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Ideal engine coolant temperature?

Posted: Tue Mar 20, 2007 6:37 pm
by beaver700
Hi,

Ive just got a question, which was instigated when I observed the new temperature gauge in my sierra...

The gauge is from 40 deg C to 120 deg C

Is it true that driving in town, the thermofan has a positive effect on cooling the radiator (i.e. lowers temp), while on the open road the fan has a negative effect on the temp (i.e. makes it higher)?. The reason I asked.... is because I have the thermo wired up to the ignition... therefore it is always going. I drove 100km's the other day and I noticed that while the thermo fan was going on this trip, the coolant temp would not go down below 96 deg... I unplugged the fan from the relay and observed that the cooling improved to aboout 92 deg C. In town its the opposite (as expected)...

Also what is the normal temp of a suzuki engine while fully warmed up. Mine averaged about 94 deg C. Is this normal or is something wrong.


Thanks in advance... :armsup:

Martin

Posted: Tue Mar 20, 2007 7:23 pm
by PJ.zook
The thermostat should regulate the engine temp around 80-85degrees i think.
Is the thermo on the front or rear of the radiator?

Posted: Tue Mar 20, 2007 9:25 pm
by beaver700
The thermo is on the engine side of the radiator, and is drawing the air towards the engine. Should I try to pull the thermostat out and drill some holes in it etc?

Posted: Tue Mar 20, 2007 9:43 pm
by beaver700
Just another question...

How hot is hot? What coolant temperature should a 1.3 not exceed? roughly, so I know if its abnormal or not....

Cheers

Posted: Tue Mar 20, 2007 10:01 pm
by MART
You shouldn't muck arround with thermostats and the water flow because if you modify the thermostat , the water travels too fast through the radiator and doesn't have enough time to cool properly , basically it doesn't stay in the radiator long enough to cool. The thermo fan becomes useless as you speed up and the air is pushed through the radiator . When driving at speed for a long distance you might get a small decrease in engine temp , with a higher volume of water flowing through the radiator continuously . While driving in traffic the thermo fan draws air through the radiator , but is not as good as higher speed driving , as you rev the 4wd in traffic areas the water flow speeds up and slows down causing a slightly higher temp . As for turning your fan off I wouldn't , I would get a temp switch to control thermo with a manual overide. Not real sure about max temp for engine , but I think it will be fine , Cheers Paul.

Posted: Tue Mar 20, 2007 10:04 pm
by beaver700
Thanks Paul, what you said makes sense :cool:

Martin

Posted: Wed Mar 21, 2007 8:31 am
by beaver700
Would the rad cool better if the thermo fan was mounted on the front side of the radiator instead of the back?

I would of done this... except ive got a/c so the condenser gets in the way...

Does anyone know a possible solution to this?


Cheers

Suzi cooling

Posted: Wed Mar 21, 2007 11:07 am
by want33s
I would throw away the thermo and refit the engine fan and shroud. Reco radiator if needed and new thermostat and check the hoses. Mine is all original cooling system (I moved radiator/shroud & fan closer to engine 15mm to clear winch better) with NO DRAMAS in mud or sand or water or traffic. Moving your spotlights outwards a bit may help.

Posted: Wed Mar 21, 2007 1:00 pm
by beaver700
Gday,

Is it possible to fit the stock viscous fan from the sierra engine to the gti engine?

Cheers

Posted: Wed Mar 21, 2007 3:30 pm
by Santos
yes, you need to swap in the sierra water pump and get a multi-rib water pump pulley from a vitara g16

another idea is to put cooling vent's in the hood so the hot air escapes faster

Posted: Wed Mar 21, 2007 3:38 pm
by Highway-Star
I don't know how hot it is, but mine is nearly always about 3mm above the bottom line on the stock temp gauge. I use a thermo fan (14"), keep it on the engine side (better). You should have a thread taped in the bottom of tour radiator to take a temp sensor for the fan, mine uses a nissan pulsar one i think, and makes the fan automatically kick in at around 76c (so probably what my car runs at, as thermo rarely comes on).

I personally wouldn't go back to the original fixed fan (not viscous, just four bolts); but if you do I'd say all you would need to fit it to a GTi is a matching water pump, and the little spacer block thy have.

Posted: Wed Mar 21, 2007 5:26 pm
by beaver700
Gday,

Took the sierra for a drive today, and noticed it sits on about 95 deg C, and on the open road, it either goes up from there, or stays at 95...
Aside from power consumption, does it really matter if the thermo runs all the time? (even on the open road).
At what temperature should I pull over?. Is 95 something to panic about?
Is there anything which could make the engine run hotter than usual. etc headgasket blown( I dont think its that).

Thanks

Posted: Wed Mar 21, 2007 5:43 pm
by PJ.zook
Cooling problems have got to be the worst thing to trace without spending lotsa money, so hopefully you find somethin easy.
Always whenever possible, have youre fan drawing air thru the radiator instead of pushing it, as air will flow nice and smooth and you will get good airflow. If you put it on the front of the radiator, the air hits the fins and becomes turbulant and has to be forced through the radiator, so isnt as efficient. Imagine it like you had a piece of string threaded thru the fins of youre radiator, its a lot easier to pull thru, and almost impossible to push.
As for what temp to pull over, youre coolant will boil and overflow if it gets too hot, so you dont really need to worry so much as max temp, but retaining the coolant.
Check youre timing maybe, if its advanced too much that can cause it to run a lot hotter.

Posted: Wed Mar 21, 2007 6:45 pm
by lay80n
Lean mixture will also cause hot running. Remember that if your cooling system is holding pressure, the water will boil at around 115 degrees, as water (or fluid) cahnge of state is altered when its pressure is changed (higher pressure requires more energy to change its state). Mine sits about 4 mm of the bottom of the standard gauge, no idea what temp that is though sorry. Though i do have a suspicion that my thermostat is stuck 3/4 open.

Layto....

Posted: Wed Mar 21, 2007 9:32 pm
by beaver700
Gday,

Thanks for the info guys, there is some great stuff here! :armsup:
One thing I noticed today after work, is I was driving home and I noticed the coolant temp was pretty normal (about 90-92 degrees in town). Anyhow when I got home I checked the engine, and the first thing I noticed was the bonnet was only closed halfway, allowing more air into the engine bay,
It does get quite hot under the hood due to extractors... could this be part of the problem?

If so, is there any way I could let more air into the engine bay. (preferably not a bonnet scoop...)



Cheers,
Martin

Posted: Thu Mar 22, 2007 7:36 am
by zooksport
Therm fans suck better than they blow.

Consider using the electric water pump setup....

http://www.daviescraig.com.au/main/display.asp?pid=47

and you can buy "lagging" to wrap the exhaust to bring down the heat.

.

Posted: Thu Mar 22, 2007 11:53 am
by beaver700
Gday, just thought I would bring up the issue here...

The check engine light (gti eng) sometimes flashes a code which says 'vehicle speed sensor'. Would this have any effect on the computer, which in turn effect how the engine runs?

Cheers

Posted: Thu Mar 22, 2007 11:58 am
by nicbeer
beaver700 wrote:Gday, just thought I would bring up the issue here...

The check engine light (gti eng) sometimes flashes a code which says 'vehicle speed sensor'. Would this have any effect on the computer, which in turn effect how the engine runs?

Cheers
Did u do the mod to the cluster with the vss? I know the vit 16v ones are a bolt in to the cluster, not sure on where or what the gti ones look like.

I beleive it may cause a small flat spot and possibly worse fuel economy.

Nic

Posted: Thu Mar 22, 2007 1:26 pm
by beaver700
Thanks Nicbeer,


I never changed the cluster...I have heard someone talk about the VSS mod, but when I started up a new thread a while back, nobody seemed to know anything...
Do you know anyone who could give me help, as I have no idea where to start...

Any help greatly appreciated..

Cheers,
Beaver

Posted: Thu Mar 22, 2007 2:24 pm
by nicbeer
Some good pics here.

http://carl.outerlimits4x4.com/viewtopic.php?t=100311

U will need to get the right vss first but after that easy as install. only 2 screws and 2 wires extra after pulled cluster apart.

Nic

Posted: Fri Mar 23, 2007 11:20 pm
by beaver700
Gday,


Just an update....

Today I decided to do an old trick... take out the thermostat and run the engine without it....

I done that, went for a drive (80km's) on the open road. The overall temperature improved greatly (90deg C, in stead of 100deg C), which leads me to believe that it was the thermostat which caused the heat...
Now the time has come to buy a replacement thermostat... I dont really understand how they work yet... so

What sort of rating thermostat should I buy, as I live in central NSW (with plenty of 30-40 deg days of recent)...

Any help greatly appreciated...

Cheers,
Martin

Posted: Sun Mar 25, 2007 2:20 pm
by beaver700
nicbeer wrote:Some good pics here.

http://carl.outerlimits4x4.com/viewtopic.php?t=100311

U will need to get the right vss first but after that easy as install. only 2 screws and 2 wires extra after pulled cluster apart.

Nic
Hi,
Just wondering where I could get the right vvs to fit into my sierra... how does it work exactly (reed switch). I have the gti instrument cluster, and I cant see anything which looks like the ones in the photos...

Will one from a vitara work?

Thanks
Martin

Posted: Sun Mar 25, 2007 2:44 pm
by nicbeer
U may have to find out where the GTI puts there vss first. may be in the gbox or output shaft area.

Cant see if the vit one woudlnt work but dont know for sure.

Nic

Posted: Sun Mar 25, 2007 3:50 pm
by beaver700
Gday again,

Just another update

1. Ive replaced the thermostat, still runs hot
2. Flushed the radiator (the tanks and core was cleaned 18months ago, ive kept it clean)
3. I took it for a drive (20k drive on the open road, outside temp was about20 degrees), the temp gauge was reading 97 the whole trip... Thought I should check to see if coolant was low, it was fine...
4. While I had stopped I checked the temp of the radiator hoses with my hands, i.e. the bottom hose was cool as a cucumber, I could even touch the top hose...

I noticed the radiator has a few bent fins, but I feel there is a bigger problem somewhere... I am about to check the timing now...

Here are some photos, it may be hard to ignore the nessyness of the engine bay... :roll:
Can anyone see anything which may cause the engine to run hot? I will try and refit the shroud soon (could that make a difference...?)


Image
Image
Image
Image
Thanks
Martin

Posted: Tue Mar 27, 2007 4:49 pm
by Highway-Star
To me it sounds like your engines not overheating, if the pipes are touchable; unless the thermostats not even opening. I would consider the possibility that the temp gauge is telling you tall stories. Try a different temperature measuring method if possible.