Weird Issues (96 LT-1)
Thread Starter
Le Mans Master
Joined: Dec 2003
Posts: 5,768
Likes: 33
From: Van Steel Corvettes
St. Jude Donor '12-'13
Weird Issues (96 LT-1)
For the christmas holidays the wife and I went on a nice 1900 mile road trip. On the way home I had some issues. It always happens once the car warms up and runs for a while.
First, the Service LTPWS light comes on when you start the car, goes out after a while...sometimes. After the car warms up to around 195 degrees and runs for awhile, the digital gauges goes NUTS. It'll start by bouncing from 160 degrees to 200, it never goes over the actual temp. The analog gauges never budgets.
Once the digital gauge goes nuts, the engine starts hesitating. Sometimes really bad, but snaps out of it pretty quick then won't do it again for awhile. During the 12 trip it did it maybe once or twice an hour, always very randomly. I first thought it was the torque converter dropping out, but it happened again (first time since the christmas road trip) on my drive to work Tuesday and it certainly wasn't the trans.
Could these three things be related in anyway? Oh, and I've never gotten a check engine light. Thanks.
First, the Service LTPWS light comes on when you start the car, goes out after a while...sometimes. After the car warms up to around 195 degrees and runs for awhile, the digital gauges goes NUTS. It'll start by bouncing from 160 degrees to 200, it never goes over the actual temp. The analog gauges never budgets.
Once the digital gauge goes nuts, the engine starts hesitating. Sometimes really bad, but snaps out of it pretty quick then won't do it again for awhile. During the 12 trip it did it maybe once or twice an hour, always very randomly. I first thought it was the torque converter dropping out, but it happened again (first time since the christmas road trip) on my drive to work Tuesday and it certainly wasn't the trans.
Could these three things be related in anyway? Oh, and I've never gotten a check engine light. Thanks.
Drifting
Joined: Sep 2003
Posts: 1,363
Likes: 7
From: 1994 LT1 Coupe 6-speed with FX3 & 2000 LS1 Vert 6-Speed with F45 Hunterdon County, NJ
For the christmas holidays the wife and I went on a nice 1900 mile road trip. On the way home I had some issues. It always happens once the car warms up and runs for a while.
First, the Service LTPWS light comes on when you start the car, goes out after a while...sometimes. After the car warms up to around 195 degrees and runs for awhile, the digital gauges goes NUTS. It'll start by bouncing from 160 degrees to 200, it never goes over the actual temp. The analog gauges never budgets.
Once the digital gauge goes nuts, the engine starts hesitating. Sometimes really bad, but snaps out of it pretty quick then won't do it again for awhile. During the 12 trip it did it maybe once or twice an hour, always very randomly. I first thought it was the torque converter dropping out, but it happened again (first time since the christmas road trip) on my drive to work Tuesday and it certainly wasn't the trans.
Could these three things be related in anyway? Oh, and I've never gotten a check engine light. Thanks.
First, the Service LTPWS light comes on when you start the car, goes out after a while...sometimes. After the car warms up to around 195 degrees and runs for awhile, the digital gauges goes NUTS. It'll start by bouncing from 160 degrees to 200, it never goes over the actual temp. The analog gauges never budgets.
Once the digital gauge goes nuts, the engine starts hesitating. Sometimes really bad, but snaps out of it pretty quick then won't do it again for awhile. During the 12 trip it did it maybe once or twice an hour, always very randomly. I first thought it was the torque converter dropping out, but it happened again (first time since the christmas road trip) on my drive to work Tuesday and it certainly wasn't the trans.
Could these three things be related in anyway? Oh, and I've never gotten a check engine light. Thanks.
It's doubtful its the temp sensor, but could be the connector or the wires to it.
It could also be a ground wire problem.
Suggest checking the ground wires on the driver side bell housing --and-- behind the driver side outer kick panel/door jamb.
Regarding the LTPWS light, it could also be a ground wire problem -- suggest checking behind the driver side outer kick panel/door jamb --or-- checking the FSM for the ground locations for the LTPWS and checking those.
Le Mans Master
Joined: Jan 2006
Posts: 6,564
Likes: 6
From: Woodstock Georgia
The sender on the water pump feeds info to the PCM and the digital gauge. Fluctuations in water temp readings from that sender can cause the PCM to do some 'strange things'.
It is easy to get to, check the wire connections first though.
It is easy to get to, check the wire connections first though.
Burning Brakes
Joined: Dec 2007
Posts: 805
Likes: 3
From: Waco TX
My digital temp gauge on my 94 also jumps around by about 15-20 degrees also. It will read 184, 190, 186, 182, 157, 188...I just figured it was air bubbles. It does this alot when the car is almost fully warmed up. Once it has reached the 180-194 range which is where it settles at (closer to 180 for highway driving, closer to 194 for city driving) and stays there for a good 10-15 minutes of driving, it doesn't jump around anymore.
My engine runs fine though. No issues there that I am aware of. Is this something I should worry about?
My engine runs fine though. No issues there that I am aware of. Is this something I should worry about?
Melting Slicks
Joined: Oct 2006
Posts: 2,238
Likes: 10
From: College Station TX
There are two temp sensors, one in the water pump for the digital readout and PCM, and one in the passenger side head for the gauge.
The digital one represents the temp that the PCM is reading, so if it is getting bad data, that could certainly cause the engine to run bad.
The digital one represents the temp that the PCM is reading, so if it is getting bad data, that could certainly cause the engine to run bad.
Thread Starter
Le Mans Master
Joined: Dec 2003
Posts: 5,768
Likes: 33
From: Van Steel Corvettes
St. Jude Donor '12-'13
Thanks fellas. I'm thinking it's a ground issues as well. Last time my LTPWS light came on the battery died within a few days...but this battery is less than a year old. Will be checking the wires for the sensor this weekend, just wanted to make sure to look for everything possible while I'm under the hood. Will check the grounds too. May go ahead and have the battery checked while I'm at it. I'll also make sure there is no air in the coolant system. So many options...ahhhhhhhhhhhhhhhhh.
