1989 Bronco II, 2.9L, 5 sp 4x4. Engine is consuming coolant. Replaced all hoses, thermostat, fan clutch. NO leaks on the ground. Exhaust is clean. Uses about 1 qt per day (40 miles driven) does not overheat if coolant level is topped off evey day. Runs a little warmer than normal if levl is low, but does not run hot. Runs and idles fine. Engine is a Crate engine replaced about 50K miles ago. It has upgraded heads made by a company called CIFIC out of California. I have not pulled all the plugs, but the ones I pulled looked fine. No indication of antifreeze in oil on the dipstick or filler cap. But when i pull it in my garage after driving it, there is an odor that seems like antifreeze coming from the vehicle.
I would say you you will need to remove all spark plugs and perform a compression test on each cylinder. This should help diagnose if you have a blown head gasket, cracked head or if you just have a leaking intake gasket. This is assumiong you have already performed a coolant system pressure test. http://freeautomechanic.com/blown-head-gasket.html
Already done the coolant system pressure test....planning on pulling the plugs this weekend.
I ran the compression test after warming the engine up...and all the cylinders were between 152 and 160...#3 was the lowest @ 152. #1, & #6 were at 155, #2,#4, & #5 were at 160. All the plugs were clean...but were gaped at about .050. They wer champian plugs so I replaced them with the stock motocraft plugs gapped at .044. I discovered some antifreeze on the #1 plug, but it was on the outside, and seemed to have dripped from above...possibly out from the valve cover. Will pull the valve cover off next, and see if I can find any leak. What is really strange, at least to me is on Monday I added about 1 galllon of antifeeze...1st time i have had to add coolant since July. Tuesday I added anothe quart, wed, I added another quart. Thursday and friday the level did not change. All week (mon-fri) I drove to work and back...about 35-40 miles round trip each day. The system was flushed and all hoses replaced about 3 1/2 months ago. I also replaced the thermostat and fan clutch at that time. At that time there was a pin hole in one of the heater hoses, that was causeing me to lose coolant. I ran it hot a couple of times back then, but never outside of the "normal range" on the guage. from July till this week I have had no issues with the cooling.
Don't forget the heater core that could be leaking. And it's hard to knotice if it is.
I have been all over my 2.9 bronco2 and it has me frazzled. sputters,idles fast to slow and back again. Tuned it up... the works... plugs wires cap rotor. Replaced throttle position sensor . what the fuck is wrong with it. It will run fine long enough for me to think I fixed it then..........whamooooooooo. Runs like shit..... HELP!!!!!!!!!
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