V6 Petrol Terrano gets a bit hot

u_o_me, Feb 6, 10:11am
Hi,

I have an 89 nissan terrano and just recently I have noticed the temp gauge moving between half and 3/4 whist going up hill with revs about 3500-4000. Once over the hill it drops off again.
Usually it sits between 1/4 and 1/2 and maybe moves to 1/2 when going up hill which I thought is normal because revs are higher than flat road cruising.
All coolant present with no leaks, oil clean as.
New thermostat about 8 months ago.
The fan makes the usual whirrr noise but I have to say I haven't herd another terrano like it but plenty of Mistals. Quite at idle until revs get up and the whirrrr gets louder.

Any ideas!

Could it be an airlock! but wouldn't it have heated right at the beginning when I did flush and coolant change!
Do I lift the front and start the truck with cap off till it gets hot to see if there is an airlock!

All help is much appreciated. :)

johnf_456, Feb 6, 10:31am
Radiator could be partly blocked, have you checked the flow! If it was neglected by the previous owner it may have a lot of crap in it, especially if anti freeze has not been used. Straight water is a killer. The thermostat should regulate the temperature.

u_o_me, Feb 6, 10:34am
I did full radiator flush when I put new thermostat in and coolant. How do I check the flow! Cheers

boon279, Feb 6, 10:37am
Theres no real way for checking if rad is blocked with out taking it out. Check that there is still resistance is the fan, could need some new oil.

johnf_456, Feb 6, 10:37am
Could be a sticking thermostat, I have seen new thermostats die. Take it out and drop it in some very hot water. Also check the radiator hoses if they are cold when warm, if so coolant is not flowing (thermostat is failing to open). Feel different parts of the rad while warm up, any cold parts is a sign somethings up while one side is hot.

u_o_me, Feb 6, 10:38am
How do I check the resistance! CHeers

u_o_me, Feb 6, 10:40am
When I did the thermostat and coolant I took radiator out tipped it upside down and backflushed it. Did both ways. Nothing come out.
Its been fine up until now.

franc123, Feb 6, 10:50am
Well done, but the problem is it still doesn't guarantee that all the tubes are clean internally.When we post on here about radiator flushing, it doesn't mean DIY, it means taking it to a radiator specialist to have one of the tanks removed and "rodding out" and they check that the flow through it is 100% before reassembling it again.This is especially important on most imports as they often only have single core radiators in them.If you are certain the visco fan unit is locking up correctly its highly likely thats where the problem lies.Good luck.

u_o_me, Feb 6, 10:53am
Cool thanks for that. Any idea how much the flush costs! The viscous fan is definately spinning. and when you rev it it get louder so I presume it is spinning faster. Cheers

franc123, Feb 6, 10:57am
If you pull it out yourself, as you know how to do, depending on where you are it shouldn't cost more than about $100-$120.

u_o_me, Feb 6, 10:58am
Cheers thanks heaps.

siren676, Feb 6, 11:05am
1 way to check the whether the radiator is blocked is to put your hand on it once the car is up to temp and check for cold spots

u_o_me, Feb 6, 11:07am
Can't get to all spots as I have put an aftermarket transcooler mounted to the front. All fins are clear of debris etc.

u_o_me, Feb 24, 8:38am
Ok so could this be the problem!

WATER PUMP- could the fins be corroded and low revs is creating enough flow to keep motor cool but as the revs get up to 3-4000 it heats up and with the corroded fins it might not circulate the water fast!

Could this be possible!

u_o_me, Feb 24, 10:00pm
Anyones thoughts!

mrfxit, Feb 25, 2:43am
Unless it's a really BIG & LONG hill or towing a frikin BIG load at a fast speed, then the temp gauge shouldn't move much at all.

Check for .
Bubbles in the radiator
Radiator cap seal ok
Murky water
Soft radiator hoses
Fan clutch is ok (hot & cold)
Fan belt is tight
Exhaust smoke volumes

Good flow rates from other water hoses including heater & turbo

robertsons-nes, Feb 25, 4:48am
shouldnt be getting louder when you rev the engine,but also as suggested take radiator out and get properly cleaned

tootsie9, Feb 25, 4:58am
no bubbles, cap near new, no murky water, fan clutch good, fan belt tight and just the usual smoke volumes cold until engine comes of temp.

Temperature around town is normal. Its long hills that rise the temp. It never gets to the H. Highest it has been is 3/4. Petrol not diesel.

budgel, Feb 25, 6:35am
The water pump could be due for replacement.

r15, Feb 25, 7:16am
1: run some radiator flush through the system, this should dislogde any grime and cause it to get stuck in the radiator. drive it for a couple of days (without cooking it)

2: get your radiator rodded out

3:replace thermostat again

4:check / replace water pump if worn / missing blades etc

it sounds like you have some mechanical skills, so this shouldnt be too hard for you.

by doing ALL of these things at once, without skipping any steps, and make sure you do #1 first,this should solve your problem, without wasting any money or time

u_o_me, Feb 25, 8:37am
Ok so how much roughly to get rodded out!
Also with the thermostat its really only about 3000km old as with the radiator flush too.
I was thinking of just checking the water pump just that it is strange why it doesn't heat up around town with hardly any air entering the front of truck.
Should I back flush the system too!
Cheers

mrfxit, Feb 25, 8:41am
Always back & forward flush the cooling system after using radiator flush fluids.
Don't forget to flush the heater system as well. (done separately)

u_o_me, May 25, 5:53pm
Yep done that the last flush too. cheers