Overheating

Ishmillion27

Test Drive
My 06 Nissan Xterra is currently overheating. I changed the thermostat did oil change and coolant flush. I did a head gasket test and the liquid remain blue with no change in color. While sitting at idol the needle spikes up gradually. I also connected my obd 2 machine and the oxygen sensor popped. I would greatly appreciate if someone can point me in the right direction to get this fix so I can start my adventure rig build.
 

TerryD

Total Tease
Supporting Member
Location
Covington, Va
Couple things to check on a 2nd Gen.

First thing is the pair of plastic tees on the right side at the rear of the engine compartment. They are notorious for cracking and the system not holding pressure and losing coolant. They are very brittle with a little age on them so be careful when you look at them. There's a thread here with the updated metal parts from Dorman and Z1 Offroad.

Next, the coolant tank on the fender won't actually show when you're low of coolant. Best to check when the actual radiator is cool. Also be sure the spring cap is on the coolant jug and the cap without the spring is on the radiator.

Next, it could be your fan clutch if it's heating at low speed and idle. When you do a cold start on the morning, do you hear the fan spinning like the clutch is engaged?

Depending on mileage, it could also be the thermostat. But it's more common to notice that issue if your heat goes away when idling at a stop light then gets hot again when you pull off.
 

Ishmillion27

Test Drive
Couple things to check on a 2nd Gen.

First thing is the pair of plastic tees on the right side at the rear of the engine compartment. They are notorious for cracking and the system not holding pressure and losing coolant. They are very brittle with a little age on them so be careful when you look at them. There's a thread here with the updated metal parts from Dorman and Z1 Offroad.

Next, the coolant tank on the fender won't actually show when you're low of coolant. Best to check when the actual radiator is cool. Also be sure the spring cap is on the coolant jug and the cap without the spring is on the radiator.

Next, it could be your fan clutch if it's heating at low speed and idle. When you do a cold start on the morning, do you hear the fan spinning like the clutch is engaged?

Depending on mileage, it could also be the thermostat. But it's more common to notice that issue if your heat goes away when idling at a stop light then gets hot again when you pull off.
Hey Terry I put a brand new thermostat in yesterday. I am waiting for vehicle to cool so I can get back under the hood at check some more on what's going on. During a cold start this morning the fan did not come on. Once I idle the vehicle that's when the fan came on and the vehicle begin to overheat.
 

TerryD

Total Tease
Supporting Member
Location
Covington, Va
Yes it was overheating before thermostat install
Ok. So how hot does it actually get? It's not uncommon for a vehicle to get a little warm sitting. Does the electric fan ever come on? Do you ever hear the engine driven fan lock up? Does it overheat while driving it?
 

TerryD

Total Tease
Supporting Member
Location
Covington, Va
First thing to check is that you have the two radiator caps in the right place. That has caused all kinds of heating problems before.

Check for collapsing hoses while the engine is running. Could be sucking a failing hose shut.
 

TerryD

Total Tease
Supporting Member
Location
Covington, Va
So couple issues. That cap is in the wrong place. The radiator cap shouldn't have a spring.

Next, that looks like an oil contamination. You need to check to see if your transmission cooler in the radiator is bypassed or if your radiator has been replaced. Immediately. Google "SMOD Xterra" and read up on it.

Check your coolant jug cap too. It should be the cap with a spring.
 

Ishmillion27

Test Drive
No @ chug don't say that lol the truck isn't showing any symptoms of head gasket. There is no white smoke plus I did the gasket test and the blue liquid didn't turn yellow whoever the coolant caps was in the wrong places
 

TerryD

Total Tease
Supporting Member
Location
Covington, Va
No @ chug don't say that lol the truck isn't showing any symptoms of head gasket. There is no white smoke plus I did the gasket test and the blue liquid didn't turn yellow whoever the coolant caps was in the wrong places
SMOD is the transmission cooler in the radiator allowing the coolant and ATF to cross contaminate. Might be old damage, might be salvageable if your transmission isn't acting funny.

I would look it all over good. Could be that it was caught and the radiator replaced but they screwed up where which cap goes, caused overheating issues and just sold it rather than fix it.

Just gonna have to figure out if you have a factory radiator or an aftermarket. If you're bypassed or not (temporary fix) and get your caps on right and bleed the system good so it will cool.
 

Prime

Some Kind of In Charge?
Admin
Location
Denver-ish
You need to flush everything. Cooling system, oil, tans fluid drain and flush the lot. Then put it back together one step at a time. If you see evidence of water/coolant in the oil, you'll need a head gasket. If you don't, then at the very least a new radiator.
 

TerryD

Total Tease
Supporting Member
Location
Covington, Va
Transmission fluid looks dirty and it wasn't thick smod like flowing out. But you gentlemen probably know better than me. I am just starting off in the Xterra overland game.
Trans fluid looks old but not SMOD. Check your trans cooler lines at the radiator. See if they are still hooked to the ports on the bottom tank. Check to see if there's an OE Nissan part number on the tank. There's a list of affected radiators in the thread linked above about SMOD. Only those OE radiators have the problem.

Like I was saying, it's possible that you just dislodged some gunk in your flush. With the lever cap style radiator cap and it being in the wrong location, I would make sure what's what before I start shotgunning parts.

What year and model do you have Terry?
My X is a 2007 "S".
 

sgsy2k66

Test Drive
Might be trapped air in coolant... I had similar problem after coolant change. You might try jacking the front up (or park on incline), remove radiator cap, run engine until thermostat opens, heater on, keep engine running, burb the coolant by squeezing the upper radiator hose, add coolant to radiator as needed.
 

jsexton

Need Bigger Tires
Supporting Member
Location
Lewis Center, OH
Replace the fan clutch and fill the coolant about 1” above the seam on the expansion tank. Ignore the “hot” full level.

you could also check to see if it has heat at idle. If not, it’s certainly low on radiator juice.
 

jsexton

Need Bigger Tires
Supporting Member
Location
Lewis Center, OH
And if I bought a 2010 or older, the very first thing I’d do is bypass the transmission so it doesn’t run through the radiator until I could put a new radiator in
 

TerryD

Total Tease
Supporting Member
Location
Covington, Va
Replace the fan clutch and fill the coolant about 1” above the seam on the expansion tank. Ignore the “hot” full level.

you could also check to see if it has heat at idle. If not, it’s certainly low on radiator juice.

And if I bought a 2010 or older, the very first thing I’d do is bypass the transmission so it doesn’t run through the radiator until I could put a new radiator in
It looks like someone put a spring cap on his radiator tank too.
 

TerryD

Total Tease
Supporting Member
Location
Covington, Va
Can you see a brand on the radiator? Might have to contact the manufacturer and see what they have to make the connections. May be that it came with the pieces but the PO didn't hook it up and just junked the fittings.
 
Top