Dumb Question Thread - no flaming or sarcasm allowed
12-27-2013, 08:51 PM
#2978
Registered
iTrader: (2)
Join Date: Oct 2007
Location: Pacific Northwest
Posts: 16,684
Likes: 0
Received 252 Likes
on
110 Posts
To me, the simple presence of rear O2 fuel trim means that the ECU uses the rear for fuel triming under certain circumstances. The OP's testing showed that with the commanded AFRs really lean and the rear O2 connected, the ECU would pull the AFRs back to stichometric. Disconnecting it prevented this. Clearly the rear O2 is used as a safeguard in the event that the front O2 fails. Regardless of what MM believes, the testing sure showed that the ECU was using it for more than just emissions, and all indications that I saw backed that up. It isn't a stretch at all to believe that the rear O2 could be used for refining trims either, since narrowband sensors respond far more quickly than wideband, and with actual data tables in the ECU that support this... I don't see any argument against why this isn't other than MM just saying that it isn't so.
MM has been proven wrong quite a few times.
MM has been proven wrong quite a few times.
Last edited by RIWWP; 12-27-2013 at 08:54 PM.
12-29-2013, 05:49 AM
#2979
I don't know, but I gave the advice given on closed loop a/f's targets above 50% load a try... And wow.
Here's my dumb question for the day. How did I get oil on the side of my engine between the rear plugs and dip stick? Can't find a leak anywhere. Oil filter, cooler line, fill neck all checked.
Here's my dumb question for the day. How did I get oil on the side of my engine between the rear plugs and dip stick? Can't find a leak anywhere. Oil filter, cooler line, fill neck all checked.
12-29-2013, 09:52 AM
#2981
That is one of my fears, but I'm extremely careful when driving in wet conditions not to hit deep puddles.
Let me rewind the issue a little bit here..
About a 3 weeks ago I changed my oil at my buddies shop. I noticed my catch can was over filled and had dumped a good amount of chocolate milk sludge in the engine bay. It was everywhere on the passenger side (can is mounted between air pump and washer bottle). Changed the oil and cleaned the mess. Well about a week later I started getting oil/fuel smell threw the vents. I took it to the car wash and sprayed down the engine again focusing on the passenger side. Almost instantly after restarting the car I can smell raw fuel. Panicked, (I am aware of 8's catching on fire due to the dealership not replacing a fuel line clip, and this is the 3rd engine in it) I drove it straight to my friends shop for a closer look.
Lifted the car, confirmed the smell, and it's location. Driver side reaks of fuel and oil. Top of engine is dry, little bit of grime in the hard to reach places, but nothing out of the normal. Only between the plugs and dip stick have "fresh" oil film. Now I always use a funnel when adding oil so Iknow none was spilled.
I understand it's totally possible that I didn't clean the driver side of the engine good and might not have removed the oil originally, but how did it get there is what is confusing me
I drove the car to work today, I smelled more simple green cooking than anything else in the vents, although the smell of fuel/oil wasn't completely gone. I plan to reinspect when I get home. And depending on what happens I'll be ripping the UIM off tomorrow on my day off.
Let me rewind the issue a little bit here..
About a 3 weeks ago I changed my oil at my buddies shop. I noticed my catch can was over filled and had dumped a good amount of chocolate milk sludge in the engine bay. It was everywhere on the passenger side (can is mounted between air pump and washer bottle). Changed the oil and cleaned the mess. Well about a week later I started getting oil/fuel smell threw the vents. I took it to the car wash and sprayed down the engine again focusing on the passenger side. Almost instantly after restarting the car I can smell raw fuel. Panicked, (I am aware of 8's catching on fire due to the dealership not replacing a fuel line clip, and this is the 3rd engine in it) I drove it straight to my friends shop for a closer look.
Lifted the car, confirmed the smell, and it's location. Driver side reaks of fuel and oil. Top of engine is dry, little bit of grime in the hard to reach places, but nothing out of the normal. Only between the plugs and dip stick have "fresh" oil film. Now I always use a funnel when adding oil so Iknow none was spilled.
I understand it's totally possible that I didn't clean the driver side of the engine good and might not have removed the oil originally, but how did it get there is what is confusing me
I drove the car to work today, I smelled more simple green cooking than anything else in the vents, although the smell of fuel/oil wasn't completely gone. I plan to reinspect when I get home. And depending on what happens I'll be ripping the UIM off tomorrow on my day off.
Last edited by 1.3_LittersOfFurry; 12-29-2013 at 10:28 AM.
12-29-2013, 03:54 PM
#2982
Update;
So as soon as I start the car I'm greeted with a raw fuel smell from the vent. I'm catless and the wind was blowing in the wrong direction, so I thought maybe its just that. NOPE. Open the hood and the smell is pretty strong. Beyond annoyed (and with a fire extinguisher in the trunk), I drove the ever living out of her home. She beeped more times today than the entire month lol.
Got home, parked into the wind, so not to confuse my self with the normal exhaust fumes, and started looking around. I was happy to find no oil anywhere on the engine. But the fuel smell is still there.. You can only smell it if you hover your nose right above the dip stick. Anywhere else in the engine bay there is no fuel smell. And I sniffed everywhere... even stuck my nose in between the alt and intake and got nothing, but every time I went back to above the dipstick I got raw fuel.
Between the rear plugs and dip stick was completely dry. In fact the only single place I saw even a sign of oil was the front bolt of the oil filter neck. Wiped it clean with a rag, but that didn't help anything..
Also the smell only happens when the engine is running, doesn't matter if it is hot or cold, but the smell is slightly stronger when hot. As soon as the engine is turned off the smell is gone. Even if I kill the engine and turn the key back to the on position (fuel pump primes) there is no smell to be found....
So as soon as I start the car I'm greeted with a raw fuel smell from the vent. I'm catless and the wind was blowing in the wrong direction, so I thought maybe its just that. NOPE. Open the hood and the smell is pretty strong. Beyond annoyed (and with a fire extinguisher in the trunk), I drove the ever living out of her home. She beeped more times today than the entire month lol.
Got home, parked into the wind, so not to confuse my self with the normal exhaust fumes, and started looking around. I was happy to find no oil anywhere on the engine. But the fuel smell is still there.. You can only smell it if you hover your nose right above the dip stick. Anywhere else in the engine bay there is no fuel smell. And I sniffed everywhere... even stuck my nose in between the alt and intake and got nothing, but every time I went back to above the dipstick I got raw fuel.
Between the rear plugs and dip stick was completely dry. In fact the only single place I saw even a sign of oil was the front bolt of the oil filter neck. Wiped it clean with a rag, but that didn't help anything..
Also the smell only happens when the engine is running, doesn't matter if it is hot or cold, but the smell is slightly stronger when hot. As soon as the engine is turned off the smell is gone. Even if I kill the engine and turn the key back to the on position (fuel pump primes) there is no smell to be found....
12-29-2013, 04:01 PM
#2983
You gonna eat that?
iTrader: (1)
Is it possible your engine is misfiring, and you are smelling the unburned fuel through the dipstick?
12-29-2013, 05:43 PM
#2984
Well a fuel smell in my oil is nothing new, in fact every single rotary car I've owned the oil smelled of raw gas. Which is why I wasn't so alarmed at first. Ignition is in tip top shape, plugs have less than 200 miles on them, BHR coils and wires.
Did more investigating... Turns out I can hear a little "psst psst" noise while the engine is running. The smell had already gotton to me, so I poured some water over the area and instantly the "psst psst" sound changed.... So now I'm waiting for it too cool back down a little and I'm going to check my spark plugs and pray I find a loose one. And hopefully fix this issue.
Did more investigating... Turns out I can hear a little "psst psst" noise while the engine is running. The smell had already gotton to me, so I poured some water over the area and instantly the "psst psst" sound changed.... So now I'm waiting for it too cool back down a little and I'm going to check my spark plugs and pray I find a loose one. And hopefully fix this issue.
Last edited by 1.3_LittersOfFurry; 12-29-2013 at 05:46 PM.
12-29-2013, 08:01 PM
#2986
You gonna eat that?
iTrader: (1)
I've never seen that. Must have been defective. You should get another one for no charge.
12-29-2013, 09:25 PM
#2989
You gonna eat that?
iTrader: (1)
Well yeah, that goes without saying.
Not to mention a possible fire hazard. I imagine gas might have been squirting out, and an arcing wire could have ignited it.
It's another thing to look for that might help someone one day.
$20 is a half tank of gas though.
Not to mention a possible fire hazard. I imagine gas might have been squirting out, and an arcing wire could have ignited it.
It's another thing to look for that might help someone one day.
$20 is a half tank of gas though.
12-30-2013, 08:22 AM
#2990
Registered
Join Date: May 2013
Posts: 72
Likes: 0
Received 0 Likes
on
0 Posts
can anyone help me understand the difference between MT oil and differential gear oil.
i've been told they are the same thing in my Rx8 (but i don't trust my source)
the manual trans calls for MT90 oil
the diffs call for 75w90 gear oil....is it the same thing?
i've found the 5cats.org walk through, but im confused on the oils... thanks in advance for helpful replies
i've been told they are the same thing in my Rx8 (but i don't trust my source)
the manual trans calls for MT90 oil
the diffs call for 75w90 gear oil....is it the same thing?
i've found the 5cats.org walk through, but im confused on the oils... thanks in advance for helpful replies
12-30-2013, 08:32 AM
#2991
Registered
iTrader: (2)
Join Date: Oct 2007
Location: Pacific Northwest
Posts: 16,684
Likes: 0
Received 252 Likes
on
110 Posts
They have the same viscosity, but they are different oils with different purposes.
MT-90 (Red Line Synthetic Oil - Gear Oil for Manual Transmissions - MT-90 75W90 GL-4 Gear Oil) is a GL-4 oil, and has friction modifiers to allow syncro operation (they do need to grip stuff), use in the transmission.
75w90 Gear Oil (Red Line Synthetic Oil - Gear Oil for Manual Transmissions - 75W90 NS GL-5 Gear Oil) is a GL-5 oil, and does not have the friction modifiers, use in the rear diff.
Using a GL-5 in the transmission will destroy your syncros in a few thousand miles (lots of examples on the forum from years back). Using a GL-4 in the rear diff will likely destroy the diff in a few thousand miles (though I don't know of any reported cases where it did happen)
(An expert on oils might correct me, if i have any of that wrong)
MT-90 (Red Line Synthetic Oil - Gear Oil for Manual Transmissions - MT-90 75W90 GL-4 Gear Oil) is a GL-4 oil, and has friction modifiers to allow syncro operation (they do need to grip stuff), use in the transmission.
75w90 Gear Oil (Red Line Synthetic Oil - Gear Oil for Manual Transmissions - 75W90 NS GL-5 Gear Oil) is a GL-5 oil, and does not have the friction modifiers, use in the rear diff.
Using a GL-5 in the transmission will destroy your syncros in a few thousand miles (lots of examples on the forum from years back). Using a GL-4 in the rear diff will likely destroy the diff in a few thousand miles (though I don't know of any reported cases where it did happen)
(An expert on oils might correct me, if i have any of that wrong)
Last edited by RIWWP; 12-30-2013 at 08:35 AM.
12-30-2013, 08:48 AM
#2992
Registered
Join Date: May 2013
Posts: 72
Likes: 0
Received 0 Likes
on
0 Posts
Thank you for the quick reply, and you helped me with another question i didn't ask...(the GL-4 vs the GL-5)
very good info
thank you RIWWP!
the last thing i wanna do is save a few bucks and ruin my fun car...
very good info
thank you RIWWP!
the last thing i wanna do is save a few bucks and ruin my fun car...
12-31-2013, 02:03 PM
#2993
Registered
Is there a preferred way to remove and change the battery in an RX? That is, should you use a jumper cable to keep power to the car so you don't have to reset things?
Sorry for a somewhat dumb question, but all my other cars do not have computers and other things like radios that have to be reset.
On the topic of the battery. If my RX sits over the weekend, the battery drains. No lights on (even checked the trunk light from the back seat). I belive I can hook a multimeter to the battery with the car off to see if there is any drain, and if there is, start pulling fuses. Any other tips? I did have the auto parts store check the battery and it came back as working fine. Car starts fine all week, just drains when sitting in the garage over the weekend.
Sorry for a somewhat dumb question, but all my other cars do not have computers and other things like radios that have to be reset.
On the topic of the battery. If my RX sits over the weekend, the battery drains. No lights on (even checked the trunk light from the back seat). I belive I can hook a multimeter to the battery with the car off to see if there is any drain, and if there is, start pulling fuses. Any other tips? I did have the auto parts store check the battery and it came back as working fine. Car starts fine all week, just drains when sitting in the garage over the weekend.
12-31-2013, 02:09 PM
#2994
Registered
iTrader: (2)
Join Date: Oct 2007
Location: Pacific Northwest
Posts: 16,684
Likes: 0
Received 252 Likes
on
110 Posts
Just disconnect negative, then positive, connect positive, and then negative. No point in "trying to keep power to the car", a periodic reset is probably more beneficial than harmful, just keep in mind that you have to reset the DSC/TCS, redo radio presets, and might having a stumbling idle for a few drive cycles. But it's all trivial.
Just please please please make sure you don't hook up the battery backwards. At best you will blow several fuses, at worst you fry thousands of dollars worth of electronics modules. There has been a rash of those in 2013 for some reason.
Yup, find the drain via multi-meter, then start pulling fuses till the drain stops, and then investigate that circuit.
Just please please please make sure you don't hook up the battery backwards. At best you will blow several fuses, at worst you fry thousands of dollars worth of electronics modules. There has been a rash of those in 2013 for some reason.
Yup, find the drain via multi-meter, then start pulling fuses till the drain stops, and then investigate that circuit.
parting
12-31-2013, 04:03 PM
#2997
New Member
Join Date: Dec 2013
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
12-31-2013, 04:14 PM
#2998
Registered
iTrader: (2)
Join Date: Oct 2007
Location: Pacific Northwest
Posts: 16,684
Likes: 0
Received 252 Likes
on
110 Posts
It would be a defective plug. Whatever bonding agent they used just didn't get enough or broke down unexpectedly on that plug, and the combustion pressures pushed the center out of the plug.
You would have obvious troubles in a similar line as he did if you had that problem too. I've only see a handful of defective plugs in 6 years here.
You would have obvious troubles in a similar line as he did if you had that problem too. I've only see a handful of defective plugs in 6 years here.
