$200 96 4.0 Project

[CDW6212R]

The under hood vacuum lines are mostly plastic, and at 20+ years old, very brittle and easy top crack or break. So get to those and check for breaks, apply a vacuum if necessary. Under the dash most of the lines are rubber, aim for the plastic ones first.

The windows likely all need new plastic gear parts, the three main pucks at least. Do those and check for power at the switch and motor connectors.

 

[RandomNerd2000]

So I examined it. The good news is there's a brand new vacuum ball on the truck, and when I say new, I mean NEW. The bad news is there's the line coming out going assumed into the intake? A foot of it is all gone. There's enough to patch with rubber line but that's unfortunate, unless it's easily replaced? (It's a black line). The line going to the heater control valve is also gone, completely, but I see where it connects so I'm just going to make a line. That explains that, except for the bit about where does the black line go? Coming out of the ball heading towards the firewall.

 

[RandomNerd2000]

So plan is to go to junkyard and snag some OEM lines and throw them on, I'm hoping the actuator and all is good inside the dash, or at least I'll be able to have heat and some functionality from it. At the current rate I'm making a decent ride out of this truck, should be pretty decent when I'm finished.

 

[RandomNerd2000]

So the lines are on now, still have a high idle although not quite as high, and zero changing of vents. I don't have AC to check to see if the temp control is working, although I think actually it is, when I change it to the cold setting I have no heat, only outside air. Next step anybody?

 

[koda2000]

So the lines are on now, still have a high idle although not quite as high, and zero changing of vents. I don't have AC to check to see if the temp control is working, although I think actually it is, when I change it to the cold setting I have no heat, only outside air. Next step anybody?

The fact that (although you have no A/C yet) you can get it to switch from heat to outside air temp tells me your TEMP control is working, however the TEMP control opening/closing the blend door is electrical only, nothing to do with vacuum. I believe you still have a vacuum issue or maybe and EATC air direction issue. What I would do next is to pull the EATC out of the dash (easy to do once the radio bezel is removed) and check for vacuum on the supply hose to the EATC. I think it's the white silicon line. IIRC there's a singe bolt/screw that holds the vacuum manifold thing to the rear of the EATC. It will also have silicon grease on the connection (don't wipe it off). Using a vacuum gauge (they're inexpensive if you don't have one) check to see if vacuum is reaching the EATC. I recall someone here chasing vacuum for a long time. He eventually found the silicon supply hose was pinched at the firewall. You should see manifold vacuum at the EATC with the engine idling.

The fact that you still have a high idle tells me you still have a vacuum leak somewhere.

Another issue that is not uncommon with the EATC is that the rubber O-rings in the vacuum solenoids inside the unit wear and then leak vacuum, but lets begin with determining whether adequate vacuum is even reaching you EATC. It couldn't hurt to run the EATC self diagnostics/reset (888 means no problems found).

Link:
ford eatc self diagnostic procedure - Google Search

Note: If this vehicle has the manual HVAC controls, the air direction selection knob controls the various functions and also uses vacuum lines to accomplish this. Check for supply vacuum there,

 

[RandomNerd2000]

I think it's a white line too, I found where the lines come in the firewall and it's a white line going across the dash. This vehicle is a base XLT so there is the regular knobs, no EATC in this one. I'll report back on what I find. I'm going to have the radio bezel out anyhow since I plan on installing new speakers and a bluetooth radio I'm pulling out my 2000.

 

[RandomNerd2000]

So I've been busy and haven't had a chance to really work with it any, but that might've helped the case some. When I'm driving and mash the brakes, the vents change and function normally? I'm serious, I can set it to blow on me, and get up 55 MPH and slow down with the brakes and the vents move. The bad is when I mash the gas again, it goes back to defrost vents. I've also discovered it does NOT have heat, which is in part to what I believe to be a partially stuck open thermostat.

 

[koda2000]

So I've been busy and haven't had a chance to really work with it any, but that might've helped the case some. When I'm driving and mash the brakes, the vents change and function normally? I'm serious, I can set it to blow on me, and get up 55 MPH and slow down with the brakes and the vents move. The bad is when I mash the gas again, it goes back to defrost vents. I've also discovered it does NOT have heat, which is in part to what I believe to be a partially stuck open thermostat.

You engine (any engine) makes the maximum vacuum when idling and not under a load. When you accelerate the engine vacuum drops to almost nothing. You have a vacuum leak somewhere. Perhaps your power brake booster is loosing vacuum? That might explain why your dash vents start working when you hit the brakes, or maybe not.

 

[RandomNerd2000]

That's what I was thinking, I discovered this completely by accident, and had a "wow" moment. I can always clamp the line with vise grips and check it that way. Old cars are a blast lemme tell ya, which for $200 I'm really happy with the car, the car itself just has odd problems.

 

[RandomNerd2000]

So I think it's something that was stuck, it's almost completely fixed itself, normal idle and all? Brake booster is my bet. That aside, I've got no heat and a new coolant leak. The radiator tanks are leaking at the seams. So I'm going to try K-Seal on that, and change the thermostat and all to attempt to get some heat, I have NO HEAT AT ALL. If that doesn't work, will a rad from a 01 SOHC work? I have one sitting here that I'm not using since it's too thick for a V8 swap.

 

[koda2000]

So I think it's something that was stuck, it's almost completely fixed itself, normal idle and all? Brake booster is my bet. That aside, I've got no heat and a new coolant leak. The radiator tanks are leaking at the seams. So I'm going to try K-Seal on that, and change the thermostat and all to attempt to get some heat, I have NO HEAT AT ALL. If that doesn't work, will a rad from a 01 SOHC work? I have one sitting here that I'm not using since it's too thick for a V8 swap.

K-Seal will not work on radiator tank leaks, Don't waste your money. You need to replace the radiator. As far as I've seen all V6 rads are the same. I have one from a 96 or 97 Ranger in my '01 ST. It's identical to the 1 year old '01 spec rad I replaced. Mine was eventually warrantied, but I got tired of waiting. The warranty money paid for the Ranger rad (brand new but never installed) and gave me a $50 profit.

No heat at all can be caused by:
- Low coolant level
- Air tracked in coolant system
- A broken blend door
- A broken blend door actuator
- A stuck shut heater control valve (are your heater hoses getting hot?)
- A clogged heater core
- Missing t-stat

I've gotten pretty good heat even with a bad (stuck open) thermostat (TEMP gauge barely off COLD) on a 5.0L.

 

[CDW6212R]

You will have to replace the radiator, with the tanks leaking. I had a slight leak from mine that went about 18 months before it got bad, and it went bad fast. I used two different stop leaks which both helped a ton, the Kseal and the aluminum powder I've preferred for decades. I have a leak now in my new 98, either from the timing cover, the T'stat housing, or the WP that looks new.

The V8 radiators mount forward more than the V6 units, note they are under the radiator support a little at the top edge. You'll need the V8 unit, unless the V6 version is the half thick sized. I'd get and use the V6 brackets for the AC condensor, and then any V8 radiator is great.

Not having heat is rare, there's something wrong as koda listed. Be sure the coolant is virtually full, with a leak you don't want to be surprised with a blown gasket etc. No/little water is getting through the heater core, or the blend door is fully shut, is my guess.

 

[410Fortune]

you can try pinching the tabs on the aluminum so it clamps on the plastic side tanks more, if that does not work then its time for a new radiator

If you have no heat first make sure coolant is flowing through the heater core, you can zip tie the heater bypass valve open or plumb around it to make sure coolant is actually flowing through the core

 

[RandomNerd2000]

Well replacing the radiator isn't a big deal, that SOHC one I have looks just like this one, so all V6s must be the same. I'm pretty sure the thermostat is completely open, the temp needle always sits low. I don't think the heater core is clogged, this truck has the best looking coolant system looking in the cap I've owned. It could be that the vacuum leak is enough that the valve isn't opening, or the valve is stuck. I'd hate if the blend door is stuck shut or the core is stopped up, anything like that, since I'm hoping to not pull a dash.

I'd love to find another V8 truck, even for just a work truck like I've been using this one for. There's one on an auction I'm going to be on the 23rd, if it's a SOHC though I'm going to walk away. There's also a Lariat 01-03 F150 with the 5.4 in it that's caught my eye.

 

[koda2000]

@RandomNerd2000 - Do yourself a favor and just replace the radiator with a known good one (or God forbid a new one). Plastic tank radiators are not worth the efforts to fools with when the tank seals start leaking. I've tried squeezing the aluminum than holds the seals/tanks on. Didn't help at all.

We have a shop in town that has I sign that says "Radiator Repair". I stopped in once and asked if they could replace the seal and they laughed and told be not to bother and to just get a new one.

 

[RandomNerd2000]

Oh that's the plan for sure, if it's not a K-Seal repairable leak, it's a definite replace item. I had figured that it was in need of replacement. I'd just order a new one off RA except I've got that SOHC one just sitting here. Speaking of SOHC radiators, you'd be amazed how many near new ones are in the junkyards here, it's always amazed me. I wouldn't dare even begin to mash on the seams of the tanks/aluminum, that's a recipe to bust it.

 

[RandomNerd2000]

So to update, I popped the hood, and felt the lines. The lines are both good and hot.

 

[koda2000]

So to update, I popped the hood, and felt the lines. The lines are both good and hot.

Blend door broken or blend door actuator not working.

 

[RandomNerd2000]

Any way of figuring out which? There a way to work it manually? I'm a real newbie in the dash side of these trucks.

 

[koda2000]

Any way of figuring out which? There a way to work it manually? I'm a real newbie in the dash side of these trucks.

If you open the glove box, squeeze the sides in to allow it to drop to the floor. Turn the key to ON and place your hand on top of the blend door actuator, which is the black thing that sits on top of the heater box. Run the TEMP knob setting from cold to hot and back. You should be able to feel and hear the small electric motor inside the actuator running. If it runs in both directions your problem is likely that the blend door is broken.