Hey, I've got a 91 Loyale and I'm pretty sure its got a clogged heater core.  Thermostat was just replaced and blower motor was replaced in the last 10000 miles but the heat is still only the faintest bit warm.  Going into another cold snap here in the midwest, so flushing the heater core seems like the next option.

 

I was planning on using the garden hose pressure + detergent method followed by hooking the hoses up backwards for a day, but I'm not so knowledgeable on the system layout, so I need confirmation that I've got the right hoses.  Are the heater core hoses the two rubber hoses that are maybe 1" diameter and enter the fire wall next to eachother directly under the spare tire mount?

Those be the heater hoses. I would swap them 1st for a bit then do a system flush, helps in breaking the stuff loose.

 

Mac's Radiator Cleanser at NAPA is some good stuff. I've left it in longer than the directions say to do. You do need to flush the system of all anti-freeze before using it.

Thanks! I'll try that.

Those are the hoses I used to flush my system this fall. I used the backflush kit from Peak at Advance. Wish I'd thought of the reversing house trick. I think most of my heater problem is still mouse related. 

 

John

Any tips on getting the hoses off the firewall input?  I undid the hose clamp and slid it out of the way and then pulled on the hose as hard as I could but couldn't get it to budge.  Is there a trick to it or a tool to use?

 

And should I drain the coolant from the system before I swap the lines, or is the heater core connection a high enough point that it doesn't all run out when you take a hose off?

One other thing to check, make sure the impeller is still on the inside of the water pump and the pump is moving water properly.

You will want to drain the system down some, but you will still loose some coolant from the heater hoses when you remove them.

 

Getting the hoses off can be a pain, as you're finding out. Chances are, they are the original hoses and have sealed themselves to the tubes.

Use a pair of pliers to twist the hose some, it may break free. Be careful though... You can crush or twist the tube if you get to rough with it.

 

Best thing to do is get replacement hose, either the formed ones, or just some 5/8" heater hose. Cut the old hoses off the tubes by cutting a slit length wise, then peel the hose off.

Clean any remaining stuff off the tubes with scotch bright.

Tom is right, you may be best off getting new hoses. Good to have just in case you botch the originals, if you don't you can take the new ones back.

And try using a hose pick to go around the edge of the hose where you're going to pull it off.

Alright thanks for the tips, I'll try again when this cold snap breaks, I just wedged some cardboard in front of the radiator for the moment, hoping to squeeze out a couple more degrees from the heater.

 

One quick unrelated question:  I've got one tire with a sidewall puncture, would prefer to just replace two tires vs. all four, but I can't find the same brand/model here; Is it bad for the tranny and differential to run two tires of one brand and two tires of another (where one set has more wear than the other) even if they are the same size?

Won't be a problem as long as you keep them paired (same tires on both sides up front, same tires on both sides rear).

cool, thanks, i was concerned about it binding in 4x4 if the wear difference created a slight size difference between front and rear, but i bought a full set of almost new winters on craigslist tonight so I don't even have to consider it now.

vise grips work well for the hoses.  adjust them so that they give a very minor clamp.  that way you can bite the hose but won't squeeze too hard (which you can do if you try by hand).

Install new hoses with white grease.  Flush core both way with water.  Previous owner may have used stop leak to cover up a head gasket leak and clogged the radiator core up solid..........  This was my experience.  We ended up flushing it twice, there was some big chunks in there.

Won't be a problem as long as you keep them paired (same tires on both sides up front, same tires on both sides rear).

 

This is bad advice.

 

If anything.....you'd want one of each at each axle so the overall difference between front/rear will be averaged out.  That would put some wear on the spiders in the front and rear diffs, but at least the AWD wouldn't be affected adversely.

 

Truely bad to have 2 different brands.

 

AWD = 4 matched tires.

 

 

***edit***

 

Just realized this was old gen PT 4wd.  As long as you on;y use 4wd in Snow/mud/gravel you should be fine with mismatched front to back.

Edited December 30, 201312 yr by Gloyale

I was about to say something til your edit popped up.