Is my Waterpump Bad?

[asp84]

My engine temp guage on my 94 4.0L stays below normal for about 3-5 minutes, and then dramatically jumps from cold to RM on Normal. When I turn My AIR Cond. on, the temp moves out of normal near the red zone. I have replaced my thermostat, and flushed the coolant system two times. Still no results.

What causes this dramatic jump from Cold to RM on Normal????

Is it my Waterpump, or Fan clutch? I have checked all fluid lines and Coolant level. All of my radiator hoses upper and lower are hot.

Thanks for your input
Al
asp84@earthlink.net

 

[Derrick C.]

I had a bad time with this a long time ago. Never did figure it out. I replaced thermostat, water pump, and everything else. Still didn't want to run right and one day I started it up and worked fine. Very weird!

 

[asp84]

The fan is very easy to spin (w/ the engine off) BUT, it seems to draw lots of air to the engine when on. I think I am going to start by replacing the fan clutch, and if that doesn't work, the waterpump. I have a feeling it is probably going to be the waterpump in the end. I have to fix this problem because at the end of this year I am moving down to Arizona, and will need to be using my AC in VERY hot weather.

If you have any more ideas let me know. Also, what are the signs of a bad waterpump?

Thanks
Al
asp84@earthlink.net

 

[Robert]

If you aren't moving down here until the end of the year, you won't be needing your A/C except during the day Whereabouts are you moving to?

I doubt if it is your fan clutch. Either the fan clutch will cease to work at all which would cause you to run hot whenever sitting still and idleing or the fan clutch could conceiveably lock solid. I don't know if that could happen or not (never heard of it). If it did, it wouldn't cause your temperature to run low when you first start it. It should have no effect on your engine until the coolant got up to the temperature of your thermostat. What kind of condition are your radiator and cap in? I wouldn't discount the possibility of a bad thermostat or possible contamination in the lines even though you had them checked. Waterpump is a definate possibility. Do you see any fluid leaking out of the water pump, right behind the pully and running down?

 

[steveissteven]

I would say your radiator is partially restricted. I had the same problem, and eventually removed my radiator and took it to a radiator repair shop where they rebuilt it for $50.00


Problem solved... mine was 60% clogged

Good luck

 

[Hotweels]

Let the engin warm up and put your hand on the top rad hose you should be abel to feel the coolant surge thru the hose, If you can check the temp sender on the motor, My explorer sits very low on the cold side but i know its normal cause its 28c outside and it still runs fine, If all elese fails take the rad out and get it hot tanked in acid by a good rad shop some times if you add stop leak or other stuff like that it will plug up the cores in the rad, Just giving you some ideas hope it helps.

 

[MikeP]

Al
The quick jump in temp from cold to RM in Normal after 3-5 min. of engine running is caused by the thermostat opening quickly, the hot fluid reaches the temp sensor, and up goes the temp gage. My temp gage shows the arrow straight up after warm up - and the arrow goes up relatively fast but not instantaneously.

Is the water pump bad? I doubt it. By the way, the water pump on my 91 Explorer went out suddenly - noticed fluid draining out while at work (drove about 2 miles from home to work) - no fluid leaking observed before it broke and my Ford is parked on a dry concrete floored garage where fluid leaks can be seen.

Battleground, Washington is located in beautiful SW Washington State, slightly messed up when Mt St Helens exploded in May 1980; I had a USFS permit in Spring 1980 to travel past the Wash State Patrol & Cowlitz County Sheriff road block into the North Side Mt St Helens parking lot area with access from about 8am Thurs to 6pm Sundays; this was a scary place to be (I graduated from Kelso High School, Wash) and we were scheduled to be at Mt St Helens on May 18th (the day Mt St Helens blew up) but luckily cancelled the trip (we were told by USGS scientists it was probably safe to be in there).
Mike in Seattle with 91 XLT 4x4 Explorer

 

[irtySanchez]

Just a thought--

When you installed the thermostat, did you install it with the little relief valve pointed up?

 

[asp84]

Thermostat

Today I put in a new radiator to see how the coolant temp responded. This newer radiator is from a 94 "X" with an AUTO transmission. Therefore it is two times the size of my manual radiator. After installing it, I took it on a test drive......Still running HOT!!!! Dang!! I have already installed a new thermostat, but I am going to buy a new one $3, and make sure I have the relief valve up. I thought I had it in the up position the last time I installed it. But I'll go back over it just in case. Would the relief valve in the down position really cause all this trouble??

Thabks for your help!! I really hope it is something simple.

Al Seybold
asp84@earthlink.net

 

[yob_yeknom]

Originally posted by asp84
What causes this dramatic jump from Cold to RM on Normal????

That is probably either your coolant temp sensor (most likely) or the gauge itself going bad. Sounds like either the sensor isn't reading the temp until it gets up high enough, or the gauge is hanging and not going up until it gets enough juice to make it go up to the RM.
The sensor is on the block or one of the heads, so the thermostat opening should cause the gauge reading to DROP, not go up, as cooler water from the radiator is coming in contact with it. If it was on the radiator it would go up as hotter water hit it when the t-stat opened, but that is not the case.

Fix the sensor/gauge problem first, then see what happens about the A/C being on.

 

[asp84]

Installed my second new Thermostat today. Made sure that the relief valve was up. Also installed a new Lower radiator hose to properly match my Auto tranny equipped Radiator. After I filling radiator with a 50/50 mix I took it on a test drive. Still Running hot....except it seemed to not jump as fast up to RM. AC on still causes it to go near red zone though. I will try a new coolant temp sender before I get a new waterpump. It looks as if there are two coolant sensors....One on the left and right side of the thermostat housing. Are they both for the cooling system?

Thanks,
Al
asp84@earthlink.net

 

[yob_yeknom]

One of the sensors would be for the gauge itself, and the other for the computer. I'm not sure which one is which though. Ask the parts department at a dealership, if no one here knows, they should be able to tell you.