Degas bottle and Bleeding Help

P

PHYS Inc.

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So I just replaced my Degas bottle with a ford part and new hoses in my 00 3.9L V8. I followed the bleeding procedure and i get heat while driving but not at idle. Car does not over heat and temp gauge stays dead center. What did I do wrong. I've tried bleeding it a few times. HELP
 
My '02 has an auxiliary 12-volt pump mounted on the fan shroud passenger side. Do other LVC members know if this pump's purpose is to boost flow through the heater coil at idle?
 
actually its more the cooling tower that you have to fill to the absolute top during that part of the process.
 
bleeding

Should the degas bottle cap be off during the complete process except only when filling the engine tower you have to have the degas cap on then so the coolant don't just run back in the degas tank. Or does it not matter if the cap is on as long as you don't have to add any to the degas tank while bleeding. Would a little air in the system cause the car to run hot and then 15 minutes later after cooling you do nothing expcept let it cool and you can drive the car for one straight hour and the temp needles stays normal under the same conditions as when it run hot. Confused!!!
 
Last edited:
all is well

PHYS Inc. said:
I rebleed it 2 more times and now all is well
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Glad to hear you got it straight, I wasn't trying to hijack your thread or anything, just trying to clarify a couple things as I am trying to figure this thing out tonight or in the morning early.
 
kitbuf said:
Should the degas bottle cap be off during the complete process except only when filling the engine tower you have to have the degas cap on then so the coolant don't just run back in the degas tank. Or does it not matter if the cap is on as long as you don't have to add any to the degas tank while bleeding. Would a little air in the system cause the car to run hot and then 15 minutes later after cooling you do nothing expcept let it cool and you can drive the car for one straight hour and the temp needles stays normal under the same conditions as when it run hot. Confused!!!
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you should keep the cap on to build pressure
 
kitbuf said:
... Would a little air in the system cause the car to run hot and then 15 minutes later after cooling you do nothing expcept let it cool and you can drive the car for one straight hour and the temp needles stays normal under the same conditions as when it run hot. Confused!!!
Click to expand...

Yes. One or both of the heads go over-temperature and that causes the warning and the failsafe cooling mode. The water temperature is still okay, so the gauge stays in the mid range until the head over-temp triggers, then it goes to the max reading. It confuses some people because they can't see that while the water temp is okay, one or both of the heads are just a few degrees from overheating.
 
joegr said:
Yes. One or both of the heads go over-temperature and that causes the warning and the failsafe cooling mode. The water temperature is still okay, so the gauge stays in the mid range until the head over-temp triggers, then it goes to the max reading. It confuses some people because they can't see that while the water temp is okay, one or both of the heads are just a few degrees from overheating.
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Basically what I was getting at is the thing run hot, or at least the guage went up and showed it was close to it (fail safe mode). And then without doing anything at all to the car other than waiting a little while you then drove the car for days, or weeks, or months and it didn't run hot again. In other words it doesn't just keep running hot routine like. Just a now and maybe later on down the road kind of thing. Wouldn't that seem like maybe a sticking thermostat.:rolleyes:
 
kitbuf said:
Basically what I was getting at is the thing run hot, or at least the guage went up and showed it was close to it (fail safe mode). And then without doing anything at all to the car other than waiting a little while you then drove the car for days, or weeks, or months and it didn't run hot again. In other words it doesn't just keep running hot routine like. Just a now and maybe later on down the road kind of thing. Wouldn't that seem like maybe a sticking thermostat.:rolleyes:
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It's certainly possible that it's a bad thermostat. My point was/is that you don't have temperature gauges on the heads, so you don't know if they are fine, or are very close to overheating. You only know when they actually overheat.
 
ahhh! Finally found something referencing my problem! (i think)

I have replaced the degas tank, thermostat, and drove the car 300 miles during 100* + temps and it drove like a champ. Then, nearing the end of my trip, sitting at a stoplight, it started overheating.

I got home and did the entire bleeding again, but it kept overheating.. but this time my coolant temp guage would get to normal temp and stop moving. The entire time I was driving (few minutes as it never got to reduced power) it was pouring fluid (boiling)... and the guage never went above normal.


Is the coolant temp sensor near the engine fill area? If this sensor were bad, would it read normal temps, even though the car was overheating? and if its reading normal, is it only the coolant temp sensor that triggers the failsafe mode? It seemed that the car was overheating and not going into failsafe because the temperature never "showed" on the guage to be above normal operating temps..

I've seen something to do possibly with the pcm.. IS it something similiar to what I've described? I can't figure what could cause the coolant to boil and the car to overheat without the failsafe kicking in or the temp guage going over normal...

Thank you all for your help! I am new to this forum, but am a member of many forums and trust me, I have done my duty to search, search, and search some more :)
 
Pearl00LS8 said:
ahhh! Finally found something referencing my problem! (i think)

I have replaced the degas tank, thermostat, and drove the car 300 miles during 100* + temps and it drove like a champ. Then, nearing the end of my trip, sitting at a stoplight, it started overheating.

I got home and did the entire bleeding again, but it kept overheating.. but this time my coolant temp guage would get to normal temp and stop moving. The entire time I was driving (few minutes as it never got to reduced power) it was pouring fluid (boiling)... and the guage never went above normal.


Is the coolant temp sensor near the engine fill area? If this sensor were bad, would it read normal temps, even though the car was overheating? and if its reading normal, is it only the coolant temp sensor that triggers the failsafe mode? It seemed that the car was overheating and not going into failsafe because the temperature never "showed" on the guage to be above normal operating temps..

I've seen something to do possibly with the pcm.. IS it something similiar to what I've described? I can't figure what could cause the coolant to boil and the car to overheat without the failsafe kicking in or the temp guage going over normal...

Thank you all for your help! I am new to this forum, but am a member of many forums and trust me, I have done my duty to search, search, and search some more :)
Click to expand...

The coolant temperature sensor OR the head temperature sensor can trigger failsafe cooling mode.
The real problem and question here is why is your LS overheating. I suspect that you have a gen I (2000-2002) LS and that you hydraulic cooling fan is not going into full speed mode. Am I correct about it being gen I?
 
Yes sir -- I knew I was forgetting something (even though my name is someone indicative of the vehicle I own) -- it is a 2000 LS8... My apologies as I have read over and over that the differences in Gen 1 vs 2. The conclusion I have come to (will test later tonight once I am done with my set of day shifts and have some time to work) is that the fan likely the culprit. I almost hit up Max for the acuator today, but want to confirm it tonight before I order parts.

I can't completely rule out any other leaky parts (thermo housings, the crazy radiator hoses/tubes, etc.) but it seemed to run well up until the stoplight incident.. that leads me to think of the pump/actuator...

the only anomaly I couldn't find in searches was the coolant guage reading "normal" while the car proceeded to overheat.. ???
 
Pearl00LS8 said:
...the only anomaly I couldn't find in searches was the coolant guage reading "normal" while the car proceeded to overheat.. ???
Click to expand...

Yes, that does seem strange and unexpected.
A Ford specific scan tool would let you read out the coolant temperature reading. You could compare that to the gauge and to a measurement of actual coolant temperature to figure out if the problem is the sensor or the gauge.
 
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