xc_ute

My 85 LX has just destroyed the, let's see, is it 15th heater core? As usual the bad core isn't noticed until it starts to get cold.

Does anyone remember the part or kit that Ford introduced about 1988 to prevent heater core rupture in the vehicles used as pursuit vehicles by the various highway patrol agencies?

I am asuming that it was a spring loaded device that kept the water pressure in the heater core down to about 10 psi.

Anyone know of another "fix"?

(Related ad in "Wanted" section of forum)

roundman

why not give the parts counter at your local Ford dealer a call and see what he can tell you about the heater cores?

vfast

they have a valve for it....

WorldMustang

Sounds funny you keep loosing heater coils, sort of sounds like maybe a plug some where else is forcing pressure in to heater coil instead of where it is meant to be. I would back presurize you lines and flush the engine block without you heater coil attached. I would put a new heater coil in and once a year in the fall disconnect the lines to the firewall and use a garden hose and wash out the coil, I am cheap this way. Anyway flush the engine every year and you should not have the problem again.

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96SilverLT1

your on the right track with the water restrictor.. but your problem might be a result of electrolosis. Get a hold of a volt meter. Place the neg lead on the ground of the battery and the pos lead in the coolant when it's up to operating temps. Most manufactures say any reading of 0.3 volts is bad.. but I would honestly look to make sure that you have even less then that. I would like to see no more then 0.1 volts. If it is high then you need to flush the entire system extreamly well with an flushing agent that contains a nutralizer. After that fill with a 50/50 mixture of the correct antifreeze and DISTILLED WATER. Distilled water is a must. do not use tap or spring water. After all that if the reading is still high look for a bad chassis/motor ground. You might find that you want to add a few extra ground anyway as well as clean all the ones that you do have. I ended up putting a gropund wire right to the core of a truck that kept blowing them.

roundman

electrolysis is also set up by dissimilar metals touching each other, especially iron and copper, so make sure the core and tube connections are protected from touching anything except rubber or plastic too.
underdive pulleys that slow down the water pump will also help some if pressure is what's causing them to fail.

xc_ute

Yes, it could be the local water but I would like to point out that popping heater cores in the mid-80's Mustangs and Capri was a VERY common problem Seems to effect the V-8's with A/C the most.

Ford dealers in this area wouldn't touch the core under warranty after the second R & R. Dealer told me it was the result of, "Driver abuse" and therefore not Ford's problem. Ha, ha.

I was also told that it was the result of high engine speeds (true) and that the engine was meant to be operated below 3000 rpm.

Talk to the Ford parts guy, another joke. Radiator shops claim I should buy frm them as they know they have "fresh" cores vs the dealer's which "has been lying round for ages". Another "HA!"

You might know that Ford did put a plug in one of the heater hoses to reduce flow to the core, I went even smaller with no luck. Best I could do was install a lower pressure radiator cap.

Someone has mentioned that Ford did offer a valve, what was the part number? I know about the valve already just trying to find one.

The actual problem is that the core Ford chose simply couldn't handle the water flow/pressure of the 5.0 engine. Distilled water? Not a great idea if you have a source when out on the road and need to use whatever is on hand (had that experience many times). (And by the way, I too have a Mechanical Engineering background and have already explored the "Scientific" routes in regards ph factors, etc. You aren't telling me anything new.)

One other Ford fix was to change the number of fins in the water pump. Mine came with eight and engines built a few months later (late 84) went to six fins. I have found that the core does last longer with the six fin units.

And of course there is another problem when the heater core is bypassed: Talk about "Driver abuse!". Since I removed the cats I get a kick out of going round some Tuna car at 4000 + rpm in second gear.

Not my second childhood, still living the first.

WHAT"S THE NUMBER FOR THE VALVE? I do know Ford only supplied them for law enforcement Mustangs so not that many units were made.


UPDATE 11/13/04

Can't be a water problem because:

#1 If it were it would be having a noticable effect on ALL types of cars in this area.

#2 The first core burst within a few weeks of purchase of the car (new). That could have been "Driver abuse" from the mechanics, not me. I was called while the car was being driven off the transport and when I arrived a short time later the odometer had 12 miles.

Two days later I picked up the "serviced" vehicle and the odo had 80+ miles. The dealer had to place the Mustang in the center of a fleet of Econolines to keep the mechanics from taking test drives. Can't understand why they of all people didn't realize my LX had the same powertrain as the GT.

The second core lasted a month and I know the local water isn't THAT bad. Core three lasted a few months but like I have mentioned the dealer refused to do anymore warranty work on the heater core.

And no, I DID NOT have the habbit of side stepping the clutch (high engine rpm's). Take into account the ORIGINAL crappy Goodyears still had legal tread when replaced after FIVE years. The original clutch lasted 175,000 + miles. I had purchased the vehilce as a "touring car" not a street racer.

It has to be the core's design and construction that is the actual problem.

Just remembered:

When I picked up the car the salesman wanted a quick peek under the hood. He ran autocross with a Vette and was very perfomance car oriented/kept up on "improvements".

Seems that during the 1985 run Ford not only change the number of blades on the water pump but according to the salesman the size of the drive pulleys was supposed to be increased to underdrive the water pump.

Turns out that if this is true the chage didn't take place to after my engine was built in late 1984.

Can anyone confirm that the late-1985 up Mustangs had larger pulleys FROM THE FACTORY (not after market)?