heater [or other coolant] leak troubleshooting?

[pybyr]

Hello all-

First, thanks to all the great advice and generosity in sharing it here. Life has been overfull lately and I have not had as much chance as I'd like to follow/ contribute here. But I really hugely appreciate peoples' willingness to offer help.

This morning I was headed to work, extra fast, as I was running late, and began to smell that sickening smell of coolant in the truck. The good news is that the temp gauge stayed normal, and there was no steam or any sign of leaks.

The bad news is that when I turn the vents off, the smell diminishes, and when I turn the vents back on, the smell gets stronger.

So I suspect that I have the beginnings of a heater core leak.

Right now the only thing that's in shorter supply than time is money.

so I need to

1) keep the rig rolling (it's my only vehicle) and avoid anything becoming more serious

2) get to the bottom of a diagnosis as fast and as reliably as possible, so that I don't start buying and throwing parts at it in trial-and-error mode

3) fix it once, fix it right.

Please tell me if there is anything else, besides heater core, that I ought to suspect or check, or how to check.

Also, if it is the heater core, can anyone point me to a step-by-step of what I do to get at it and change it out? I know all the basic concepts from lots of other USA vehicles, just have not done it on this series/ vintage truck.

Also, any recommendations on a good quality heater core source at a favorable price? This truck only has 33,000 miles on it, so I want something other than a bottom-dollar-cheapo, but I can't afford to get anything gold plated.

Thanks in advance for the help!!!

Trevor, in Vermont

 

['94IDITurbo7.3]

33,000 miles, wow I thought it said 333,000 at first.

If the heater core on your year truck is the same as a '94 then it is a real simple job.

Pull out glovebox.
Take out about 5-7 screws that hold he heater core access panel on. pop that out.
Then go under the hood and take off the two heater hoses.
Then pull the heater core out.

Install is reverse of removal.........IF of course your's is the same design as mine.

After you get to the heater core you will be able to tell if it is leaking.

I got my heater core from auto zone for $25.


Here are some pics of my heater core......
http://www.oilburners.net/forums/showthread.php?t=50946&page=2

 

[pybyr]

Beautiful that it's that simple if I do need to get into changing the core (I assume that it can't be more complicated on a slightly earlier truck).

Yes, it's really 33,000 miles. I bought the truck with only 12,000 on it. It's got various issues cropping up from the sheer passage of time (mostly leaks), but it's stout as can be.

Any other things I ought to check besides suspecting the heater core?

Thanks!

 

[flareside_thun]

That sounds about fitting. Feel around on your passenger floorboard for wetness. If none, it doesn't hurt to start the removal of the heatercore and check for antifreeze in the bottom of the heater box.

 

[pybyr]

My radiator looks pristine inside as I went to top off the coolant due to whatever slow leak I have going on.

Do heater cores just crap out from internal corrosion over time?

 

[flareside_thun]

Yea, they'll get pinholes in em eventually.

 

[pybyr]

Got a new brass/ copper heater core coming from RadexNH for $28 and should be arriving by UPS tomorrow. Apparently the late 80s bricknoses were the first trucks to use aluminum heater cores, and corrrosion from dissimilar metals can occur (though thankfully apparently it's the aluminum heater core that takes the beating, not the radiator or engine components). Also found a TSB about this issue, which includes taking measurements with a voltmeter and linking the heater core, engine block, etc., with ground wire if stray voltage is found. I think I am going to go ahead and take the preventative measure of tying the heater core, block, radiator, and battery ground with a set of ground wires, simply to nix any possibility of electrolytic corrosion.

 

[icanfixall]

Heater core replacement is simple on your truck. Its just like described above...

 

[snicklas]

pybyr,

One other thing... does your truck have a "shoreline" on it. Being it was a fire truck. Most of our apratus have a shoreline that is connected to a drop cord while the truck is in the bay. Wonder if that system could have caused some of the issues.....