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  #1  
Old 08-27-2011, 12:20 AM
'91 Ranger XLT 4x4 4.0L
 
Join Date: Jul 2011
Posts: 2
Default used "dex cool" coolant ... big problems!

I have a 1991 Ford Ranger XLT with a 4.0L. It has 280,000 miles, but I dropped a newer used engine in it a year and a half ago that only has abt. 80,000 miles on it now. It has been running just fine, except for the typical knocking caused by carbon buildup that I recently cleaned out using the Ford "MP3" that worked like a charm.

Anyway... about a month ago, I was running down a small leak in my coolant system. Found the leak : abt. one drop every 10 or 15 seconds, but that added up to abt. a 1/2 gallon every 4 to 5 weeks. The upper rubber return hose was stretched and a little loose where it attached to the pipe coming out of the thermostat. I replaced the hose and clamps, and decided it was a good time to flush my system and add all new antifreeze.

Unfortunately, I bought a Prestone "extended life" antifreeze that I now realize was "recommended" for GM Dex Cool coolant systems. Nowhere on the jug does it say that you shouldn't use this in a Ford or coolant system that was not specifically designed for Dex Cool. In fact it says it can be used in any car or light truck with an aluminum radiator, and specifically lists coolant numbers for Ford and Chrystler, etc. I never read that fine print, but I guess it means it was a mistake to use this in a Ford Ranger with a 4.0L.

The result is, after a month running the Dex Cool antifreeze, I noticed I started loosing a little coolant again, and located a very very slight leak that seemed to be coming from somewhere near the right front area of my valve cover that was not there before (I have been very diligent looking for coolent leaks in the past few months trying to run down the little leak I described above). It was hard to see exactly where it was coming from, as this area is hidded by the alternator and idler pully, etc. Since I was afraid it was an internal gasket, I added some of the high-end Bar's Leaks Liquid Copper, and the leak stopped almost immediately. No more problems for four more days.

But today, my engine started overheating at an alarming rate : I drove three miles from a cold start, and it was pushing the high end of normal and going up. There was obviously pressure in the coolant system, and a lot of coolant had overflowed into and overflowed the reserve tank. So I popped the radiator cap and added water to the running engine for a few minutes until the temps were normal and below. Had to get to work, so I topped off the radiator and drove less than 10 miles, and it was overheating again. Popped the radiator cap again and added water to the running engine until it cooled down to low normal and parked it. There she sits... I am going to flush the whole system with water before I have to drive home tomorrow, and have more water to use if it starts getting hot. But obviously, whatever damage has already been done will need to be repaired--and I'm really worried that repairing the damage might be more work than the truck is worth.

As I read up on the Dex Cool this evening, it seems that there have been serious problems with this coolant eating gaskets ... there were even class-action lawsuits a few years ago! Amazing they keep selling the crap!!! Even more flabberghasted that they don't have a big warning on the jug that says don't use this in any conventional "green antifreeze" coolant system!!! I am especially concerned because I also read that it can damage a plastic intake manifold (which my 4.0L apparently has).

So here's my QUESTION:

What gaskets that come in contact with the coolant might have been damaged?

I would really appreciate if someone could list each gasket and any other parts I need to examine and possibly replace.

Thanks in advance for any advice!

--Nick
in Cottonwood, Arizona

1991 Ford Ranger XLT 4.0L 4x4

Last edited by ponderosa; 08-27-2011 at 12:27 AM.
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  #2  
Old 08-27-2011, 03:58 AM
Ban Survivor. (x2)
 
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Default Re: used "dex cool" coolant ... big problems!

head gasket. you will need a head gasket set wich includes head gaskets, upper and lower intake, valve cover, and probably IAT, Throttle body, etc. Usually run about $100 You should also buy new head bolts. But old ones can be re-used, but not recommended as they stretch

----------

I dont think that the coolant comes incontact like it does with GM's 3800 motor. So you should be fine. You must have like a 95ish motor? as up to 94 they had aluminum intakes.
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  #3  
Old 08-27-2011, 04:33 AM
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Default Re: used "dex cool" coolant ... big problems!

I wouldnt jump to the head gasket just yet. Best thing to do would be to rent a coolant system pressure tester to help you pin point the leak more accurately. My bet would be the lower intake gasket went, they usually go out at the back of the motor but I have seen them fail in the front as well and at first glance it will look like its coming from the head area. The coolant you used probably had nothing to do with the issue at all, Dex Cool is a product made by GM and it did cause issues but all over the counter universal coolant isnt the same as Dexcool.
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2001 Ranger 4x4 Stepside
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-4:56 gears
-Auburn gear LS
-James Duff traction bars
-Headers
-Flowmaster duals
-SCT X-Cal2 and some small exterior mods

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Last edited by 01_ranger_4x4; 08-27-2011 at 04:36 AM.
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  #4  
Old 08-27-2011, 07:06 AM
Ford Ranger Driver
 
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Default Re: used "dex cool" coolant ... big problems!

i would also get the waterpump gasket and the thermostat gasket..... and from what i hear if the dexcool mixes with the normal green antifreeze it creates some sort of gas.....
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  #5  
Old 08-27-2011, 07:56 AM
Ban Survivor. (x2)
 
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Default Re: used "dex cool" coolant ... big problems!

I've heard that green and dexcool will gel..

Also, I say HG since they have a film on them that the dex-cool will eat. There is also stuff used for semi's, its like an aqua color. This will also eat the HG if used in regular cars/trucks.
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Quote:
A Gladiator does not fear death. He embraces it. Caresses it. Fucks it. Each time he enters the arena, he slips his c0ck in the mouth of the beast, and prays to thrust home before the jaws snap shut. - Oenomaus
Ball Joints/Upper A-Arms How To
Replace Door pin/bushing
Repair broken dome light tabs
VIDEO OHC Install
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  #6  
Old 08-27-2011, 08:05 AM
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Default Re: used "dex cool" coolant ... big problems!

Quote:
Originally Posted by pooleo View Post
I've heard that green and dexcool will gel..

Also, I say HG since they have a film on them that the dex-cool will eat. There is also stuff used for semi's, its like an aqua color. This will also eat the HG if used in regular cars/trucks.
Youre right, Dexcool mixed with green coolant will gel and it will happen almost immediately. The issue with the dexcool in the GM's was that it would eat the plastic intake gaskets. The fords use metal intake gaskets so its not as much of an issue, but as I stated before, almost all over the counter universal coolant is formulated to be safe to use with any coolant in any car UNLESS you buy actual Dexcool. Also to the OP, your lower intake is the only part of the intake that comes into contact with coolant and it is still made of aluminum, the upper intake "plenum" is plastic. Get a pressure tester to help pin point the leak, fix it, flush the system with the correct coolant and youll be trucking again.
__________________
2001 Ranger 4x4 Stepside
-RCD Suspension lift
-33x12.5 BFG KM2's on Mickey Thomson classic locks
-4:56 gears
-Auburn gear LS
-James Duff traction bars
-Headers
-Flowmaster duals
-SCT X-Cal2 and some small exterior mods

http://www.cardomain.com/ride/2321189

2005 F-150 Lariat 4x4
-LED third brake light
-Weathertech floor liners
-Edge tuner
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  #7  
Old 08-28-2011, 07:34 PM
'91 Ranger XLT 4x4 4.0L
 
Join Date: Jul 2011
Posts: 2
Default Re: used "dex cool" coolant ... big problems!

I read that the Dex Cool contained a plasticizer that compromised regular gaskets as well as the plastic intake manifold on some models--hence my concern that all my coolant system gaskets were compromised. However, the Prestone dex-cool compatible coolant said it could be used in any vehicle with an aluminum radiator, which my 1991 Ranger has. Also, I looked and I do have the stock aluminum intake manifold (rather than a later plastic one).

Well, it's been a couple days, and I am not sure that my overheating issue was due to a head gasket or any other gasket issue. I flushed the orange Dex Cool coolant, and have been running straight water thinking I might have to drain the system to do repairs.

The oil was just changed and is clear and clean, so there doesn't seem to be any coolant getting into the oil. I can't tell if there is any oil in the coolant right now, but it is not dirty or bubbly like I have seen with other obvious head gasket ruptures. There didn't seem to be any oil up till it overheated (and I was checking the coolant every day or so). However, it looked like there was a very little bit of an oil sheen on the water running out of the radiator as I continually ran a hose in the open radiator to clear out the orange coolant... don't know what that means (could just be some oil on the ground from old oil leaks and changes).

When I drained the coolant, it was definitely a bit clumpy. And this was after I thoroughly flushed the system a month ago and added the orange dex-cool stuff. But I don't know if some of that residue might have been from the stop-leak addative I had put in the week before.

Is it possible that the orange "Dex Cool compatible" coolant and the Bar Leaks Liquid Copper stop-leak additive reacted with each other? (The overheating occured six days after I added the stuff, and I drove 60 miles during that time. No problems until the day it overheated rather suddenly.)

Since flushing and running with water only yesterday, I have idled and looked for issues for almost an hour, test drove around for 20 minutes, and driven 10 miles four times. I don't seem to have any water loss, no overheating and no pressure build up in the coolant system. I get up to operating temp, and it never goes above mid-normal, which is typical.

If it were a ruptured head gasket, I would think that pressure would still be getting pushed into the coolant system. Any thoughts there?

The only other things that I could mention that may or may not be related is that there was a belt squeel the day I overheated (and a couple days since) ... it sounded like it might have been the water pump or fan clutch, but it goes completely away when I just spit on the belt, so I think it is just the a belt squeel from all the water/coolant that has been oversprayed around the pullys. And the engine had a fouled plug a week before this... it was the front right cylinder... that was the same area where I noticed the very small coolant leak around the same time.

Any more thoughts?
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