Oil/air conditioning problems in my 96 Neon

dodge
oil
neon

#1

I drive a 1996 Dodge Neon. It’s not a great car, but it belonged to my sister for the first decade of its life and she and I have both treated it well. At 125K, it’s in okay shape. I have two problems though, and my mechanic doesn’t seem worried about either.



1) My car seeps oil. When I drive short distances, I can smell a slight burning odor from the oil leaking onto hot parts without seeing a noticeable drop in my oil level. When I drive long distances, the oil thins out and I leak/burn significant amounts of oil (~2 quarts on a 250-mile highway trip) and see oil spots beneath my car right after the trip. When I use “stop leak” products, they generally reduce the amount of oil I lose. I never see oil on the ground unless I’ve returned from a long trip, so I don’t think I have a steady leak.



My mechanic says its not worth the cost to search for the problem, and that I should continue using stop leak and adding oil when the level drops. My sister had the head gasket replaced (a common problem on Neons) about 2.5 years and 20K miles ago, so I’m inclined to think I have a seal problem in another part. Is there anything I can do to narrow down the problem, or do you agree that it’s not worth fixing?



2) My air conditioner doesn’t work, but I live in central NY so I can deal with the warm weather. It broke when my sister owned the car, and she was told by her mechanic that it would be $700 to fix a leak in the system, so it hasn’t been fixed. I tried recharging the refrigerant, but it didn’t seem to work and I noticed an odd sound that makes me think there’s something wrong with the fan or compressor (in my inexpert opinion), so I think the problem is more severe than a leak. When I run the air conditioner, I hear a cyclic revving or whirring noise. It sounds as if something is turning on, revving up to speed, shutting off at its peak, and then starting the process over. It’s not really a clicking sound, which I’ve heard is common if the refrigerant is low.



I noticed that if I have my headlights on, they dim slightly for just a second when the revving sound kicks off. That makes me think I’ve got some kind of electrical problem with my air conditioning system. I haven’t had any other problems with my headlights/radio/other electronics. Does anyone know what sort of problem I might have? I’m not concerned with getting the air conditioning working (unless it’s an easy fix), but I want to make sure I’m not going to destroy my car.



2A) My air conditioner kicks on automatically when I turn the window defrost on, and I hear the same revving noise and see the headlights dim. If the air conditioner isn’t easily fixable, is there a way to prevent it from trying to come on with the defroster, like a fuse I can remove? If it doesn’t work anyways, I’d like to stop the annoying sound!



Thanks for your insight!


#2

“I tried recharging the refrigerant, but it didn’t seem to work”…The sound you hear is the compressor cycling on and off because the freon is still low. Try adding another can…

A quart in 250 miles? That WILL leave oil on the ground if it’s an external leak. Sounds like you might be BURNING it. Any competent mechanic should be able to quickly locate any gasket or seal leak…


#3

No idea on the oil leak without seeing the car, but considering the age/mileage and the amount of oil used the first thing I would check would be the oil pressure sending unit.
Over time the plastic dries out and distorts and since direct oil pressure is appplied here it can be a serious leak.
It’s also inexpensive to fix.

As to the A/C I’m undecided if you have a noisy compressor (internally) or a whirring compressor clutch bearing.
If the problem appears to be an internal compressor noise then I would strongly advise adding some refrigerant oil to it and see if it shuts up.
Auto A/C systems will lose oil over time along with refrigerant. This is entirely normal and often gets overlooked.

If you do not want the compressor engaged with the DEF on (this is entirely normal also) then simply unplug the compressor if A/C does not mean that much and you do not want to spend a large amount of money on a repair. Hope that helps.


#4

“I tried recharging the refrigerant, but it didn’t seem to work”…The sound you hear is the compressor cycling on and off because the freon is still low. Try adding another can…

I’m glad to hear you think it’s just the compressor cycling. Is there a reasonable explanation for my headlights dimming as the compressor kicks off?

I’m hesitant to continue adding refrigerant because R-134a is not very cheap. When I added the first can, I stopped about halfway through because the pressure on the gauge wasn’t changing (making me think it was immediately leaking back out). If I have a $700-to-fix leak, is it possible that I can’t keep refrigerant in the system for any period of time?

A quart in 250 miles? That WILL leave oil on the ground if it’s an external leak. Sounds like you might be BURNING it. Any competent mechanic should be able to quickly locate any gasket or seal leak…

I DO see oil on the ground after long highway trips, though not a quart or two’s worth. I would imagine that I am losing it as I drive or burning it, but I see no smoke coming from my tailpipe, so I think I’m seeping oil normally and leaking it when it becomes less viscous.

My mechanic doesn’t do transmission work, and he seemed to think that finding the leak would involve dismantlig my engine and moving the transmission, which he doesn’t do at his shop. He also seemed to think it would cost hundreds, if not possibly thousands, of dollars to find and fix. Should I try a different mechanic? Mine’s a good guy, a friend of the family who’s always been fair. He looked at my car for free earlier this week, and he doesn’t overcharge for parts or labor.

Thanks for your help. Hope my additional information is useful! I just started my first job after graduating from college and I’m trying to make this car last!


#5

“Is there a reasonable explanation for my headlights dimming as the compressor kicks off?”

The lights dim when the compressor kicks IN, loading the engine down and slowing the RPM so the alternators voltage is reduced somewhat…

You can buy a lot of oil and a drip pan to for a $1000…


#6

Thanks! It’s good to hear the car’s not going to catch on fire or anything. I think I may look into fixing the air conditioner, but if I decide it’s not worth the expense, I may just find a way to disable it.

I’ve got an okay understanding of how stuff works, but when it comes to actually doing work myself I get nervous. Is there a way to disable the air conditioning with the defrost? I found a resource online that suggested cutting the metal contact behind the defrost dial, but that’s pretty permanent. Is there some sort of fuse for the whole air conditioning system I could remove?