1999 exployer problems 4.o sohc

:banghead:Hi, I've been having over heating problems of late. Repaced the radiator and thermostat. Was afraid I had a blown head gasket as I saw steam at tail pipe . It was cold and almost dark when I noted the steam.Next day I found leak in the radiator and put a bottle of Bars Stop Leak in...(not a good idea I know)...Wife ran car a total of 34 miles and had to add water, so that didn't fix leak.Was hoping to seal any head gasket leaks since a head gasket job wasn't in our budget at this time.Yesterday I replaced the above mentioned radiator and later that day the thermostat.Fist I flushed the cooling system, then replaced the radiator .May have over filled some as after driving 6 miles the coolant was pushed into the over flow tank and was pushing out the top over flowing..Noted only one heater core hose was getting hot and thought maybe the thermostat was bad.Changed that ( getting dark now)and warmed engine up for ten minutes.Noted that all a/c coponents under hood were getting really cold and even with heat on still blowing cold air at vents.Reved engine some and noted heat hand droped slightly from half way point.Then heat started working.The A/C components under the hood were now warm.During the time before the heat started working and the A/C components were cold my voltage at the alternator and battery was reading around 12.44 volts... When the heat started working a re-check showed 14.88 volts..I did change engine oil after seeing some foamy looking stuff on the oil cap, and will be changing it again today.The oil still looks good and shows no sign of water, but I just wanted to remove the sludge.Hasn't pushed any water out since I replaced the thermostat and only filled the radiator, so maybe I just had too much in it.The low voltage thing along with the heat and a/c trying to run togeather worries me though..Any ideas what could be going on here? Thanks, and sorry for the long post.

If the vehicle experiences or has experienced primarily short trips, the foamy stuff in the oil fill cap is not necessarily abnormal. It could just be due to the engine rarely getting warm enough for long periods to fully evaporate all moisture out of the oil. Also, on cool mornings with a cold engine it's not abnormal to see what appears to be water/smoke from the tail pipe. The catalytic converter converts unburned fuel to water vapor. This water vapor can settle in the exhaust. When the cold engine is started, this water vapor burns off and can cause people to suspect head gaskets if they are not used to seeing this.

As for the charging system voltage concerns, I'd suggest you remove the cables from the battery, clean them well, reconnect them and make sure they are tight. Then continue to monitor the charging system voltages. You might pick up one of the inexpensive 3-LED monitors that just plug in to one of the lighter sockets. Ask your wife to pay attention to if the LEDs drop to the yellow or red when idling at stops lights, etc.

-Rod

The a/c is demanding on power, that is why the voltage was lower with it running, why it was running however is beyond me, along with it cutting off by itself, are you sure you don't have the control pushed in for the a/c, you never mentioned how often this problem occurs. The a/c being on the voltage you were getting is completely normal. You need to find out why your a/c is coming on when it isn't supposed to. I'm not familiar with your vehicle however so I wouldn't know where to start. If it was me and I didn't have time to look into seeing why the a/c was coming on I would just remove the fuse until I had time to look at it, and if it was still coming on after that I would disconnect the electrical connector to the a/c compressor.

Thanks so much for the quick reply! I feel better reading you'r comments.Iv'e replaced heads on older cars, but these engines are so much more complexed with all the chains and tensioners and special tools required.You give me hope that I jumped the gun on the head gaskets.I still wounder why the a/c was trying to run when I had the heat set to high.reving the engine seemed to futher open the thermostat and cause the heat to start working and the a/c to stop...Is there a temp. switch somewhere on the engine that could have caused this problem you think?Again, Thanks so much.This site is the best! P.S. Thank you ctwright for you'r input also!

There are various settings on the HVAC control that will call for A/C even if it's not an A/C or Defrost function.

And 12.44 Vdc with the engine running, even with the A/C on, is low. Keep an eye on the voltage.

-Rod

Thanks Rod, I will.It seems to be charging ok so far.drove it to store tonite (8 miles round trip).Two miles from home the temp gauge was still showing cold. Then all the sudden it rose to 3/4 hot .A few seconds later it droped back to normal(1/2 way on gauge)...It droped slightly from normal then rose back to normal several times but never rose to hot again ..Was thinking maybe temp sending unit,but when I got home I raised hood and noticed some coolant seeping from radiator cap.Not sure how much I lost but the over flow tank was nearly empty.Could a clogged radiator cause this? Maybe air locked? Runs great aside from this problem.. Thermostat is a new Stant brand...190 degree..Oh,Also noted while driving that the heat wasn't as hot as it used to be when it finally kicked in. Was alot warmer and faster to start heating..Thanks again everyone

I wouldn't expect a blocked radiator to let the engine temp fluctuate like the gauge reported. Trapped air could explain the fluctuations in the gauge, but would not explain the apparent boil over situation from the radiator cap.

If it were by truck, I'd start by performing a pressure test on the radiator cap as well as the cooling system to see if maybe the cap is not properly pressurizing the system followed by confirming the system holds pressure. If you find the cap works to the rated pressure but the pressure bleeds off the system, then check very closely for leaks, including from the heater core. If you don't find any leaks, then you might still be looking at a head, block, or gasket issue. :(

-Rod

Thanks again, Will try to pressure test today.Was out there this morning removing belt so I could wiggle water pump better and check for play in pump shaft.Went to losen belt tenison and went the wrong way first.Tenisioner easily moved 2" toward the tight direction,so thats got me thinking it's weak and slipping the belt and may not be turning the water pump fast enough.Smelt the tail pipe for smell of coolant, but didn't smell any thing. Also looked at oil fill cap for sludge and moisture but none was present.Is there a good way to bleed the coolant system that don't require special equiptment? Didn't have an air lock problem three years ago when I replaced heater core and flushed system, so I'm not thinking it's my problem unless I got lucky then...lol...Tenisioner isn't applying full pressure to belt, so I'll also get it replaced. And you've all been really nice and I thank everybody for bearing with me. Thanks

Bought all the testing tools and tested the cap first. Noticed it missing a small cornor of rubber on the lower rubber seal, but it held pressure when tested.( will still replace it.)Put tester on the radiator and applied 20lb. In three hours it had droped to 19lb. During this time i've been spraying soapy water on all hoses,but can't see any leaks.Will keep looking though as some of these hoses are really hard to see at connections.Will do a basic compression test today also. Maybe it will tale me something, but I don't expect to see any low compression because it runs so well and doesn't use any oil to speak of...But introducing compressed air into each cylinder may help find a bad head or gasket.Five hours now and still at 19lb. Is there an easy way to get the next piston to TDC once iv'e tested #1? I asume I need to follow the fireing order and want to use a remote starter tool to rotate engine if possible.Do all plugs need to be out during this test to hear excaping air from one cylinder to the one next to it? Will have coil pack in hooked .Anything else I should un-hook? Thanks again!

If your cooling system has only dropped one psi in 5 hours, there either isn't a leak to speak of or it will only show up when the engine is warm.

What is the system rated for? It should be on the pressure cap. I'd be surprised if it's more than 16psi. If that's the case, you really don't want to keep the pressure at 19 psi for too long or you might cause leaks that you don't already have.

-Rod

You'r right..16lb. cap...Wasn't getting any leaks that I could see at 16lb. so I increased it hoping to see leak better. Sprayed soapy water on every thing. Did compression check and found #5 low.Also found #3 low on other side..Had been getting mis-fire code on #5, so left plug out and pressurized coolant system again and spun engine over.. Coolant sprayed out #5 this time, so it's a bad head or gasket I guess.Didn't check #3 on the other side(hard to get to)but #5 leaking showed me enough to know I need to pull heads.Anyone know what it cost to get heads checked for cracks ect.? Thanks to every one here for all you'r help.I've learned alot from you guys, and now have the tools to test future problems.

Eeek, sorry to hear that!

-Rod