Cooling system problem 3fe (1 Viewer)

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Sep 21, 2006
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Temecula
Well here is another post about my ongoing cooling system problem. I thought I fixed it with a new radiator but I still have the same problem. The truck runs great on the freeway uphills and all, no signs of overheating. I drove 250 miles yesterday with no issues. When I get off the freeway it heats up until I get moving again. This sounds like a fan clutch what has got me is the coolant overflow bottle gets so full that it overflows and I lose some coolant. I think this is why I am getting the above normal temp. readings. It seems like it is getting too much pressure. Do the bypass hoses do anything like this? I just used regular hose so they are kinked. What else could it be. I have been thinking headgasket but I really am hoping it is something else. The exhaust doesn't smell and the oil and coolant don't show signs of cross contamination.
 
Could be as simple as a bad radiator cap. You mentioned new radiator but not a new cap. (worth a shot).

If the overflow bottle is pushing coolant out prior to an overheat (and the cap doesn't fix it) then it is probably being caused by compression via/head gasket. That would suck, but worse things have happened. Good luck.
 
I am afraid it is the headgasket but it shows no other symptoms. It runs great and doesn't smoke or anything. I did replace the cap. It does act like a bad cap but like you said the pressure from a bad head gasket would do exactly the same.
 
So tell me again why you *don't* think it's the fan clutch?

A bad fan clutch can easily cause it to overheat, and when an engine seriously overheats, it spews coolant (since the coolant in the system starts to boil).

On the other hand, from reading between the lines of your post I'm guessing you've had the gauge into the red on at least one occasion, and probably more. If that's the case, who knows what damage you've got by now.

Good luck,

Curtis
 
Sounds like a new thermostat is needed.

Edit:
Just read the other post. Have you noticed the clutch fan change rpm's?
 
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I know my post sounds confusing but that is why I am having trouble diagnosing this. First off it has NEVER been into the red not even once. The overflow tank gets full before the gauge begins to show above normal temps. I think that after it loses some coolant it begins to heat up. I know this sounds backwards but that seems to be what is happening. For example I can drive around town all day and it won't go past normal on the gauge but the overflow will begin to fill. This sort of problem is new to me. I may just throw a new t-stat and fan clutch in it, hope for the best and report back. Thanks for all the input, I am at a loss on this one.
 
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I know my post sounds confusing but that is why I am having trouble diagnosing this. First off it has NEVER been into the red not even once. The overflow tank gets full before the gauge begins to show above normal temps. I think that after it loses some coolant it begins to heat up. I know this sounds backwards but that seems to be what is happening. For example I can drive around town all day and it won't go past normal on the gauge but the overflow will begin to fill. This sort of problem is new to me. I may just throw a new t-stat and fan clutch in it, hope for the best and report back. Thanks for all the input, I am at a loss on this one.

Head gasket/ or cracked head. Bout 99% sure, (from experience on another vehicle); assuming your cap is good, and I think you already said it was new.:frown:
 
Well thats a bummer. Anyway to confirm this? Pressure test the radiator or??? I put another new cap on today just for wishful thinking.
 
Sounds like a new thermostat is needed.

Edit:
Just read the other post. Have you noticed the clutch fan change rpm's?

If you haven't replaced the thermostat, I would give it a try. Mine was cooling real nice on the highway, but when in traffic it would start heating up. My thermostat was opening only about 1/16 of an inch which was causing a flow restriction.
 
A cast iron head, that's hard to believe.

You said you checked the oil and it's not tan, at least that's what I interpret.
Take Curtis' advice, replace the clutch fan. Then the thermo if needed. That's less expensive than a rebuild.
 
If you haven't replaced the thermostat, I would give it a try. Mine was cooling real nice on the highway, but when in traffic it would start heating up. My thermostat was opening only about 1/16 of an inch which was causing a flow restriction.


Opposite happen to me. The PO never noticed something was wrong with the rig. My thermo separated and was open all the time. Nothing told me that I had to investigate a problem after I bought it. I only discovered it when I decided to put a new thermo on.

There are three principals that govern the cooling system, pressure, circulation and thermo exchange. Fix one or all of the problems and you'll be set.
 
I know my post sounds confusing but that is why I am having trouble diagnosing this. First off it has NEVER been into the red not even once. The overflow tank gets full before the gauge begins to show above normal temps. I think that after it loses some coolant it begins to heat up. I know this sounds backwards but that seems to be what is happening. For example I can drive around town all day and it won't go past normal on the gauge but the overflow will begin to fill. This sort of problem is new to me. I may just throw a new t-stat and fan clutch in it, hope for the best and report back. Thanks for all the input, I am at a loss on this one.

Ah.

Thanks for the clarification.

Hang in there,

Curtis
 
Well thats a bummer. Anyway to confirm this? Pressure test the radiator or??? I put another new cap on today just for wishful thinking.

Wait until the cruiser has reached it's operating temperature, turn it off and you should feel the fan clutch resistance with your hand versus running freely with the engine off and totally cool. There should a very noticeable difference between them.

If it runs freely when hot, your clutch is busted.

Do a pressure test, it should stay steady for a long time if there is not any leak present. No leaks and the pressure drop fast unfortunately could mean a blown head gasket and I saw cases were the engine were working smooth ( not yet on a cruiser) but the radiator had to be replenished very often.
 
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Couple of things:
Folks are very quick to point to head gaskets and cracked heads around here without a real diagnostic. If it was a cracked head or head gasket this motor would most likely be running like total crap, but you say it runs well.

You said you replaced the radiator, but gave no reason or details. OEM or aftermarket?

You mentioned the fan clutch but failed to say if it was replaced. Did you look at it or did you replace it? Since it has been mentioned on this board many times before that there is no definitive test for the fan clutch, and they have a lifespan of around 100K miles, I would replace it with OEM and move on.

You have been asked several pertinent questions about what has been replaced and what you replaced things with. Radiator cap, thermostat, etc. Without answers no further diagnosis is possible.
 
Sorry for the delays and lack of info. I was in the middle of a road trip and I had limited time. I made it back home with no issues climbing mountain passes and LA traffic and while I did hear bubbling in the radiator after turning it off I had almost no coolant loss the return trip. OK, the radiator was replaced with an aftermarket due to the old one havening broken tubes. Again even with the old radiator it has never overheated. I thought this was where my coolant was going and apparently that was only part of the problem. The fan clutch has not been replaced yet and neither has the thermostat. The cap was replaced with a stant lever cap because it has made it easy to peek in the radiator with this ongoing problem. I am going to take a better look at it now and replace the fan clutch and thermostat soon. My only diagnostic tools on the road were ears, eyes and a bottle of coolant. I was getting passed going up hills with the 3fe power but I was suprised how well it ran the whole way despite this problem. Almost 600miles and used about 1/2 gallon of coolant but nothing that made me stop or worry while I was driving.
 
It sounds like you have a issue or two. It boils down to flow. I have a hunch you will find the t-stat not functioning fully and the Fan clutch is not working at all. But the other kicker is where is the coolant going?
If you have no external leaks you can find and the coolant is not boiling over during driving, then it must be leaving the tail pipe. Typically a HG will show up under load more than during Idle(why I suggested looking at the fan clutch), the t-stat may not be fully working as well contributing to this low speed or idle time.
You really need to find where the coolant is going to. This may be another issue as well. Good luck with this.
 
I know this sounds simple but had it happen to a friend of mine...

As you have been adding apparently alot of liquid to the cooling system to make up for your losses, are you assured that you have at least a 50% mix in the system. Antifreeze has the obvious anti freezing properties, however they have anti boiling properties also. I had a friend that had this bubbling/boiling problem going on in his truck and come to find out he had mostly water in his system, not much coolant. When shut down or idling he would boil over...almost every time because the mixture was so diluted.
 
I know this sounds simple but had it happen to a friend of mine...

As you have been adding apparently alot of liquid to the cooling system to make up for your losses, are you assured that you have at least a 50% mix in the system. Antifreeze has the obvious anti freezing properties, however they have anti boiling properties also. I had a friend that had this bubbling/boiling problem going on in his truck and come to find out he had mostly water in his system, not much coolant. When shut down or idling he would boil over...almost every time because the mixture was so diluted.


Testing your logic....I always thought that a system with more water compared to a system with more anti-freeze was better off in hot weather. I thought anti-freeze was just that, anti-freeze. Products like Water Wetter are what I thought did what you are saying coolant does.
 

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