RWCreative

Ok, I'm in a process here. I have been experiencing a temperature gauge fluctuation from normal (In the middle at 50%), to all the way hot. Mostly staying at HOT.

So this is what i have done to this point:

Car - 1998 Maxima (4th Gen I believe its called)
Mileage - 244,645
(Slight oil leak around water pump area. I check oil regularly)

Engine runs great. It is still very tight and strong.

Along with the rising temp gauge I have experienced boiling water in the overflow once or twice after long runs in the car, that is what really started it all. Just prior to that i had been hearing a very slight quiet intermittent grind/sound from the passengers side 'serpentine belt and water pump side'. I had thought this slight intermittent sound might be the water pump finally going out. It comes and goes, BUT, there is absolutely no leaking of antifreeze anywhere in the system.

I can smell slightly overheated antifreeze when it is a hot day, but not that much.

I discovered one of my dual radiator fans was out. I quickly replaced that fan. Both fans work great and at the right times within the design of the fan system. The fans kind of just holds temperature from going any higher, but they don't bring the cars temperature down to normal. - SO NO CHANGE.

I then changed the thermostat (put in an after market). - NO CHANGE.

I replaced the radiator cap with a square type style with a little plastic lift to release pressure. It works very well and seals the system. It was about $12. - NO CHANGE.

I replaced the water temperature sensor. - NO CHANGE.
I replaced the Engine Temperature sensor (These 2 are close to each other). - NO CHANGE.

I flushed the radiator and system using the flush chemical and then flushed it 4 times with plain water. Then i filled the system with prestone antifreeze (the green color stuff). (- the flush seemed to cause the temperature gauge to run a little cooler, but I still have the problem.)

I substantially burped the system for some time to be sure there was no air captured in the system or heater core after the flush.

Now the temperature gauge rides consistently at 3/4 hot and still goes up to hot when stopped after driving around. If I start the car in the morning and let it just sit, the gauge stay just a little at 50% or a bit above for 20 or so minutes then it slowly surges up to hot.

So now I am thinking it is indeed the water pump under-performing, maybe deteriorating fins? I checked the water flow in the mouth of the radiator and could not really see it move very much, a little, but not much pushing from the pump. So i stuck my finger in the water and could not really feel any meaningful flow. I then revved the motor and the water comes up out of the rad neck so it looks as though the pump is pushing but not really that hard.

Does anyone have any suggestion or ideas as to how to narrow this problem down even further? Next step? - without spend anything on labor?

You expertise is very much appreciated!

Roger

kjlouis

When my water pump went bad it was leaking out of the weep hole, idk if that for sure means water pump is bad or just o rings. I had no other symptoms. If you're gonna take it on on your own follow fsm to the t, don't be like me and let the chain jump.

97_GXE

Well, if it is the water pump, it doesn't help by using green prestone. That stuff has silicates (sand). I read that can "injure" the impellers on certain vehicles. What you wanted was Xerex Asian formula, Or Nissan coolant (Xerex works great for me).

I used to have a Camry that would have seized waterpump 2-3 times in the most inconvenient situations. No warning, just boom. Dead. Every time it was being given green prestone. My Max I believe never seen silicated coolant, and I believe also (based on all the other cooling system parts were calsonic/Nissan) the waterpump is OE.

otherwise, I've had cooling issues similar to what you were saying, turns out the thermostat wasn't opening enough to let in enough coolant. What kind of thermostat did you buy?

RWCreative

The thermostat was a Duralast from Autozone.

I see your point on the thermostat not opening up enough, because the flushing of the radiator has caused the temp gauge to run a little bit cooler. So it stands to reason that a little more 'flow' (meaning a thermostat that may open more or perform according to what the maxima cooling system requires) may be the issue.

So I will try an OEM stat in (prior to replacing the pump) to at least eliminate the thermostat as an issue, and report back. Thanks!

RW

ef9

iTrader: (8)

That's a lot of miles on your Maxima!


I would recommend changing all other coolant parts that have not been changed yet:
1. Radiator
2. Lower and upper radiator hoses
3. Water Pump.

cashoit

Drain system.

Run water through the radiator to make sure its not clogged. If all other parts are working and you dont have a coolant leak, I would say your pump fins have disintegrated. I have seen it happen before. SEARCH. Its a time consuming job not for the faint of heart.

RWCreative

Are their any special tools required to do the water pump replacement? Can someone send me the link to the Nissan repair procedure? Please.

Any words of wisdom, tips or warnings before i jump into this job?

I've heard; "while you are in that deep you might as well change the timing chain/belt, and, you might as well change the thermostat as well." ?

Thanks Guys!

RW

JvG

I have replaced all of my cooling system except for the thermostat and heater core.

You mentioned that you had some improvement after cleaning the radiator. I feel that your radiator is partly blocked. New radiators don't cost all that much. I bought a koyorad for 110 bucks. there was /is? a group deal on this forum. the koyorad is a decent product.
You are dealing with the process of elimination. having replaced or looked at the fans and the thermostat, the radiator is the most likely cause of your problem. replacing the radiator is less costly than paying a mechanic for a diagnosis.

I replaced the water pump recently. I was loosing coolant. I only saw small drips by the pump. you did not mention coolant loss. so coolant is either not circulating (water pump)
or cooling (radiator).
The radiator is simple to replace. You should replace the radiator hoses while you are in there. I'm almost certain this will fix your problem.

Now the water pump is not expensive, but get a good brand. Installing the pump is something you might need to do once, but you don't want to do it again any time soon.

The work is not awful.But it is tedious. Professional mechanics might be able to do it in
3-4 hours, but it took me easily twice that. I've been wrenching on my own cars for over 40 years, so I'm not a newbie. 3-4 hours? more like all day. better stretch that in to most of a weekend. You will need to take frequent breaks, mostly to maintain sanity. It would be helpful to be left handed. Most of removing and installing was done left handed.

You need to raise the car. you will do some work from the top, some from the bottom.

There are good instructions on this forum. YouTube is very helpful. A couple of guys documented the process in 3-4 episodes.

I have a mechanic work on my cars maybe once in four years. Replacing the water pump on the Maxima is something I would pay the mechanic for in the future.

asand1

iTrader: (1)

Download the service manual from my signature below. Go to a shop with a block tester and have your coolant checked for combustion gasses.Good luck.

JvG

agreed on the block test to check for a failed head gasket. It is certainly a possibility, especially in case of a bad overheating situation.


For those who will read this post in the future, it is a good idea to do a block test if the reason for the overheating is not known, or before a major time or money investment.


A block test is also a good idea if you are considering buying a car with a known overheating situation. You do not want to buy a maxima with a bad head gasket.