I have a 1990 ranger 2.9 L 5 speed with over drive. I've tried 3 thermostats. Flushed coolant system compleatly twice sprayed all derby out of radiator front n back. Checked water pump its good. I drive it 5 or 10 minutes and the over flow is boiling and pumps fluid to the ground. Im also compleatly in the red. Help please.

 

All I know about this engine is that it is supposedly prone to cracked heads. Have you done a compression test yet? Checked the oil for contamination? How about a new rad cap or even a water pump (you said checked good, how was it checked)?

I had a similar problem on a bus I drove, turned out to be a clogged radiator, but it never did overflow, just got too hot.

Need a little more input for folks to help.

 

5-10 minutes to get from cold to boiling over has to be a head gasket or a water pump.

 

Could be like mentioned above, but make sure you have purged all the air out of the system when you fill the radiator. Run the engine at idle with the radiator cap removed until you are sure the thermostat has opened and top off the radiator before replacing the cap. If it still boils over you will be in for probably pulling the heads.

 

I agree with the above. Does it push the coolant out forcefully, or does it just spill out? Does it start right away, or does it have to warm up a little first? If it has to warm up first probably a crack somewhere. If it starts right away, blown out head gasket, or possibly under filled radiator.

 

I really am thankful of every one for their input. Im not very mechanically inclined. I explained it the best way I could. How do I do a compression check?

 

I really am thankful of every one for their input. Im not very mechanically inclined. I explained it the best way I could. How do I do a compression check?

 

A CC requires the removal of all the plugs and a tester that can usually be rented or gotten for use at autozone or oriellys or.... Actually they are not all that expensive if you are wanting to develope a toolbox. anyhow you pull plugs insert the compression tester plug into one of the holes have someone open the throttle, and crank the engine for about 20 seconds and record the reading indicated. Repeat the process for all cylinders. Then see what the book calls for as being in the catagory of good/bad. all should be within about 15% of each other. Look to see if there is coolant on the tester at each plug.

If you want o do easily take rad cap off make sure the rad is totally full run the engine and look for burping of the coolant. It would be an indication of a bad head or gasket. It is also the cheapest thing to do if you have no tools. Take the cap if nothing else to a auto store and have them do a pressure test on it. Its a $5 at most part to replace if bad and will also cause overheating if bad. Just a couple of simple things to do 1st.

Also make sure the hoses are not old and collapsing when hot.

Go here and register to gain access to the repair help and read to see what you need to know and how to do things:

http://www.autozone.com/myzone/profi...ipBenefits.jsp

 

I would have suspected cylinder head cracking, and suggested testing for exhaust gas bubbling from the radiator as a check. You can also use a rubber glove over the radiator cap fitting to capture gases if they are being expelled from the combustion chamber.
A scope to look inside is also a quick way to inspect for cracks. Clogged exhaust or converters would take longer, I think, to cause coolant to overflow. Did you post this elsewhere?
tom

 

You can get a kit to check the coolant for combustion gases. Well, actually you test the air above the coolant in the reservoir or radiator. The test basically pulls that air through a fluid, and if the fluid changes color it indicates combustion gases. Now what is causing that is where you can do more investigation, but I agree your problem is potentially cracked head or bad head gasket. Either one can result in excess pressure to coolant and cause the coolant bottle to bubble over.