bad water pump?

[bd6993]

My CJ7 temp gauge pegs on the hot side after a few minutes. I was looking at the thermostat and noticed the fan and pulley wiggled a bit side to side it just doesn't seem like it should do that. Also I can turn the fan by hand, but it does not spin freely which honestly I'm not sure if that is normal for a clutch fan. Should it be like that? I'm thinking possibly, because of the wiggle that its the water pump. Any ideas?

 

[BusaDave9]

the fan and pulley wiggled a bit side to side it just doesn't seem like it should do that.

That sounds like an alignment issue that I don't think is causing your overheating problem. The pulleys may not be lined up. Keep it in mind but I dont' think it's the problem.

I can turn the fan by hand, but it does not spin freely which honestly I'm not sure if that is normal for a clutch fan.

Yes that's normal. The clutch should grip harder when hot. Look to see if the fan clutch is leaking oil. That's the sign it's failing. When the oil leaks out the clutch doesn't work properly.

I don't think the pump is your problem. The most common reason a water pump goes out is it leaks. The internal part of the pump rotates the same as the pulley. Does the pulley turn when the engine runs?

The most likely cause of your overheating is the coolant isn't flowing.
My first guess is a bad thermostat. You said you were checking it out. Did you replace it?

2nd guess it a radiator that is getting clogged.

 

[bd6993]

THANK YOU FOR REPLYING!

I haven't replaced the thermostat yet. I stopped when I noticed the fan wiggle thinking I could use a little more info and figured if I needed to do the pump I would do the 'stat at thee same time. I understand what you mean regarding a bad pump leaking. I had that happen in my wife's van, water all over the place but thats another story. there is no leaking from the pump and doesn't appear to be oil leaking from the fan clutch.

I'll hit the parts store today and change out the thermostat. Thanks again and I'll let you know how it turns out.

 

[bd6993]

The most likely cause of your overheating is the coolant isn't flowing.
My first guess is a bad thermostat. You said you were checking it out. Did you replace it?

2nd guess it a radiator that is getting clogged.[/QUOTE]


I changed out the thermostat, it was very simple. I also flushed the radiator and put a new cap on, the rubber washer on the old one had a big crack in it.

Unfortunately my gauge is still spiking after 5-10 minutes.

anymore thoughts?

 

[bd6993]

you had asked if the pulley turns when the engine is on, yes it does turn.

 

[BusaDave9]

Unfortunately my gauge is still spiking after 5-10 minutes.

spiking or pegging out?
does it boil over?

It could be a bad gauge. Do you still have the OEM gauge that simply says "H"?

 

[bd6993]

the needle travels as far to the right as it physically can (beyong the H). There is no boiling over. It is the simple OEM gauge with a C on the left and the H on the right.

 

[BusaDave9]

If it is not boiling over I say you have a bad gauge. I would replace it.
If I am wrong you may need a new radiator. That costs a lot more than a gauge but I would replace the gauge soon. Get an aftermarket one that is more accurate.

 

[bd6993]

Thanks busadave, I'll order up a new gauge.
I appreciate all your advice and I'll let you know how it turns out.

 

[mtnwhlr]

You might try a sending unit first.

 

[Vvajk]

I've had this happen one time before, but my problem was obvious . . . I had coolant spouting from a hole in my radiator. Good luck finding the problem.

 

[BusaDave9]

You might try a sending unit first.

Good thinking Mtnhlr. It might need nothing more than a new sending unit to restore the OEM temp gauge to mediocrity. You can test the sending unit by checking its resistance. It should be 9 ohms when hot and very high resistance when cold.
Check out these links:
Fuel and Temperature Gauges Troubleshooting 1972-1986 Jeep CJ's

Basic Troubleshooting for CJ gauges

Does the fuel gauge work? For the temp gauge to work it relies on a voltage regulator in the fuel gauge. If they are both not working then a bad fuel gauge may be causing both gauges to read wrong.

 

[bd6993]

Thank you, that was a thought of mine as well. I figure when I order up the gauge, there are a couple of other things I'll add, the sending unit being one of them. save on freight and if I end up with some extra parts, thats ok too

Any input on a quality gauge? I was going to get just a stock replacement, but upgrading to better quality is definitely an option.

 

[bd6993]

here's my update:
First - I replaced the thermostat and at that point also flushed the radiator. It wasn't a power flush but I basically kept running a hose to it until just plain clean water was coming out the drain.
Second - I replaced the temp sending unit.
Neither solved the problem. I waiting on a new temp gauge (also a fuel gauge). I don't have a tester but I guess I'll need to pick one up and lean how to use it if the new gauge doesn't solve it.

again I'd like to thank all of you for your input

 

[73CJ]

Fan and pulley wiggling?

The water pump bearings are going. Take the belt off and try wiggling it and give it a spin. Not a big deal to replace it. I'm on number 4 in 39 years.