Can't Find Anti-Freeze Leak in 1998 Nissan Sentra (vehicles, air bag, valve)

[y04185]

My wife's 1998 Nissan Sentra has an anti-freeze leak. It leaks on the front passenger side. I have not been able to find the location of the leak. I have had the car pressure tester and no leaks.

The leak appears overnight or after the car has been driven and sits for several hours. The car sat recently for two weeks and the puddle got larger.

Any suggestions as to where the leak is coming from?

[usafracer]

When you pressure test it is the car cold or hot? It sounds to me like it only leaks when it is cool or cooling off.

Also they have a dye that you can put in the coolant and it will glow under a black light. I use it at work to help find leaks.

[y04185]

usafracer, the car was hot for the pressure test. I will look into the dye. I didn't think of that. Thanks.

[M3 Mitch]

Keep in mind that like a roof leak, the antifreeze leaked out may travel laterally along some tube or body part, so that it drips off the car fairly far away from where it leaked out.

If you lift the car, (be safe) and get under and look up using a good flashlight, you can probably find where the leak is. Could be as simple as a hose that's got old and cracked.

[High_Plains_Retired]

I'm not familiar with Sentras but it sounds like you have a heater core leak. Sometimes they leak in really strange ways.

This suggestion is based on the assumption you mean it is leaking "into" the passenger side floorboard, or do you mean it leaks under the car on the passenger side?

[M3 Mitch]

Originally Posted by High_Plains_Retired

I'm not familiar with Sentras but it sounds like you have a heater core leak. Sometimes they leak in really strange ways.

Damn, I hate to say it, but I was thinking the same thing. Hope not, but that might be what it is.

Maybe this year Senta a heater core is not that much of a PITA job, but in general outside of older pickup trucks (really older...) heater core R&R IS a PITA.

[High_Plains_Retired]

Originally Posted by M3 Mitch

Damn, I hate to say it, but I was thinking the same thing. Hope not, but that might be what it is.

Maybe this year Senta a heater core is not that much of a PITA job, but in general outside of older pickup trucks (really older...) heater core R&R IS a PITA.

I don't think I've ever seen a heater core R&R I wanted to do. They can be a real headache especially when your flexibility and eyesight is gone like mine.

[Loudclear]

You need to test it with the engine running and the heater turned on so the anti-freeze is circulating through the heater core. Most vehicles' heater blend valve operates from vacuum or electric. It must be open for a test. When the heater is turned off you are not putting pressure on the heater core when you put pressure in the radiator.

[Hemlock140]

If that's the original heater core you are lucky to have gone this long, they will typically last about 8-9 years regardless of miles driven. Shop around, you can pay $39 to $150 for that one depending where.

That's a good one, requires both air bags and the steering column to be removed. Try Barsleak first just in case it helps. In summer you can loop the hoses together and bypass it.

[y04185]

Thanks everybody. I apologize for my failure to communicate properly that the antifreeze leak was outside on the passenger side. I will keep all the suggestions in mind if the heater core ever goes bad.

The leak was actually coming from a weep hole in the water pump.

You guys have been very helpful. Once again, thanks.