Water Temp Question

[OkieFishMan]

I have my aftermarket water temp gauge hooked up to it's sending unit with the sending unit in the head. It has a 180 degree thermostat, but the gauge always reads around 210-215. That seems a little hot to me, or do the heads run a bit hotter that if the sending unit were in the intake?

I'm thinking I will install an additional guage in the intake to see. I will soon be towing 10k with this truck and am just trying to make sure all is well before I take off pulling my fifth wheel camper.

Thanks for the input guys!

 

[1987 GMC Jimmy]

I'd verify the head temperature with a non-contact thermometer to see. If it's running a 180* thermostat, the gauge should read 180* where it's at now. I know I bought another temp sender from NAPA for the factory gauge, and it worked well for a few days and started reading high not long after because I verified that my head temp was a stable 195* when fully warm, and the thermostat is opening on time. In my opinion, the cylinder head is the best place to read temperature.

 

[OkieFishMan]

I'd verify the head temperature with a non-contact thermometer to see. If it's running a 180* thermostat, the gauge should read 180* where it's at now. I know I bought another temp sender from NAPA for the factory gauge, and it worked well for a few days and started reading high not long after because I verified that my head temp was a stable 195* when fully warm, and the thermostat is opening on time. In my opinion, the cylinder head is the best place to read temperature.

I've used two different gauges and sending units, one an electric sender, the other gauge mechanical. Both read within 5* of each other when used in the exact same location of the driver side head (I've swapped them back and forth twice). I've just been told several times that the head location always reads hotter (I have no idea if there is any truth to that).

The truck has a brand new radiator, aluminum stock replacement (the radiator shop told me it is the equivalent of the 4 core factory radiator). Brand new fan clutch. New hoses and thermostat.

Truck runs great, lots of power, no water leaks. Weak water pump maybe??? I'm at a loss. I just know that 210*-215* is at the edge of my comfort zone.

 

[1987 GMC Jimmy]

The head does read hotter than the intake, but it should match the temperature of your thermostat and be the truer version of the two. There are about two ways that the water pump can fail. There's bearing failure where the water pump leaks and makes noise. There's also impeller erosion, which decreases the volume that the pump can flow. A water pump is like $17 dollars at Autozone if you want to replace as a preventative measure. It sounds like you have everything else replaced. The thermostat could be opening late, but I'd still verify with a non-contact thermometer. I appreciate that you have two separate sources that confirm what you're seeing, but I'd still do it if it were me.

 

[Honky Kong jr]

Unfortunately A-zone has lifetime warrantys for a reason.......there **** is Chinese junk.

 

[1987 GMC Jimmy]

I've been there. I will say that the Valucraft water pump I bought for seventeen dollars has done me just fine.

 

[Honky Kong jr]

I've been there. I will say that the Valucraft water pump I bought for seventeen dollars has done me just fine.

I put an alternator on a Lancer from there and well after the 3rd warranty one I less then a year it cured me from going there.

 

[OkieFishMan]

I was afraid someone might agree with what I have been kinda been thinking in the back of my head. I have not ever done a water pump on a big block. I've done several on small blocks, and small block chryslers. Hopefully it doesn't require pulling every damn accessory off. Water pump will probably be one of the next few things I try.

 

[Honky Kong jr]

I was afraid someone might agree with what I have been kinda been thinking in the back of my head. I have not ever done a water pump on a big block. I've done several on small blocks, and small block chryslers. Hopefully it doesn't require pulling every damn accessory off. Water pump will probably be one of the next few things I try.

Just like a small block....

 

[OkieFishMan]

The head does read hotter than the intake, but it should match the temperature of your thermostat and be the truer version of the two. There are about two ways that the water pump can fail. There's bearing failure where the water pump leaks and makes noise. There's also impeller erosion, which decreases the volume that the pump can flow. A water pump is like $17 dollars at Autozone if you want to replace as a preventative measure. It sounds like you have everything else replaced. The thermostat could be opening late, but I'd still verify with a non-contact thermometer. I appreciate that you have two separate sources that confirm what you're seeing, but I'd still do it if it were me.

I tested the new thermostat in a pan of water on the stove and used a thermometer. It began opening at 180, so it is good.

 

[OkieFishMan]

Just like a small block....

Thank you sir!

 

[Cuba]

Yeah, not bad at all. In fact most accessories can stay. After removing the top half of the shroud, I'll use cardboard to protect the fins on the radiator. I stick it in between the bottom shroud & flat against the rad. Sometimes working on the pump or bolts I tend to bounce back with my ratchet or whatever. Just a thought

 

[Honky Kong jr]

Yeah, not bad at all. In fact most accessories can stay. After removing the top half of the shroud, I'll use cardboard to protect the fins on the radiator. I stick it in between the bottom shroud & flat against the rad. Sometimes working on the pump or bolts I tend to bounce back with my ratchet or whatever. Just a thought

Not to mention raking your hands across a hundred razor blades.

 

[OkieFishMan]

Yeah, not bad at all. In fact most accessories can stay. After removing the top half of the shroud, I'll use cardboard to protect the fins on the radiator. I stick it in between the bottom shroud & flat against the rad. Sometimes working on the pump or bolts I tend to bounce back with my ratchet or whatever. Just a thought

Thanks for the idea, that's a good one!

 

[OkieFishMan]

So I've been thinking about my little problem and I think I'm going to go back and check every other little thing before I break down and take the time to replace the water pump. It has new radiator, hoses, thermostat (that I verified in a pan of water on stove).

Check plugs and to rule out a lean condition

Check lower radiator hose to make sure it's not collapsing when revved

Check head temp with a non contact IR thermometer


Anything else I might check?