# Coolant Problem



## piekid (Jul 21, 2003)

The coolant level in my '97 Sentra (bought used 2 months ago) drops well below the minimum line every few days or hundred miles or so. The first time it did this it started overheating, but I've been adding coolant every couple days since then and it hasn't overheated again.
I've taken it to 4 places, including a Nissan dealer, and they can't figure out what's wrong. They've pressure tested it up to 26 pounds. There are no visible leaks, & no white smoke or coolant in the oil.
Has anyone had a similar experience or might know what's wrong? It seems to run fine, but it's a pain to have to add coolant so often. Thanks.


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## zakezuke (Mar 22, 2003)

To me it sounds like you have a slow leak somewhere, the question is where.

I don't exactly have the experence in this area, but I would think that some form of dye that apears under a blacklight would be of some great benifit as to isolating the cause of this coolent loss. I'm not sure if they make such a dye for coolent systems, but i'd say it's worth asking about. 

In theory with a clean engine you can spot the usual coolent leaks. On my old car for example, I have a small leak round and abouts of the theromistat... so small that I never noticed coolent loss but the crusty white stuff is a dead give away. I was only able to notice this though because I cleaned and painted anything I replaced on this auto.


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## Katana200sx (May 13, 2002)

they do make dye for cooling systems. your best bet is to clean everything up nicely and add the dye to the cooling system.


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## UNISH25 (Aug 12, 2002)

The pressured tested the system to 26psi!
Wow! Something should've defenitly leaked outta somewhere! That is really really F*ing weird!


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## max31abc (Dec 2, 2003)

*Same Problem*



piekid said:


> The coolant level in my '97 Sentra (bought used 2 months ago) drops well below the minimum line every few days or hundred miles or so. The first time it did this it started overheating, but I've been adding coolant every couple days since then and it hasn't overheated again.
> I've taken it to 4 places, including a Nissan dealer, and they can't figure out what's wrong. They've pressure tested it up to 26 pounds. There are no visible leaks, & no white smoke or coolant in the oil.
> Has anyone had a similar experience or might know what's wrong? It seems to run fine, but it's a pain to have to add coolant so often. Thanks.


I have exactly the same problem with my Nissan Sentra (97). Did you find a cure? I have another appointment at a garage next week. Please let me know if you found the solution to that problem.
Thanks


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## wes (Apr 30, 2002)

Are you talking about the level in the overflow tank? That will rise and fall depending on driving conditions... The fact that it overheated either means you have a blown headgasket and it is leaking into the oil internally, or that the coolant system was not properly bled and you had an air lock. I would completely drain the cooling system and install new coolant per the FSM.


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## piekid (Jul 21, 2003)

max31abc said:


> I have exactly the same problem with my Nissan Sentra (97). Did you find a cure? I have another appointment at a garage next week. Please let me know if you found the solution to that problem.
> Thanks


They finally found that the coolant was leaking slowly from the cylinder head outward. What they told me was that the aluminum cylinder head had become porous, and that this occasionally happens with Sentras--said it wasn't a blown head gasket. They added some pellets made by GM to the coolant system, which they told me adhere to aluminum and would seal the porous cylinder head. I was kind of skeptical, sounded like they just added stop leak. But it was done about 3 months ago and we've driven it quite a bit and haven't lost any more coolant since then.

Before they did this the coolant would slowly leak out, and if I didn't put more coolant in every 3-5 days it would run dry. But now it seems to be ok.


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## max31abc (Dec 2, 2003)

Thanks very much for the reply, I'll show this to my mechanics. He suggested to replace the waterpump and head gaskets for app $1450 !!! Propably your experience will help to save my money...


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## wickedsr20de (Apr 30, 2002)

Bah those coolant pellets are only a temporary sollution and it will leak really soon.
I Own lots of nissans but I work at a GM dealership (oh the Irony) as a service advisor and GM did have problems with thier 5.9 v8 engines becoming pourus.
We have tried putting the pellets in but in a few months the cars come back and have to change motor. You could try taking it to a machine shop and weld a plate over the pourus area(depending where it is at). But I would not feel secure with those pellets. I even had a customer put JB weld over the area and it has not leaked since. Just giving you suggestions and I hope everyhting works out for you.


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