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Okay, here’s what I understand so far:
1999 Dodge Ram 1500, 5.2L V8, 46RE auto trans, 4X4, 260K miles
Symptoms:
1. Poor mileage (14 mpg)
2. Knocking at idle in park/neutral, felt in steering wheel especially
3. Knocking/misfire under brake torque
4. Shaking at idle in any gear
5. Almost stalling in drive/reverse, and the RPM falls by 200 accompanied by a shake
6. Noticeable exhaust smell inside and out when idling
7. CEL with misfire codes P0300-307, but not 08. No other codes, and most are pending.
8. Can definitely hear vacuum leak with throttle
9. Trans:
a. In park: Knocks
b. In neutral: hums
c. In drive: Every few seconds it misses when it does, the RPM drops by 200 with a shake
d. In reverse: Drive and neutral symptoms combined. Stops if throttle appliedTroubleshooting:
Plenum gasket, plug wires, cap, coil, plugs and rotor replaced
Reroute plug wires per TSB 18-48-98
Checked for vacuum leaks, couldn’t find one
Checked the timing
Has fuel pressure
Not burning excessive oil
Relative compression test sounds good
If you spray carb cleaner in the TB, it may run perfect for a few minutesI had to check my 46RE books to verify my thoughts. Here’s what I found: In park, park pawl/sprag is engaged to lock output shaft & fluid isn’t sent through cooler. In neutral, park pawl/sprag is disengaged and fluid IS sent through cooler via the l/u switch valve. I also attached the troubleshooting list for ‘buzzing noise’ in trans. As you’ll see, that also is pointing toward the trans cooler.
Symptoms 1-7 & 9c-d are classic ‘misfire’ symptoms. As I said earlier, the ignition system has been fairly well verified, let’s start looking at air/fuel side.
For #8, try this: http://ericthecarguy.com/videos/7-videos/27-fuel-and-emissions?start=15&videoid=9CPqbaSgcok Don’t forget to check/test/cap the little vacuum hoses. Those little SOBs have gotten me more than once!
[quote=”LJ11194″ post=47514]I’m not seeing your attachment.
Why would I get a sound in neutral but not in park? Other than the block on the output shaft, how are they different?[/quote]
Is knocking sound loud enough to drown humming sound? BTW, which trans model are we talking about?
[quote=”LJ11194″ post=47514]I’m not seeing your attachment.
Why would I get a sound in neutral but not in park? Other than the block on the output shaft, how are they different?[/quote]
Is knocking sound loud enough to drown humming sound? BTW, which trans model are we talking about?
when I put it in neutral …. I hear a strange humming sound. (doesn’t do it in park, it makes a knocking sound then)
Thinking about this, do you have/can get/borrow a mechanic’s stethoscope? Knocking sounds are never good, we need to isolate to one area of the drivetrain. (It does seem to be trans related. Flexplate perhaps. See attachment.)
when I put it in neutral …. I hear a strange humming sound. (doesn’t do it in park, it makes a knocking sound then)
Thinking about this, do you have/can get/borrow a mechanic’s stethoscope? Knocking sounds are never good, we need to isolate to one area of the drivetrain. (It does seem to be trans related. Flexplate perhaps. See attachment.)
[quote=”LJ11194″ post=45885]Today, when COLD it decided to almost stall out at a red light. Idle dropped to about 400 every few seconds. I cycled it into park and back to drive and it stopped.
So just for grins I decided to check the transmission fluid. It’s fine, but what’s weird is when I put it in neutral (Chrysler recommends you check it in neutral w/ brake on as opposed to park), I hear a strange humming sound. (doesn’t do it in park, it makes a knocking sound then) And more interestingly, when I leaned on the vehicle it creaks very loudly. I turned off the engine, and… it didn’t do it anymore. Didn’t do it at all in any other gear other than neutral and only with the engine running. The engine itself appears solid, it doesn’t move or shake visibly by itself in any gear at any RPM. But now I suspect the transmission may be loose. Is this a reasonable conclusion?[/quote]
Hi. Glad to hear you’re making progress.
OK for the loud creak I’d check suspension bushings and shocks.
For the trans sounds, is there anyway you can record and post them? That would help a bunch.
It sounds as if you’ve done the common items for ignition misses. Let’s do a compression check and vacuum test next. Also if you can get short and long term fuel trims that will give more evidence to look at.Really sounds as if we’re looking at multiple problems, so lets take them ‘one bite at a time’.
[quote=”LJ11194″ post=45885]Today, when COLD it decided to almost stall out at a red light. Idle dropped to about 400 every few seconds. I cycled it into park and back to drive and it stopped.
So just for grins I decided to check the transmission fluid. It’s fine, but what’s weird is when I put it in neutral (Chrysler recommends you check it in neutral w/ brake on as opposed to park), I hear a strange humming sound. (doesn’t do it in park, it makes a knocking sound then) And more interestingly, when I leaned on the vehicle it creaks very loudly. I turned off the engine, and… it didn’t do it anymore. Didn’t do it at all in any other gear other than neutral and only with the engine running. The engine itself appears solid, it doesn’t move or shake visibly by itself in any gear at any RPM. But now I suspect the transmission may be loose. Is this a reasonable conclusion?[/quote]
Hi. Glad to hear you’re making progress.
OK for the loud creak I’d check suspension bushings and shocks.
For the trans sounds, is there anyway you can record and post them? That would help a bunch.
It sounds as if you’ve done the common items for ignition misses. Let’s do a compression check and vacuum test next. Also if you can get short and long term fuel trims that will give more evidence to look at.Really sounds as if we’re looking at multiple problems, so lets take them ‘one bite at a time’.
[quote=”LJ11194″ post=45885]Today, when COLD it decided to almost stall out at a red light. Idle dropped to about 400 every few seconds. I cycled it into park and back to drive and it stopped.
So just for grins I decided to check the transmission fluid. It’s fine, but what’s weird is when I put it in neutral (Chrysler recommends you check it in neutral w/ brake on as opposed to park), I hear a strange humming sound. (doesn’t do it in park, it makes a knocking sound then) And more interestingly, when I leaned on the vehicle it creaks very loudly. I turned off the engine, and… it didn’t do it anymore. Didn’t do it at all in any other gear other than neutral and only with the engine running. The engine itself appears solid, it doesn’t move or shake visibly by itself in any gear at any RPM. But now I suspect the transmission may be loose. Is this a reasonable conclusion?[/quote]
Hi. Glad to hear you’re making progress.
OK for the loud creak I’d check suspension bushings and shocks.
For the trans sounds, is there anyway you can record and post them? That would help a bunch.
It sounds as if you’ve done the common items for ignition misses. Let’s do a compression check and vacuum test next. Also if you can get short and long term fuel trims that will give more evidence to look at.Really sounds as if we’re looking at multiple problems, so lets take them ‘one bite at a time’.
[quote=”LJ11194″ post=45885]Today, when COLD it decided to almost stall out at a red light. Idle dropped to about 400 every few seconds. I cycled it into park and back to drive and it stopped.
So just for grins I decided to check the transmission fluid. It’s fine, but what’s weird is when I put it in neutral (Chrysler recommends you check it in neutral w/ brake on as opposed to park), I hear a strange humming sound. (doesn’t do it in park, it makes a knocking sound then) And more interestingly, when I leaned on the vehicle it creaks very loudly. I turned off the engine, and… it didn’t do it anymore. Didn’t do it at all in any other gear other than neutral and only with the engine running. The engine itself appears solid, it doesn’t move or shake visibly by itself in any gear at any RPM. But now I suspect the transmission may be loose. Is this a reasonable conclusion?[/quote]
Hi. Glad to hear you’re making progress.
OK for the loud creak I’d check suspension bushings and shocks.
For the trans sounds, is there anyway you can record and post them? That would help a bunch.
It sounds as if you’ve done the common items for ignition misses. Let’s do a compression check and vacuum test next. Also if you can get short and long term fuel trims that will give more evidence to look at.Really sounds as if we’re looking at multiple problems, so lets take them ‘one bite at a time’.
