Do I need a new radiator? Or just some mods?

[titansarrow]

I have a 91 explorer with about 262k on it. I got it from a friend 4 months ago and have done some work to it since. But there's still one problem, and it has the potential to be BIG.

This truck gets too hot, too easily.

first, let me start by saying, the temp gauge doesn't read right. nominal is on the first n. So when it get to the boiling point (literally) it's reading somewhere around or just before 3/4.

I've read that gauge error can be because of the sending unit....but it still gets too hot regardless. I have also relocated/rebuilt the air intake. It happens in any conditions, seems to happen most when parked (on) after driving for a bit.

my girlfriend is pregnant, so i'm doing what i can to baby safe the truck, this is one of the few things left to take care of.

 

[inh]

Sounds like an internally clogged radiator or an externally dirty one. If theres mud between the fins or covering the gaps, air cant flow, so it will get hot. Same if there is small particles inside it, clogging the tubes. Is the coolant brown? It might be time for a flush, and possibly a new thermostat, that can cause issues too...

 

[titansarrow]

coolent's fine, just need to watch the levels due to heat. there's some normal bug coverage on the front side of the radiator and some crushed/flattened fins front and back

 

[inh]

Flatten those fins out, if there's a good number of them, that could be your overheating issue. I find a small pocket knife works great for fixing fins.

 

[titansarrow]

is there a way to see if the radiator is stock, or if there's a manufactured date stamp anywhere on the radiator? if it's too old I may want to replace it regardless. but I'll try to open up the fins in about an hour.

thanks for the advice thus far btw

 

[inh]

I doubt theres a date stamp or anything, but regardless I would never worry about a radiator being 'too old' It either works or it doesnt, ya know?

 

[titansarrow]

right. well while i'm waiting for th truck to come back to me, how to I go about checking internal damage/clogging and what-not. i know there's flow throughout, but whether or not it's optimal, or if it even matters, I'm not sure.

and along the same topic, I know I can just hook up an electric fan to run as a secondary/auxiliary fan. But I'd really rather things just work they way they should. I've put a decent amount of time, money and learning into this truck to do otherwise.

 

[eXcali]

You can also use a comb to straighten out the fins, I have an old black one with the thick ends snipped off, it works great. I'd check your thermostat as well, sounds like you are having an issue with it. Run a pressure check on it to see if you have any hidden leaks.

 

[titansarrow]

oops, sorry, forgot to mention i just replace the thermostat, that was my first thought. The old one looked rather knew anyway

 

[inh]

As far as I know the only way to diagnose a bad radiator is process of elimination. If its not the thermostat, and its probably not the water pump, then a good chance its your radiator. Only other thing it might be is your hose collapsing once it gets hot. Only way I know of to check for that is to get it hot and check..

 

[eXcali]

you could also have an air bubble stuck in your system somewhere, a pressure test should flush any out.

 

[titansarrow]

i don't think it would be the hose, if it was collapsing under heat if should be leaving stress/fold marks correct? I'll check for that as well soon.

and short of bringing it to a shop, how is a pressure test done?

 

[titansarrow]

k, just checked it all out. the radiator cap end of the hose has a possible crimp in it, but that's it for the hoses. there's no flattening on the inner side, but there's a big spot (about 6"x5") on the outer side. i could only save a bout 1/3 of it, the rest is too crushed. it almost looks burned too, but maybe that's just me.

it must have got hot today, as there's no coolant. thre was a few days a go. i think i may just replace the radiator

 

[shaggymane]

first thing I'd do is pull the Tstat out, close it back up. (you'll need a gasket)
Does it still heat up with unobstructed water flow?

And is water flowing?

Can you see water flowing down inside the radiator with the cap off.
(water pump)
As it warms up when you rev up it should pull the coolant level down and the come back up when you let off. The warmer it gets the more this will happen till it spills out over the rad top.

You have coolant going somewhere. If it's not on the ground then your burning it or it's flying off when your driving. Does the exhaust smell like antifreeze?
(Head gasket maybe lower intake gaskets)

Check out doonze's thread about cleaning his radiator http://www.explorerforum.com/forums/showthread.php?t=246423

good luck

Boggs1227 wrote this:
check the front of the motor for a mineral/coolant stain ( right around the timeing chain cover / p/s pump / lower intake manifold )

if you do see a stain from coolant then most likelly the lower intake could have a bad gasket .mine has a lower intake leak ( water jacket overhang ((ford design flaw )) ...been doing it for over a year an a half) . when mine leaks out you wont see any hit the ground because it evaporates before doing so ...but yet you can see the trail it leaves behind .

 

[titansarrow]

i'll have to wait till the weekend to take out the tstat, i'm out of money and spare coolent till then...plus its kind of a pain in the ass.

i'll try taking the cap off and checking that later today (about 7eastern).

i'll have to sniff the exhaust later too. on the same topic, i have a stock exhaust still, so wouldn't the cat be fried?, and wouldn't i just smell the carbon?

just read his forum and i'm looking for his how to right now. i think i may just try flushing out the radiator and cleaning it all around. again- this weekend.

and i have no idea what a coolant stain would look like. there's assortments of stains on the lower portion of the motor.

as far as where the coolant goes, i don't know. i know that sometimes it must be cooking off. there's been a few times i could hear it boiling while sitting (so i turned it off), but i have yet to smell it.

i've had some performance machines and a few trucks, but this is new to me. when i get the time and money i'm going to build a motor from the ground up. but for now, i need to get this fixed. it's not safe, and not very cost effective to replace coolant every week lol.

thanks for everyones help, i'll check back in when i get my hands on it this weekend.

 

[doonze]

Haven't done my How To yet..... will get it up this weekend. Had it all written up, was proof reading it, had been using the wifes laptop, wife came home, I got up and she got on computer and closed all tabs... *doh*

Btw, I've gotton to where I can change the thermostat in less then 10 mins from the time I start unscrewing the air breather tube till the time I'm screwing it back on..... ,

I can even get my radiator out of the truck in less then 5,

Course I have the M5, and so no trans coolers, makes it easier!

 

[titansarrow]

i can get a new radiator for $100 if nothing else. i hope cleaning it does it, it looks pretty beat up and dirty.

for the tstat i just used i knuckle and 1/4" ratchet......although i lost the socket and 3" extension somewhere in the engine, tried everything to find it/get it out....no avail, the truck ate it lol

 

[shaggymane]

i'll have to wait till the weekend to take out the tstat, i'm out of money and spare coolent till then...plus its kind of a pain in the ass.

i'll try taking the cap off and checking that later today (about 7eastern).

i'll have to sniff the exhaust later too. on the same topic, i have a stock exhaust still, so wouldn't the cat be fried?, and wouldn't i just smell the carbon?

Got any RTV? Reuse the old gakset for the Tstat out test.

It could be that if you want 10 -15 years of life out of a water pump antifreeze is needed for lubrication. But there's nothing that I know of that says you must have anti-freeze in at all times. A month or two in summer won't hurt it. I've done it lots in old pickups with small raditator holes. Only went to antifreeze when it got cold.If it was me, i'd drain all the antifreeze out, save it till i got the problem solved. Because your right, it's not so cheap anymore.

I don't know if antifreeze ruins Cats. Someoen else will have to answer that. Point was to try and get a clue what's happening or rule it out. Anti freeze has a disticnt *sweet* smell. Splash a few drops on a hot manifold, have a whiff. You should never be able to smell it at all when it's running. or parked for that matter.
Time honored way of checking the water pump was to look at the weep hole on the bottom side. When fans were solid, grab a blade and push front to back. should be tight. Not sure you can do that with clutch fans. Mines got a skoosh of play in it. Could take the fan off, does the pump shaft have play at all?

Coolant stain - streaks of greenish or white calcium like deposits.


That it belches after shut off makes me think head gasket. Compression check. Wonder if AZ loans those out.

There's alwys small things to look for. MAke sure there's not a peice of debri keeping the Rad cap from sitting tight. Go with what don't cost money first.
Do a doonoze on the rad.

 

[inh]

Antifreeze does more than keep it from freezing. It helps prevent corrosion and raises the boiling point of the water higher than the 212 degrees it normally is. Granted, the radiator cap raises the pressure, which also help, but so does the antifreeze.

Ive seen generators ruined in just a couple weeks because no antifreeze was used. It will rust internally and clog the radiator.

 

[titansarrow]

my mechanic buddy had advised me to not run it with water. both because of bearings and the boiling point. i fully intend to clean out the radiator this weekend.

sorry if what i said was misconstrued, i wasn't asking if coolant would ruin cats. my point was that my cat is still stock, and i was wondering if it would have build up in it, thereby not letting me smell any sweet smells. off hand i don't think there is one anyway.

and i can't say i say any stains other than oil/grease. if there is any staining, i can't tell the difference between the 2.

let me try to give a lil more info if i can:

the first time i noticed it running too hot was a few months ago. i was heading up a mountain (not hill) coming out of colorado, towing a small uhaul. i had to pull over because i could only make it up the hill in first or second, which was causing it to heat up extremely fast. so i pulled over and shut it off. my girlfriend and i noticed it was boiling. i popped the hood, and saw some coming out of the side of the coolant storage, and was very obviously boiling.

it's done this a few times here and there...with out towing. usually we just notice it gets pretty hot and either pop the clutch and coast, crank the heat, or pull over and kill it.

again, thanks to everyone. it'd be easy to get a new truck, but i have plans for it, and would like to make it into th beast it has the potential for