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masonea 06-09-2010 07:58 AM

Clogged Radiator?
I just recently replaced my thermostat and gasket due to a leak coming from the thermostat housing. But now I have a very slow drip coming from the radiator drain plug. I snugged it up a little tighter, but there is still a drip. I took the radiator cap off to take a look and it is full to the brim. The fluid in the reservoir is halfway between the add and full lines. When I squeeze the upper radiator hose nothing happens. I'm used to seeing bubbles or something in the reservoir when I would do that on previous vehicles. I haven't had any overheating issues, so I am not sure what is going on.

Possible theories are 1) water pump has gone bad. 2) clogged radiator.

I do know there is some rust in the radiator. You can see where the previous owner spliced in a hose hook-up to flush the system. And there are bits of rust in the top of the reservoir.

My questions for you gurus out there are:

1) Is there a way to troubleshoot the water pump, without going and buying one, replacing it, and finding out that's what it is?

2) If it's not the water pump, how bad is it to get a new radiator core?

3) Is getting a new radiator better than getting a new core? (effort vs.cost)

Thank you in advance for any input.


alsyj 06-09-2010 08:35 AM

Sounds like you have several concerns, obviously they all need attention, however the first question I have is; was it operating properly before you "fixed" the small leak at the t-stat housing? If it was and now you have a problem with no circulation then you need to retrace your steps...then look into the drips, etc.

erickpl 06-09-2010 08:47 AM

Personally, I'd drain the coolant and do a reverse flush. When I did this, it accomplished two things. 1) it got my heater core cleared out nicely! and 2) it revealed that my water pump was not pumping at all and a waterfall came out of it when I refilled it with water to test. $32.00 later, it was running just fine and the swap was NOT hard at all. Just have to remove a few pulleys and the fan. Just be sure to get the right type/direction and you're golden.

A new radiator will be about $150 or so depending on where you go. Stock radiators are NOT worth it. Go aftermarket. The effort for this is just a bit less (you don't have to remove the fan, but you WILL have to remove the fan shroud since it attaches to the radiator - the fan being removed just makes that easier.

rrich 06-09-2010 09:40 AM

So it's not overheating, it's working fine except for a tiny drain plug leak? And it doesn't have air in the system like your previous junk?

Get a new drain plug!

Don't fix it if it's not broken!

4x4anyone? 06-09-2010 05:22 PM

I am still trying to figure out what we are trying to diagnose. Nothing is broken/failing, except the drain plug, so replace it!

If you see no air bubbles in your coolant system, that should be a good thing. You want it air free.

masonea 06-09-2010 07:27 PM

alsyj - That is one thing I didn't think of. I'll take a look at the new thermostat as well.

And maybe it could be my previous "junk", but I always thought that if a system has a reservoir, and you force the fluid inside the system to move (as in squeezing the hose), you should see the fluid level rise, or slosh around. I think I may have used the incorrect word when I said "bubbles". I guess one of the questions I was trying to figure out, is if my radiator should be completely full to the actual cap? To me, it seems odd, that the upper radiator hose has no fluid in it, but the radiator is full to the cap. I am in no way an expert. Just wondering if I should be concerned about anything before I try taking in out on the trails, and find out halfway through a mudhole somewhere. Thanks.

doclouie 06-09-2010 09:00 PM

Use some teflon tape on the drain plug threads before you replace it.

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