2000 Nissan Frontier V6 Overheat Issue *Video*

[TenorTim]

Been having an overheat issue for a few years. Happens very sporadically ... Mainly in the warm months. Sometimes it happens when going through town at low speeds, but it has happened several times at constant highway speeds. The temp gauge will just suddenly and steady start to rise. I can turn on the heat, clutch it and rev the engine to about 4K and the temp hand will stop rising and usually eventually return to normal. Sometimes I can drive for several hours again without incident, sometimes it will start to rise again within a minute two. Within the past two years I've replaced: The radiator, thermostat, radiator cap, and temp sending unit. The water pump is about 3 years old. (it was only 1 year old when this first started happening) I've posted a video of this happening at the link below. I had just stopped the truck when it started overheating in the video. When the video starts the engine is just starting to overheat, I'm able to rev the engine to bring the temp back down... after about 30 seconds the engine starts overheating again. Any direction would be greatly appreciated.

[BRubble]

What's the Coolant level in the Radiator? Not the Reservoir.

When the engine is idleing, with radiator cap off, do you see any active bubble's in the Radiator? Have someone to rev the engine just a little, and again,, look for active bubble's.

Has any radiator Stop Leak ever been put in the Coolant?

Have a pressure test done to see if the coolant system has a leak.

Thing's I suspect; Low Coolant, Leak in Head Gasket, Thermostat sticking closed.

Good Luck

[Desert Rat]

Let me guess - V6 and automatic?

Bottom line, the radiators in these trucks are just not adequate. Look for an upgrade to a 3 or 4 row aftermarket radiator that has a higher coolant capacity.

Also, make sure your fan shroud is intact and that the fan clutch has proper resistance. Give the fan a spin by hand. If you give it your hardest spin, it shouldn't turn a full rotation. If it does, the fan clutch is worn and needs replaced.

[Adverse Effects]

could it also be the pump has lost some of its vanes? so at lo RPM its not pushing the coolant around enough

[TenorTim]

Thanks for the replies. No Stop leak has ever been put in the radiator, and the thermostat was replaced about a year ago with no improvement. What ever the cause is, it happens suddenly.... not gradually. Most times I can stop at a traffic light for several minutes with no change in temp, other times it will suddenly rise... sometimes while just cruising at a constant highway speed... ? Very unpredictable...

[Desert Rat]

Check the fan clutch.

[TenorTim]

Check the fan clutch.

I'll check it according to your suggestion this afternoon...
BTW it's a V6 Manual Trans.
thanks for the help

[JB'sTitanXD]

Try this from the service manual, sound like there is air in your system. You can use air bleed bolt located ontop of the intake manifold to bleed air from the cooling system. Also i believe the air bleed bolt is a 10 MM

—REFILLING ENGINE COOLANT—

1. Install reservoir tank, radiator drain plug, and cylinder block
drain plugs.
Apply sealant to the thread of cylinder block drain plug.
: 34.3 - 44.1 N·m (3.5 - 4.5 kg-m, 25 - 33 ft-lb)
2. Fill radiator slowly until coolant spills from the air relief plug,
then install air relief plug.
Air relief plug:
: 7 - 8 N·m (0.7 - 0.8 kg-m, 61 - 69 in-lb)
3. Fill radiator and reservoir tank to specified level.
Pour coolant through coolant filler neck slowly to allow air in
system to escape.
Use 50% genuine NISSAN anti-freeze coolant or equivalent
mixed with 50% demineralized water or distilled water.
Coolant capacity (Without reservoir tank):
10.15 (10–3/4 US qt, 8–7/8 Imp qt)
Reservoir tank capacity (for MAX level):
0.8 (7/8 US qt, 3/4 Imp qt)
4. Warm up engine to normal operating temperature without
radiator cap installed.
If coolant overflows radiator filler hole, install filler cap.
5. Run engine at 3,000 rpm for 10 seconds and return to idle
speed with radiator cap installed.
Repeat two or three times.
Watch coolant temperature gauge so as not to overheat the
engine.
6. Stop engine and cool it down.
Cool down using a fan to reduce the time.
If necessary, refill radiator up to filler neck with coolant.
7. Refill reservoir tank to Max line with coolant.
8. Repeat step 5 through step 7 two or more times with radiator
cap installed until coolant level no longer drops.
9. Check cooling system for leaks with engine running.
10. Warm up engine, and check for sound of coolant flow while
running engine from idle up to 3,000 rpm with heater temperature
control set at several positions between COOL and HOT.
Sound may be noticeable at heater water ****.
11. If sound is heard, bleed air from cooling system by repeating
steps 5 through 7 until coolant level no longer drops.
Clean excess coolant from engine.

[TenorTim]

Check the fan clutch.

Ok so I tried spinning the fan when cold and could only get about 1/2 a revolution. So i drove it for a about 30 miles and then tried again... Same result about 1/2 revolution. No perceivable difference in resistance. So I started the truck back up while it was still hot and tried the rolled news paper test, only I used card board (all I had) dragging the cardboard along the tip of the blades it seemed like the fan wasn't going to stop.. but after about 5-6 seconds I noticed the sound change and it started slowing... eventually (10-15 seconds) it stopped. It took a reasonable amount of pressure to make it stop...

[Desert Rat]

Check the fan clutch.

Ok so I tried spinning the fan when cold and could only get about 1/2 a revolution. So i drove it for a about 30 miles and then tried again... Same result about 1/2 revolution. No perceivable difference in resistance. So I started the truck back up while it was still hot and tried the rolled news paper test, only I used card board (all I had) dragging the cardboard along the tip of the blades it seemed like the fan wasn't going to stop.. but after about 5-6 seconds I noticed the sound change and it started slowing... eventually (10-15 seconds) it stopped. It took a reasonable amount of pressure to make it stop...

hm. that sounds like it's working as it should.

Air in the system as has been mentioned is a possibility. And I'll stand by my assertion that the VG33 trucks don't have enough radiator in them.

[TenorTim]

I have flushed and purged the system as detailed above a few times over the past year or so that this has been happening with no improvement... nonetheless i will do it again sometime this week for good measure.

[JB'sTitanXD]

Could be a small leak in the head-gasket

[TenorTim]

UPDATE: The truck maintains the same symptoms as was originally outlined. No improvements, no changes. I have refilled the coolant as instructed above with no change. I am noticing in the warmer months that i have to add about 16 oz of water to it every week or two. A distinct gurgling sound can be heard after shutting the engine down during an "overheating event". Bubbles are visible in the expansion tank and a slight hissing sound can be heard from the radiator cap. As originally stated, revving the engine returns the temp to normal and I've been able to drive the truck using this method all summer. I have changed the oil a few times and have not found any signs of coolant in it. The gurgling in the expansion tank only occurs during "overheating" ... No bubbles are visible in the radiator during idle at normal temps. A laser temp gun shows a max temp of 215° at the upper radiator hose housing during an "overheating"... All other components (thermostat housing, lower hose housing, radiator cap ect.) read temps below 215°. Also the lower hose usually reads 10°-20°less than the upper hose...Any suggestions would be greatly appreciated.

[hardbodyhero]

Possibly the thermostat needs replacing.....

I say that because I, myself, in a 96 Hardbody experienced the same issues none the less.

Cooling systems are all rudimentarily the same, a closed circuit fluid system. You just have to figure out the weak point. I went all out and replaced pump, thermo, and cap (all OEM parts) and noticed extreme differences. I was running 210-215 with AC on before, after the job, 180-199. I still was not too happy with the 199, so I installed an electric fan. 178.9 degrees all day long, rain or shine, ac on or off. I have it perfectly balanced now.

The parts I pulled off did not show any signs of failure at all, however it didn't mean that they were not performing to their designed efficiencies either. I recommend starting at the pump, thermo, and cap and see where that take you. At this point, I would consider the truck deadlined until then. Not to mention the extra wear and tear that may have happened to your gaskets or head with the additional +10 or more degrees your system was designed to run at.

Desert Rat has a valid point too, I believe engines in the smaller Nissan trucks tend to have some under-engineered tendencies.