Sulfur/rotten egg smell on low mileage 06 (1 Viewer)

[baltik]

as title states, sudden, smell from exhaust on a sub 100k mile 06. no CEL light or obvious driveability issues. My initial thought is clogged cats and was going to reach for a techron concentrate or something along those lines. Anything else i should try?

 

[fjl40]

That smell usually means your battery is bad. Be careful when checking the battery.

 

[KFunk740]

An alternator with a faulty voltage regulator can overcook the battery, getting it hot/egg smelly and possibly explodey; which yes is first thing I'd look for out of precaution. Make sure voltage isn't going over 15V.

But also, if its actually from exhaust, then yeah cats can do that. It could just need the old italian tune-up (run the crap out of it), and burn off some old leftover hydrocarbons. Maybe the PO didn't run it very hard or that often. Have you been running it hard or hot when it happened?
I had an unrelated CEL for lean condition for a while, of which it probably overcompensated for by running rich. After I finally got that sorted and ran it uphill at full throttle onto the highway, with ECT PWR on, it started reeking like all hell, so much that we took the next off-ramp to check it out. No battery overheating, and all seemed good. Never had the smell again, musta just had to get the pipes clean.
IF you do have a clogged cat though, you can test it with an IR temp gun before and after cat. You can google on how to diagnose that.

 

[baltik]

Bad voltage regulator seems like a decent theory. I replaced the alternator with a rebuilt one 6 month ago... I presume my only option is to replace the alternator or is there a way to replace the regulator/add an external one? obviously will put a voltmeter tonight to get to the bottom of it

 

[KFunk740]

an alternator from a parts store? (not DENSO or OEM?)

My experience is that all parts store alternators are garbage. I've numerous fail in all different ways. Went through 6 all under warranty for my wife's car.

You should have a volt gauge on your dash, unless they did away with that by '06.

 

[Julian Stead]

A bad catalytic converter can smell like rotten eggs

 

[baltik]

an alternator from a parts store? (not DENSO or OEM?)

My experience is that all parts store alternators are garbage. I've numerous fail in all different ways. Went through 6 all under warranty for my wife's car.

You should have a volt gauge on your dash, unless they did away with that by '06.

Seems like good advice. were any of the failures voltage regulator related? are the remanufactured Densos ok? where does one source a good alternator (besides the dealership)

 

[Julian Stead]

Sorry, I should’ve said an inefficient CAT, it doesn’t mean the CAT is at fault but a fuel delivery issue. A sensor, fuel pressure regulator etc..

 

[KFunk740]

Seems like good advice. were any of the failures voltage regulator related? are the remanufactured Densos ok? where does one source a good alternator (besides the dealership)

My experience with parts store alternators are limited to Subarus, Nissans, etc. I haven't replaced one on my LC yet, but may do it pre-emptively soon.
I have had a few VR failures on nearly new parts store alternators. One of the new-ish Nissan alts I put on my Datsun as an upgrade really went crazy. I took it back to test at the parts store, and it actually broke the test machine somehow at both Autozone and Advance Auto (went to 2nd store after first broke). The only reading they could get was 28V, and the machine shut down almost immediately.
My understanding is that they outsource rebuilds to the lowest bidder overseas, who only replace the broken part with terrible quality stuff.

I'd expect DENSOs and dealerships to be pretty good, but haven't bought an alternator from them yet. My preference is to now rebuild them myself. When the original alternator went bad on the wife's latest Subaru, I got a rebuild kit from Maniac Electric Motors online for $50 and replaced the bearings and VR myself, and its been fine for like 20K miles. Maniac EM has some rebuild kits listed for LCs, but not all years. I was considering getting one of those kits soon.

 

[baltik]

Finally got to look at the car today. Smell is definitely coming from the battery which is visibly boiling. the odd part is that the alternator appears to be putting out 14v. I went ahead and cleaned the terminals thoroughly but didnt seem to solve the issue. the -ve terminal appears is hot to the touch, will have to check the grounding point... Seems like the battery is toast, anything else that could be causing this odd behavior?

lastly my costco doesnt appear to carry 27F, is there any other battery size that is plug and play and more readily available?

 

[kruisinkid]

24f

 

[KFunk740]

Did you check the voltage with the engine idling, or revved up? If the regulator is broken, it can still put out only 14V at idle, but when you rev up the engine it'll go sky high.
It's possible the battery just fried internally on its own, but often they have help somehow.
I'm not sure if the parts store tools have any other specific tests they run on the alternator, but I'd try to get to the one that sold you the alternator and have them verify its good before putting another battery in and risking killing one more.

 

[trdcorolla]

Unless your short on funds try to put in a 27F. A 24F fits, but the 24F is smaller and also fits toyota camry's. If you have a Sam's Club membership you can buy a H8/49 AGM, they are on $20 right now.

 

[AlpineAccess]

The wrong size cable or a bad connection going from the alt to fuse block will send the wrong voltage to the regulator and the regulator will overcharge the battery. Having swapped the alternator it would be worth looking at those connections and the cable if you replaced it.

Could just be a bad battery. They do go bad and swelling is often a trait.