Rusty / Leaky Exhaust Question

Hey guys,
Quick question. When I was fluid filming the undercarriage yesterday I realized the flange (I think that’s what it’s called) that connects the exhaust is super rusty and has a small super slow leak when the car runs (see pictures).

Im wondering if I should replace the flange or possibly the gasket inside? Maybe just get a MBRP lol $$$ ‍♂️

I was a sucker and bought all the warranty’s when I bought the truck. Only 26k miles currently. So we’ll see what the dealer says when I call them mañana.

Any advice / suggestions would be appreciated!

 

My knee jerk reaction is that it looks like what most newish exhaust pipes look like in the rust belt. Consider yourself lucky that it's not full of huge holes and hanging down and scraping the ground.

 

the exhaust is the rustiest spot on the truck. There’s a little in the hitch and on a few screws / bolts but the frame is in good shape. It was like this when I got it (Pennsylvania) ..I’m just OCD

 

Exhaust pipes are prone to rust.

 

Here's an older thread on the subject.

https://www.tacomaworld.com/threads/confirmed-exhaust-rust.428803/

If you live in a dry warm state it's NOT normal. If you live is a cold wet state it is normal.

I'm curious if high heat paint would help and, if it is does, why OEM's don't paint them.

 

Thanks man appreciate it

 

I never got more than 10 years out of a stainless exhaust system, usually much less here in connecticut. Back in the day when they were plain old steel, 2 years and they'd be leaking. Short trips is the biggest exhaust system killer here in the rust belt.

 

Why short trips the worst? Do you suggest going with a stainless exhaust ?

 

RE: Short trips
When you start the truck from cold the the moisture in the air condenses in the pipes and also makes steam out the tail pipe. On a short trip the engine and therefore the exhaust system don't achieve full operating temperature. This condensate is somewhat acidic and corrodes the pipe from the inside out.

On a longer trip the system is hot enough to completely bake any moisture out of the exhaust.

In your photo showing the black drip spot had you just started the truck? If so there probably is nothing to worry about, if you check with the truck fully warm (15 - 20 miles of driving) you will probably not be able to feel an exhaust leak at the joint.

 

Thanks for the detailed reply. That’s correct I had just started the truck. Really appreciate the explanation thank you!

 

Glad to help!

I had a neighbor who got a new exhaust during the winter, a week later the car wouldn't start. It would only crank a few turns at a try and we noticed a hiss sound each time. We put the car in a heated garage and pulled the exhaust system, warmed it up with a torch and drained at least 2 gallons of water out.

She drove 1/2 mile to work and back every day, the old system had holes and allowed the condensate to drain out, the new tight system allowed it to accumulate and freeze until it blocked the pipe.

 

Wow.

 

I was thinking that rust from within is likely the reason OEMs don’t bother to paint the exhaust. They would have to paint the inside and that might not be practical; albeit you’d think they could simply dip the exhaust in paint. I wonder if the exhaust gas tends to react with a ruin the paint. I’m curious. Never thought about this before.

Whatever the reason, it must be more expensive to paint the exhaust than make it out of stainless steel judging by the aftermarket products.

 

Most of the time the exhaust will make it out of the warranty period so they wouldn't see much gain by making it last longer. In the early 60's Rambler (AMC) had a ceramic armored muffler and tailpipe with a lifetime warranty to the original owner.



I had a 1987 Oldsmobile that went 280,000 miles on the original stainless steel exhaust.

 

That makes some sense, but they paint just about everything else. I’m sure the frame, for example, would survive the warranty period without paint.

 

Probably not. Moisture is the enemy of steel, the exhaust gets hot enough to be completely dry during normal operation (short trips excluded) and survives well unpainted, it is made of 409 grade stainless steel on the 3ed gens I believe.

The frame on the other hand is exposed to very little heat and is seldom thoroughly dry. Unpainted and in a salt belt state it would have holes in a very short time -- even with the (apparently poor quality) paint that Toyota uses they have been replacing frames clear back to 1995. You have to wonder what discussions go on in the boardroom...

 

It’s not clear to me if the stock exhaust is stainless, galvanized, or something else, but many of the aftermarket cat backs are stainless. Why stainless instead of painted cheaper steel is what I’m curious about. High heat spray paint can be had at a reasonable price

 

I believe the factory system is 409 stainless.

After market systems are stainless because it makes for a better and easier to manufacture product with less potential for customer complaints.

1) easier to manufacture -- painting processes are expensive: materials, prep, labor, curing, emission concerns -- all eliminated by using stainless

2) finished product is easier to ship, store and install -- paint scratches and chips easily

3) reliability (warranty) of the paint finish would be a constant headache -- parts of the exhaust system can approach red hot temperatures under some conditions - a brutal environment for any coating to last providing it didn't get chipped and scratched up from shipping, installation and (off) road hazards first