New C5 Owner Here...
09-04-2016, 01:32 AM
#1
Pro
Thread Starter
New C5 Owner Here...
Hi C5 Owners.
I just recently picked up a really high mileage 98 Auto. I picked it up as a project and have been going through it to see what it needs.
The car has 199,915 miles on it. I'm pleasantly surprised that it actually drives pretty well for a car of this mileage, especially one owned by a non-car guy...if you know what I mean.
So far, what I've discovered is that it needs a new oil pressure sender, passenger side window regulator, the HVAC controls are really dim, the DIC doesn't work right, the seat covers are really, really worn, and (at least) the driver seat slides a little bit under braking, the engine seems to run a little hot, and upon driving it around today, the DIC said the TPMS needed servicing.
Questions I have for you C5 experts:
1) What's the normal operating temp on these? The gauge was reading 230 as I came out of my development, then crept up some, and came back down to 220. It would stay at 220 as long as I kept the A/C on since it kicks on the fan. When I shut the A/C off, it would get to about 238, then come back down. Do the temp sensors go bad on these as much as the oil sensors do? If so, where's the temp sensor located?
2) The DIC doesn't work. No buttons do anything. I can't clear any display notices. I've been reading the problem is in the IPC. When I do replace the IPC, how do I get it reprogrammed for the mileage?
3) For the sliding seats...does this shim kit really work? http://www.westcoastcorvette.com/p-2...97-2004-c5-z06 I read one thread that mentions it stops the "rocking", but didn't address the "sliding".
4) This car has aftermarket 20" rims. I'm not sure if the monitors were installed correctly or not, what else should I be looking for to check the TPMS system?
This is a long thread, and for that I'm sorry; any help would be appreciated though.
Thank you!
Constantine Pappas
I just recently picked up a really high mileage 98 Auto. I picked it up as a project and have been going through it to see what it needs.
The car has 199,915 miles on it. I'm pleasantly surprised that it actually drives pretty well for a car of this mileage, especially one owned by a non-car guy...if you know what I mean.
So far, what I've discovered is that it needs a new oil pressure sender, passenger side window regulator, the HVAC controls are really dim, the DIC doesn't work right, the seat covers are really, really worn, and (at least) the driver seat slides a little bit under braking, the engine seems to run a little hot, and upon driving it around today, the DIC said the TPMS needed servicing.
Questions I have for you C5 experts:
1) What's the normal operating temp on these? The gauge was reading 230 as I came out of my development, then crept up some, and came back down to 220. It would stay at 220 as long as I kept the A/C on since it kicks on the fan. When I shut the A/C off, it would get to about 238, then come back down. Do the temp sensors go bad on these as much as the oil sensors do? If so, where's the temp sensor located?
2) The DIC doesn't work. No buttons do anything. I can't clear any display notices. I've been reading the problem is in the IPC. When I do replace the IPC, how do I get it reprogrammed for the mileage?
3) For the sliding seats...does this shim kit really work? http://www.westcoastcorvette.com/p-2...97-2004-c5-z06 I read one thread that mentions it stops the "rocking", but didn't address the "sliding".
4) This car has aftermarket 20" rims. I'm not sure if the monitors were installed correctly or not, what else should I be looking for to check the TPMS system?
This is a long thread, and for that I'm sorry; any help would be appreciated though.
Thank you!
Constantine Pappas
Last edited by cadillac531; 09-04-2016 at 02:44 AM.
09-04-2016, 02:19 AM
#2
Melting Slicks
nice score, im sure you got it for a good price
The operating temps is right at normal, it will hit 235 and then the fans will kick in sending it back down to 220 or so, on the highway it should be running cooler, like 190 or 200 depending on the weather
The tpms code is probably going off because the previous owner didn't bother installing them on the new wheels , my guess is if you remove the wheels and check they simply wont have any sensors installed at all. I have never used the tpms on any of the two c5's ive owned, so its your choice if you want to spend the money fixing that problem or not....my vote would be "don't bother"
Not sure about the DIC, im assuming you would need to send it in for a fix or replace it altogether, seems like a rare problem to me as ive never heard of that before
Sliding seat should be fairly simple , im sure some other people will post in with a little more helpful info on that
The operating temps is right at normal, it will hit 235 and then the fans will kick in sending it back down to 220 or so, on the highway it should be running cooler, like 190 or 200 depending on the weather
The tpms code is probably going off because the previous owner didn't bother installing them on the new wheels , my guess is if you remove the wheels and check they simply wont have any sensors installed at all. I have never used the tpms on any of the two c5's ive owned, so its your choice if you want to spend the money fixing that problem or not....my vote would be "don't bother"
Not sure about the DIC, im assuming you would need to send it in for a fix or replace it altogether, seems like a rare problem to me as ive never heard of that before
Sliding seat should be fairly simple , im sure some other people will post in with a little more helpful info on that
09-04-2016, 02:49 AM
#3
Pro
Thread Starter
nice score, im sure you got it for a good price
The operating temps is right at normal, it will hit 235 and then the fans will kick in sending it back down to 220 or so, on the highway it should be running cooler, like 190 or 200 depending on the weather
The tpms code is probably going off because the previous owner didn't bother installing them on the new wheels , my guess is if you remove the wheels and check they simply wont have any sensors installed at all. I have never used the tpms on any of the two c5's ive owned, so its your choice if you want to spend the money fixing that problem or not....my vote would be "don't bother"
Not sure about the DIC, im assuming you would need to send it in for a fix or replace it altogether, seems like a rare problem to me as ive never heard of that before
Sliding seat should be fairly simple , im sure some other people will post in with a little more helpful info on that
The operating temps is right at normal, it will hit 235 and then the fans will kick in sending it back down to 220 or so, on the highway it should be running cooler, like 190 or 200 depending on the weather
The tpms code is probably going off because the previous owner didn't bother installing them on the new wheels , my guess is if you remove the wheels and check they simply wont have any sensors installed at all. I have never used the tpms on any of the two c5's ive owned, so its your choice if you want to spend the money fixing that problem or not....my vote would be "don't bother"
Not sure about the DIC, im assuming you would need to send it in for a fix or replace it altogether, seems like a rare problem to me as ive never heard of that before
Sliding seat should be fairly simple , im sure some other people will post in with a little more helpful info on that
I'm with you on the tpms, I will most likely leave that alone. I think I can check my own tires LOL.
09-04-2016, 02:58 AM
#4
Pro
Thread Starter
I'll give questions #1 and #4 (or the second #3) a shot at answering.
1) C5's do tend to run a little hot but I think yours is a bit hotter than I would be comfortable with. The cars are bottom feeders for air to cool the coolant. As such they suck up everything on the road and lodge it against the radiator fins and the AC condenser. Not uncommon for the radiator fins and AC Condenser to look like this or worse if they are not cleaned regularly:
https://www.corvetteforum.com/forums...post1592840685
The cooling fans BOTH run in a low speed mode which comes on at about 226 and goes off at about 219. If the coolant gets to 235 then both fans come on in high speed mode. When the coolant temp drops to 226 the fans revert to low speed mode.
When the AC is turned on the fans come on in low speed mode at about 185 degrees.
The fans are commanded OFF by the PCM when the vehicle speed exceeds 35MPH irrespective of coolant temp. The above fan turn on temps are for the later year cars but the temps on the early year cars are similar and perhaps a few degrees lower.
I suggest that you take steps to clean the debris off the radiator fins. When you clean the radiator DO NOT use water or air in a direction TOWARD the engine as this will just lodge the debris deeper into the fins. I take my radiator out of the car about every 2nd year to clean it. Others will tell you they do a good enough job with the radiator in the car.
#4) Since the DIC doesn't work you are going to have to rely on what the sensors would look like if installed in the car. Here is a link to some pics of the TPMS for both the early and later year cars:
http://forums.corvetteforum.com/1574148527-post10.html
Notice the gray "nut" that is used on the outside of the wheel to retain the TPMS. If you do not have those then you most likely do NOT have TPMS installed.
If/when you get the DIC repaired/replaced you can pull codes up into it. The TPMS will set codes and display messages in the DIC if they are not operating correctly. You will also be able to use the GAGES button to cycle through information including the front and rear tire pressures. When the TPMS are either missing or have failed you will see XX for the tire pressures.
Here is a link on how to display the codes for when the DIC is operational:
https://www.youtube.com/watch?v=SviRjIsy9G4
OR
http://www.c5forum.com/ayc/dtcdic.php
1) C5's do tend to run a little hot but I think yours is a bit hotter than I would be comfortable with. The cars are bottom feeders for air to cool the coolant. As such they suck up everything on the road and lodge it against the radiator fins and the AC condenser. Not uncommon for the radiator fins and AC Condenser to look like this or worse if they are not cleaned regularly:
https://www.corvetteforum.com/forums...post1592840685
The cooling fans BOTH run in a low speed mode which comes on at about 226 and goes off at about 219. If the coolant gets to 235 then both fans come on in high speed mode. When the coolant temp drops to 226 the fans revert to low speed mode.
When the AC is turned on the fans come on in low speed mode at about 185 degrees.
The fans are commanded OFF by the PCM when the vehicle speed exceeds 35MPH irrespective of coolant temp. The above fan turn on temps are for the later year cars but the temps on the early year cars are similar and perhaps a few degrees lower.
I suggest that you take steps to clean the debris off the radiator fins. When you clean the radiator DO NOT use water or air in a direction TOWARD the engine as this will just lodge the debris deeper into the fins. I take my radiator out of the car about every 2nd year to clean it. Others will tell you they do a good enough job with the radiator in the car.
#4) Since the DIC doesn't work you are going to have to rely on what the sensors would look like if installed in the car. Here is a link to some pics of the TPMS for both the early and later year cars:
http://forums.corvetteforum.com/1574148527-post10.html
Notice the gray "nut" that is used on the outside of the wheel to retain the TPMS. If you do not have those then you most likely do NOT have TPMS installed.
If/when you get the DIC repaired/replaced you can pull codes up into it. The TPMS will set codes and display messages in the DIC if they are not operating correctly. You will also be able to use the GAGES button to cycle through information including the front and rear tire pressures. When the TPMS are either missing or have failed you will see XX for the tire pressures.
Here is a link on how to display the codes for when the DIC is operational:
https://www.youtube.com/watch?v=SviRjIsy9G4
OR
http://www.c5forum.com/ayc/dtcdic.php
I knew I could check codes via the DIC, but since the buttons dont work, I hooked up my scanner. It gave me the ecm info at least and there are no codes there. So that's good.
If the buttons on the instrument panel aren't working, is that in fact an IPC problem, or is there a possibility that the buttons just aren't working?
I didn't realize I had (2) #3's in my original post. It's been edited. LOL.
09-04-2016, 08:54 AM
#5
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09-04-2016, 11:37 AM
#6
1/4 mile/AutoX
Congrats and welcome to the Forum !!!!!
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09-04-2016, 11:53 AM
#7
Drifting
The HVAC dim display is a very easy fix if you can use a soldering iron. I bought mine with the display completely blank and about 1/3 of the backlight bulbs out. I bought replacement backlight bulbs and replaced all 13 of them. I also resoldered the six flat resistors on the secondary circuit board in just a few minutes. Two-hour job including the time to remove and reinstall the controller from the dash.
Last edited by any4xx; 09-04-2016 at 11:54 AM.
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09-04-2016, 01:56 PM
#8
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Congrats on getting your C5. Good luck getting all the issues fixed and then being able to enjoy the car.
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09-04-2016, 05:47 PM
#11
Safety Car
my passenger window stopped working today but there is a simple fix if you here a click from the window motor when you press the window switch down...So does it click?
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09-04-2016, 09:36 PM
#15
Pro
Thread Starter
The HVAC dim display is a very easy fix if you can use a soldering iron. I bought mine with the display completely blank and about 1/3 of the backlight bulbs out. I bought replacement backlight bulbs and replaced all 13 of them. I also resoldered the six flat resistors on the secondary circuit board in just a few minutes. Two-hour job including the time to remove and reinstall the controller from the dash.
.This fix is one of the first ones I'm going to do. I won't be able to get to it until mid week coming up, but first thing I will do is pull the unit out and solder that all up.
09-04-2016, 09:37 PM
#16
Pro
Thread Starter
Thank you!
09-04-2016, 09:57 PM
#18
Pro
Thread Starter
Do you see only one fan running? BOTH fans are supposed to run in low speed mode and high speed mode. Complex wiring setup with 3 fuses and 3 relays. Fans are electrically configured in series for low speed operation and then changed to parallel wired for high speed mode. If only one fan is operating that will contribute greatly to the high temps. 
Coolant temp sensor is monitored by the PCM to do the switching,
Here is the wiring diagram if you need it:
Coolant temp sensor is monitored by the PCM to do the switching,
Here is the wiring diagram if you need it:
Awesome. Thanks. I didn't know they ran in slow speed, so maybe it just sounded to me like one is running. I will do a visual next time I turn it on. Thanks again for all the valuable tech. info.
09-05-2016, 01:27 PM
#19
Pro
Thread Starter
I took the door panel off to inspect things and I felt the window motor....super hot. It's just burnt up now. The computer in the door (or express down control box) still clicks, just the motor won't operate.
I'll get a new regulator this week and throw it in there.
That simple fix was worth a shot, though. Thanks for the tip.
Last edited by cadillac531; 09-05-2016 at 01:32 PM.
09-05-2016, 02:05 PM
#20
Safety Car
Darn....I was hoping you would have one less issue...
I did a search here and found that simple fix for the window. I tried it and it worked....for 2 seconds. The window came down and I thought that was awesome. Then, when it started to come back up, it stopped about 1/4 of the way and that's where it sat.
I took the door panel off to inspect things and I felt the window motor....super hot. It's just burnt up now. The computer in the door (or express down control box) still clicks, just the motor won't operate.
I'll get a new regulator this week and throw it in there.
That simple fix was worth a shot, though. Thanks for the tip.
I took the door panel off to inspect things and I felt the window motor....super hot. It's just burnt up now. The computer in the door (or express down control box) still clicks, just the motor won't operate.
I'll get a new regulator this week and throw it in there.
That simple fix was worth a shot, though. Thanks for the tip.