Attention: TDR Forum Junkies Hi all, I just had some very strange symptoms crop up.
Truck is a CTD 2001. 5 2wd, auto trans, 4:10s, 4 wheel discs. No power mods ever. Airtex style pump on the frame rail, Vulcan draw straw, BD Fuel Pressure switch & LED. About 75,000 miles. Original VP44. Mileage has been slipping to 15 loaded, 17-18 empty highway. Puff of white smoke upon first startup.
About 2 minutes after a cold start, when accelerating in 2nd in the speed range 20-30, I felt what I thought was the transmission slipping. It only happened once. Never had this feeling before. It was a slight lack of acceleration. I'd don't recall if the engine RPMs climbed or dropped... it just felt like a slip. Continued running errands for the next 4 hours, multiple turn-offs and ons, city streets to highways. No further problems.
Upon returning home, I check the trans fluid level. It's slightly low, but still in the OK range.
What I noticed upon opening the hood was a new noise, centered in the VP44 - vacuum pump area. I'm in Indianapolis, and the vacuum pump has been groaning in the morning due to the winter weather. It usually stops when the truck gets some heat - I figure the PS fluid finally becomes... fluid.
The noise is ... . a noticeable squeally whine. I did not hear it with the hood down, so it is NOT loud... but I did hear it over the engine running, so it must have some volume.
I checked the codes. P0500 and P1693 showed up. P1693 is nothing. P0500 is "No Vehicle Speed Sensor Signal". Hmmm. Funny... speedo was working. I may have had some wheel spin while out & about. NO CEL or other trouble lights on the dash.
I have a $35 cheapy CAN-buss OBD2 reader from Harbor Freight. It didn't see the P0500 code. But it did have some Freeze-Frame data when the P1693 was set.
Here's what I recall from the FF data:
1) engine RPM was 1149
2) VSS = 0 mph
3) TP = 0 (I assume this was throttle position)
This data seems contradictory, as I was in motion when I felt the slip. I know I had my foot on the go pedal, so a thottle position of 0 would be way wrong.
There were actually 8 data fields in the FF data... but I didn't realize how the code reader worked - this is the first time I've really had to use it. I failed to write everything down, and it got erased... . stupid me, eh?
The other data fields were a few temperatures, a voltage, and... I don't remember what else ... the other things did not look wrong to me. I just vividly remember the data fields that looked wrong.
I cleared the codes, went for a drive, everything seems OK, no codes set.
BD Fuel Pressure LED never flickered. It's only on when the engine & LP is not running... or has bled off after a few moments of shut off with key on engine off.
Mystery... .
Has anyone ever encountered a squeally, noisy, VP44? I'm assuming this could be a failure mode. Or... I'm hearing the vacuum/PS pump... But the noise was there at idle with the truck fully warm.
Thanks in advance for your advice.
Truck is a CTD 2001. 5 2wd, auto trans, 4:10s, 4 wheel discs. No power mods ever. Airtex style pump on the frame rail, Vulcan draw straw, BD Fuel Pressure switch & LED. About 75,000 miles. Original VP44. Mileage has been slipping to 15 loaded, 17-18 empty highway. Puff of white smoke upon first startup.
About 2 minutes after a cold start, when accelerating in 2nd in the speed range 20-30, I felt what I thought was the transmission slipping. It only happened once. Never had this feeling before. It was a slight lack of acceleration. I'd don't recall if the engine RPMs climbed or dropped... it just felt like a slip. Continued running errands for the next 4 hours, multiple turn-offs and ons, city streets to highways. No further problems.
Upon returning home, I check the trans fluid level. It's slightly low, but still in the OK range.
What I noticed upon opening the hood was a new noise, centered in the VP44 - vacuum pump area. I'm in Indianapolis, and the vacuum pump has been groaning in the morning due to the winter weather. It usually stops when the truck gets some heat - I figure the PS fluid finally becomes... fluid.
The noise is ... . a noticeable squeally whine. I did not hear it with the hood down, so it is NOT loud... but I did hear it over the engine running, so it must have some volume.
I checked the codes. P0500 and P1693 showed up. P1693 is nothing. P0500 is "No Vehicle Speed Sensor Signal". Hmmm. Funny... speedo was working. I may have had some wheel spin while out & about. NO CEL or other trouble lights on the dash.
I have a $35 cheapy CAN-buss OBD2 reader from Harbor Freight. It didn't see the P0500 code. But it did have some Freeze-Frame data when the P1693 was set.
Here's what I recall from the FF data:
1) engine RPM was 1149
2) VSS = 0 mph
3) TP = 0 (I assume this was throttle position)
This data seems contradictory, as I was in motion when I felt the slip. I know I had my foot on the go pedal, so a thottle position of 0 would be way wrong.
There were actually 8 data fields in the FF data... but I didn't realize how the code reader worked - this is the first time I've really had to use it. I failed to write everything down, and it got erased... . stupid me, eh?
The other data fields were a few temperatures, a voltage, and... I don't remember what else ... the other things did not look wrong to me. I just vividly remember the data fields that looked wrong.
I cleared the codes, went for a drive, everything seems OK, no codes set.
BD Fuel Pressure LED never flickered. It's only on when the engine & LP is not running... or has bled off after a few moments of shut off with key on engine off.
Mystery... .
Has anyone ever encountered a squeally, noisy, VP44? I'm assuming this could be a failure mode. Or... I'm hearing the vacuum/PS pump... But the noise was there at idle with the truck fully warm.
Thanks in advance for your advice.
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