Recent Topics
Yet another M1 0W-20 grade flavor!
by fdcg27
02/25/18 07:40 PM
The Winter Olympics
by BlueOvalFitter
02/25/18 07:23 PM
Enchilada casserole
by car51
02/25/18 07:21 PM
John Force Crashes at Phoenix!
by KneeGrinder
02/25/18 07:11 PM
Need floor jack that can use Pinch Weld adaptor
by MI_Roger
02/25/18 07:10 PM
The new Champ ST9688 is fat like the 3593
by slacktide_bitog
02/25/18 07:10 PM
Do you drink milk regularly?
by Reddy45
02/25/18 07:05 PM
What Is This Symbol?
by BlueOvalFitter
02/25/18 05:29 PM
Can't believe I fixed it
by Stelth
02/25/18 04:40 PM
Cruise Control Set at 55
by das_peikko
02/25/18 04:39 PM
Who here has satellite radio in your vehicle?
by ZZman
02/25/18 04:01 PM
Oil choice for new to me 07 escape V6
by gabriel9766
02/25/18 03:10 PM
Super cleaning windshield
by mclasser
02/25/18 02:36 PM
New WM oil filters...
by rollinpete
02/25/18 01:49 PM
Swapped Out Bunch of Indoor Flood Bulbs to LED ...
by LoneRanger
02/25/18 01:45 PM
Scanner ABS Transmission and Engine Codes reader.
by littleant
02/25/18 01:38 PM
Meijer - Quaker State buy one, get one 50% off
by Bighorn2500
02/25/18 12:50 PM
Anyone own a 3rd generation Toyota Tacoma
by 007
02/25/18 12:47 PM
Best "wax as you dry" type spray wax?
by aquariuscsm
02/25/18 12:39 PM
Any current Edge 0W20 users here ?
by aquariuscsm
02/25/18 12:27 PM
Newest Members
A1ex, Grozd, swc, coronad0, davidsain
64288 Registered Users
Who's Online
106 registered (A310, asiancivicmaniac, Astro14, andyd, antonmnster, AV8R430, 11 invisible), 1743 Guests and 91 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
64288 Members
65 Forums
278798 Topics
4653118 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: 294
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: 8317
Loc: Phoenix
No way.
_________________________
2015 Grand Cherokee 3.6
M1 5w-30 Wix 10010

2017 124 Spider 1.4T
PP Euro 5w-40 Wix 57341

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


Registered: 09/06/15
Posts: 4917
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: 3604
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: 7067
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-15k 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: 9560
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: 599
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 Offline


Registered: 09/11/04
Posts: 2418
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