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Hi guys,

I am going to install a gauge and sensor to better monitor the temperature of my engine. From what i have read and was told, the best place to fit it is in one of the heater core hoses.
I want to install it as i have no idea what temp its running just a random level on the L series gauge that i just can't trust since i got no idea if its hot or not.

My main question is what is the safe operating temperature range? My gauge is in degrees.

Regards
Guy

I replaced the standard EJ temp gauge sender in the water crossover pipe with the one for my Speco temp gauge.

When I had a healthy EJ18 with stock radiator, operating temp was normally just under 95 degrees celsius, getting up just past 100C when working hard. The very unhappy EJ22 I'm running now is up around 110C, and occasionally goes off the top of the gauge (120C) . Any day now...

Dane.

it says to wire the gauge to earth and ignition switch? which wire is the ignition switch on the L?

I don't think of putting it in the crossover pipe. Hopefully its the same thread and thats what i'll do:)

Pick any wire that has 12V+ when the ignition is on. I spliced into something at the back of the fuse box, possibly the fuel pump.

Use a bit of thread tape or a tiny smear of silicon when you install the sensor, and remember you might need to bleed the cooling system afterwards.

Dane.

thx, i'll try it today

note that if ur replacing the std subaru sensor make sure u replace the one for the temp guage, not the one for the ECU

is that the small one?

I would recommend to replace both to be on the safe side.
About 2 years ago, I found out that my EJ22's temp ECU sensor was shot and giving more fuel than what it shouldv'e,
Cheers
AP

I've tapped an old style mechanical temp guage into the top heater hose - I think its in the thread about my conversion. Anyway, from that my EJ22's operating temp is about 82 degree's when running on the cool side of things, about 95 when running hot - near 91 is where the L's thermo fan kicks in and normal temp is usually in the middle between 82 and 91. I havn't had it hot enough so that the thermo fan can't hold it - at least since the fiori one was installed behind the radiator. So to sum it up:

- cool temp 82
- normal cruising 82< but >91 (usually about half way between)
- "hot" is on the thermofan kick in - 91
- runs a little closer to 91 at night...

It will also peak at 95 on a cold morning without a warm up before hitting the road, although the L's dash temp guage doesn't say its running hot - when the EJ is bouncing off the thermo fan kick in (91) the dash guage will rise clearly above the "C" letter on the guage... I'd like to change the EJ's sensor for an L one, but I'll do it when I need to remove the manifold - which I hope is not anytime soon

Cheers

Bennie

hi guys,

ive just finished fitting an EJ22 to my vw bug and im running a speco sports series gauge

ive fitted the sender in place of the stock liberty dash one in the coolant manifold

they're the same thread (1/8th npt) but the lib sender was very narrow and i had to very carefully remove a lip that was inside the hole with a drill without damaging the thread

without doing this the speco sender wouldnt fit

granted mines a totally different setup. ie engine in rear, rad in front but it seems to sit around 80c on the open road and upto 90 around town in slow moving traffic

my fan cuts in at 102 and off at 97

I installed the gauge 2day and ran the car for a short while. Looks like all my fears of overheating was only the engine running at normal temperature unless the gauge is not giving an accurate reading. I will monitor the readings and update next time i take the car for a drive.

I've noticed that on really cold mornings as the motor is heating the coolant in the radiator the temp will sit on about 95 until the thermostat can open up to warm coolant entering the motor. Slowing down, dropping a gear and giving it some will drop the temp quickly too - sometimes I have to do this twice before the temp drops and steady's on it op temp...

Hope the new radiator is going well!

Cheers

Bennie

Hi bennie, When you say op temperature, what temp is that? Where did you get your gauge sensor and adaptor?

Ok this is very wierd!!!!! The gauge never went over 70deg since 4 days. Sometimes i drive it and the gauge indicates the temp is 50deg for a 20k drive. That can't be right???? I have a Engine light problem on the car since the start and the fans are always on. Woul this cause that? Or is the gauge not working?

Since i've been driving my car, the normal dash gauge level was just over the two "c" mark. but now the gauge tell me that this is about 50deg, and when i thought the car was over heating from the dash gauge, the new gauge tell me that thats about 70deg.

Where does you dash gauge on your L series normally sit on your car? I'm totally confused and noting makes sense:S

I was thinking, to test the gauge, i could boil some water, put the sensor in it, monitor the gauge reading and use a normal thermometer as a control?

guyph_01 wrote:Hi bennie, When you say op temperature, what temp is that? Where did you get your gauge sensor and adaptor?

Well the rated temp of the thermostat is 78 degrees, but the best I've had it sitting on is about 82 degrees while cruising at 110 or 100... I've posted my observations above, but did notice yesterday that on a warm day that's rated as a T-shirt and windows down, the temp will sit on the 82 degree mark without moving where as on cooler days the operating temp seems to be higher and at night it goes even higher (but lower than the thermo fan kick in) as the outside ambient temperature drops. I guess this is just the ECU compensating for the temp change for the best economy...

The temperature guage was sourced from my local parts joint, its mechanical and came in a set of three - oil pressure (at cruise it sits on about 70 psi!, cold it "clocks" the guage at a little over 80 psi!) amps and coolant temperature. They're mechanical, except the amps one The temperature guage is tapped into the coolant out of motor into heater - this gives me a reference that has not been cooled and is rather "raw" in a sense.

For your thermofans being on all the time, this I believe indicates that there's a fault with the ECU, which would be why your check engine light is on also. If your EJ is only sitting on 70 I'd be checking the ECU temp sender unit - its a two wire sensor near the single wire dash unit, I think its got a green plug from memory. The haynes manual should tell you the voltage references at different stages of engine temp (cold/hot etc). Do you know the rating/age of your thermostat?

Also check the reference code on the ECU to see what its telling you - I've still not worked out how to do this as the MPFI EA82 had an LED on the side of the ECU that would flash you codes.

Cheers

Bennie

The number on a thermostat is just its opening temperature - not necessarily the engine's design operating temperature. The unmodified, healthy engines that I've had proper temp gauges on have run in the low to mid 90s.

Has anyone out there put a temperature gauge on a stock EJ22 powered Lib?

Guyph, yes, test your sender in some boiling water against another thermometer and tell us what you find.

Dane.

bennie, I was talking of the T shaped adaptor that your sensor bolts to, where did you get that? I had to custom make mine but i suspect that the sensor sits to far in and it can't get enough water.

For that constat fan issue i have tried everything, i swapped Three different ECU and its the same thing.

The 70deg was the only one time it went up, just normal trips it get to 50 on the gauge. Does you standard dash gauge work? how high does that get? My thermostat is new and i think its 78deg. Im pretty sure the thermostat opens when i drive so why does the gauge only show 50?

I will do the hot water test this week and hopefully both the gauge and thermometer will indicate the same temp:S

Guyph, the T piece I've used is just a regular brass plumbing T piece, then used the larger adaptor that came with the kit to fit the temp guage. On the other two openings I got some male hose adaptors with plumbing tape and used some hose clamps to hold the hoses to the T piece. It was pretty simple to do:



My dash guage:

Between the needle being just off the top of the C with some black background able to be seen and being completely off with maybe 2mm between the two, the EJ is running the thermo fan or heating the coolant in the radiator at the start of a run from cold.
At cruising the needle sits directly over the top of the curve of the C on the dash, this is when at 82 degrees. Between the directly over the top of the curve of the C position and just before leaving the top of the C is the region of 82 degrees and about 91 degrees.

I don't really use the factory dash guage to tell the temp as the movement is usually very small - its there for a quick visual reference to see if I need to check the aftermarket unit for a more accurate reading. The reason why I do this is that the factory guage is closer to the view of the road than the aftermarket unit which is mounted infront of the little open compartment above the driver's right knee.

Hope that is of some help...

I've recently read about the re-drilling of the dash sensor in the coolant channel to fit the L series temp sender unit. This makes the L dash respond the way it did from factory. I kinda wish I knew about this earlier when I had the EJ out of the L series before it was filled with coolant and in use as I probabily would've done it then, if I need to remove the intake manifold or drop the coolant I'll probabily do this job at the same time...

Cheers

Bennie

oh well i had the dash temp gauge get about twice the height of the c so im pretty sure thats hot!!!!! ok well with the needle sitting around the top of that c curve, my external gauge reads 50deg or sometimes less. Could the thing be faulty? or could my T adaptor piece false the readings? (Gauge&sensor is a cheap hongkong ebay one:S )

So you've got your sensor in a T in a heater hose like Bennie's pic? That won't be getting any flow past it, so it won't be representative of the engine temp. Bennie that might explain your very low indicated temps (well that and your monster radiator).

And if you've used the heater hose that comes off the water pump, it could be getting coolant straight out of the radiator before it goes through the engine (can't remember exactly how the heater circuit it set up on these).

Dane.

Ok, So, I'd like to keep the std sensor and dash working, so whats the next best spot to put the sensor at?