I highly doubt the coolant is the culprit.Sounds more like a t-stat problem to me.I also wouldn't bother with changing the coolant.Its a long life design.

 

Is it possible to change the T-stat without draining the coolant?
Rob

 

No. I always use a 3' piece of 3/8" fuel line and syphon it out.Only have to remove about 1 1/2 gal. to get it below the t-stat.

 

That's cool, thanks for the info.. I looked online and Amsoil (i'm sold on their products) sells coolant. $33 a gal. Makes me wonder how the dealer can do a flush and fill for $110.

 

My temps were doing the same thing until I got all the air out. I just verified this the other day.

 

Well, initially, I tried this, in this order:
1) Removed the radiator cap
2) Started the truck
3) Waited till the top hose was hot
4) Watched as the coolant started to circulate
5) Added coolant as the level dropped (just barely)
6) Waited about 20 minutes for the "burp" (nothing but sputtering, and level stayed the same)
7) Started to get scared I was gonna end on one of those "Dumbest Moments" shows and put radiator cap back on.
8) Added coolant to the resevoir untill it was at the full line.

I was told to leave the cap off till I was sure all the air was out but I chickened out. All I could imagine was hot coolant flowing out of the radiator and down the driveway.

And when I drive the truck I do not baby it, and a couple of places on the trip to work is over substantial RR tracks (serious vibrations, and bucking). Maybe I should try it again. the whole proceedure. Or maybe just bite the bullit and replace the t-stat. That sounds like a sure way of getting all the air out. And I'd know if the t-stat was the problem. I've wasted more to find out less in the past.

Know what I mean?
Rob

 

Lots of techs and I do on my own is fill the coolant tank to about 3/4 full after servicing the cooling system.Once it goes through a hot/cold cycle it usually will drop a fair amount as it looses air and vacumn draws in more liquid.

 

That didn't work for me when I put my Opie bypass on. I even replaced the radiator cap thinking it may be the culprit, which I have found many times. Not!!!! It won't shoot hot coolant all over you, LOL, if you have the radiator cap off with it running at idle. This issue is normaly only after you replace the water pump that it can be a pain. One thing to check, if you don't have all the air out, you will not suck any coolant out of the resivor, at least mine didn't. It would fill it up, but not suck it back into the system. I got so aggrivated with it I just started from scratch and did what I have always done. The only issue is it take a while for this engine to get up to operating temperature. Make sure the radiator is getting hot along with the top radiator hose and you have no leaks anywhere.

 

Drain and refilled mine last year.Filled my coolant bottle 3/4 full.Next morning it needed a couple cups to bring it to the cold fill mark.I remember some pain in the butt Nissan V6s that took LOTS of bleeding to get the noise in the heater system to go away.

 

Well, situation normal, it's my truck...LOL I would love to hook my truck up to one of those new BG coolant exchange machines.

Nissan Quest vans were fun after a timing belt/water pump replacement.

 

I just ran the truck to temp turn off overdrive run above 2400 rpms to get the lines purged. You may want to try it my lazy way. lol