2004 Freestar (Antifreeze Flow)

userpete1037 · 12-04-2009, 09:16 PM

I had the waterpump, drivebelt and thermostat replaced. If I let it warm up for a while, it stalls out, well it makes a real loud screeching sound before it stalls out. When it's running though the upper radiator hose that runs to thermostat isn't hot at all. As a matter of fact, it's cold. It seem like something is restricting the flow. What could be causing this?

serge_saati · 12-05-2009, 07:02 PM

When the thermostat is open, fluid should passes through the upper hose directly.
There's nothing that can restrict the fluid there. If it's cold, maybe it's because the engine is not enough hot. It should be above Cold mark to feel the heat on the hose.

Are you sure that the problem is related to that?

userpete1037 · 12-05-2009, 07:53 PM

I'm not sure if that's related to that. What I do know is I let the vehicle warm up for about 30 min with heat the on and the upper hose was still cold. After I let its warm up, I heard a squeeling sound and I pressed the gas and it shut off.

serge_saati · 12-05-2009, 09:39 PM

After 30 minutes, does it overheat on the gauge? It's more than the half of the gauge?

Maybe the hose is cold, but the radiator is cold too?

userpete1037 · 12-06-2009, 02:06 AM

That's the weird thing about it. It's not overheating at all. I noticed that the coolant resorvoir was a little low. I doubt that has anything to do with it.

serge_saati · 12-06-2009, 09:52 AM

Maybe you have air trapped in your system. Fill the reservoir to the cold range level.
Then open the radiator cap (or any coolant cap) and start your engine. Air bubble may goes out. After 1 minutes, or when it overflows put the cap back.

userpete1037 · 12-06-2009, 11:22 AM

I didn't think about that. I'll give it a try.

userpete1037 · 12-06-2009, 04:40 PM

I tried it and I think you were right about the thermostat not restricting the flow. I forgot to mention that my check engine light has been "on" for a couple of months and the scanner says its my EGR valve. I'm not sure if this causing the engine to squeel and then cut off.

serge_saati · 12-06-2009, 06:37 PM

Quote:

Originally Posted by userpete1037

I tried it and I think you were right about the thermostat not restricting the flow. I forgot to mention that my check engine light has been "on" for a couple of months and the scanner says its my EGR valve. I'm not sure if this causing the engine to squeel and then cut off.

Yes, it can be the EGR valve that is stuck open. The EGR system works only when engine is hot.

When engine is hot, it opens EGR valve to let exhaust gas recirculate to the intake. It lower cylinder temp. to reduces NOx production. If valve is stuck open, too much exhaust (CO2 and water) goes in intake and choke the engine.

It's like if someone breathes exhaust gas, he will die.

Maybe your DPFE sensor is defective. DPFE contols the vacuum in the EGR valve.

EGR valve raraly fails on a Freestar/Windstar. DPFE fails often. But it could be also the EGR vacuum regulator.

If you have to replace the DPFE, I suggest you the one with black plastic coated, not the metallic one.

userpete1037 · 12-06-2009, 09:30 PM

How can I tell which is giving me the problem. Is there a way to troubleshoot it?

serge_saati · 12-06-2009, 10:06 PM

It may take a long time to troubleshot completely.
*To test the DPFE: unplug DPFE sensor, turn key ton ON and check reference voltage on DPFE connector. It should be between 4 and 6V if it's good. I don't know the freestar, on windstar it's pin at top when clip is on your left. If you're not sure, test 3 pins.

*Check also signal voltage on the bottom pin of the DPFE sensor (not connector) when engine is running. When engine is cold, voltage must be between 0.2-0.7V. When it heats up, EGR actvates, so voltage must be between 4-6V (like reference) if it's good.

Don't let temp gauge getting to the operating temperature when connector is disconnected. When heater start to be enough warm (120°F), turn off engine and reconnect the connector.

*to check EGR regulator, disconnect the 2 pins connector, turn key to ON, you should have ~12V at bottom pin (clip at left). Then check resistance on 2 terminals, it should be between 30-70 ohms if it's good.

If all are working, I'll tell you how to test the rest... It could be also ECT, MAF, TPS... that affect the EGR system and can be bad.

I suggest you to buy the Freestar service manual if it's not the same connector.

userpete1037 · 12-06-2009, 10:56 PM

Ok so basically what I'm going to do is test the DPFE and EGR tomorrow and I'll let you know the results. Thanks for all your help.

userpete1037 · 12-07-2009, 05:27 PM

I tested the EGR Valve to see if it would hold vacuum and it did. I applied about 5-6 in-Hg of vacuum and it held. I test the connector to the DPFE sensor and it read 4.86V. I also backprobed it and I got 4.02V. I tested the connector to the EGR Vacuum Regulator and I got a voltage of 12.87. I then did an ohm reading and it was at 9.87ohm. The book says it should be between 30 to 70 ohms. Could that be the problem?

serge_saati · 12-07-2009, 07:41 PM

No, I don't think it's the vacuum regulator the problem, cause when resistance is too low compared to output resistance of PCM (I don't know what is it), voltage drops on the regulator. If you have less voltage, the EGR should be less active, so it should not cause the engine to choke.

Try to disconnect the connector, turn engine and see if the problem gones. Don't let engine run more than 30 minutes like that, just to confirm that the problem is related the EGR system.

If it's the problem, test the MAF, ECT and TPS sensor. They can cause the EGR system to not work properly.

userpete1037 · 12-07-2009, 07:47 PM

Disconnect the connector to the Voltage Regulator or EGR Valve?

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