Over the past few weeks I've noticed that my truck is running a little less boost and a little more RPM at highway speed- 65 mph on the speedo used to be around 3.5-4 lbs boost and 1600-1700 RPM, now I'm down around 2-2.5 lbs boost and 1700-1800 RPM at the same speed. My first thought was up-pipes leaking, but I haven't checked them yet. I can still build good boost, towing the 3 horse bumper pull trailer with 2 hay burners in it up to WA I set the CEL for overboost about 1/2 dozen times at least. Is there anything else I should be checking? FWIW, I pulled the trailer with hayburners for about 400 miles and ran with no load for about 250 miles and averaged 12 mpg. Yes it's low, but when I was pulling the trailer it was a lot of climb/fall and accelerating (curvy **** road) and I wasn't exactly easy on the go pedal.

 

Check for the basic stuff first like leaks. After that, it's gonna get tricky.

Heck, my last episode with my truck turned out to be a bad alternator. Go figure.... anything is possible with these trucks.

 

i dont know man thats what im seing on my stock setting. but i have 6637 and exhaust im runnin 2.5 cruisin at 60

 

I checked it out last night and I'm not too sure but I might have a slight leak where the up-pipes meet the baby's butt. I'll try and get pics tonight.

 

Chase-

I'm running into the same issues on my truck. I noticed it running empty about a month ago. Boost is running lower than normal, and rpm's at highway speeds are up 200-250 or so.

I'm pulled all the intercooler pipe boots as well as the intake boots under the y-pipe. Cleaned everything really well and reinstalled, but no change in boost. Up-pipes are not leaking. I CAN'T FIGURE IT OUT!!! I talked to Brian at BTS quite a bit and he thinks the rpm thing is the torque converter. He thinks the TC is not fully locking up or as he said, "It's pushing through the converter."

I've replaced the filter, fluid, flushed the system of old, and it's slightly better, but still not right. The next step is to replace the converter, which I plan on doing within the next month or so.

Brian doesn't know if the boost and rpm issues are related, or just happened to present themselves at the same time.

If anyone has any ideas for Chase or myself, I'd gladdly hear them!

 

I don't know anything about the auto's, but I'd be interested to hear if the new torque converter fixes your problem.

 

Crap just what I wanted to hear (and was fearing)... TC taking a dump. Wifey's gonna love this one!

 

That made two of us. I'm hoping that is all it is. Like Brian said, if you catch it early enough, then all you have to replace is the TC. I want to get a fully built BTS but don't have the money right now. Don't really want to put alot of money into a stock tranny, but don't have a choice.

He said to get a stock ford tc so that's what I'm going to do. My thoughts are if I have to put $500-$700 into it now and it gets me by for another 40K to 50K miles, then it's worth it. That way when I want to and can afford a BTS, then I can do it.

 

Read this thread initially and thought the same thing. When cruising at highway speeds (65) the converter is locked. The low boost shouldnt affect the rpm's as the rpm's/converter is directly related. The only way your rpms would increase is if your slipping the clutch in a 6 spd or the converter is going. The only way it would be related to boost is with the converter slipping, your egine would see slightly less load, and therefore decrease your boost ever so slightly. That make sense? haha i'm almost rambling, but i can clean it up

 

Makes sense to me Will.

 

Today when I was driving to work and back I can't be certain, maybe it was paranoia, but it seemed to be shifting harder than normal. Not bad hard (yet) but harder than it normally does. It might be time for a 6leaker TC I think I have a few extra $ from my b-day I was hoping to spend on a leveling kit but it doesn't sound like that will be happening. I guess I'll start rodding the shizz outta it until the TC fails.

 

That does make sense and I was thinking this might be taking place. Only way to know for sure is to change the converter.

Be careful, you don't want to rod it too much and end up shelling the whole tranny with pieces of the t/c when it goes. If larger metal shavings get into your valve bodies and into the internals, then that could spell disaster and you might be spending alot more than just a few hundred for a t/c.

 

I was in somewhat of a bad mood when I posted that last night I posted this on another site just for giggles and the first thing anyone said was "TC slipping" but he had a good point- if it's slipping my trans temp gauge should be showing it in the form of high temps which it hasn't. I'm going to call or email Jody on Monday and see what he thinks.

 

No worries! That's one of the first things Brian asked me about also was if my temp gauge was running high. But it wasn't. He still thought it was the t/c getting weak though. So I guess we'll see when I replace it.

Let me know if you find out any different from Jody.

 

When do you plan on replacing your TC? I'm curious if it will solve the problem for you. If it does, I'll probably try to convince wifey to let me buy a 6 leaker converter and a VB so both can go in while the trans is empty. Her Exploder got tires today, now it's my turn again