Gen 3 overheating issue, or is it?

Motacilla wrote:

And if that didn't do the trick, then I would spend the money for the IR camera.
 

An IR camera & an IR gun are two very different things, and even more so when it comes to pricing.  The IR gun is used to measure localized temperature, in this case the water outlet elbow or maybe the radiator top hose, whilst an IR camera would be used to perhaps take a picture of the entire engine bay showing the location of all the hot spots.

"Post COVID", the market has been flooded with inexpensive IR guns, you can get a decent gun for USD$20~50, an IR camera can cost between five and ten times that.

NY cheap reader gives real time readings 


I would say check voltage on battery after an overnight rest 

jackonlyjack wrote:

NY cheap reader gives real time readings 
 

Real time readings of what the ECU is seeing, which may or may not be the actual temperature the engine is running at, and please be aware that some vehicles may use different sensors for the ECU and the gauge.

In the past few years I've experienced several repeated sensor failures on both coolant temperature and oil pressure light sensors, it's fairly easy to determine you have a bad coolant temperature sensor when the gauge needle hits red immediately on a cold start, not so easy if the sensor is slightly out of spec.

You can pickup an IR gun from Amazon UK for less than twenty quid.

fordem wrote:

An IR camera & an IR gun are two very different things, [...]  you can get a decent gun for USD$20~50, an IR camera can cost between five and ten times that.

Very true.  I have a camera and get a lot of use out of it -- wouldn't be in the shop without it -- but a simple gun is very cheap indeed.

Thanks all. New sensor is on it way in the post, same with my thermostat cap.

I have the original thermostat in the garage still, and it was opening in a pot of water right around the 83C mark and fully open by about 94C. Only reason I hadn't put it back in, was the gasket/seal around the thermostat was big and stretched and no longer tight fitting. I'm trying to see if they sell a factory gasket/seal but so far not finding much.

While waiting, I have been playing around with getting it hot and taking some readings with IR thermo.

Temp gauge needle was just below the top of the temp gauge at the max line, the top radiator hose, right at the point it comes off the metal pipe work on the head at most I could get it to read was 94.1C.

Thermostat cap was reading about 89C on the thermometer, and the pipes going into the heater matrix on the firewall read about 88-89C.

While the temps up high on the gauge still, took a few other readings:

Front of the valve cover right in front of the oil cap was reading about 77C

back of the valve cover close to the firewall behind the PCV Valve read 87C

and at the same time, the water pipe where the ECT sensor plugs in was reading 92C.

Header temp at the back cylinder, closest to that ECT temp was showing a reading as high as 281C on the header.

I will re-do this testing again after my drive home from work this afternoon and see if the results are replicated, and I will take a bit longer drive and go highway speeds for a while to ensure I am getting good readings.

So far, it seems that the heat coming off those extractors may be causing me a bit of grief.

Trying to find something to do a bit of shielding, but also strongly considering spending $30 on some exhaust wrap to see how much of a difference I can make. It certainly is toasty at that exhaust side of the engine, near the firewall after running.

I have also tried code readers, but unfortunately my AUS delivered 2003 is not OBD2. Tried about 6 different readers from about $10-1200 and none of them could read the Jimny unfortunately.

I was hoping to get a read from that sensor before and after replacement for my own curiosity.