87 GL water pump question

[OregonYeti]

Thanks in advance for any help on this. I have a huge coolant leak. I suspect it's at the water pump. Today the dash temperature gauge went barely into the red and I pulled over and parked for a while. I was needing to add coolant every month or so, but this time I added a lot a week ago and a lot is gone.

 

The water pump is on the same axis as the fan, and right behind the fan, right? There is metal tubing going into the water pump on the right side, looking from the front of the car, that is loose on the outside (slides in and out). Is this supposed to be a tight connection or is the seal internal?

 

If this is the leak, what's a temporary fix? I will most likely have to go to orientation for a new job on Monday and I want my car to be working. Backup plan is rent a car tomorrow but I'm pretty broke since I've been unemployed a while.

 

Any help is appreciated.

Edited August 12, 2016 by OregonYeti

[DaveT]

Yes, the water pump is what the fan is mounted on.

 

Sounds like the intake tube to the pump.  It seals with an O ring to the pump housing.  Sometimes, the tube rusts, or the pump corrodes and it won't seal well.   Have to get it apart, and inspect.

 

That hot, with that much coolant loss, I will be very surprised if your head gaskets are not damaged.

[OregonYeti]

Yes, the water pump is what the fan is mounted on.

 

Sounds like the intake tube to the pump.  It seals with an O ring to the pump housing.  Sometimes, the tube rusts, or the pump corrodes and it won't seal well.   Have to get it apart, and inspect.

 

That hot, with that much coolant loss, I will be very surprised if your head gaskets are not damaged.

 

Damn. But thanks. Better to know than not know.

Edited August 13, 2016 by OregonYeti

[OregonYeti]

Is the O-ring on the outside or the inside of the housing? Ok never mind. Must be inside to hold pressure.

Edited August 13, 2016 by OregonYeti

[DaveT]

If it really looks like that is where the leak is - Note - the shaft seal on the pump can fail, that's what I have seen most often causing a leak near the pump.  Also, the small 90 degree hose on top of the pump. 

 

Unhook the - battery wire.

Unbolt the AC compressor, and swing it out of the way with the hoses attached.  Remove the alternator.  Now you can get at the pump and the hose and the tube with the O ring a lot better.

 

If you fix the leak, you can closely monitor the coolant system to see if it is ok. 

[somick]

On my 92 Loyale the water pump is driven by the timing belt. 

 

One of the possible leaks is a rubber elbow.  You can get access to it if you remove the AC compressor.

 

Good luck,

Sam

[OregonYeti]

Thanks very much DaveT and somick. As it turns out it was not the O-ring at the water pump. I'd assumed it was that connection because I didn't expect to be able to move the metal tube connecting to it. The O-ring explains it and it is not leaking there.

 

The leak was at a smaller hose at the top of the engine. I think it's called a bypass hose. I found the leak by filling the coolant system again and it leaked there. I replaced that hose today and I will be looking for oil floating in the coolant. I sure hope the head gaskets are okay. There is no coolant leak and the engine is running fine so far. If there's oil in the coolant I will stop driving it and put it for sale to someone who is willing to make repairs, or scrap it. It's got Turbo wheels and almost brand-new tires.

Edited August 14, 2016 by OregonYeti

[DaveT]

oil in the coolant, or coolant in the oil is only caused by VERY bad headgasket failure.

 

How to check for the more common failure:

Before starting the engine, check coolant level in the overflow.  Note level.

Sharply squeeze the upper radiator hose.  Listen for gurgles and the giggle pin.  Note the sound.  If it sounds like a LOT of air, add coolant to the radiator.  If not, don't open, as you let in air.

 

Do a drive cycle.

 

Before starting, check again, repeat.

 

Over at least a few cycles, the air should reduce, and the  level in the overflow will go down to match.

 

If it continues to go down, and the air never goes away, you have to watch it closely, as there is a slow leak, or pinhole head gasket fail.  IT may work for a long time that way, or it may progress to where the pinhole pumps so much air in that the overflow gains water, to the point of overflowing.

 

Do not use the temp gauge as a way to troubleshoot the coolant system, it is too late by then.

[DaveT]

Oh, if that smaller hose was bad, it would be good to replace all 7 coolant hoses.

[OregonYeti]

What do you mean by "giggle pin"?

 

I replaced the upper radiator hose last year because it was leaking and this makes a 2nd, and I will replace the remaining 5.

Edited August 15, 2016 by OregonYeti

[DaveT]

In the oem and good quality aftermarket thermostats, there is a small loose pin. When you squeeze the hose, it makes a small sound so you can tell there is fluid in the hose, etc.

 

It's probably a good idea to replace the thermostat since the overheat. Oem or the best Stant brand.