Chaz El Posted October 25, 2008 Share Posted October 25, 2008 Long time lurker, first time poster... I was out sneaking a smoke in the only place on the property my wife will not go-- the cab of my '88 MJ-- and I noticed a small squirt of coolant on the passenger side floor mat. Poking around, I found that the housing covering the vacuum motor et al had a fine film of the stuff. I couldn't spot any leaks under the hood and the coolant tank is pretty much full... I was hoping for a pointer as to what the 'most likely' cause might be before I start tearing stuff up. I'm sure this is pretty common, but I couldn't find any threads that covered this particular problem. Any help is appreciated, and I should thank everyone for all the problems you guys have helped me solve in my lurking! Link to comment Share on other sites More sharing options...
FxRacing282 Posted October 25, 2008 Share Posted October 25, 2008 heater core or lines to the heater core. Link to comment Share on other sites More sharing options...
Eagle Posted October 25, 2008 Share Posted October 25, 2008 heater core or lines to the heater core. ^^^ What he said. Link to comment Share on other sites More sharing options...
Pete M Posted October 25, 2008 Share Posted October 25, 2008 Yup. And there could be coolant under the carpet too. I've had that happen. :( Link to comment Share on other sites More sharing options...
Chaz El Posted October 25, 2008 Author Share Posted October 25, 2008 Looks like my Sunday is planned... Thanks for the replies! Link to comment Share on other sites More sharing options...
comanche87 Posted October 26, 2008 Share Posted October 26, 2008 That sucks. How much of a pain Is it to change the heater core? Just curious Link to comment Share on other sites More sharing options...
dfreeman616 Posted October 26, 2008 Share Posted October 26, 2008 it's a fair amount of work, you pretty much have to rip out the dash. Link to comment Share on other sites More sharing options...
comanche87 Posted October 26, 2008 Share Posted October 26, 2008 when the time comes should I tackle it or let soMeone else deal with it? Link to comment Share on other sites More sharing options...
Chaz El Posted October 26, 2008 Author Share Posted October 26, 2008 It's looking like an enormous, stinging, pain in the arse. However, the estimated cost at a shop as figured by Repair Pal is somewhere between $500 and $900. Being that I just shelled out for a transmission rebuild, it's a job I'll have to tackle myself-- well, with a little help from a mechanically inclined drinking buddy... I just hate, hate, hate draining coolant, what with the three dogs. I may just have to warn passengers to watch their shoes for a while... Link to comment Share on other sites More sharing options...
Pete M Posted October 26, 2008 Share Posted October 26, 2008 I shiver at the thought of what the answer might be, but... what trans did you have rebuilt? Please don't tell me it was the Ba-10 Peugeot :ack: Also, I have a similar issue with my 90 and the plan is to just disconnect the heater core from the system. :D Link to comment Share on other sites More sharing options...
Chaz El Posted October 27, 2008 Author Share Posted October 27, 2008 Nope, not the Peugeot, it was hard enough getting someone to work on the Aisin! When I took it to my first choice of shops, a nice little Mom & Pop that's been there for decades, Pop took one look and said there was no way he'd touch that "Jap Tranny." Link to comment Share on other sites More sharing options...
Eagle Posted October 27, 2008 Share Posted October 27, 2008 It's looking like an enormous, stinging, pain in the arse. However, the estimated cost at a shop as figured by Repair Pal is somewhere between $500 and $900. Being that I just shelled out for a transmission rebuild, it's a job I'll have to tackle myself-- well, with a little help from a mechanically inclined drinking buddy... I just hate, hate, hate draining coolant, what with the three dogs. I may just have to warn passengers to watch their shoes for a while... You can disconnect and plug the hoses going into and out of the heater core, or just stick a short length of copper tubing in the ends to make it a continuous loop under the hood, with nothing flowing through the heater. You won't have heat, but you also won't have leaks. Link to comment Share on other sites More sharing options...
FxRacing282 Posted October 27, 2008 Share Posted October 27, 2008 from the looks of your picture it seems as if you don't have it on the road. if that is the case you could probabally get it done fast-like if you put some time into it and asked all these guys on here what to watch out for and tips and tricks to doing it. Link to comment Share on other sites More sharing options...
JeepcoMJ Posted October 27, 2008 Share Posted October 27, 2008 you don't have to drain the coolant to do this project. first, remove the dash. to remove the dash, you need a 15mm socket or wrench, and a phillips head screwdriver as well as a 5/16" socket plus long extension. first remove the dash bezel, gauge cluster, radio, switch panels (if you have factory switches), clock, cig lighter, and heater controls. remove the top panel over your defroster vents as well. unbolt the steering column supports from the dash mount with the 15mm, then remove the two 15mm bolts holding the sides of the dash to the side of the cab. remove the four 5/16" screws that hold the METAL tabs up by the defroster vents. do not remove the plastic ones yet (you will once the dash is out) from there, pull the dash forward and disconnect the wiring from it. pull the wiring off, then pull the dash up over the steering column and out the passenger side door. from here, remove the upper vent tubes from the cab, then disconnect the box from the cab via the 6 (or 7) nuts holding it through the firewall. disconnect the heater/a/c lines from the firewall, and then disconnect the wiring for the heaterbox. from here, you're on your own. I just replace bad boxes, have never needed to completely rebuild one. re-assemble in opposite order. after 7 or 8 dashes, I can have a dash and heaterbox out in around 20 minutes if I book it and use a screw gun. Link to comment Share on other sites More sharing options...
Chaz El Posted October 27, 2008 Author Share Posted October 27, 2008 @ FxRacing282: Actually, it only looks like a lawn ornament! It's my daily driver and has been for almost 8 years. Luckily my commute is a short one, although lately I've been making excuses to drive it because I've got the engine purring like a kitten right now... @ JeepcoMJ: Thanks for the more detailed breakdown! I think the only thing I can say is, "Yikes!" I knew I was gonna have to get into the dash, but that's a whole lotta dash! 20 minutes for you sounds like a weekend for me. I think that with the mild Atlanta winters, Eagle's temporary workaround might be the way to go until I can line up some other projects (like swapping out the gauge cluster) I've been meaning to get to. If anyone has any heater core horror stories to share as cautionary tales, I'm listening... er, reading... :popcorn: Link to comment Share on other sites More sharing options...
jteckmann Posted October 27, 2008 Share Posted October 27, 2008 Before you go to the trouble of tearing out the heater core, triple check all the connections. I learned this lesson the hard way. I had the same problem you describe - turns out on mine it was small leaks in the engine compartment, on the hoses where the heater control valve hooked up. The system developed small pinhole leaks under pressure, and the coolant ran down the pipes to pool up in the passenger-side floorboard. Feel the rubber pad where the heater core comes out from the firewall. If it's saturated or slick from coolant, that could be a tell-tale sign the leak's around the HCV instead. Link to comment Share on other sites More sharing options...
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