2.3 no heat or pressue

[jdm95civ]

I got a 93 ranger 2.3 no ac , Ive replaced the heater core , water pump , many t stats , flushed. There is no pressure in the rad hose unless I remove fan and idle for 30 mins. then the heat works. What gives I want heat when driving

 

[Mark_88]

Sounds like you have an air lock in the system...when the engine is cold, remove the rad cap and start the engine...bring it up to operating temperature (2-5 minutes) and you should see the fluid level drop when the thermostat opens...this should also allow you to add more coolant to the system...

If you don't see the fluid level drop then you may have a stuck thermostat...time to change it out...but otherwise this should help clear the air lock and your heater should blow hot air after about five minutes...

There are other ways to do this, but the above way has always worked for me...

 

[RonD]

^^^ +1

You should be using a 192-195deg thermostat.
The t-stat sets the minimum operating temp of the engine, which should be around 200-220deg
The t-stat has a rubber gasket that must be installed or coolant will flow past the t-stat and engine will run colder than it should.
T-stats often have a "jiggle" valve, a hole in the plate with a metal pin in it, this is there to vent any air that might get in the system, so this "hole" should be mounted at the 12:00 position so the air will purge out.

The Lima 4cyl engines don't generate alot of heat at idle, but should warm up to 190deg within 8 minutes of driving maybe 10min. idling.
These engine also have an intake pre-heater that has coolant flowing thru it, that acts as a radiator in colder weather.
Some put a piece of cardboard in front of the rad in the winter to kept temp higher.

A cold engine has no cooling system pressure and idling for 10 minutes while warming up without rad cap should be fine, it should not overflow.
The water pump circulates coolant so the "pump" description is a bit misleading, it generates no pressure, it just pushes coolant around engine.
If there is air in the heater hoses the water pump can not push it out of the way easily, so you have an "air lock".
It is often a good idea to get 2 hose clamps and a hose connector(metal) and cut a heater hose at it's highest point.
Then when refilling leave this hose open and raised so all air is vented(make sure heat control is on HOT, so if there is a valve it will be open), after coolant is coming out BOTH heater hose ends connect the hose and tighten clamp.
If one end of the hose doesn't have coolant coming out then use a funnel to fill it, jiggling it to purge the air.
Any air left won't be enough to cause an air lock.

Put rad cap on and start engine
Any air left in the system will be purged via the rad cap into the overflow tank when coolant gets above 220, make sure overflow tank has coolant and is filled to the COLD mark before starting engine.
If overflow tank ever gets empty air WILL be sucked into the engine, also give the overflow hose a good look, a crack in that hose will let air into the system.

 

[jdm95civ]

Ive tried every trick in the book to release the air with no luck. I did notice when I started the truck cold with the cap off the the water level never went down , so I guess ill take out the t stat for the 10th time and go from there

 

[RonD]

Why would you take out the t-stat?

Is it not a 195deg?

The coolant level won't drop if there is an air lock that the water pump can't push out.

I would first loosen or remove a smaller hose and see if there is air or coolant there.

With engine running(cold, rad cap off) loosen a heater hose or intake manifold hose and see if you can bleed any air out.
And this will also check if there is flow in that hose, there is no pressure but there should be flow.
If there is little or no flow then maybe hoses are crossed or one is kinked or plugged.

 

[jdm95civ]

I took out the t stat to just check that it was in right o ring ect..and it was all correct. Ive also removed the heater hose and water is flowing. I'm thinking airlock also but have not had any luck getting it out , idled with rad cap off , parked on very steep hills with cap off. the blend door works also. still no heat

 

[Road Angels]

Is your fan clutch seized?? are the heater hoses getting warm? do you have a hose that is sucking closed, is there a heater valve on your year thats bad

 

[kimcrwbr1]

How cold is it outside there? Try putting a piece of cardboard in front of the radiator I have read here that may help?

 

[jdm95civ]

The fan clutch is seized , but I have the fan removed. No heater control valves on this truck and its about 40 degrees out side so no really that cold . Both heater lines are warm and water is flowing to the brand new heater core.The heater used to work fine but as I recall it stop working after I changed the water pump. Could the water pump be flowing to much?

 

[kimcrwbr1]

It just sounds like the thermostat is being bypassed somehow. Normally the heater and bypass circuit should allow flow thru the engine to bring it up to temp then when hot enough the thermostat opens letting coolant into the engine. You should get no flow through the radiator until the thermostat opens. Maybe check the bypass circuit if it is plugget maybe the failsafe for the thermostat is popped from too much pressure is another possibility. Pull the small hoses and look for plugged nipples on the housungs? Get a large drill and ream them out.

 

[kimcrwbr1]

If that helps I`m not sure if the failsafe will reset you may want a new thermostat just to be safe?

 

[jdm95civ]

Don't think I have a bypass circuit , and the t-stat housing is also new. There is just two lines to the heater core one from the water pump and one from the t-stat housing. My temp gauge never gets above C

 

[simpler=better]

Don't think I have a bypass circuit , and the t-stat housing is also new. There is just two lines to the heater core one from the water pump and one from the t-stat housing. My temp gauge never gets above C

As far as I can tell the 2.3/ 2.5 is extremely cold blooded (this is good for longevity...not so much for heat). My electric fan only kicks on when I'm sitting in traffic.

Long story short these three things help me get up to temp and keep it there:

1. Grill block (I use metallized bubble wrap AKA windsheild heat reflector) $10
2. Electric fan with a 210*F on and 185*F off switch (from a 2.3L foxbody). Ending up being around $100 said and done for random new parts.
3. Installing a small "spun" style catylitic converter as close to the header as possible, and wrapping the header/cat with fiberglass. $250, needed a new exhaust anyway.

 

[jdm95civ]

I do not have a muffler do you think that could cause my problems?

 

[Mark_88]

Having no muffler will not affect the cooling system...it may affect the engine somewhat due to less back pressure, but the heating system should work regardless of the muffler.

I would go back to square one...the cooling system...that is your source of heat in the heater core. If it does actually blow heat when the engine has been running for a while then the system is actually functioning...somewhat...

I have an 88 2.3 (of mixed background) and I get REALLY good heat out of it...takes a bit to warm up in colder weather, but once it is warmed up I usually have to shut down the fan and open a window...even in Canada!

So...still sounds like an air lock or possible thermostat issue.

Do you know what thermostat is actually in the block...temperature wise?

If you don't and you did not change it that could be a good place to begin...since you mentioned that you'd already tried to top up the coolant after idling with the rad cap off.

Sounds to me like an issue I had years ago...it would not throw good heat at all...turned out to be the thermostat was stuck open and the block never got a chance to actually heat up the coolant enough to throw good heat...which is partially what the T-stat does...it lets the coolant heat up to a designated temperature and then opens to allow the coolant to flow into the places where it would be cooled before going back into the engine.

There are a number of T-stats available, but I've almost always used the 192* one so the heat inside the block is higher before it opens...and the failsafe ones will stick open after just one overheat...meaning the engine doesn't get too hot at any point...especially in colder weather...

Blocking off half of the rad might help increase your temp until you change the T-Stat, but be careful with doing that...one warm spell could cause you to overheat and...the heads crack very easily if they get too hot...