Anyone have experience replacing the front O2 sensor? I was diagnosing some idle and ping issues and decided to change mine. Thought this would be an easy change but no such luck!
Using a long break bar it still took an exhaustive amount of time and force to slowly remove. It came out bent and the threads are beat up. I’m unable to reinstall the new sensor, and there is an obstruction in the exhaust manifold where the sensor should sit.
Does this seem right? Should there be a clear path in the exhaust manifold?
And if there is a problem with the threads or manifold can it be repaired or possibly replaced?
C59CF1A5-857D-4735-9213-088C46509E68.jpg
Can you get a picture of the obstruction in the hole?
I've used an M18x1.5 thread chaser to clean up the threads on the manifold for the O2 sensor. Here is the exact one I bought:
Lisle 12230 Oxygen Sensor Thread Chaser , Black
https://www.amazon.com/gp/product/B000XETMW0/
'81 E21 320i / '90 E30 325i / '̶9̶2̶ ̶E̶3̶4̶ ̶5̶2̶5̶i̶t (sold) / '15 Toyota XW30 / '̶̶8̶0̶ ̶E̶2̶1̶ ̶3̶2̶0̶i̶A̶ (sold)
When I look into the O2 opening it seems like I’m just seeing the manifold casting.
But it seems like the there is not enough depth, and the O2 sensor is hitting the casting.
In any case the threads are really bad, so I’ll at least give the thread chaser a go.
1FFB3DE1-91A9-444F-AABA-5C8555612C86.jpg 8C70DAB5-192B-4C15-AE6F-5A8B7142B85F.jpg 81CD041B-9F8C-4FC9-9FFA-6F75CC456537.jpg
I think you need a shorter O2 sensor, is the new one the correct application?
Yeah try to clean the threads first so it is easier to screw on the new O2 sensor.
You can also measure the depth until it hits that divider. I don't have another manifold laying around but maybe someone else and share their measurement.
'81 E21 320i / '90 E30 325i / '̶9̶2̶ ̶E̶3̶4̶ ̶5̶2̶5̶i̶t (sold) / '15 Toyota XW30 / '̶̶8̶0̶ ̶E̶2̶1̶ ̶3̶2̶0̶i̶A̶ (sold)
I’m pretty sure I have the right part, Bosch #1011542-11032. Matches the old one exactly, but maybe that one was wrong to begin with.
I’ll start by measuring the depth, and cleaning and checking the threads. I found bits of thread on the ground so that’s not promising.
The original sensor tip is definitely bent, like it was forced in.
Might have to get an oem sensor from dealer or elsewhere if it turns out aftermarket sensors are too long.
FWIW heres a manifold and sensor off of ebay.
It does appear the sensor is pointed straight at the manifold divider.
https://www.ebay.com/itm/294525510131
Yes Bosch 11032 is the right 02 sensor , never seen a O2 sensor bent like that, looks like it was torqued way to far in beyond normal tightness.
Good Find on the thread chaser, I have a set of metric thread chasers yet not that one.
Randy
Last edited by 320iAman; 11-21-2022 at 09:54 PM.
Looked around and found this kit for $16 / free shipping on eBay and bought it. My threads on the exhaust manifold are in good shape , this will beat using a 22 mm open end wrench for change overs. Sale for 7 days. When you chase threads easy does it don't force it put it in and turn and clean one or two threads, back it out, clean the thread chaser- re-oil or anti-sieze it- a small amount will do and keep going till its done, last resort would be a 18 mm x 1.5 mm tap same procedure as thread chaser. I measured a O2 sensor-11032, they have 22 mm drive nut and 17.88 ~ 17.9 mm thread which is standard-the female thread just slightly larger than the male thread. Taps are tapered which makes an easy start into the hole, whereas most thread chasers are not tapered so they have to fit the first thread right off the bat.
s-l1600.jpg
1X Straight 80mm Deep, 3/8"Sq Drive, 22mm.
1X Offset 31mm High, 3/8"Sq Drive, 22mm.
1X Offset 50mm High, 1/2" Sq Drive Octagon Drive, 22mm.
1X M18 X 1.5mm. Thread Chaser
1X M12 X 1.25mm. Thread Chaser
https://www.ebay.com/itm/23467811051...Bk9SR6LIqvyTYQ
Taps at amazon 2 for 1. 18 mm x 1.5 mm,,, $14. most charge $14 for 1
https://www.amazon.com/ApplianPar-Ta...s%2C166&sr=8-4
61Zh5bmCwOL._AC_SL1200_.jpg
Randy
Last edited by 320iAman; 11-22-2022 at 10:43 AM.
Then the new sensor is hanging up on the bad threads and not hitting the tip.
If you haven't yet tried cleaning the threads up with a chaser or tap, use plenty of lubricant with either tool.
Make sure you have it started on the threads straight and rotate the chaser backwards intermittently to clear the threads of debris.
O2 sensor thread size is the same as 18mm sparkplug threads and the same thread tools will work.
Good news, I bought a thread chaser and anti-seize lubricant and got everything back together. I think someone installed the old one at the wrong angle and just torqued it in!
It took several rounds of turning in, backing out, cleaning, and threading again. I really thought I was going to just replace the entire exhaust manifold at one point, but I stayed patient and it eventually spun in almost completely by hand.
While I was there, I went ahead and sanded and painted the manifold heat shield. Not my best work, but it's much nicer than the rusted metal until I figure out how to properly repaint or replace it.
FYI, in the last couple of months, I've replaced the fuel accumulator, fuel pump, fuel injectors, and the O2 sensor. It's starting and running smooth again, but I still need to tune the AF/idle just a bit.
Idle seems to drop under 1000 rpm when sitting, but while driving it's still staying around 1100 rpm. I'd like it to idle just a bit lower.
IMG_0768b.jpg IMG_0769.jpg IMG_0775.jpg
Very nice and glad the thread chaser worked out for you.
In the future if you ever have to remove the exhaust manifold from the head, instead of getting the individual gaskets for each cylinder get the gasket from an '84-85 E30 318i with the M10. It is a 1 piece gasket with integrated heat shield. Part Number 11621723876 and it looks like this: https://www.fcpeuro.com/products/bmw...8i-11621723876
Also a good time to replace all the studs and nuts.
'81 E21 320i / '90 E30 325i / '̶9̶2̶ ̶E̶3̶4̶ ̶5̶2̶5̶i̶t (sold) / '15 Toyota XW30 / '̶̶8̶0̶ ̶E̶2̶1̶ ̶3̶2̶0̶i̶A̶ (sold)
O2 sensor kit came in. Good you got your issue sorted.
IMG_20221130_124251_563.jpgIMG_20221130_124324_056.jpgIMG_20221130_124509_587.jpg 11032 O2 sensor. Sale is still on---sold out---- with an 3/8's extension or two can remove and install an O2 sensor without going underneath the car.
Randy
Last edited by 320iAman; 12-02-2022 at 10:04 PM.
Bookmarks