K
Krankin
Guest
Seems the Delo 400 is a "one size fits all" oil.
Strange overheating
- Thread starter Hobs
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ken47
Member
If the thermostat is OK check the bottom hose to see if it is sucking together (hot motor and a few good revs while you watch the hose should do it ) . have the radiator checked to make sure it is clean . if turning on the heater cools it down it seems like the coolant isn't getting through the radiator . Cheers Ken
d22dave
Member
Take it out and get it flushed, Wont cost much more than a $100
dunkmuddie
Member
ive been having the same overheating prob only done it a few time but always when fully loaded ive since had radiator flushed and thermostat replaced also checked the head gasket nothing there only to have it do it again not sure where to go from here thinking fan hub and water pump. any other ideas
I know that I am resurrecting an old thread but I have a theory.
Where the thermostat sits at the front of the head, there is a small housing that bolts to the front of the cylinder head that the thermostat sits in.
Looking down into this housing with the thermostat out, it appears to have a "seat" that the thermostat closes off when fully open to prevent the coolant from bypassing the radiator.
The "seat" area in my car is fairly corroded, and I have the same issue on long hills.
I believe that the coolant is designed to circulate around the engine block and head only until it heats up to operating temperature, when the thermostat opens and the disc on the bottom of the thermostat "should" close off this gallery.
If corroded like mine, this can no longer seat and allows some of the water to bypass the radiator and just circulate around the block and head, creating an overheat condition.
The good news is that this part is replaceable, I dont know how much or how available it is but since Nissan have sold millions of TD27's around the world, it should be available.
Has anyone explored this before?
if I have the wrong end of the stick, please let me know.
Tony
Where the thermostat sits at the front of the head, there is a small housing that bolts to the front of the cylinder head that the thermostat sits in.
Looking down into this housing with the thermostat out, it appears to have a "seat" that the thermostat closes off when fully open to prevent the coolant from bypassing the radiator.
The "seat" area in my car is fairly corroded, and I have the same issue on long hills.
I believe that the coolant is designed to circulate around the engine block and head only until it heats up to operating temperature, when the thermostat opens and the disc on the bottom of the thermostat "should" close off this gallery.
If corroded like mine, this can no longer seat and allows some of the water to bypass the radiator and just circulate around the block and head, creating an overheat condition.
The good news is that this part is replaceable, I dont know how much or how available it is but since Nissan have sold millions of TD27's around the world, it should be available.
Has anyone explored this before?
if I have the wrong end of the stick, please let me know.
Tony
kevinm1962
Member
i could also suggest only if you have changed the coolant and some if not most may turn to gel. does happen some coolants cannot be mixed only guessing
Nick-palmer1
Member
I had the radiator out of mine a while ago when i had to do the head, What i did to clean it out was just blocked off the bottom and filled it up with a bit of radiator flush and water, let it soak for a bit and emptied it out, also if block the bottom off with your hand, fill it with a hose and when you take your hand of it should empty pretty quickly.
I do a fair bit of driving on gravel roads and i also noticed a lot of dirt clogging up the fins on the core so i used a kartcher to clean that out, you should be able to see straight through the core. Mine was filthy took ages to get all the crap out but its been all good since i put it back together. Getting the radiator out isnt to hard so that could be a good place to check! hope that helps
I do a fair bit of driving on gravel roads and i also noticed a lot of dirt clogging up the fins on the core so i used a kartcher to clean that out, you should be able to see straight through the core. Mine was filthy took ages to get all the crap out but its been all good since i put it back together. Getting the radiator out isnt to hard so that could be a good place to check! hope that helps
correct. thermostats close off the bypass port when they open.
if its corroded or thermostat doesn't reach far enough, the port won't be closed and it will cause it to overheat.
Hi fellas, thanks for the replies. I should have explained that I have tested the cooling system thoroughly and so far everything checks out, except maybe the fan clutch and the housing I mentioned.
Thanks for the confirmation tweak'e, it seemed logical to me. I think I will be buying a new cast iron housing to put this to the test.
I wonder how many other Navaras are overheating because of this?
Thanks for the confirmation tweak'e, it seemed logical to me. I think I will be buying a new cast iron housing to put this to the test.
I wonder how many other Navaras are overheating because of this?
dunkmuddie
Member
Hi fellas. With nothing left to try, I pulled the fan hub and waterpump (all one unit) out and found the hub to be stuffed. Since then didn't have any problems for a few months only to have it happen to me again just after new years. After testing the head again the mechanic suggested replacing the temp sender (he sean this prob. on some patrols). Since doing that haven't had it happen again so fingers crossed I've finally fix the problem. Hope this helps you out.
