temp. I had stuck open thermostat and it wouldn't go above the second notch, it should be just a little below half way normally. If its lower your MPG will suffer, the blower will be cold in winter, also i imagine you could be subjecting the engine to extra wear as its not warmed up properly.

[Ryan S]

What parts of the engine would wear?

[jimGTS]

if it only gets to 1/4, then its likely the temp sensor for the guage is busted, this sits the opposite side of the green temp sensor on the coolant elbow.

the car should 100% be just below 1/2 way when warm ALL THE TIME!
it should not lower or raise from this point when up to temp.

[shinny]

Ever since I bought my turbo, the temperature gauge has never went to half way. Last night after an hr run it only went up to just over a quarter. Do they normally sit half when warmed up. It has never been half way ever. Is my green temp sensor bad? If so is the usual problem low mpg?

Sounds like a stuck thermostat to me, although it could be the sensor. As has been said above, the needle should rise to halfway or just below and then not budge from that position. Running the car with a failed or missing thermostat will result in extra engine wear as nothing (and most importantly the oil) will not be getting up to temperature correctly.

You should try swapping either the sensor or the thermostat when you next can and see if that fixes things.

[jimGTS]

To add to shinnys comments, low water temps will indeed effect oil temps.

I'm sure Noone needs to explain why low oil temps cause wear

[Dame]

Temperature gauge should sit just below the halfway point. I've driven several MR2s and they have always been in exactly this place. Something is wrong with the sender or thermostat.

[Peter Gidden]

Temperature gauge should sit just below the halfway point. I've driven several MR2s and they have always been in exactly this place. Something is wrong with the sender or thermostat.

or gauge.

[shinny]

Temperature gauge should sit just below the halfway point. I've driven several MR2s and they have always been in exactly this place. Something is wrong with the sender or thermostat.

or gauge.

Or wiring!

Personally, if I saw the temp gauge never reaching that "fractionally below horizontal" position I would probably swap the 'stat first. That said, the sender is an easier change so I wouldn't blame anyone who swaps that first instead. If I swapped both and still had a problem, only then would I look at the gauge and wiring.

[Peter Gidden]

Short temp gauge wire to earth. If gauge goes to hot, then that eliminates gauge and wiring.

Then change stat. Maybe it's missing?

[joemacmr2]

Where would I get sender?

[shinny]

Where would I get sender?

http://www.camskill.co.uk/m5b0s605p4332 ... p_to_11_92

http://www.camskill.co.uk/m5b0s605p4333 ... E_11_92_on

Thermostats are not much more, and IMHO a more likely cause:

http://www.camskill.co.uk/m5b0s605p2725 ... thermostat

http://www.camskill.co.uk/m5b0s605p2724 ... thermostat

[joemacmr2]

Maybe il try the thermostat then. Do I have to remove oil filter to get it out? Also I assume u need to bleed coolant? This is a nightmare for me as the plastic drain plug on top of radiator is broken and I have to use vice grips to open it (one of wings is broken off).

If I replace coolant temp sensor and sender for good measure, will I need to bleed?

[jasongtr]

the hard coolant pipes under the car have drain plugs too, about a foot from the firewall towards the front of the car