BroncoII4x4.com

so, i have NO heat. the t-stat was replaced twice (actually got a dud first time), the leaky rad replaced, and the pissing water pump replaced. got no heat, except when the rpm's hit about 3000 rpm. sounds to me, like all this work that has been done, shook up / stirred up a piece of crap into the core. sound plausible? so i call the rad shop, and inquire about a core flush. he says, oh, well, we back flush the whole system, and replace the thermostat, and steam clean the inside of the rad, because over the years the scale...i cut him off and said i got a rad from you a month ago. oh, well, sometimes a rubber seal comes off the shaft of the waterpump...sorry dickhead, it's new as well. okay, a system flush is $160, but it would be a little less for you. okay good.

he says, what year rbv is it? 90. uh oh - he says. what??? "i'll bet your heads are cracked. wtf? I said no, it runs like a top, i just had a tune-up, where compression #'s are excellent, and what does that have to do with anything??? he says, oh, that 2.9's heads crack, letting exhaust gasses get into the water jacket introducing bubbles and causing and air-block. i said we'll try the flush first.

is he way out to lunch or is this a possibilty? it has never overheated, it is a 90 xl, last month of production, and has 160000 kilometers on it. it is -30, the grille is insulated, and the fan clutch took a dump oin me so i removed it. i have lots of heat on the temp-ometer, and when i revvv it, i get heat. the heater core (in) line is hot, but the core (out) line is cold.(well cooler at least) could this really be cracked heads with it running so well???!!!!

Head cracks are less likely in the later models but it could be
take it to a shop where they can test for combustion gasses in the rad.
next step air in heater core or clogged, take off return hose at the heater core, run engine, and see if you get air or nothing if nothing replace heater core
check to see if your air door is working if it is stuck closed that would explain it!

Well if your inlet is hot and outlet is cold something is clogging it. Take out the heater core and flush it with high pressure water. Its quick and cheap (nothing). Then replace and run the engine with the radiator cap off letting it bubble out all the air. Then run and see if heat returns. If so easy fix and and cheap. Try it out and report back...

I'm betting you just have air in the system. If the heater core was plugged, you wouldn't get heat at any rpm.

hey nobody, how much are we willing to wager??

I took 'er to Yukon Rad today, and they were crawling all over it. did just a core flush only, and they said i had some scale, and some silly-cone, and some old gasket material clogging up the core. you could burn yourself with what pours out of the vents now!! oh the luxury!!

so, these guys didn't realize i bought my rad from them, (i picked up the b2 and the boss guy was like " geez that's a purty rad in der!!"), so because of this, they gave me a deal. "how's fourty bucks sound?" i put two shiny twenties in his hand so fast he didn't know how they got there!!

so yeah, all in all it was a cheap fix. thanks to all for letting me bounce the idears off ya.

N8

Ok i have a similar problem.my heat also sucks.the air coming out of the vents is hot.the fan sounds like its running hard but theres barely enough pressure to defog the window let alone give any heat worth a shit out of the vents.yet the heat that it does have is hot?any ideas?

ist gen or second? the first gen plenum has slots, while second has holes. the slots are notorious for letting in leaves, debris and detrietus. all i can think of is that the intake for the blower is obstructed. or your blower is pooched - although it makes non-pooched noise, eh? i guess things don't always die quietly. i think your best bet would be to pull the blower and see exactly what's going on. keep me posted.

n8

My 88 was full of leaves after not being regularly driven for a year. Amazing how they will accumulate sitting still. Nearest tree is a pin oak, about 200 feet from where I used to park it. Yes, it was pinoak leaves it was full of.
My heater core was also partially plugged, driving at high rpm did produce heat too. I bought a new core and pulled the old one out. Just for $hits and giggles I stuck a house pressure water hose(about 55psi) to one of the fittings and turned it on, it took about 30 seconds of waiting for the explosion for it to dislodge the garbage that was inside, once it started running wwater out and the output water turned clear it flowed just fine so I put it back in and returned the new one. Heat works nearly as well as my F250 pickup

I have always found that the internal corrosion factor has been pretty high on my ford engines. It seems that you should flush the engine once every two years after you get over 100k.

What mixture of anti freeze do you use? I presume since you are in Washington that you do use anti freeze. I have always mixed 25% waterand 74% anti freeze. Yes i know that the freezing point is maximized at 50/50, and pure anti freeze will freeze at about 8 degrees fahrenheit. But my corrosion problems have been much less than they used to be.

i use a low-tox anti-freeze from prestone. it is not harmful to pets or the environment - go ahead and laugh mixed about 50/50, and it's good to about -45 celsius (we had that cold in october).

hey bob, what is the other 1% in your coolant, crud, or air bubbles?!?!

whatever you do, there is a product (not sure who makes it) called water wetter, designed to lubricate, protect, and increase the efficiency of blah blah blah - CAREFUL, IT FREEZES, and dramatically reduces the freezing point. learned that the hard way...

well, since I use tap water for my mix I was not going to hazard a guess at the rest of the formula

This is enlightening... this talk about heater performance. My heater puts out a decent amount of heat, but not an eye openner and I alway figured thats all a BII is suposed top do.

But whats weird is the noise it makes and it's all making sense now. Whetever I step down on the gas and it revs up from idle the heater makes a noise just like water flowing from a faucet into a sink. Ya know, like a trickle - trickle sound.. Like it's actually filling up the core.
I'm now convinced it's blocked bad and needs a back-flush bigtime.

As my nitwit boss likes to say, "Good dialog"!

dave

bower100 wrote:This is enlightening... this talk about heater performance. My heater puts out a decent amount of heat, but not an eye openner and I alway figured thats all a BII is supposed top do.

But whats weird is the noise it makes and it's all making sense now. Whatever I step down on the gas and it revs up from idle the heater makes a noise just like water flowing from a faucet into a sink. Ya know, like a trickle - trickle sound.. Like it's actually filling up the core.
I'm now convinced it's blocked bad and needs a back-flush big time.

As my nitwit boss likes to say, "Good dialog"!

dave

With the description I am seeing it sounds like you may be air locked.. ..

Something I wanted to add here while we were discussing heater cores. How may of you have attached a separate ground wire from your heater core to the body? I did some research about heater core failures and the number #1 problem of corrosion in the core was from electrolysis.
the problem stems from the heater core sometimes not getting grounded properly. When ever I replace a core I solder a small wire lug onto the tank of the core and attach the other end to ground. Cheap insurance.

Is there an air purge tap somewhere in the heater core circulation loop? Or on the top of the engine somewhere?
I just figured the water pump pushes the coolant in the core and air basically can't be trapped in it.

dave