[alien]

I still reckon it's missing the plastic tray under the radiator...

[DC3PTIKON]

Defective sender or gauge?

Use a infrared gauge and verify rad tank temps. Also if you can get your hands on a potentiometer test the gauge. Some gauges when defective will jump up or down at a certain range. You can also test the sender with a multimeter if you can get the specs (resistance) at specified temps.

It can't be this hard to find the issue.

[JrZook]

^^This
Alien: That plastic tray doesn't do much to the running temps at all

[alien]

Without it on mine (it fell off while driving) my temps went up at highway speeds. Replaced it and back to normal.

[DC3PTIKON]

There seems to be a lot of throwing parts and theories at this car. Called me old school but maybe test and measure a few things, then diagnose.

[dzasta]

I have no idea what the problem is that is why I am here. I was hoping someone might have had the problem and could help me. I have tried to take the advice given here and worked my way through some of the suggestions here. I am no closer to solving the problem so I will have to send it to a mechanic cos it is way beyond my very limited skills.

[Qthefun]

we all start off with limited skills I hope you benefit from the experience of some on here and pay it forward I try to and hope that the advice is good

[Gwagensteve]

My point is we can't help until you tell us what you've tried and the effects. I'm 100% sure the cause has already been suggested but until we know if you've tried it we can only go around in circles nominating possible causes for so long.


Steve.

[shiv]

I am chasing a similar issue now.

g16b, sj70, 6.5tc, 4.3 diff ratio, 32" tyres, not sure what radiator or shroud i have.
When i sit on 100kmh @ 3900 rmp on the highway on a hot day it sits on 3/4 temp constantly, other driving it sits on about half.

I am not sure what the gauge should read to be considered normal? if 3/4 temp is fine ill leave it as is, if its not ill start pulling it apart.

Thanks for any responses.

[Gwagensteve]

Find out what shroud and fan you have and report back.
G16b's are designed to run hotter than g13a's, so the needle will sit a little higher than with a stock carby motor.

[shiv]

Thanks, yeah i been searching for post that might say what the temp gauge should read.

How can i tell the difference for the radiator and shrouds? Ill grab photos this arvo when im home.

I am happy to leave it as is cause it is running well, just the days will get hotter and i feel un easy being 3/4 on the temp gauge.

[clanger]

I don't really ever post on here but i have read auszookers every day for the last 3 or 4 years ( even though i had to sell my pride n joy a couple of years ago) .
I recon you should read this again from the top and pay particular attention to
everything Gwagonsteve has said, everything has been covered. I also recon the radiator hasn't been ruled out as not blocked, Ive blocked a perfectly good radiator in a lot less than a few months trying to flush the system...

Nathan.

[dzasta]

I can tell you mine turned out to be the fan. I met an old bloke and he gave me the answer. The fan appeared to be working fine but it wasn't. I pulled the thermo bit apart and filled it with silicone. This means the fan works all the time. This fixed the problem so I just replaced the fan and all good now.

[sideways]

shiv wrote:

I am not sure what the gauge should read to be considered normal? if 3/4 temp is fine ill leave it as is, if its not ill start pulling it apart.

Get a proper temperature gauge on it, they're very cheap on eBay. Get something that's either digital or has a 270 degree sweep with lots of graduations. The VDO 90 degree sweep style gauges might look pretty but having 1.5cms between 80 and 100 degrees with a graduation every 10 degrees is a bit shit, still better than stock though.

No point in chasing your tail if there's no real issue.

[Gwagensteve]

Sometimes I'm the only one swimming against the stream on this issue, but I see little value in adding another gauge. I don't know what value it adds. The engine has an operating range, if the thermostat is the correct temperature for the engine, and the engine has the correct fan and a radiator in good condition it won't overheat. If those things are fine and it's overheating it's most likely a head gasket. Adding another gauge will only tell you that one of the things I've mentioned is incorrect. As they're all easy to fix and there are known solutions, adding a second gauge isn't fixing anything.

I understand using a graduated gauge in a highly strung, boosted or unusual engine swap, but with a g series swap there's no need-just get the cooling system to scratch and forget about it.

[sideways]

Gwagensteve wrote:

Adding another gauge will only tell you that one of the things I've mentioned is incorrect. As they're all easy to fix and there are known solutions, adding a second gauge isn't fixing anything.

Which is my point. The OP had questions if it was actually getting hot or not. A gauge is cheaper than replacing parts. If it's getting up to the top without boiling over then that certainly raises questions about the standard temp gauge and in my experience they are inaccurate and slow to react at the best of times. An aftermarket gauge will also help pinpoint what the issue is.

I'd certainly want to avoid overheating a G16b.

The radiator is new so it's unlikely that's it.

He's tried the thermostat so that's not it.

Not the water pump.

That leaves fan, shroud, inadequate radiator, radiator cap, cracked block/head/headgasket.

Another way to test a viscous fan hub is to get the motor up to temperature and turn the motor off. A good fan will stop as soon as the motor does, a buggered one will keep spinning for ages. Given it's only getting hot on the highway it's unlikely to be a fan issue.

FWIW I've had overheating issues with almost every car I've owned and by far the most common issue has been the radiator cap or the surface it seals on. I imagine you got a new cap with your new radiator though.

[shiv]

I had a bit of a leak and coolant was low (just under the top of the element) so hopefully this arvo is a hot one and i can try it out and see if its a simply fix

[shep]

One of these and conferm that it actually is overheating.

[shiv]

Righto i will poke around with a temp gun when its hot. What are the common g16b temps?

[shep]

thermostat opens before 90 degC. I wouldn't be worried as long as coolant temp isn't over 105degC when driven hard. Shouldn't be at risk of boiling until 115-120degC

[shiv]

Thanks shep

[losfer]

invaluable tool for diagnosing a lot of problems those laser temp gauges.

[shep]

Yeah I probably should give it back to ball seeing as it would be a year at least since I borrowed it

[losfer]

haha posession is 9/10 of the law ?

i also have a hd borescope , 8 channel digital oscilloscope , a cf card reader that can read and write cards for obd2 scanners . hardly ever bring them out but when i do it shits on anyone elses diagnosis , you just cant argue with electronics. i also loaded a cool app on my phone it has a bucketload of usefull stuff for luminosity , db readings , gforce and more . its called physics toolbox suite , would recommend.

[shiv]

So was driving it hard today (100-110kmh) up hills ect. Pulled over when gauge was 3/4 maybe abit more. Held the gun on the radiator and thermo and was 99-104 degrees with an average of about 102 most of the time.

[Gwagensteve]

Well that would be 3/4 on the gauge, but the internet tells everyone that the gauge is useless and you have to have another gauge.

[JrZook]

shiv wrote:

Held the gun on the radiator and thermo and was 99-104 degrees with an average of about 102 most of the time.

Spit test to verify 100+C?

[shiv]

No. What is that and how does it verified

[shep]

JrZook wrote:

shiv wrote:

Held the gun on the radiator and thermo and was 99-104 degrees with an average of about 102 most of the time.

Spit test to verify 100+C?

Works better if the spit is still on ya tongue. Sizzle gets you within 10degC but taste gets temp spot on

[henno]

That's the same way I taste-test voltage in my batteries.