RUnning a little Hot... any ideas why?

[Ed]

do you have a good shroud around your fan?

I ran into this prob a while back and went through a whole series of deductive tests to conclude it was the lack of a shroud.

http://fefcholden.org.au/forum/index.ph ... 243.0.html

Cheers

Ed

[samprinci]

Devilrod »
"nope higher as in 170, 180 etc..."
is the theory- as it is opening later / high temp, creats a better circulation & better cooling?

harry186: I'll keep that in mind

trev thanks mate

Ed. hummmmmmm / dont really wanna do any modifications... but I'll keep it in mind. TA

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Ok Ive booked her into get a professional engine block clean. c how we go.???

I think that the filter hose has a little kink in it, which may be restricting flow a little, so would I be better after the clean running NO filter, thus having the original hose back on???

thanks guys

[Harv]

Sorry Mick, I may not have worded the "myth" bit real well . One of my jobs involved designing, installing and troubleshooting heat transfer equipment (including radiators).

Radiators (and any heat exchanger for that matter) will transfer more heat (i.e. cool better, run a lower temperature) if the flow through them is increased. Inside the radiator, the water closest to the radiator walls forms a slower-moving "skin" (like custard sticking to a pot wall) that acts as a partial insulator. By increasing the flow, the "skin" gets stirred up, and you get better heat transfer (more cooling).

You're right though, the thermostat is critical. It keeps the water in the block on startup, allowing it to warm up quicker (which reduces engine wear and emmissions). Once the block is up to temperature, it opens and allows circulation. If the radiator is sized big enough (and is clean...), the thermostat will act as a control valve, opening and closing to keep the water temp close to the correct operating temperature. These cars are a pleasure to drive - the temperature gauge comes up to operating temperature quickly, and stays there regardless of load. As the vehicle gets older (and the radiator/water jackets start to foul), the thermostat loses the ability to keep up with the desired amount of cooling - it opens once the block is warm, and stays open. These cars are less fun to drive - the temperature will wander around depending on load (higher load like towing, higher water temperature). In these cars (and old Holdens mostly are like this), putting in a high-flow thermostat can help as the extra flow increases cooling (about 30% higher water flow for Triton high-flow thermostats) and gives the thermostat a chance to control (rather than just staying open).

DR: Original grey motor thermostat depends on whether a heater was fitted. If a heater is fitted it is permissible to use an thermostat with a “Start to open” temperature of up to 173ºF (78.3ºC) to improve the heater performance. However, should excessive detonation (pinging) be detected or if hard driving is employed, it is advisable to use the standard thermostat with a “Start to open” temperature of 160ºF (71ºC). Bearing in mind that modern fuels are significantly higher in octane than the original FB/EK Holden fuel (current unleaded petrol is 91RON and premium petrol is 95RON versus the original FB/EK Holden fuel of 86RON), detonation is less of an issue.

Sorry for the long explanation (maybe it helps Sam though ).

Cheers,
Harv.

[samprinci]

thanks Harv. certainly does help mate.

I'll give the pro flush a chance, c how we go. if no better? will look at getting a "HOTTER" thermostat. fingers x the flusher works???

[Harv]

Sam,

I may be proved wrong, but if it was mine, I'd try a high-flow thermostat first. DR may be right and a hotter thermostat may work, but I can't think of any engineering reason why.

In any case, the part numbers you need for grey motors are below - happy playing!
Part number Type Opening temperature
TT1-160 Conventional 71ºC (160ºF)
TT2000-160 High flow 71ºC (160ºF)
TT1-167 Conventional 75ºC (167ºF)
TT1-170 Conventional 77ºC (171ºF)
TT2000-170 High flow 77ºC (171ºF)
Note that the corresponding TRIDON thermostat gasket is part number TTG29U.

Cheers,
Harv.

[Cal]

Another thing people neglect is the radiator cap. Check that it's the correct pressure cap and that the spring is actually working.

It's gotta be something simple that's causing the overheating. It's a standard grey for fecks sake

Usually if it's overheating on the freeway and not in city driving it will be a blockage somewhere thats causing circulation problems. I'd put money on it that a proper flush will cure it.

Sam, are you losing any coolant?

[Devilrod]

Sam,

I may be proved wrong, but if it was mine, I'd try a high-flow thermostat first. DR may be right and a hotter thermostat may work, but I can't think of any engineering reason why.

I can't explain it but saw first hand a big block f..d in an old fairlane running hot. They tried all sorts of fixes (mates workshop) spoke to an old guy at a radiator place he told them to go up in the heat range and problem solved!! Go figure... I don't get it either.

[samprinci]

rodger all that fellarzzzzzzzzzzzz. I'll keep u posted.

hey Harv, u wouldnt happen to be a TRIDON sales rep would u only joking mate... thanks mate I appreciate your detailed answers.

Pete: yer Im hoping the pro flush solves the problem??? but its a brand new cap too. not loosing any coolant/water either

DR: I think the theory is it doesnt open till later thus holding water in radiator long which gives it more of a chance to cool down???
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just out of interest. I ran a little test, flushed the radiator out. checked location of temp gauge, its good. gave it a good clean. put it all back together. filled her up n let her sit idling to c what happened. I wanted to see when the thermo would open up. watching waiting..... & hand on radiator... it got upto 195 b for the radiator when hot.. does that mean thermo not working right. or is it work correctly starts to open at the 160 mark, but then 180 full open but by the time it registers its at 195??????


thanks again guys. much appreciated
laterz

[Harv]

Sam,

The temperature sender is normally a long way from the radiator. When things are cold, and the thermostat is shut, there is bugger all circulation of water around the thermostat. The block will creep up above the thermostat opening temp (160ºF for your thermostat), waiting for the hot water to conduct heat to the thermostat. The thermostat will then start opening once it gets to 160ºF (i.e. its normal for your gauge to read higher than the thermostat opening temp during startup). Only way to check the thermostat is opening at the correct temp is in a coffee mug of hot water (yours is a new thermostat though... probably working OK).

Cheers,
Harv (definitely not a Tridon rep, but a chronic parts-book reader ).

[Blacky]

How accurate is your guage ? Can you get hold of an infra red type temp reader ?

[samprinci]

"(i.e. its normal for your gauge to read higher than the thermostat opening temp during startup)."

thanks harv.

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Hey Blacky: yer its a brand new guage.

[Blacky]

jUST BECAUSE ITS NEW DOESNT MEAN ITS ACCURATE ...........

[samprinci]

ok point taken.. it did actually cross my mine, the gauge might not be working. whats the best way to test it then?

think Harv mention - boil water in kettle & test it that way????

[Blacky]

Do you have a thermometer ? stick the thermometer and the sender of the guage in a jug , switch it on and check the guage reads the same as the thermometer as the water heats up.

[samprinci]

aaaaahhhhhhhhhhh.. theres always a simple an logical answer...

love-et. thanks blacky. I'll give it a go.