Overheating 2.9

[danger88ranger]

I just got my truck together, its an 87 ranger 4x4 blah blah blah. Anyhow, i bought an electric fan for it to replace the garbage clutch fan that was on it. When its running the temp gauge goes almost all the way up the "normal" heat zone. I have flushed the system, put a 180 degree thermostat in it, but the thermostat doesnt seem to be kicking on in time. I know the thermostat works properly and opens at the correct temp, but is it still running too hot? I'm going to buy a 4.0 radiator and a 160 degree thermostat soon. Is their something i'm missing here? Any input would be greatly appretiated.

 

[Big Jim M]

The 180 is too cold for a modern engine! If it gets too hot it will puke it's coolant out.. Until it does that it ain't too hot! The word NORMAL on the gage is thought to make unknowing drivers more comfortable with the temp range of an engine.. Until it actually gets to puking it will be Ok.
Please don't put a 160* in there.. I'm pretty sure your engine should have a 195* to run as it should, which is about 200/205* under normal conditions. With a pressure cap on the radiator the coolant won't boil until 230* or more is reached.
Big Jim

 

[pimtool]

Put the 4.0 radiator in it and the stock thermostat.
Since I have done that it has not come close to over heating.
Before I did it it would constantly over heat due to the mud in the fins.

 

[WildSide]

You replaced the garbage fan so the next thing to do is replace the garbage temp gauge. Common now are you trying to tell us this engine is overheating without knowing the true water temp?

Plus most likely the cores are plugged in the rad or the coolant passageways are still filled up with rust etc but also tell us the CFM and brand of the fan.

 

[Psychopete]

How quickly does it over heat? In a pinch, it might be worth while to try to stock OEM fan w/ approperiate fan shroud. Unless there have been extensive mods, there's no reason why it wouldn't suffice.

Is the fan turning on even (but this would relate to my first question)?

IMO, this engine cracks OEM heads (especially the older ones) under slight overheating, sometimes they just crack. I wouldn't wait until it overflowed, +1 get an aftermarket gauge and be safe about it.

I am guessing the engine was rebuilt, were there any similar problems prior to the rebuild?

Pete

 

[MAKG]

Put a working clutch fan back on it. It's a FAR more appropriate design than the electric fan. If you really want to, you can put an electric pusher on as well, but make DANG sure it isn't an obstruction.

The thermostat does NOT improve cooling. It tells the cooling when to start. Why do you think the stock thermostat won't start early enough to be "normal?" A wide open thermostat at 180 deg is also wide open at 230 deg. And 160 deg will cause your computer to run in warm-up mode all the time. You LIKE spending $4+/gal on wasted gasoline?

A plugged rad is likely. Feel the back for cool spots after shutting off a warmed engine. But if this high temperature is occuring at low speed, it can be explained by the fan alone.

A POS gauge is also likely. All electric gauges depend upon the condition of the electrical system. You might have found a problem there.

 

[Big Jim M]

The guy is complaining about his gauge registering in the "NORMAL" range! His vehicle hasn't OVERHEATED! NORMAL means just that! It is NORMAL temperature..
Big JIm

 

[MAKG]

Big Jim, it's been my experience that the high end of so-called "NORMAL" is a bit dangerous for a 2.9L. It appears to be an attempt to keep a hosed instrument voltage regulator from looking like an overheating event. Which may be exactly what is going on here.

This is definitely true for the oil pressure "gauge." "NORMAL" = > 6 PSI. 6 PSI at 4000 RPM will cause quite a lot of damage, and is very far from normal (should be more like 80-100 PSI).

 

[danger88ranger]

You replaced the garbage fan so the next thing to do is replace the garbage temp gauge. Common now are you trying to tell us this engine is overheating without knowing the true water temp?

Plus most likely the cores are plugged in the rad or the coolant passageways are still filled up with rust etc but also tell us the CFM and brand of the fan.

The reason why i asked if being that high up the normal scale was okay because i know 2.9's are notorious for cracking heads, i wanted to make sure.
Its a flexalite fan, not sure on the CFM but i got it from lmc truck.

How quickly does it over heat? In a pinch, it might be worth while to try to stock OEM fan w/ approperiate fan shroud. Unless there have been extensive mods, there's no reason why it wouldn't suffice.

Is the fan turning on even (but this would relate to my first question)?

IMO, this engine cracks OEM heads (especially the older ones) under slight overheating, sometimes they just crack. I wouldn't wait until it overflowed, +1 get an aftermarket gauge and be safe about it.

I am guessing the engine was rebuilt, were there any similar problems prior to the rebuild?

Pete

An aftermarket gauge will be in order, the guy that owned it before me rebuilt it, keep in mind this thing was sitting a year before i bought it and sat another six months while i wrenched on it. Its sounding like i could use a 4.0 radiator so i'm going to order one.

Put a working clutch fan back on it. It's a FAR more appropriate design than the electric fan. If you really want to, you can put an electric pusher on as well, but make DANG sure it isn't an obstruction.

The thermostat does NOT improve cooling. It tells the cooling when to start. Why do you think the stock thermostat won't start early enough to be "normal?" A wide open thermostat at 180 deg is also wide open at 230 deg. And 160 deg will cause your computer to run in warm-up mode all the time. You LIKE spending $4+/gal on wasted gasoline?

A plugged rad is likely. Feel the back for cool spots after shutting off a warmed engine. But if this high temperature is occuring at low speed, it can be explained by the fan alone.

A POS gauge is also likely. All electric gauges depend upon the condition of the electrical system. You might have found a problem there.

Big Jim, it's been my experience that the high end of so-called "NORMAL" is a bit dangerous for a 2.9L. It appears to be an attempt to keep a hosed instrument voltage regulator from looking like an overheating event. Which may be exactly what is going on here.

This is definitely true for the oil pressure "gauge." "NORMAL" = > 6 PSI. 6 PSI at 4000 RPM will cause quite a lot of damage, and is very far from normal (should be more like 80-100 PSI).

Thanks MAKG, as far as the oil pressure gauge goes, i'm going to install an aftermarket gauge along with a temp gauge too.