Leaky radiator

[mbtech208]

It started like this. I drove through Death Valley on Monday, where it was 115 degrees in the shade. My Maxima's A/C hasn't worked in years, apparently. It ran fine for most of the trip. A few times the temp needle was creeping up nearly to H, so I'd pull over and run it at a fast idle until it cooled down. No problem. Driving back to LA on I-15, there was a strong headwind, with the accelerator held just above the kickdown switch, it wouldn't go faster than 72, very frustrating when traffic is going 85-plus. Flooring it would only kick down and produce copious amounts of black smoke. On Tuesday, I decided since the A/C didn't work, I would take all of it's components out to save weight and gain a little power. I removed the compressor, receiver-drier, condensor, evaporator, compressor belt idler pulley and adjustment mechanism, expansion valve, and hoses. While doing this, I accidently broke off the radiator drain cock. It was leaking, but I was able to go to the dealer, order a new drain, and drive home. On the way home, it felt quite a bit more powerful due to the lighter weight. Anyways, I just put in the new drain, and it's still dripping in the same area. Is there a seal I'm missing? Maybe I cracked the radiator around the drain area? I won't know until I drive it to work and put it up in the air. Any ideas?

[kassim503]

Are you talking about a little plastic screw in thing that acts as a drain for the radiator? If so there is a rubber washer that acts as a seal, it probably wouldnt seal the radiator without it. Try looking around where you worked, mabye the washer fell off and got washed somewhere, or if you are really unlucky it landed somewhere under the rad and it got blown away as you drive

[philip]

It started like this. I drove through Death Valley on Monday, where it was 115 degrees in the shade.

One of our FAVORITE places ... but not during THIS time of year!

My Maxima's A/C hasn't worked in years, apparently. It ran fine for most of the trip. A few times the temp needle was creeping up nearly to H, so I'd pull over and run it at a fast idle until it cooled down. No problem. Driving back to LA on I-15, there was a strong headwind, with the accelerator held just above the kickdown switch, it wouldn't go faster than 72, very frustrating when traffic is going 85-plus. Flooring it would only kick down and produce copious amounts of black smoke.

Pretty sad. My ol Datsun would have passed you up. Maybe even with the A/C running!

On Tuesday, I decided since the A/C didn't work, I would take all of it's components out to save weight and gain a little power. I removed the compressor, receiver-drier, condensor, evaporator, compressor belt idler pulley and adjustment mechanism, expansion valve, and hoses.

For all that labor, you accomplished neither of those goals in any measurable sense.

While doing this, I accidently broke off the radiator drain cock. It was leaking, but I was able to go to the dealer, order a new drain, and drive home.

If plastic, PepBoys and the like have a selection of these things. NAPA has the rest ... in most cases.

On the way home, it felt quite a bit more powerful due to the lighter weight.

The mind is self decieving.

Anyways, I just put in the new drain, and it's still dripping in the same area. Is there a seal I'm missing? Maybe I cracked the radiator around the drain area? I won't know until I drive it to work and put it up in the air. Any ideas?

You may have cracked the lower tank. Then again, is this a plastic drain plug or a metal drain valve? The plastic wingnut drain plugs always have a rubber sealing washer and/or an o-ring.

[asavage]

Plastic "wing" bolt, fat neoprene washer. My guess -- and it's only that -- is that the washer is missing or deformed. I've had the cheap ones that don't fit well completely deform out of whack when tightened.

The tank is brass, so it's unlikely to be damaged. However, any core or seam leak will drip in that area. You know the drill: pull the upper plastic shroud, strong flashlight down to the lower tank seam.

Driving back to LA on I-15, there was a strong headwind, with the accelerator held just above the kickdown switch, it wouldn't go faster than 72, very frustrating when traffic is going 85-plus.

It's only an 80 HP engine! 70+ into a headwind (and I know I-15) is doing pretty well for an 80 HP-powered heavy sedan with all the aerodynamics of a shoebox!

[kassim503]

...heavy sedan with all the aerodynamics of a shoebox!

More like a School Bus

[mbtech208]

You probably would have passed me, Philip. I never claimed my car was fast, just sexy. Although I did have it up to 101 in the desert (as confirmed with portable GPS). I think it really does feel lighter without all the A/C components, it may be all in my mind, but I wouldn't be surprised if I gained 1 or 2 mpg. I'll have to check next time I fuel up. If I didn't gain anything, well, I only spent an hour and a half removing everything, so I didn't waste too much time.

I am missing the washer, by the way. Thanks for the help.

[asavage]

I think it really does feel lighter without all the A/C components

The entire A/C system doesn't weigh 200 lbs.

I wouldn't be surprised if I gained 1 or 2 mpg.

Does that mean that if I ride along with you (260 lbs) on a trip, you lose one or two MPG? I don't think so.

I only spent an hour and a half removing everything

Including the evaporator? Did you put the glovebox back in!?

I replaced the TXV on my evaporator a couple of years ago, in a fully-equipped shop, and it took me over two hours, plus the evac & recharge time. You must be a devil with an electric screwdriver!

[mbtech208]

I'm sure what I did doesn't hurt the power-to-weight ratio or fuel mileage in any case. The freon has long since leaked out, so I didn't have to evacuate the system. The evap is a piece of cake, there's only the glovebox and the evaporator case. You want to see a difficult evaporator, try one on a Chrysler LH car or Mercedes W140 S-Class. Easily an 8-hour job.

[asavage]

I've done a heater core on a Dodge RAM, flat is 6.5 hours. Yeah, I know.

[Carimbo]

While doing this, I accidently broke off the radiator drain cock.

I did something like this last week while changing the thermostat-- drained out enough coolant to clear the tstat housing, then while retightening the nylon wingnut drain plug, the head sheared off flush. Old nylon.

Found a replacement plug (incl. the rubber sealing washer) at the local FLAPS and went to work removing the "stud" inside the drain housing. Clamped a #2 phillips bit in a visegrips, heated it w/ a propane torch and pressed it into the remaining nylon "stud." This left a suitable impression that allowed the (now cooled) bit to back the piece out.

mbtech208, how did you get yours out?

[mbtech208]

While doing this, I accidently broke off the radiator drain cock.

I did something like this last week while changing the thermostat-- drained out enough coolant to clear the tstat housing, then while retightening the nylon wingnut drain plug, the head sheared off flush. Old nylon.

Found a replacement plug (incl. the rubber sealing washer) at the local FLAPS and went to work removing the "stud" inside the drain housing. Clamped a #2 phillips bit in a visegrips, heated it w/ a propane torch and pressed it into the remaining nylon "stud." This left a suitable impression that allowed the (now cooled) bit to back the piece out.

mbtech208, how did you get yours out?

I had changed the coolant a few thousand miles ago, so the threads were relatively clean and smooth. I was able to turn the stud with a small pick and back it right out.

[asavage]

I did something like this last week while changing the thermostat-- drained out enough coolant to clear the tstat housing, then while retightening the nylon wingnut drain plug, the head sheared off flush. Old nylon.

See, this just proves that you should never do any maintenance on the cooling system!

Or you should continue to stimulate the various world economies by throwing away the whole car every ten years.

Or something like that.