Hello everyone. Just had to cancel a mini-vacation with the family due to my car. Problem disappeared so hard to diagnose...

Car is a 2006 RL, automatic transmission, Tech Package (?) with radar cruise control. 105 k miles. Last oil change ~1300 miles/2 weeks ago.

City traffic, 60 F weather, we started smelling burning smell in cabin. I would describe it as an electrical burning smell but I guess that could be any plastic or hydrocarbon (fluids?). Ignored as long as I could. At the next light, light smoke came up from the drivers side of the hood.

When pulling over to stop, I thought the brakes were fading as a pumped multiple times to get it to stop. It is possible this was just me panicking as I thought the car was on fire. Could not reproduce brake fade.

Pulled over, ripped out as many little plastic covers as I could, found nothing. Drove all the way home with no smells at all.

Not even sure where to start as I have done little under the hood on this car. Not even sure if there is a Chilton manual for it.

Any help would be appreciated. My searches turned up references to a PS hose issue. Is that what this is?

 

could it be a plastic bag or debris on the exhaust?

have you gotten the power steering recall done?

 

I know this will be a frustrating response, but since you cannot reproduce it to see where the source of the smoke is, it's going to be impossible to diagnose for you, let alone us on a forum without physical sight of the car. I'm assuming no warning lights are showing up?

But I'll tell you one weird experience I had with a friend's car recently. His alternator went bad and something must have shorted inside because the car was dead with no lights on at all. When you drop in a fully charged battery, the alternator started smoking WITHOUT the car even being on. I have never seen this before on any car I have owned in the last 20+ years. Normally, alternators die and not charge, but for it to smoke without even running is a new one. I'm sure this is exceedingly rare. Just an example of the many things that it could be.

If the smell was electrical, I doubt it has anything to do with the mechanical Power Steering pump. You'd be looking for something that is electrically powered.

I know this probably doesn't help much... but you probably have to wait for it to happen again unless you can find a component that is obviously burnt.

 

The only thing that comes to mind is the Brake Master Cylider recall that was to be performed on 2005-mid 2007 cars. Something about a part getting hot and melting wires, but my memory very well may be disservicing me.

 

I did some sniffing under the hood. Burnt smell is very faint now and strongest at/behind the air filter housing. There are a pair of electrical things in the fender there. One is a small black relay box. Inspected that and no issues. Below that is a small gray box, maybe another relay? Cannot access it very well so not sure.

The idea of an overheating electrical component on the master cylinder would tend to match the symptoms. But the FAQ on this forum does not list such a recall for this generation RL.

I guess I will just put it back together and drive with my fire extinguisher readily accessible.

 

The reality is that if nothing failed its probably not electronic. By the time you smell the smoke its usually to late.

So you either picked something up off the road or you have a fluid leak.

 

Went through and read the 3 recalls for the early 2G RL. While there was a brake master cylinder related recall, the one I was thinking of was the over heating power steering hose. That is the only common guess besides a leaking valve cover gasket.

Get under your car and look for oil accumulating on the lowest parts of the engine. If there is any, wipe it away. Check back after a few drives to see if any more has accumulated. This will indicate whether you have any active leaks or not.

 

Just a quick update on this subject. Continuing to have intermittent brake issues.

Took car into dealer and had master cylinder recall performed. They could find no cause for the smoke/smell. No notable change after recall done.

A week or two ago the wife took it on a 1-2 hour drive and it threw a CMBS warning light. Did nothing with it but drive as usual for a week or so and the light went away by itself.

This week driving home, the brake pedal seemed to have a shorter travel and the brakes shuddered a bit, like a warped rotor or bad pads. Then, almost home, the brake pedal travel went long again and braking was smooth.

I have no idea what any of this means other than everything about cars has gotten way too complicated. Please let me know if you have any insight.

Thanks,

-Dave

 

I would suggest taking the car back to the dealer and have them bleed the air out of the brake lines, which is most likely the cause after they had the master cylinder out of the car.

 

Yea sounds like there is air in the system

 

From what I remember, the master cylinder recall was due to after market brake fluid (not honda dot 3) being used by the consumer and the gaskets "rolling" in the brake cylinder causing brake fade and possible failure. I just had the recall done. Aslo cant remember if they rebuild or replace it. My brakes were noticably stiffer - in a good way after the correction.

 

They usually just replace a seal on the inside of the master cylinder and re-install unless brake fluid has leaked down into the brake booster which at that point, the booster is to be replaced...either way the master cylinder has to be removed from the car. If they don't do a proper brake bleed, the pedal will feel soft/spongy/low.

 

Brakes now behave in three distinct ways:

1. Normal, smooth, short brake pedal travel

2. Shuddering, short pedal travel. Seems to come before mode 3...

3. Smooth, looong brake pedal travel. Tends to occur in stop and go traffic. I believe this is a classic brake fade.

Mechanic has it now. Of course it behaved like a good little RL for him. Will know more tomorrow, I hope. I have a 1300 mile drive ahead of me and it it sure would be nice to have some resolution.

 

Mechanic tore into front brake calipers. Found pistons to be sticky and actually made some clunky noise in the caliper??? Sticking piston = cooked pads = high heat = brake fade?? $775 got me two remanufactured front calipers, rotors turned, and new pads. If I don't repost on this then the problem is fixed.