Recent Topics
Cleaning sweet and sour sauce out of carpet
by jj51702
04/24/17 04:04 AM
Brake Calipers media blasted
by Spetz
04/24/17 02:15 AM
Super Tech 9688 Cut and Post
by FordBroncoVWJeta
04/24/17 01:57 AM
2002 Taurus hot re-start rough idle
by Scout1
04/23/17 10:41 PM
Anyone ever moved a vehicle that's in your way?
by motor_oil_madman
04/23/17 09:58 PM
ACDelco tweet. How special!
by CapitalTruck
04/23/17 09:48 PM
Adding a switch to my electric fan
by Nick1994
04/23/17 09:41 PM
Off the shelf oil with highest ZDDP ?
by 97XLTsplash
04/23/17 08:35 PM
2007 Pontiac G6 maintance
by mrichards
04/23/17 08:01 PM
2001 jeep Cherokee oil recommendation
by Quickman28
04/23/17 07:48 PM
still the spec of this oil?
by yvon_la
04/23/17 07:30 PM
updating ECU for newest Dexos spec
by RichardS
04/23/17 06:19 PM
Oil recommendation - high mileage GM LY6 6.0
by intheburbs
04/23/17 06:10 PM
Breaking in a Stihl 4-Mix
by 5AcresAndAFool
04/23/17 05:46 PM
Fluid for Aisin 4-Speeds
by ET16
04/23/17 05:23 PM
Family Dollar removes old oil
by NH73
04/23/17 05:14 PM
75w-90 vs 80w-90
by logcar
04/23/17 04:57 PM
If the price was the same, which would you pick?
by 2000RX300
04/23/17 04:38 PM
Thumbs up for Bridgestone tires
by aquartlow
04/23/17 03:55 PM
Valvoline SynPower 0w20 6 - 1 qt. case $22.54
by BrewCityR
04/23/17 03:32 PM
Newest Members
dorvin, CommandoDude247, Napi, krzychulbl, gwtx
61312 Registered Users
Who's Online
41 registered (Char Baby, BigCahuna, Astro14, Bandito440, bullwinkle, 2015_PSD, 2 invisible), 861 Guests and 14 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
61312 Members
66 Forums
264176 Topics
4362493 Posts

Max Online: 3590 @ 01/24/17 08:07 PM
Donate to BITOG
Topic Options
#4384713 - 04/20/17 10:46 PM Would a leak at an oxygen sensor burn valves?
NoNameJoe Offline


Registered: 06/03/15
Posts: 93
Loc: New York
There's an age old (possibly myth) telling that open exhaust systems or systems with leaks would burn exhaust valves.

If there was a loose oxygen sensor such that a small amount of exhaust possibly blew past it, how likely would it have messed with things? If the oxygen sensor was totally gone would that change enough back pressure to damage valves?

Top
#4384721 - 04/20/17 11:00 PM Re: Would a leak at an oxygen sensor burn valves? [Re: NoNameJoe]
dishdude Offline


Registered: 11/14/08
Posts: 7250
Loc: Phoenix
No way.
_________________________
2015 Grand Cherokee 3.6
M1 5w-30 Wix 10010

2017 124 Spider 1.4T
FF

Top
#4384741 - 04/20/17 11:40 PM Re: Would a leak at an oxygen sensor burn valves? [Re: NoNameJoe]
BrocLuno Offline


Registered: 09/06/15
Posts: 3265
Loc: Kalifornia Kollective
No. Burnt valve are due to lean condition. That's intake leak, bad injector, or something along those lines ...


Edited by BrocLuno (04/20/17 11:41 PM)
_________________________
Formerly in marine engineering. In an earlier life I owned my own petroleum tank truck, and hauled for the majors and independent's.

Top
#4384886 - 04/21/17 08:20 AM Re: Would a leak at an oxygen sensor burn valves? [Re: NoNameJoe]
daves66nova Offline


Registered: 04/11/04
Posts: 3459
Loc: los angeles
Originally Posted By: NoNameJoe
There's an age old (possibly myth) telling that open exhaust systems or systems with leaks would burn exhaust valves.

If there was a loose oxygen sensor such that a small amount of exhaust possibly blew past it, how likely would it have messed with things? If the oxygen sensor was totally gone would that change enough back pressure to damage valves?
If the o2 sensor was indeed messed up, it probably would make the car run richer. I don't see where people get this about back pressure. If anything, a leak in the exhaust would vent exhaust gasses out, resulting in LESS backpressure in the system. but also, depends on your year car,such as a sensor after the rear cat, which might throw off the mixture too.
_________________________
THIS SPACE FOR RENT, PLEASE PM ME.

Top
#4384899 - 04/21/17 08:36 AM Re: Would a leak at an oxygen sensor burn valves? [Re: NoNameJoe]
KrisZ Offline


Registered: 12/23/06
Posts: 6389
Loc: Toronto, Canada
If the oxygen sensor fails, and the system cannot determine the appropriate A/F ration, it will switch to open loop and pre-programmed maps. So when that check engine light is on, the ECU is already ignoring the signal from the oxygen sensor, no damage will happen.

Exhaust valves being too tight, that's when they are super quiet, is usually the cause of them burning up.


Edited by KrisZ (04/21/17 08:37 AM)
_________________________
2015 Dodge Grand Caravan-10k miles.
2006 Mazda 3-145k miles

Top
#4384944 - 04/21/17 09:33 AM Re: Would a leak at an oxygen sensor burn valves? [Re: NoNameJoe]
HerrStig Offline


Registered: 08/24/11
Posts: 9011
Loc: Boston, MA
There maybe some truth to it with respect to air cooled engines running lean. The vaporization of
fuel has a cooling effect. On a liquid cooled, emission controlled car engine it's not an easy answer. Running retarded timing was also said to cause burned valves. The switch from leaded fuel was as hard on exhaust valves.

Top
#4385495 - 04/21/17 08:35 PM Re: Would a leak at an oxygen sensor burn valves? [Re: NoNameJoe]
circuitsmith Offline


Registered: 12/17/09
Posts: 518
Loc: Wash, DC
When a pressure wave goes down the exhaust pipe and reaches the end it can return as a rarefaction (suction) wave.
So air can be periodically sucked into an exhaust leak.


Edited by circuitsmith (04/21/17 08:36 PM)
_________________________
2006 Toyota Matrix 5-sp. 1zz-fe 5000mi/12mo OCI
Any major brand dino 5w-30 on sale

Top
#4385660 - 04/22/17 01:49 AM Re: Would a leak at an oxygen sensor burn valves? [Re: NoNameJoe]
punisher Online   content


Registered: 09/11/04
Posts: 2358
Loc: snowblind in TX
There was talk about engines that had really short primaries that just dumped to atmo that it was possible for reversion to potentially suck in cool air over a hot exhaust valve and cause warpage. Like a lot of things, I have heard of it, but never seen it.

Top