driving with broken exhaust studs

[92gsxbafaro]

Is it okay to drive with 3 broken exhaust studs just to a shop to get it fixed

 

[007jimmy]

Yea if you stay out of boost. You will run super rich and suffer slow spool. Dont drive it like that for too long.

 

[mcrae_06]

I bet you could pick up a set of EZOUTS, aka:bolt extractors, for around $15. If you had a drill and a Crescent wrench you could fix them yourself.

 

[pauleyman]

You will run super rich and suffer slow spool. Dont drive it like that for too long.

Explain this please. Leaking exhaust would have no effect on air fuel ratio. It could slow the car down but mass air flow is still mass air flow.

Broken studs won't hurt anything. Wortst thing i could think of is melting plastic if the leak is bad enough on the drivers side.

 

[boosteddsm98]

yea you will be fine. were are the broken at, at the head? Just be easy with it and do not hit boost.

 

[SmoochDarling]

Exhaust leaks pre O2 sensor do affect the A/f ratio. Delta 488 Explains it well:

"Exhaust leaks can make the sensor read lean or rich depending on the exhaust pressure. Usually lean at idle/low throttle/cruise and rich at higher load/boost. How lean or rich is tough to say but it will certainly screw with the fuel trims the longer it has to learn the wrong condition. If it's only at WOT or above 4k rpm, then it isn't just because of the O2 sensor since the car is in open loop and completely ignoring O2 feedback, but it might be related to the O2 sensor by way of the fuel trims. The way to test whether the fuel trims are causing the knock is to reset the ECU and immediately log a pull through the gears. If the knock is gone, then the long term fuel trims are probably causing the knock, if it's still there then look elsewhere for the cause of the knock."

 

[pauleyman]

I disagree. It would have to be a big enough opening to take in air. Think about it this way. You have a giant vat of water and you add some salt to it to make it 5% salt solution. You run a hose out the bottom and measure the salt solution with a sensor. Then you develop a leak on the side of the vat which leaks some of the solution out. Does the percentage of the solution change at the sensor? Unless an exhaust leak is big enough to introduce a signitifant amount of air into the stream then it is merely a leak so some of the exhaust doesn't see the sensor. Wouldn't change it's percentage, just it's volume and rate of flow (very very slightly). Discuss.

 

[bryzenga]

It will be fine if you baby it, but I wouldnt wait too long to get that fixed. With 3 less studs holding the weight, it puts more stress on the other studs/nuts. Once one of mine broke, it didn't take long for a second to crack and break, and then eventually a third.

 

[GSLENK]

I disagree. It would have to be a big enough opening to take in air. Think about it this way. You have a giant vat of water and you add some salt to it to make it 5% salt solution. You run a hose out the bottom and measure the salt solution with a sensor. Then you develop a leak on the side of the vat which leaks some of the solution out. Does the percentage of the solution change at the sensor? Unless an exhaust leak is big enough to introduce a signitifant amount of air into the stream then it is merely a leak so some of the exhaust doesn't see the sensor. Wouldn't change it's percentage, just it's volume and rate of flow (very very slightly). Discuss.

This doesn't work. water doesn't pressurize like air. poor comparison (technically , but i do get what you are getting at, I think it will be fine to go to the mech.). so yes you are right, said vat will behave as you stated, but not similarly to an engine that runs on air (and fuel/spark/timing etc...)

What they mean is that exhaust leaks out, "diluting" the less pressurized exhaust, altering (reducing) the amount of o2 that passes the sensor, setting the reading off. then the ecu compensates, until it reaches a cylinder rich, but exhaust "normal" equilibrium. This effect is magnified by back pressure, and the turbo supplies plenty of that at the manifold. so a pre-turbo leak is more serious than post turbo, especially since most o2 are not too far post turbo.

 

[WES_393]

I disagree. It would have to be a big enough opening to take in air. Think about it this way. You have a giant vat of water and you add some salt to it to make it 5% salt solution. You run a hose out the bottom and measure the salt solution with a sensor. Then you develop a leak on the side of the vat which leaks some of the solution out. Does the percentage of the solution change at the sensor? Unless an exhaust leak is big enough to introduce a signitifant amount of air into the stream then it is merely a leak so some of the exhaust doesn't see the sensor. Wouldn't change it's percentage, just it's volume and rate of flow (very very slightly). Discuss.

True if exhaust is only exiting. But exhaust pulses will draw fresh air past the leak and into the system. So it would be like your giant vat of 5% saltwater was in another vat of 20% saltwater. As the 5% leaks out, the 20% leaks in and skews the readings.

 

[pauleyman]

True if exhaust is only exiting. But exhaust pulses will draw fresh air past the leak and into the system

Now this reasoning I'll buy. I'm just doubtful of two things. That air gets pulled in during most driving and not coasting and unless the leak is really large would it really matter?
Would it affect a fuel ratio? Yes I guess it could. I still wouldn't be concerned about it short term.

You do have point on exhaust pulses

 

[WES_393]

Now this reasoning I'll buy. I'm just doubtful of two things. That air gets pulled in during most driving and not coasting and unless the leak is really large would it really matter?
Would it affect a fuel ratio? Yes I guess it could. I still wouldn't be concerned about it short term.

You do have point on exhaust pulses

Right, it would only affect idle/cruise AFR's. So you would burn a bit more gas and maybe run a little funky. But WOT would be completely untouched and driving the car short-term shouldn't cause any harm at all. Maybe some black suit on your plugs, but that's it.

 

[SmoochDarling]

If your still having trouble believing this, try driving a DSM with a cracked exh manifold, cracked enough to leak exhaust. You will definitely get poorer mileage due to running rich. I have seen it first hand a couple times, buy a car, terrible mileage, later find out my exh mani is cracked, slap a good one on, reset ECU and voila, wonderful DSM mpg.....