StephenD

I've run into 2 problems with my 1995 SE automatic with 80k miles. I live in the NorthEast.

1. Heater fogs up windows.
I've owned many cars including an 89 Maxima. This is the first car that fogs this badly unless I use either the "heat and defrost" or straight 'Defrost' settings (the two rightmost buttons) almost all the time (esp below 32 degrees F). I've always used "recirculate ON" in my other cars including the 89 Max but I've never seen the fogging like the '95.

I thought "Heater core gone" but the rugs are dry and the Nissan Dealer checked. No leaks. Pressure test negative. I ride to work early and I almost have to keep the back windows open 1" just to clear the windows (mostly the back)

My wife has a 1997 Maxima GXE (auto) that doesn't have this problem - even when I drive the two cars 1/2 hour apart from cold startup (to try to do a controlled experiment so I could more or less weed out different weather, etc), the '97 is always OK using the foot/chest heating option + recirculate button but my '95 will fog up in 10 minutes.

2. The engine 'rattles' for about 5 seconds during startup (I use Mobil 1) then goes away. It sounds like spark knock.

As an FYI, there is a NHSTA site that has a lot of information on defects.

http://www.nhtsa.dot.gov/cars/problems/tsb/

When I looked up 1995 Maxima, I got:

Service Bulletin NTB98050
NHTSA Item #: SB601730
Component: Engine
Date: 1997
Summary: Experiencing Spark Knock during engine start.

Service Bulletin NTB96086A
NHTSA Item #SB613975
Component: Engine
Date: 06/2000
Summary: This bulletin contains a new timing chain tensioner, tensioner gasket and guide if a rattle f either several seconds or continuously is heard coming from the area of the timing chain cover when the engine is started after a cold soak for vehicles within certain vin ranges.

Has anyone (esp in the Northeast) had problems with fogging up (not being able to use the leftmost 3 buttons for heating.)

Has anyone had problems with the rattling and had the timing chain replacement from the dealer? Is this a nuissance issue or will the chain fry if I don't get this fixed.

Matrix

when you are using the recirculate button and the air is not conditioned (A/C) the windows will fog up. This is because you are not removing the moisture from the air as you are recirculating it. So if you want to not fog up while heating, turn the AC on when you are using the heater and recirculation.

I have a 97 and it automatically changes to uncirculated air when you hit the defog buttons for this very reason.

If you turn on the defog the windows will tend to fog a bit right away and then defog afterwards. I think this is due to the moisture in the air that initially hits the windows.

But anyways, yeah its really annoying to have to keep the A/C on when you are running the heater with the recirculation on, cuz its an extra burn of fuel.

StephenD

I don't have any problem with the 89 or 97 Max. Only the 95. It really acts like the heater core is blown.

(I get musty, moist vaper coming from the vents with recirculate on even though the dealer checked the radiator (pressure test) for leaks and na-da.

From reading the 5th Gen forum, it seems like the 3rd generation has the 4th and 5th beat as far as defogging. (my experience too with my 3rd Gen) How could they have screwed up something as basic as ventilation?

No car I've ever owned (after driving 1/2 hour and warmed up) had to continually go from normal to Defrost or AC just to keep the windows clear in all cold conditions (not just the ones you expect to fog a lot like cold and rainy conditions but in dead dry, low humidity too).

Daniel B. Martin

The symptom is condensation on the inside of the window surfaces. This is evidence of excess moisture in the passenger cabin. You are confident that the heater core is not the source, so look elsewhere. A leaky windshield might be the source. Look in the trunk, too. See if the spare tire well contains water. A wet trunk will share it's moisture with the cabin.

Has this car ever been in a crash? Has the windshield ever been replaced?

StephenD

First, thanks for answering my post. I've been struggling with this fogging problem for a few months.

- Far as I know, no crash (I checked the VIN to see if it was flooded too - nada)

- Yes, the windshield has been replaced. I'm not sure how long ago - maybe a year just judging from the lack of pits - and it's definitely not a Nissan OEM windshield. It was not replaced by me (previous owner). That's an interesting thing to suspect.. won't rule that one out but I'm not sure how to confirm this is it (no apparent air leakage noise that I can tell).

- I checked my 95's trunk. Spare tire area bone dry. Rest of flat surfaces like brand new. Hard to get into the rear quarter area (where jack is stored). Nothing obvious but there was some sand in there and it felt a little moist. That's a possibility. I was surprised that the row of holes near the back speakers are vents right into the trunk so I see what you mean about suspecting the trunk.

- We looked at some other sources. The "Box" that is part of the heater core housing has a drain hole to get rid of condensation (I guess). We checked that. It wasn't plugged - it was bone dry. I thought for sure that would be it (condensation that can't get out).

The interior as much as I could see and feel under carpets was/is dry in the front.

Daniel B. Martin

One way to test for rain water getting past the windshield seal is to apply duct tape to cover the entire outside of the seal. This is ugly, but temporary. If you leave the duct tape in place for two weeks and the condensation problem is not markedly improved, you may declare the windshield blameless and remove the tape.

Mike S.

I have a 93GXE with manual controls. On the way home from school today I turned OFF the heater. The windows started to fog. Why drive with the recirc ON when you should have it OFF to get fresh air. I only recirc when the car ahead is putting out lots of smoke.

I think the problem is that your driving with the recirc ON....fogging the windows...then putting on the defrost(which may or may not turn on the ac) but ALWAYS turns off the recirc by its electronic overide. Thats why they will then unfog.

easy problem easy answer

Daniel B. Martin

Does the car have a sunroof? If so, that could be the cause of rainwater infiltration. The sunroof has multiple drain hoses concealed within the bodywork. They are intended to carry rainwater to drains in the lower part of the unibody. If one of those drain hoses is damaged, some of that water might be going where it isn't wanted.

Daniel B. Martin

When the engine is running the oil pump draws oil from the sump and sends it
upward through passages called oil galleries to cool and lubricate all the
internal moving parts of the engine. When the engine is turned off,
gravity will cause the oil in the galleries to flow "backward" through the
oil filter and return to the sump unless something prevents that. The
anti-drainback valve is a one-way valve (a "check valve") which prevents
this from happening.

If the filter has a leaky anti-drainback valve the galleries become empty
when the engine is not running. When the engine is started it takes a few
seconds for the oil pump to refill the galleries. During that refill time
the engine parts, especially the valves, make an unpleasant knocking,
clicking, or clattering sound. This symptom is more noticeable after a
long period of rest, 24 hours or more.

Oil filters made for use in an inverted or horizontal position have an
anti-drainback valve. This is true for ALL brands of oil filters. The
difference (if any) from one brand to another is the material used and the
quality of manufacturer. Any individual filter might have a bad
anti-drainback valve.

The filter media, bypass valve, and anti-drainback valve are all internal
parts of the oil filter. Therefore an oil filter is a "blind item"
because the user cannot judge the condition or quality by sight, sound,
smell, taste, or touch. When buying a blind item we make purchase
decisions based on "image" factors such as the influence of advertising and
brand loyalties. Choosing a good filter is further complicated by the fact
that the same product may be sold under several brand names. Filter brands
A, B, and C may be identical except for the brand name and exterior color.
The supplier for filter brand D might be the same as brand A for this year,
but be changed to brand B next year. Industry insiders will know about
this but most consumers will not.

If your engine exhibits the symptoms of a bad anti-drainback valve you
should replace the filter. You might try a different brand of filter but
(as explained above) it might turn out to be an identical product. I
personally do not believe in the inherent superiority of the factory part
but respect the opinion of those who do.

StephenD

Yes it does have a sunroof but it doesn't leak but I understand about the drain holes. I've seen these clog up causing leaks. I'll keep that in mind. You don't know where these things drain do you? Inside the wheelwells? They're not rubber hoses, are they?

The heater controls are the manual ones.

The windshield might be a possibility too. Maybe I'll use clear tape so my friends don't think I'm just trying to save money by doing a blow-and-go bondo job.

Daniel B. Martin

[QUOTE]Originally posted by StephenD

Quote:

Yes it does have a sunroof but it doesn't leak but I understand about the drain holes. I've seen these clog up causing leaks. I'll keep that in mind. You don't know where these things drain do you? Inside the wheelwells? They're not rubber hoses, are they?

My own Maxima does not have a sunroof, so this response is based on information in the factory service manual. It has a line drawing of the sunroof drains. It shows two drain lines, but the drawing shows one side of the car, so perhaps there are actually four drains. The forward drains follow the A-pillar down to the rocker panel. The rear drains follow the C-pillar down to the lower edge of the rear fender.

I'm not suggesting that your sunroof leaks. I am speculating that a drain hose is damaged or misrouted such that its contents are getting inside the passenger cabin rather than dumped on the ground.

The manual does not specify the material of those drain lines. I imagine they are rubber tubes.

[Edited by Daniel B. Martin on 02-01-2001 at 11:17 PM]