Once again, the battery is dead in my 2002 SC. No surprise there. It's a pandemic and I'm not driving. I hooked up the trickle charger and tried to start it. Five hours wasn't long enough. Click, click, click.

When I turned the key off, a roaring sound like an angry hippopotamus came from behind the dashboard. I thought "What the hell is that?"

I charged the car for a few more hours and got more click, click, click. Thought "I'll have to call a guy for a jump start," and turned off the key. There's the hippo again.

I'm an older woman and no mechanic. Last time I took the car to the Lexus dealer for service, my representative told me the radiator would need replacement next year, which was three months ago. I've only driven the car about 500 miles since he told me that. I have heard a similar sound before, in a 1988 RX-7. The hippo indicated the radiator was low on fluid. A search of the Lexus owner's manual came up empty. I called the dealership and my service guy was stumped, but he did have a solution for the battery--a permanent installation of a trickle charger with a plug in the grill so I don't have to open the hood and attach the electrodes to the battery to charge it. I can leave the charger attached, and it will cut off automatically when the battery is at full charge, then I can unplug it and go.

Does this loud roaring sound mean the same thing in the SC430 as it did in the RX-7? The car's been in the garage and there's no coolant under it. If that's what it is, can I put water in the radiator, call the jump-start truck so I can drive it 50 miles to the Lexus dealer and get the radiator replaced and the trickle charger installed, Or do I have to find some Toyota Long Life Coolant like it says in the manual?

I've owned the car since 2011. It has 93K miles. Replaced the TB two years ago. No engine problems ever, just rear shocks and the nav door.

Help me, SC430 Lexus community. What's my next step?

 

Find a good local independent Lexus mechanic and get them to listen to it.

 

Your engine was never ran because the dead battery, right? So the roaring noise was not related to engine moving parts. I’m baffle. What could it be? Can you record the noise?

 

Aa suggested, a recording of the sound would be helpful.

Without that, I would suggest you open the glove box and pull it down and pull out the cabin air filter. Then listen again. I'm suggesting this as I think it might be something in the HVAC system. Perhaps a failing servo motor or a fan spinning down. Cars from the 2000+ era do a lot of housekeeping things after the key is turned off.

By listening at the glove box, you should be able to better isolate/identify the noise.

 

As someone already mentioned if the engine never turned over probably not radiator related. What I think your referring to is if your system runs low on coolant it can pull air pockets into the system. My example was when it happened on my GS300 it sounded like pebbles were hitting the firewall. The sound changed with engine speed.

 

An overall engine check including fluids should be done to make sure everything is OK, prior to starting a witch hunt.

 

If you have a voltmeter available or know someone that does, measure the voltage on your battery with the trickle charger disconnected. If it is less than about 12 Volts, then then battery needs to be replaced. I'm guessing that your battery may have a cell shorted out internally. That will likely take care of your starting problem and get rid of the "click click click" noise. (The battery really needs to be load tested, but I suspect that you likely won't have access to a load tester. A car parts store will though and they'll test it for free but you have to get it there first.)

Since you only occasionally drive it, be sure to have the trickle charger connected up whenever you aren't driving it. If you continue to have problems, get a deep cycle battery. It will cost a bit more but will survive deeper discharges.

Regarding the "rhino noise", if you suspect the AC is making the noise, just turn it off once you turn the key to ON. If the noise goes away, then it is related to the AC. If not, then you'll have to search elsewhere. (And I agree, a recording will help.)

 

DrTrekker,

You don't give your location other than CA, but perhaps there is a fellow SC430 owner near you that could give a lookie see. If I were in the area, I'd be happy to.

Give us some idea where you are and let's do a shout out to see if we can round up some help.

 

If you’re located in Orange County I can recommend a great independent shop in Costa Mesa.

 

My trickle charger, "Battery Tender Plus" will not charge a deeply discharged battery - ever!! A "normal battery charger" is needed to get the battery "fully charged". Subsequently, the trickle charger will do the job - install of the "quick connect" wire for the tender is simple. If a new battery is needed at some point, strongly recommend an "AMG":

"AGM or Absorbent Glass Mat is an advanced lead-acid battery that provides superior power to support the higher electrical demands of today's vehicles and start-stop applications. AGM batteries are extremely resistant to vibration, are totally sealed, nonspillable and maintenance-free."

My old battery would last a week and then would not turn engine over. Replaced battery with an AMG and now SC can sit for three weeks an still turn engine over to start. Hope this helps!!

 

I have AGM's in all my vehicles, but they do have a couple drawbacks. If they become completely drained, it can be difficult to get them to take a charge again. I ended up buying a $200 charger with a good reputation for charging depleted AGM's, but even it has its limits. The other drawback is their cost. They can be double the price or more than a flooded cell battery.

 

I agree, a failing servo motor or stuck mechanism attached to a servo motor could make a loud noise. Or, perhaps a failing brake booster pump?

 

Thanks, doodles. I'm in the Central Valley. We're short on good Lexus mechanics here unless we want to drive to the East Bay.

 

Hi Wilson,
The first year I owned the SC, the chronic battery problem became apparent. I haven't been able to find any superior batteries—like Optima or AGM to fit it. Been stuck buying those Interstate year after year. Where do you shop?

That permanent install trickle charger may be an economical solution at about $165 out the door.

 

Hi Harold,

Yeah, this year-old battery is toast. I don't need to test it to know that. Still under warranty though.

I always have the AC off when starting.

The consensus here on the rhino noise is that it's not anything that's going to hurt the car if I jump-start it and drive it to the mechanic, so that's what I'll do.

1. Battery replaced under warranty
2. More convenient trickle charger installed
3. Get noise diagnosed and repaired if necessary
4. Get radiator checked to see how much closer to replacing it we are

Watch it not make the noise for the.mechanic.

Thanks for much for your help, fellow SC lovers!