So I got an issue with my 1995 Nissan Maxima with 166.5K miles. Car runs great, doesn’t overheat and the radiator is always full of coolant. However, the reservoir loses coolant. I would fill it to the full mark, then after 2-3 weeks it would be a little bit left in the reservoir below the minimum mark. I would leave it (not refill it) and the small amount of coolant will remain in the reservoir and still not overheat. Radiator remains full as well. The radiator and both radiator hoses were replaced last summer, so I don't think those are leaking. I’m thinking either the reservoir is leaking or it’s leaking from the hose that goes from the radiator to the reservoir or leak from both. Any help is appreciated.

 

Can you smell a sweet aroma outside of your engine ? If so, then you are probably leaking antifreeze.

 

My max had this symptom few years ago. I think WP seal gets weaken but leak happens during freeway speed, not at idle when coolant pressure at WP is not high enough. Now I gets some drips on floor right below the WP. Mine is 97 with 260KM & original WP.

 

Two possible issues.

1. There is a slight leak in the overflow tank, or the hose from it to the radiator.

2. A leaking water pump.

the WP has two O rings.

​​​​1. . One between pressurized coolant and the outside of the engine. Coolant will seep on to the ground.
place some cardboard under the car and look for coolant.

2. The second O ring is between pressurized coolant and the timing cover. A leak will drop coolant into the engine oil pan. Evidence would be milky engine oil at first, and a rising oily milkshake later on.

Some have paniced and thought bad head gasket.
Yet that is generally not true.

 

I'll start simple by just replacing the coolant reservoir and the hose that goes from the radiator to the reservoir then refill reservoir drive for a while see if it still lose coolant. Would I have to bleed the cooling system if I replace the hose and reservoir? So I'm aware the water pump on my car is driven by timing chain and is hard to replace. If it's the water pump, would the engine have to be removed to change the water pump? Not sure if I can do it myself. How much do mechanics charge and is it even worth doing a water pump if I have to pay a mechanic?

 

You don't want the reservoir to get to empty. If the tubing traps air, it won't refill the radiator as it should.

 

You don't need to bleed the cooling system if you replace the coolant tank and hose.

Do monitor the coolant level in that tank afterwards.

Do check your oil from time to time to see if it's milky.

you might have a small leak in another hose. .

The water pump can be replaced with the engine in place. You do need to put the car on jack stands so that you can get under it. Or pay a mechanic to replace it. It's like three hours , or so I've read.

I have replaced my water pump myself. It takes several hours. Not easy to do. Yet many membees have dome the repair successfully.

 

As far as the coolant reservoir go, should I get one from a junkyard or buy an aftermarket one? I would assume the oem part is already discontinued. Would you know what size is the hose that goes from the radiator to the coolant reservoir?

 

OEM replacements are available from a number of retailers including Rock Auto, Advance Auto, Auto Zone and O’Reilly’s.

As I recall, the new overflow tank also includes the overflow hose.

 

So I haven't driven the car since Wednesday. I went out to look at the ground and there's a small puddle of coolant by the passenger side front of the engine. So I filled the radiator just to see if it's low and seem like it is a little low but not by much. Oil doesn't look milky. JvG you mentioned there 2 seals. Is there possible for the water pump to be leaking, but not with mixing with the oil? At this point I'm pretty sure it's a water pump leaking could there be anything other possible leak source from this area?

 

A leak from that area does indicate a leaking water pump. It would leak either by the pump shaft like any other car, or due to a leaking o ring.
The good news it that the leak in not going into your engine oil.

You need to plan on replacing the pump. You could continue to add coolant for a while until you can do this. Do monitor the coolant level.

 

So this is definitely a job that I can't do myself as it's very hard and in a very tight space. Also, I don't have space to park a non-functional car. I haven't called around for quotes yet as it's Sunday night. But I imagine it can be $500+ or even more. Is there any sealer I can pour in the coolant to let it possibly seal for a bit longer? Like would At 205 work? I really don't want to junk the car over a water pump, but I might have to if it costs a lot.

 

Another car will cost more than the water pump bill.

A replacement car will have its own list of mechanical issues.

I advise an assessment of the rest of the car.

If most of the car is still sound, fix the pump and enjoy the Maxima.

If most of the car has been neglected or if other expensive problems are likely to happen soon, it's time to move on

 

Check freezer plug behind ac compressor area.

 

If the water pump is leaking, it should be leaking out of the weephole, locate that weephole and see it that's your leak. Maybe you can add some UV dye stuff and find the leak easier? I just did my waterpump, and I'd make sure that's where your leak is before you dig into it.

also that overflow reservoir will lift right up out of the slot with no tools and you can look underneath to see if there's any coolant pooled there by the little hole it slots down into.

 

It’s not complicated.

It might be a little difficult due to the location of the pump and it’s access, but it’s not complicated.

Simply resign youreself that it’s going to consume an entire weekend, prepare your parts and tools, take your time, stay calm and do it.

Do you have a Haynes or Chiltons manual? If not you might want to get one.

On the other hand, if you’re contemplating adding a leak inhibitor, formulated for automatic transmissions, to your cooling system, you might want to leave the tools where they lay.

 

don't use snake oil, it won't last and will probably make it worse in the long run. if your not super handy with the vq then shop around to a few mechanics and get some quotes, a mom and pop shop might be able to give you a hand and tell you that there's nothing to worry about after they look at your car. i think your freaking out over nothing imo, good luck

 

Pressure test your coolant system!

 

THIS!!!! I once had a pretty decent leak coming from the passenger side of the car, I thought the water pump had gone bad. Turns out, the lower radiator hose had sprung a leak from being so old. I replaced the hose along with the thermostat and bam good as new.

 

Rock Auto sells them....