Ford Powerstroke Diesel Forum banner

Low turbo pressure problem

4K views 38 replies 7 participants last post by  85_305 
#1 ·
I have a '99 F350 diesel. I have recently noticed this hissing (turbine?) noise and slight loss of power only when I haul horses (approx 10K lbs). Only when I am accelerating after stopping. 1-2 seconds then back to normal. I have read through many of the posts and found similar symptoms (like that of EBPV) but different codes and I dont want to ignore the signs of something worse. Took it to the mechanic today and it threw two codes. He erased them before I wrote them down, so this might not be exact phrases:
Computer Module KAM Malfunction
Turbo Pressure Low

He told me to take it to a diesel mechanic, but I have to make a 8 hr round trip with the trailer Saturday and can barely afford the diesel. Have to make several other 16 hr roundtrips to Oklahoma in Nov. I'm hoping this truck doesnt break down on me...I am a 30-something girl that knows what all can happen when stranded out the middle of nowwhere...and pulling a gooseneck makes rescue attempt difficult! I have owned this truck since '01, never had this problem before...seemed more common yesterday when I hauled to San Antonio and back. I am planning on baby-ing it throught the weekend, and praying for a safe trip. Any ideas? Should I be worried?
 
#2 ·
It almost sounds like it could be the EBPV but being in TX I wouldn't think it's that cold. What have your temps been there lately?

You can unplug the valve and see if that fixes it. The connector is in the base of the turbo pedistal pretty much right in the middle. It can be a bit of a bear to get to. It's got a metal bail that clips it on to the pedistal connector.

Other than that I'm really not sure what else it could be without looking at it which is going to be a little hard being I'm in WA and you're in TX.
 
#3 ·
No the EBPV won't engage while you're driving, only at idle in N or P. You probably just have a boost leak. Check all the connections between the compressor wheel on the turbo (all the blue/orange boots) all the way to the point at which the spider enters the heads.
 
#39 ·
Didn't read the whole thread, but yes, the ebpv DOES engage while you are driving. On cold mornings I can hear it engage when I'm just cruising at the same rpm. When I let off the throttle or engage it with MORE throttle, the hissing stops. When my cruising speed picks up again, it comes back on until the truck is at the desired temperature.
 
#4 ·
When it rains it pours...
I did make an appointment to take it to a diesel mechanic in the morning...but my truck had other plans. It wont start. Acts like a dead battery, but that is not the problem...been having this problem for the 3rd time in 3 weeks. They think they fixed it...but nope...obviously not! I dont want to bore you with the details as I know this is a diesel forum. All I know is, now I'm really up a creek.

And no... it is definitely not cold here at the moment.
 
#7 · (Edited)
Well the first obvious thing was a loose battery cable, so I made sure all were tight. Then to be sure, I had them tighten them too. The next time it happened, all seemed tight but it did respond to jump start...although it might have started anyway as I will explain later. Batterys checked out ok both times...they again said one still wasnt tight enough...I'm thinking...how could we tighten and retighten several times within a week and it not be tight enough? We also cleaned battery terminals and cables even though no visible sign of corrosion. The clamps are fairly new, the cables are only 1-2 yrs old. But I dont think that is the problem. The odd things that I see going on are:

When I turn my key on, the battery gauge only goes halfway up. At this same time you can hear a little motor running...I always thought this was the glow plugs...as it would stop when the wait to start light would go off. Now it takes longer. And when it does turn off my battery gauge jumps up and I have been able to start my truck. Not tonight. Same thing happening, the gauge goes up...but it still wont start. That little motor keeps running...shuts off for a second, clicks on and off a few times, but when it is off, it still wont start. I tried moving the gear shift around, also tried Neutral...nothing. It draws power, but no turnover.
This motor is in front of the blower for the a/c...cant give a better descrip right now as it is dark and pouring down rain. If I recall it is incased in black plastic. I showed this to my mechanics a few weeks ago...they said maybe my a/c had lost compression, and that it was trying to get it back? Well, that doesnt make sense to me...the way it is acting right now. And by the way, all the time this is happening the a/c, blower, everything is turned off.
And right now, as I am describing this, I am remembering that it acted similar to this (not starting/not turning over) when the cam shaft sensor went out. It went out the first time before the recall. We put several in it before the recall...it kept throwing codes for it...different symptoms every time. Could this one have gone bad? The code said KAM malfunction with a K, so I figured that was something totally different. Also, a few months ago, it threw a code for a speed control sensor...they couldnt get the part quick enough, so they cleared the code. It has never thrown it again. Computers... any ideas?
 
#8 ·
That motor running is probably the vacuum pump. Mine does that too sometimes. The glow plugs don't make noise when they are on.
When they tested the batteries did they test them with all the cables off or were the batteries still connected by the cables? They need to be done completely separately.
The batt gauge would go up when the WTS (wait to start) light went off or when the vacuum pump went off?
p0603 "Internal control module keep alive memory (kam) error." "the P0603 is just a code that can be set when the power to the PCM is intterrupted like unhooking the batteries not a problem code."
Maybe still the CPS (camshaft position sensor). There is a color difference in the new ones and old ones.
Found this - "One sign of a failed CPS is your Tach will not move while cranking the engine over. This is on long extended cranking. Short cranking, on a good CPS will not register either.The Tach gets its reference from the CPS sensor and if its not sending a signal, no tach."
 
#9 ·
Your right about the CPS, but the first time it went out, it would not turn over at all. The next few times it went out, it would turnover a long time and not start. I recall that about the tach. Another symptom I just remembered is that the other gauges (speed) would not work temporarily. I think I remember it doing that briefly once lately. Sorry, I have a bad memory...I have some-timers.
And yes, Vacuum pump, that is what they said. that is what keeps switching on and off tonight. usually it just does it once...but it was fairly irradic tonite. Every time it switched on the gauge was drawn down by about a quarter. The second it goes off...way after the wait to start light, the gauge goes back up to 3/4.
Also, while I was on trail ride this year, a campmover, was too rough with my truck and my ignition went out. Another member had someone in their business fix it for free...could something be screwy and just now show up? Also my gear shift seemed a little looser than normal...and on that subject, a year ago it slipped out of park into reverse and nearly ran over me. Yeah, some people think its time to get a new truck, but normally it runs like a top, doesnt leak or burn oil...no smoke, and after finally needing to put a new tranny in it, I'm getting great mileage...although fully loaded yesterday, I got just under 10mpg. Im around 260K and hoping to double that like my first truck.
 
#10 ·
I've got a problem where if I hit a bump hard enough, the engine drops to idle, the gauges zero out and all the dash lights come on and I'm assuming the computer is restarting. Not sure what it is.
Maybe the batteries are just SO LOW that the vacuum pump is pulling them way down. Might be a short or loose connector for the vacuum pump. Maybe it's goin out and drawing WAY too much power.
Man that's scary.
Sometimes these trucks go through little bouts of problems then are perfectly fine. Once you figure this out, you should be set.
Now it won't start at all right? Or will it crank but nothing else?
 
#11 ·
Wont crank at all right now, but after the vacuum pumps shuts off the battery power is way up there...about 3/4 of the way.
And also to answer the other question about the batteries. It happened in Dallas last time...on a Sunday...they did not unhook them to test them even though I argued with them about it...I knew then I was dealing with idiots. When I got back, my mechanics unhooked them to test them and both tested good. They are a year old...still under full warrantee.
Yes, I am thinking the same thing. I dont think that vaccuum pump should draw that much on the battery...pretty substantial, but I have nothing to compare it too. Next time you start your truck and it makes that noise, see if you see a huge gain in battery power when it shuts off. Come to think of it, it seems to use more power to run the pump than it does to start the truck...that cant be right.

But if I can get it to crank, it usually starts. I will see if battery cables help in the morning.
 
#12 ·
As much as I love my truck...the only thing I cannot defend is the electical system. It has given me hell since I got it. But luckily it has been minor things so far...stuff I can live with. My 97 F250 I had previously, was a different story. I owned it for 6 months and it was in the shop 12 times for computer problems...under warrantee, but basically I was paying a hell of a lot of money to drive a rent-a-car. It almost ruined me on Fords! But I had too many good times in my '84 Bronco to let that happen. Not to mention our 1923 Model T. Luckily, I found this truck.
No the truck wont crank...can hear the ignition work, but the starter is not engaging.
 
#13 ·
I replaced three sets of batteries and three alternators and a batter cable before it all finally worked out. A lot of ppl have to do that sometimes and I'm not sure why.
What you can do is just unplug the vacuum pump. No reason it needs to be plugged in to start.
I hate having to just help people online. Always wish I could be there and try to actually fix it myself. That's why I wanna be a diesel tech. So if for some reason you ever get to Lubbock and it does it, let me know and I'll come check it out :hehe:
 
#14 ·
Thanks so much for all your help. About the 20th time I tried to start it, it had no draw...and what do ya know it started! Headed back to the mechanic. Seems they never checked to see how much voltage the starter was pulling when I had this problem the last two times! Seemed kinda logical to me...having had this problem with the Bronco...got a whole checklist in my head...but I try to let them do their job. Yes, nothing in my life is more important than the guys that work on my truck and the guys that work on my horses... they can make me successful or they can make me into a failure. Thanks again!
 
#18 ·
Update... Well got the new starter. Got a new KnN filter...cause 8 yrs was apparently enough for my old one...but with it breathing better, the noise only got worse, and more consistent. I then realized it happened when my automatic transmission shifted from 2rd to 3rd gear. Rechecked the fluid when it was cold...it was low added a half a quart at the auto shop...and we both thought we actually overfilled it. Had the trailer on it to take it to the transmission shop that put it in last year. Checked it again...still low. He said you have to look at the lower level fluid mark...but every time he stuck it back in it registered different...til he was frustrated. Can't they make a better dipstick? I don't ever remember having any problem reading a Trans dipstick in the past. I guess that is why this got by not just me but everyone that has worked on my truck in the last few months. Don't see a leak, so it had to be a slow progression. I guess some of the problem could be splashing from the vibration of the motor can cause it to read higher than it truely is. But bottom line...we put about a quart and a half in plus the half quart I had put in that morning. The truck drives perfect now...of course who knows if I did any damage to it while it was low. The manager of the transmission place was apparently upset with the mechanics honesty of telling me that I might have gotten lucky. He of course told me that I have to bring it back immediately...that something is definitely broken inside there...that it has definitely got to come out! Well, I couldn't run away faster.

So what now, oh wise ones? Do I drive it a while and have the transmission serviced (not flushed) or do I just keep driving it. I have always serviced my transmissions in the past, but alot of people don't even believe in that. I have put about 51K on this transmission in a little over a year... I didnt realize I had done that many...and have done it every 25K in the past.
 
#19 ·
Uh K&Ns aren't too good for these trucks. Some people say they are ok but there's a lot of people who have run them then had compressor wheels dusted and some engines too. Might wanna think about a different filter.
What kinda noise is it making again?
I would probably drop the trans pan and filter and just see what kinda shavings you have in there. If it's a lot or really big pieces, it's a problem. If not, should be ok. Fresh fluid never hurts.
 
#20 ·
What air filter options do I have? The one that the powerstroke repair shop showed me was a little more than I wanted to spend without knowing that was the problem. It would require a modification. I have had pretty good luck with my KnN as compared to the horrible design of the factory models they made for my truck manuf date 4/98. My friend has a later 99 and they corrected the problem, with a different design. The KnN was the only filter I knew of that would fit my truck as is. After I deal with the transmission issues, I would consider other air filter options...but right now I kinda want to hold onto my pennies. The proble/noise was only when pulling a trailer...going from 2nd to 3rd...started out just an air blowing type sound...not a whistle...then in the last day or two developed into a noise similar to touching some plastic to a grinder for 1 second and then it was gone. I will do the service next week. If it ruined it is already ruined, and I want to make sure I take it to the right place. I dont want to burn the bridge with them as they are the only ones that offer 3 yr or 36K warranty. I really need that many miles to see if it is gonna be good. And if all of this is because of low transmission fluid...then I can only blame myself.
 
#22 ·
Its a drop in air filter - rectangular in shape with the pleated, oiled filter material. The factory ones had an additional layer of foam that would get blocked up in a week of driving down my dirt road.

I would have to say that the noise was definitely coming from the transmission...and after putting 2 quarts in total...it is not making the noise anymore. I guess it was grinding or slipping, although it was shifting perfectly smooth...it was like it was backtalking after the shift was done.
 
#23 ·
#24 ·
Yesh, that sounds great! Now who can I get to put that on. I don't suppose the tranny shops would use those, especially cause they wouldn't get as customers returning as often. I would ask that powerstoke shop, but they are so high priced on everything. Gonna have to do some checking around. So I would preferably do that at the same time as I get my transmission serviced, or can it go on anytime thereafter?
 
#25 ·
I'm not sure how much you can wrench, but that shouldn't be too hard. Bolt it on, run the lines and hook em up. You can call them there at Dieselsite at their toll free tech line and ask em how to install it. I think his name is Bob. Lots of people have great stuff to say about how helpful he is.
Sooner is always better than later but anytime would be fine.
 
#26 ·
I used to work on the old Bronco,,,but have done very little to my diesel trucks. I have gotten spoiled in relying on others. And goteen scared of screwing something up. But gosh it looks really simple.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top