Trans Temp Sensor and EGT Sensor...

[lswing]

Well, car goes in for diagnosis next week, so just fishing for any ideas. One of the EGT's is now acting up, and the Trans Temp is back, both "Implausible - Intermittent", EGT shows up much sooner. Car basically drives fine except for WOT in third wanting to slip up to 4th as mentioned in my other posts, and I would say my TC lock/unlock feels a bit rougher than normal, but everyday driving you really wouldn't know something was up.

Oddly enough, last year I was getting the "Implausible - Intermittent" on all O2 sensors, and that hasn't shown in 6 months or more now that I have added more fuel.

Could be seperate issues I'm chasing, we'll go over the TCU to trans wiring and plugins, and then onto replacing the trans temp sensor if needed. Also looking for grounds to be solid and any wiring that could be kinked or loose.

On a related note, my brother who was a mechanic at Buick years ago, mentioned that there were repeated problems with the TC in them when it locked up, causing heavier load on the engine, and small issues and rough driving. Solution, change the plugs and wires, fixed! So we'll go over the wires and check plugs.

Think I'm gonna name my car Implausible - Intermittent - Beast:revs:

Thanks!

[Chung]

My trans temp sensor implausible started firing a few months ago. I cleared it one but it came back after a month or so. I think the only cure is a 6-speed :).

[MaxRS6]

^Sounds plausible..;0

[lswing]

I'm more on the implausible side....

Chung, you notice anything different with shifting, TC, or general driving? Like I mentioned, I probably wouldn't have known something was up if not for that slip from 3rd to 4th when in Tip and WOT...

[lswing]

If it is the sensor, I can send you the details on it. Looks like a little resistor, sits open once the VB is opened up. It's removing the trans fluid, pan, and bottom of VB that's a pain, sensor just sits there. It's below the fourth green solenoid from the left, little orange thing in the wire. This is almost a bulletproof sensor, so most problems have been in the wiring from the tcu to the trans, especially the connection port to the trans that is exposed.

14300

[Chung]

My slip is occasional from 2nd to 3rd at full throttle (torque converter not locking up, not sure is that is the same as slipping). I need to do a fluid replacement so I was thinking about replacing the whole harness when I do.

[lswing]

My slip is occasional from 2nd to 3rd at full throttle (torque converter not locking up, not sure is that is the same as slipping). I need to do a fluid replacement so I was thinking about replacing the whole harness when I do.

I've been reading what I can find, and talking with Tozo and a few others. Might just be the connection at the trans, most common culprit. Plan for me is to go over wiring, if no luck then replace the sensor. Sounds like about the same thing, TC not locking up right either putting too much or not enough pressure on the trans. Guessing mine would slip in 2nd if I tried, I just always log data in 3rd so that's when it's happened.

If TC doesn't lock or at wrong time it can transfer too much power into the trans, or it seems the computer could sense something off and shift up...

[lswing]

Well, trans temp sensor came back. Took about a week and 150 miles. Seemed to take longer than before. Mechanic had checked all wiring from TCU to Trans and I thought that had fixed it.

Plan is to change out sensor next week. Also checking shift cable linkage to make sure that is not triggering the shift. Will be putting Shaeffer trans fluid in based off recommendations.

Here we go again....

[MaxRS6]

^Uggghh- I feel your pain going through the endless mind loops "WTF is it???"

Unfortunately- Often when I go through the "lil thing hunt"- it normally turns out to be the big thing that I hoped the lil thing would fix.

Good luck on a resolution and getting your monster back under ya

[lswing]

Yep, thanks Max! Going to keep digging around here and hope it's not the big thing.....the big thing's a PITA!

Back to the shop next week....my car likes the shop...and my money....

[hahnmgh63]

Part of the exhaust manifold deteriorating and eat the Turbine?

[lswing]

Part of the exhaust manifold deteriorating and eat the Turbine?

Gawd, I remember Max posting the pics of that. I put newer manifolds on last time we had the engine out because of him.

I'm thinking the V10 S6 will help carry me through the current troubles.....need to test drive it soon.

[G2]

FWIW, there's no plug wires......but hope it gets resolved. Keep us posted.

[lswing]

FWIW, there's no plug wires......but hope it gets resolved. Keep us posted.

Yep, it's a search for sure. I was referring to the wiring from the TCU to the trans, which has a plugin point that can become corroded so I've heard, does that seem about right? Hoping its the shift selector cable, will see!

[ttboost]

Let me know if you need the shifter/neutral safety switch..I have mine from my swap for sale.

14443

[lswing]

Let me know if you need the shifter/neutral safety switch..I have mine from my swap for sale.

14443

Thanks TT! I'll know more in a week or so...

[Chung]

One thing I did learn by having the car break is that my trans temp sensor hasn't thrown a code since I have replaced my battery. I am wondering if it threw a transient error because of lack of power when cranking.

[lswing]

One thing I did learn by having the car break is that my trans temp sensor hasn't thrown a code since I have replaced my battery. I am wondering if it threw a transient error because of lack of power when cranking.

Interesting...it does take a week or two for the code to show...we replaced the sensor, but I'll check for codes soon.

But, my battery has been cranking low this fall/winter, and I now put it on a battery tender every few weeks, cranks great. It's one of those tiny Optima batteries, but has been great.

[G2]

I've also started trickle charging- going to wire in a 6 or 10amp smart charger. Turning off power consumers isn't quite enough, despite a 20min commute.

9.6 volts is generally the threshold for 12v systems to still temporarily function. A good battery is a must. Low voltage can throw codes, if not general mayhem.

[lswing]

With my 10 miles of driving 3-4 days a week not much time for charging. Usually sitting at 14v on the dash. Maybe 12.5-13 when cranking low. Temp sensor code isn't back yet!

[hahnmgh63]

I use the much smaller Odyssey 925t battery and only put it on the Battery Tender when I'm not going to drive it for more than a week. After a week it will crank a little slower but no codes.

[lswing]

I use the much smaller Odyssey 925t battery and only put it on the Battery Tender when I'm not going to drive it for more than a week. After a week it will crank a little slower but no codes.

Same here, about two years old now. Keeps a great charge when I drive more miles, and just put the tender on when not driving much.