coolant Temperature issues

[matrox02]

Hey all while I'm working on other niggles I've also been working on the cooling system, when I purchased the truck it would get to quarter temp but never to the warm temp like I thought I would see, I thought this would either be a bad thermostat or sensor so I replaced both and low and behold.... Its still the same, now when I drive on a normal day it takes about 7 to 14 minutes to get to quarter temp, the air blows hot and both hoses are even temp and hot, on a cold day kid be lucky to see the truck even get off the needle in a 20 min journey and the temp from the heater doesn't blow warm its a coolish air, I replaced the thermostat again but its the same again, now when looking up part numbers I realized I had a 97 and up terrano 2 td27ti sensor as there is no listing for the td27 non intercooled I wouldn't think this is the issue though because when going up a steep hill at motor way speeds it then gradually gets up to temp then immediately drops when on flat ground again, so.... Any thoughts on this? I'm stumped

Oh and the guage seems to work fine when I ground it out it does goto hot

Tl;Dr the truck won't warm up

 

[clivvy]

unfortunately first port of call is, of course, thermostat. Id be going for the higher temp ones, I think 98 degree. BUt there may also be some other issue such as water pump perhaps but if you have flushed the system, fitted new thermostat etc then id expect it to get to about half way in around 5-10 mins and stay there....

 

[matrox02]

unfortunately first port of call is, of course, thermostat. Id be going for the higher temp ones, I think 98 degree. BUt there may also be some other issue such as water pump perhaps but if you have flushed the system, fitted new thermostat etc then id expect it to get to about half way in around 5-10 mins and stay there....

Yeah Id expect the same, though if it was the water pump being faulty if expect it to Over heat, I forgot to mention in the previous post, so far i have...

Replaced the Radiator, Replaced the sensor, replaced the hoses, replaced the thermostat 2x times, flushed it several times ( was really bad )and im using the proper coolant as well, Unless there is a bad ground to the engine causing a bad reading on the gauge?? what should the resistance be when the truck is warmed up? and when its cold? if anyone knows...

 

[Terrano Steve]

Try checking the engine temp with an infra red thermometer.

Engine running cold is a better problem to have than one that runs too hot:augie

 

[matrox02]

Try checking the engine temp with an infra red thermometer.

Engine running cold is a better problem to have than one that runs too hot:augie

Yeah been trying to get a hold of one, Just got back from running a test, I locked the fan up, and let the truck idle, and it wouldnt warm up( hoses cool, no real temp on guage ) so I put a bit of a load on it and let it run, almost 10 minutes later and we have a good temp, both the hoses and the gauge reading good, and let it warm up slightly more then unhooked the fan and the temp started coming down.. all the way back to quarter temp, hoses even and hottish, so yet again, im thinking 3 faulty thermostats in a row?? ( original and the 2 new ) or... the fan clutch is a bit too early

 

[clivvy]

couldn't it still be the pump? that rotates the viscous, so maybe the viscous is at fault?

just throwing ideas around, sounds like the viscous is cooling the engine too much...

 

[AlexD333]

Well I'm confused... Can't be a blockage as it would be hot not cold.. :nenau

I certainly want to know the result of this one though.

Unless a blockage is keeping the thermostats open :nenau

 

[firebobby]

You say you had to flush the engine a few times, so it was well silted up then??
If so, it could be the heater matrix is still bunged up and may need a more powerful flush, like a jet washer.

Clivvy has said about the viscous fan playing up an I think Rick (Solarman) has mentioned this in the past too.
I'm sure Rustic's powers of dredging the old post's will bear fruitful here.

 

[macabethiel]

Engine Temperature Issues

I am trying to use some straight forward logic here the engine produces heat and if left uncooled it will overheat and seize up.

Cooling system consisting of a radiator,fan, thermostat and water pump keeps the engine running at optimum temperature and is designed by the manufacturer to this end.

When the thermostat is closed the flow of water through the radiator is effectively switched off so the water around the engine gets hot again that should cause it to open the thermostat again and maintain a designed running temperature.

If as well as the temperature guage showing a low reading you have poor heat output from the heater then clearly too much cooling is taking place compared to the original design.

Q1. Is the heater matrix the original one or has it been replaced at some time with one with moore cooling tubes ?

Q2. Is the water pump the original design and not an aftermarket higher flow one ?

Q3. Is the fan circulating air over the radiator and engine block all the time due to viscous drive being faulty ?

Q4. If it is a petrol engine they can run on the cool side if the mixture is too weak though not enough to cause your issues.

As you have replaced the thermostat more than once and the engine is producing extra heat when under load my finger would be pointing at the fan being at fault.

As a test of the thermostat operation you could try putting a partial blind in front of the radiator to reduce the air flow through it. Do not block it off completely just try reducing the area by about a half at first then see what it is like. If you see a rise in the running temperature as you almost certainly will then that to me would make me look at the fan.

 

[matrox02]

I am trying to use some straight forward logic here the engine produces heat and if left uncooled it will overheat and seize up.

Cooling system consisting of a radiator,fan, thermostat and water pump keeps the engine running at optimum temperature and is designed by the manufacturer to this end.

When the thermostat is closed the flow of water through the radiator is effectively switched off so the water around the engine gets hot again that should cause it to open the thermostat again and maintain a designed running temperature.

If as well as the temperature guage showing a low reading you have poor heat output from the heater then clearly too much cooling is taking place compared to the original design.

Q1. Is the heater matrix the original one or has it been replaced at some time with one with moore cooling tubes ?

Q2. Is the water pump the original design and not an aftermarket higher flow one ?

Q3. Is the fan circulating air over the radiator and engine block all the time due to viscous drive being faulty ?

Q4. If it is a petrol engine they can run on the cool side if the mixture is too weak though not enough to cause your issues.

As you have replaced the thermostat more than once and the engine is producing extra heat when under load my finger would be pointing at the fan being at fault.

As a test of the thermostat operation you could try putting a partial blind in front of the radiator to reduce the air flow through it. Do not block it off completely just try reducing the area by about a half at first then see what it is like. If you see a rise in the running temperature as you almost certainly will then that to me would make me look at the fan.

Heater Matrix is the original, its not pluged up, it flows freely

The Water pump is a OEM replacement, so not high flowing or what not

Honestly I dont know what a "good" viscious fan feels like, I can stop it at idle with a piece of rubber tubing, when off it spins bug has a bit of drag, so could possibly be a bad fan

And its a Diesel, the td27t Non intercooled

I kinda wunna pull the fan off for a day to see if it runs properly during that time.

Oh and does anyone else have a pipe temp sensor on the bottom rad hose? when i first dove into the issues I replaced the hose and the parts stores dont have a listing for the temp sensor that goes in-line of it, looks like its after market, but at the same time uses the OEM style connectors and fittings to lead me to believe its factory standard,

Attached a pic of the Hose itself::

 

[firebobby]

Christ your coolant is/was bloody dirty
Like I said, I'm sure Rick (Solarman) did a piece about the viscous fan, on here a while back.

 

[rustic]

...
I'm sure Rustic's powers of dredging the old post's will bear fruitful here.

Yep.. here I am.
Like a Genie in a lamp..

Found this one on Viscous fans..
http://www.nissan4x4ownersclub.com/forum/showthread.php?t=22864&highlight=viscous

If the fan runs at full pelt, just the air flow alone just across the huge engine surface is enough to air cool it, so it will not get that hot.
When I start off, you can clearly hear the roar of the viscous fan change around 400 yards down the hill.
In winter, I have a board I place behind the grill, that allows the top half of the rad and engine, to get it up to temperature quicker.
On mine nothing has been replaced in the 20 years of ownership, same thermostat, same water pump and viscous fan, same temperature sensors, and always at the same point down the hill when the fan stops roaring give or take 50 yards. The temperature gauge always at the same point, just below halfway.

You could remove the main fan and see how it goes, with the back up, should it get too hot, then put the interior heater on full with the vents facing an open window, a trick I used to do on my first car a Mini, when it overheated in the summer in traffic jams.:thumb2

Hope it helps..
I'll have a look for other posts too.:thumb2

Edit... just found this too

http://www.nissan4x4ownersclub.com/forum/showthread.php?t=13920&highlight=viscous


Rustic

 

[rustic]

Christ your coolant is/was bloody dirty
Like I said, I'm sure Rick (Solarman) did a piece about the viscous fan, on here a while back.

Well he did post as per my link above...
http://www.nissan4x4ownersclub.com/forum/showthread.php?t=13920&highlight=viscous

:thumb2

 

[clivvy]

that temp sensor in the hose....that's not right, I'm not 100% on that as you have the none intercooled engine, but ive not seen that before...

is the viscous constantly roaring? or does it roar from cold /start then simmer down as Rustic says, after a few hundred yards?

have you tested your thermostat - put it in a bowl of boiling water and it should open...

 

[rustic]

that temp sensor in the hose....that's not right, I'm not 100% on that as you have the none intercooled engine, but ive not seen that before...

The sensor is an after market set up, often used to trigger an electric fan, in place of the viscous fan. This can save a few horsepower from the engine, and reduce over cooling too.

You could test at what temperature the thermal switch cuts in, and chase the wiring to see it it goes to any unused modules like an after market relay.
Is there any evidence that an electric fan has been fitted?
Or is there an after market indicator lamp unaccounted for, on the dashboard ?

We have a workshop down load No. 30 that shows how to fit an electric fan, so might help you search for other components.
see..
http://www.nissan4x4ownersclub.com/downloads/workshop/wk31.pdf


Rustic

 

[Banshee]

that temp sensor in the hose....that's not right, I'm not 100% on that as you have the none intercooled engine, but ive not seen that before...

is the viscous constantly roaring? or does it roar from cold /start then simmer down as Rustic says, after a few hundred yards?

have you tested your thermostat - put it in a bowl of boiling water and it should open...

Was just going to say that!!! I've never seen that before

Here's how to test your stat, my Maverick one failed shut and nearly boiled my head :doh

http://www.nissan4x4ownersclub.com/forum/showpost.php?p=194587&postcount=41

 

[macabethiel]

Heater Matrix is the original, its not pluged up, it flows freely

The Water pump is a OEM replacement, so not high flowing or what not

Honestly I dont know what a "good" viscious fan feels like, I can stop it at idle with a piece of rubber tubing, when off it spins bug has a bit of drag, so could possibly be a bad fan

And its a Diesel, the td27t Non intercooled

I kinda wunna pull the fan off for a day to see if it runs properly during that time.

Oh and does anyone else have a pipe temp sensor on the bottom rad hose? when i first dove into the issues I replaced the hose and the parts stores dont have a listing for the temp sensor that goes in-line of it, looks like its after market, but at the same time uses the OEM style connectors and fittings to lead me to believe its factory standard,

Attached a pic of the Hose itself::

Mis-speak / typo error when I said heater matrix I meant radiator matrix still thinking its the fan..

 

[briggie]

well just to throw a metaphorical spanner into the works ...... my mistral ( sally R.I.P. ) the temp guage used to sit at a quarter ..... hardly ever went above that . on the odd occasion it reached half way , but maybe a couple of times a year if that .

 

[matrox02]

Mis-speak / typo error when I said heater matrix I meant radiator matrix still thinking its the fan..

Oh yeah, Its a brand new Radiator after market EOM replacement no fancyness on it

 

[matrox02]

Oh and for the fan, I dont hear it when i start it, but when i drive down the road the first few meters of acceleration i hear it then it dies down, now ill have to drive it and listen to see if it does it all the time or not because i dont really remember hearing it after that