water pump gone bad?

russkiypenguin1 · Post by **russkiypenguin1** » Tue Dec 14, 2004 10:17 pm

I've been having issues with overheating even in very cold temperature. Normally the car runs fine and has super hot heat. The fan is running just fine. I have fluid.
I don't think it's the thermostat stuck shut as I can tell when it opens. The temp gauge will dip for a few seconds and suddenly I get heat from the heater. So my theory is the water pump is dying.

I'm going to have a friend idle it for me(the car dies if you don't apply the accelerator...I'm getting it fixed on Monday) and then see what kind of pressure the hoses have.

Any comments from anyone?

Teddy1 · Post by **Teddy1** » Tue Dec 14, 2004 11:34 pm

Overheating Issues:

1. Bad cap on radiator. These caps need to be replaced every 3-4 years.

2. The thermostat might open SOME, but could STILL be "stuck" (ie; it is only opening a FRACTION of what it should be).

3. Head Gasket breach (you can use a gas analyzer on the radiator neck to easily check for combustion blow-by gasses in the coolant).

4. Water pump faulty, or belt slipping on pulley.

5. Radiator clogged/fouled.

Check to see if your water pump has a "tell tale" or "weep" hole...
if it DOES (its usually on the bottom) and it is leaking water, then it is a failed water pump.

However, in ORDER of likelihood:

Thermostat
Radiator Cap
Radiator Plugged
Water Pump drive belt slipping
Water Pump
Head Gasket

So, as you can see, the water pump is NOT the immediate culprit... Russkiypenguin, I have been servicing these cars for a long time now, and, the above is my opinion/suspicions.

- Teddy

Teddy1 · Post by **Teddy1** » Tue Dec 14, 2004 11:39 pm

Also, the hoses will have pressure regardless of whether or not the water pump is spinning... what pressurizes the closed system is the expansion of heated water and air (both thermal laws and hydraulics apply here).

However, the hoses WILL get REALLY ballooned if the car is severely overheating (again, regardless of whether or not the water pump is working).

Does any of this help?

takza · Post by **takza** » Wed Dec 15, 2004 6:41 am

I vote thermostat. Then I vote exhaust into coolant.

The fan on my car only runs when the car is idled offroad in warm weather...if you have a head gasket allowing exhaust into coolant....you have a lot of extra heat...plus "air" pockets.

A test for this is to start the car cold with coolant visible at the rad cap...watch for "air" bubbles...you might see a very small stream of them or if it's bad...a gush of "air" if you rev it.

russkiypenguin1 · Post by **russkiypenguin1** » Wed Dec 15, 2004 11:33 pm

ALL OF THIS HELPS! sorry it took a while to reply. Work is really busy at the moment.

OK, so here are my thoughts. No matter what I planned on replacing the thermostat and for the reason that everyone describes. Yeah, it might be opening, but not enough, or it may have sediment around it's openings. Plus, it has the original thermostat on it and I want to swap it with a fail-safe thermostat. Plus it's the cheapest and easiest overheating solution. No matter what it's worth trying.

Radiator cap: I had forgotten about this. My opinion on this is similar to the thermostat. They're so cheap, why not try it.

Plugged Radiator: I doubt it. I'm not a mechanic, but I think I would have seen a progressive problem in this area. Especially since I live in an area that gets to 100 degrees in the summer.

a)Water Pump drive belt slipping
b)Water Pump
c)Head Gasket

I clump these three together because they're beyond my ability to guess or analyze. I have never adjusted/located the water pump drive belt. It might need tightening. I do not know where the water pump is, but I'm betting it's buried behind the timing chain. I can state that I know it's not weeping. I looked for that right off the bat and it's not. I don't know if that's standard on this vehicle or not. I had it happen on an early 90's silverado and I knew what it was right off the bat. And if it's the head gasket I'll go for an engine swap instead of a head gasket repair.

So, I'm going to swap the thermostat and radiator cap and see what we get. Beyond that, I'll probably be paying someone to do the work because I don't have the time or tools to make it a break even solution. I'll have to wait til the weekend to update you guys as I don't have the cash for parts until Friday.

Retroloc1 · Post by **Retroloc1** » Thu Dec 16, 2004 8:19 am

I bought an used engine (150.000mi). It warmed quickly. But the temp needle raised immediately each time I opened the throttle and then downed to normal.

The water pump was completely worn, the sole axle was remaining.

Old engines with brass pump could suffer pure water in the cooling system. Modern engines with steel pump don't.

Teddy1 · Post by **Teddy1** » Thu Dec 16, 2004 11:55 am

absolutely.

russkiypenguin1 · Post by **russkiypenguin1** » Thu Dec 16, 2004 5:53 pm

Teddy is that for me or Retroloc? My hunting tomorrow may have just been canceled, so I may be able to update you guys with a fix by tomorrow.

Typrus · Post by **Typrus** » Thu Dec 16, 2004 8:05 pm

The thermostat is a real easy fix. You may want to backflush while you're at it, just to kick out what sediment you can, if there is any in there. I probably should've done it now that I think of it, oh well.
The water pump is the thing that the top Rad hose goes into.

russkiypenguin1 · Post by **russkiypenguin1** » Sat Dec 18, 2004 12:58 pm

I'm an idiot.

A tip for others. If your car is overheating, check to see if you're low on coolant.

anyhow, now I have to replace the lower rad hose as it's leaking. I suppose I should just be happy that it's a cheap and easy fix.