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I'm trying to figure out what's going on with the coolant temperature in my GQ RB30 carby vehicle.
Stock gauge was showing lower than normal temperature for a while now.
I thought it's the dodgy gauge and decide to install an aftermarket one to get
a correct idea about the coolant temperature when the engine is fully warmed.
68 degrees celsius is as high as the temperature would go whether it's idling or driving on the road for about 15 minutes or so.
The aftermarket gauge is accurate as I tested it outside the vehicle today.
The gauge sensor location is T joint between LPG converter & the engine block.
I removed the thermostat and tested it separately. The thermostat open at around 74 degrees
the way it's suppose to work, and it doesn't open stuck.
I'm beginning to think the engine is not getting hot enough for some reason.
I'm assuming it is an issue, 'cos I believe fully warmed up engine temperature should be bit higher than 68 degrees, regardless of where in the coolant system I take the temperature from. I'm kinda pretty sure, whether I drive the vehicle for a longer period or not won't make any difference.
Can you please help me with some advice, tips, guides on how to tackle this issue?
Thanx in advance.
Last edited by dom14; 13th August 2016 at 07:49 PM.
is that the in or the out line? if it is from the converter expect it to be cooler, when gas changes state it get really cold.
my car has the same issue cant get it hot. sits about the same when i'm sittin on 100 lower if i slow down. most i have ever got was 1/3 on the gauge ( 3 rd gear foot flat up a hill for a long time)
i'm running a 77 deg thermostat.
i'm still looking for a solution as running too cold isn't good. but not as bad as too hot.
i prob suggest that you should of had a 82 deg thermostat for a petrol.
is that the in or the out line? if it is from the converter expect it to be cooler, when gas changes state it get really cold.
my car has the same issue cant get it hot. sits about the same when i'm sittin on 100 lower if i slow down. most i have ever got was 1/3 on the gauge ( 3 rd gear foot flat up a hill for a long time)
i'm running a 77 deg thermostat.
i'm still looking for a solution as running too cold isn't good. but not as bad as too hot.
i prob suggest that you should of had a 82 deg thermostat for a petrol.
Hi mate,
It looks like I might have gotten the spot of the sensor installation wrong by the looks of it.
Please have a look at the diagram below and let me know if I got it wrong.
I didn't mark the direction of the water flow on the LPG converter/heater core water lines, 'cos I'm not too sure.
BTW, my statement "'cos I believe fully warmed up engine temperature should be bit higher than 68 degrees, regardless of where in the coolant system I take the temperature from.", is obviously incorrect.
Pardon my brain fog.(calorie controlled diet ). There's obviously a reason why the stock temperature sensor is installed at the coolant port on the cylinder head where the coolant comes out of and enter the top port of the radiator.
The reason I couldn't install the aftermarket temperature sensor at the right spot on the cylinder head is 'cos the sensor wire is tad short to reach there. So, I chose water lines towards the back of the engine where it comes out of the block.
I thought it might be a good representation of the water temperature where it comes right out of the engine block.
Last edited by dom14; 13th August 2016 at 11:39 PM.
put the sensor in the correct place and extend the wire to reach. You may need to install a genuine thermostate or at least the correct temperature range. To cold means more fuel will be used. As the ECU will think the engine is cold and needs more fuel. Been there done that.
umm i'm not familiar with the set up that has been used for the gas converter. we usually put the converter in series rather than parallel like it is in your picture. (if your converter is too hot to hang onto after its been running shouldn't be a problem) but it does look like your temp sensor might be after the heater or converter so it will give a lower reading than actual. kbchez is on the money here even carby will use more fuel.
Hi Guys,
I put the sensor in the next T joint where I believe the inlet line for heater core/LPG converter as in the below diagram.
There's no improvement so far.
Idling temperature didn't go above 66 degrees, so it's kinda worse than before.
When I took off for a drive it went up to 68 degrees.
After I stopped at the supermarket for ten minutes and got back to the car, the gauge was
showing 71 degrees, which immediately went down to 66 degrees after I started the engine.
I can extend the sensor wire with another one, but I'm not sure that would affect the accuracy of the temperature reading, though I can get some idea about any discrepancy by putting the sensor again in boiling water to see how much the wire extension off sets the temperature reading accuracy.
I'll do that tomorrow and post the outcome.
The next temperature gauge controller kit I'm getting has the ability to calibrate the gauge, so extending the sensor wire won't be an issue with that. But, it's a good week away from arrival.
put the sensor in the correct place and extend the wire to reach. You may need to install a genuine thermostate or at least the correct temperature range. To cold means more fuel will be used. As the ECU will think the engine is cold and needs more fuel. Been there done that.
No ECU atm. It's a carby. The existing thermostat is the stock nissan one, which I tested and it opens at around 76 degrees as it's printed on the thermostat. I think the thermostat is fine, and it's the correct range for RB30 engine, but I may have to do something about this. Either get a thermostat that opens up at a higher temperature or I need find the exact cause of engine's running too cold(assuming it is running too cold).
umm i'm not familiar with the set up that has been used for the gas converter. we usually put the converter in series rather than parallel like it is in your picture. (if your converter is too hot to hang onto after its been running shouldn't be a problem) but it does look like your temp sensor might be after the heater or converter so it will give a lower reading than actual. kbchez is on the money here even carby will use more fuel.
Thanx mate.
How does the carby burn more petrol when the engine's running too cold all the time?
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Originally Posted by garett
). There's obviously a reason why the stock temperature sensor is installed at the coolant port on the cylinder head where the coolant comes out of and enter the top port of the radiator.