Temperature fluctuations

[tashtego]

Hi all,
I am getting to know the surf, it has only been with me a few weeks, and I have started to wonder whether the thermostat has been removed...- it takes quite a long time for the temp gauge to move up on cold starts and even when it reaches the 1/3 mark on the gauge still it easily drops to almost cold on long downhills. - I thought that if the stat is in then Temp stays pretty constant, as the stat regulates amount of fluid going in/out.

I hear that vehicles exported to hot countries sometimes get the thermostats removed by the importers...

The vehicle has recently been imported, my mechanic says red coolant is very clear and clean, if we do a flush we might chuck away a whole load of new-ish coolant, and this is Africa after all, don't really want to waste!

Is there any way to know if the stat is in or not without physically opening it up?

Cheers and have a good day!

[Bogus]

Looks like your stat is stuck open, or some idiot has removed it. Fit a new one. and be done with it, and new coolant or not, do a flush at the same time. Its cheap enough.

[tashtego]

Thermostat

Thanks a lot,

That makes sense, so that's why temperature goes back down when driving downhill or just cruising, then picks up again uphill, then down again...so is that a symptom of missing ( or stuck) thermostat?

[tweak'e]

it wouldn't hurt to replace the thermostat.
but it also may have a modded gauge and is showing the normal up/down temps that you get. ideally ditch the factory temp gauge and fit and aftermarket that will give you some accurate numbers.

[tashtego]

Not sure...THERMOSTAT

I am not sure if I understand:

If the Temp gauge goes up and down,(I don't mean overheating, coolant level is constant,I just mean moves between Cold and just above 1/3) depending on the type of road, uphill or downhill, is this a definite indication that thermostat is either stuck or "not there"?

Shouldn't the gauge stay pretty much at the same level, once the engine has reached working temperature?

Just would like to know before I try getting to it

Cheers

[Bogus]

Thanks a lot,

That makes sense, so that's why temperature goes back down when driving downhill or just cruising, then picks up again uphill, then down again...so is that a symptom of missing ( or stuck) thermostat?

Yes, going downhill your engine is not "working" so with a good airflow over the rad and full water circulation due to a stuck or no stat present, you are cooling down to ambient. On cruising your engine is "working" but not working too hard.
Going uphill your engine is working hard, work generates heat.
I,ll be pretty sure this is a stuck, or removed stat situation and gobsmacked in the extreme if its a modded gauge. Go straight for the stat, and if that doesnt fix it, then you can start loking for the unusual.

[Bogus]

I am not sure if I understand:

If the Temp gauge goes up and down,(I don't mean overheating, coolant level is constant,I just mean moves between Cold and just above 1/3) depending on the type of road, uphill or downhill, is this a definite indication that thermostat is either stuck or "not there"?

Shouldn't the gauge stay pretty much at the same level, once the engine has reached working temperature?

Just would like to know before I try getting to it

Cheers

Question 1. Answer YES

Question 2. Answer YES, IF THERE IS A WORKING STAT, answer NO if there is no stat. The stat is there to control that working temp. With a stat, coolant temperature will remain relatively constant regardless of ambient temp, speed , uphill, downhill etc. Without a stat, coolant temp will fluctuate depending on how hard you work the truck.

Dont do this, but if you start your truck which has no stat, and leave it on idle it will sit all day with the gauge sitting at cool. Now put your foot on the loud pedal, sit it at 3000rpm and watch the gauge

[tashtego]

Now we are talking

Right,
Thank you very much,Bogus, your explanation is very clear and it really makes sense. Just by thinking of any other vehicle I have driven, the temp gauge sits still once engine has reached working temperature.

Will open it up and find out.

Cheers!

[tweak'e]

just want to make something clear here.

even with a working thermostat the engine water temp still will go up and down depending on how much fuel is burnt. very hard to get a thermostat to keep a perfect level temp. that up/down is normally hidden by the idiot friendly factory tamp gauge.
to get a factory gauge to go up/down while driving requires a really big change in temps.

[TonyN]

The temp guage is designed to sit reasonably still over the average range of engine temps, and will only start to move when it starts to get properly hot enough to cause troubles.

If you want to scare yourself everytime you squeeze the throttle there is a resistor mod you can do to make the guage react sooner to mild rises in coolant temp.

Personally i'd leave it alone, and fit an aftermarket gauge if you want to moniter temps properly.

An engine that only get up to normal temps under load, and then cools down so the heaters don't blow hot at idle or coasting definatly has no stat in it.

[tashtego]

Stat was stuck open

Thank you all for your advice,

I have indeed got the old stat out and the black rubber bit was stuck open, and lost its function. - have replaced with new original one (plus gasket), and now the Temp is stable! No more going down to Cold on a downhill road, which was weird. - am glad it hadn't been removed, co I heard that it get removed on imports when they get to Durban or Dar. Maybe they couldn't get to it?the rad has a sticker with an Esso logo saying" long life coolant": decided to keep it in until next service. How do I post a pic of the truck (purely for vanity reasons)? Can I do it from the BlackBerry?
Cheers and thanks for effective advice!

[tashtego]

80 series fan in surf?

Hi all,

This is a newbie question: foik here suggest replacing the 3rd gen fan with an 8 blade fan from a LC 80 series. Apparently same type of attachment using four screws. Has it been done before by anyone out there? And is it effective? I have used the search to find similar thread/posts but not much luck...

Cheers!

[TeaMonsta]

....and fit an aftermarket gauge if you want to moniter temps properly.

My Surf's been showing exactly the same symptoms that are mentioned in this thread. I'll start with a replacement stat but where can I get an after-market gauge, too? I've looked at Milner's and Roughtrax but no luck.

[Overland Tonka]

For most things in life there is ebay....don't forget the sensor.

Or if you want to go down the 1980's route try a motor factors...

Attach to the top hose.

[TeaMonsta]

Of course. Good ol' eBay. I'll have a butcher's.