boiling coolant...any ideas

[unka_paka]

hello all,
so here it is. i replaced my radiator about a month ago, because it has a fracture in it. no big deal, car stopped overheating for a bit, but now i keep getting that boiling coolant smell when the car is running, and for about 10-15min. after i shut it off. i really have no idea what else it could be, except for the water pump(hopefully not) but any other ideas would be appreciated before i start digging into random things. thanks

ps - running a 91 240. kinda new to the nissan world.

[DarkRaptor42]

I had an over heating problem when I first did my engine swap. Flush the engine out and then see if it still does it. Then if it still does check the thermostat, do this by touching the lower radiator hose after the car has been running and see if its hot (be careful it could be hot). Then if thats not the problem go to the water pump, but on a car that old (going on 13 years right?) you might want to replace the water pump anyways.

[misnomer]

Er, check your radiator cap first. A bad cap won't hold pressure, lower pressure == lower boiling point for the coolant. If your cap holds pressure, THEN go on to the pain in the ass stuff.

[onboost]

yea, check the cap, that is good 1st step. But also think about it, there might be air pockets trapped inside the coolant passage. So bleed the cooling system might help too.

[misnomer]

Yeah, bleeding is good, very easy too.

There's a screw labelled "Do not remove when hot" on the upper side of the head just past the upper radiator hose. Remove this, fill with coolant until some splurts out the top.

[unka_paka]

thanks for the help guys, im gonna start bleeding the cooling sys. tomarrow, but just in case that doesnt work, and by some bad karma i have on my head i have to replace the water pump, are there any write-ups on how to do it. i really dont want to shell out +700+ to get it done at a shop. ive searched this site, but really couldnt find anything. thanks again.

[NutzDrifta]

If it's your waterpump, coolant must be leaking from it. You can tell if you look under your car; you'll see it leaking by your oil pan. Mine was leaking so I got it fixed at the shop. It's not all that bad, it was like 140 dollars I think.

[unka_paka]

the cheapest place i can find around me is in salt lake city, and they want aroun $400, which seems a little pricey for something i could do myself. every other shop in my town wants about 500-700, parts & labor. i figure i could spend $50(are they that cheap?) and do it myself. just looking for a decent write-up/diagram so i have a general idea, and not mess it up.

[Gunburn]

Ya its most likely the cap.

I know this because my brother just bought one yesterday and he had the some problem, I told him to get a new cap when he did it stoped.

(oh and get a chilton!)

[USMC240]

that sucks,

i did a water pump on my buddys Z31. it was overheating, and nothing was leaking, we figured we had to do the water pump anyways. Well when we took the old one off, there was no impellers! I guess after a while they just wore down to a little spinning nub.

Makes you wonder where the little flecks of metal went.

anyways, is the smell inside the car? Cuase i hate to be the one to tell you, theres a chance that it could be your heater core too. I figured if you have your heat on, b/c it is winter and all, you might be smelling it when the heat is on.


theres my two cents

[unka_paka]

i can only smell the coolant from the outside. so no problem there. im starting to wonder about the temp gauge, like is it just kinda of a guess of where the heat is in the car? because its always jumping, like when the car is just idling, it jumps up, then when i start to move it comes back down. maybe a faulty thermometer? got a new one, just need to install.

[underdog17]

if it turns out to be the cap go buy a 92+ z32tt cap.. it'll fit and it has a higher psi rating so it will raise your boiling temp