I've been fighting high egt's for the past 6 weeks, I'm just about sick of this thing... Thought I had it fixed a couple times for sure.

2 months ago I upgraded the compressor wheel. It soon after lost the shaft seal and the new wheel slowly ate into the housing, think lots of aluminum dust, no chunks as far as I can tell. It was in the midst of the wheel trying to gnaw a hole through the housing to find freedom that the higher egt's started.

When I installed the kc38r I cleaned out the intake tube, installed new filter, cleaned the intercooler system out really well.

It runs pretty good, the boost psi is lower than the old setup, but it sucked the filter minder clear shut on the intake, something the old one never quite did even with the old filter in it, so it's flowing more air, just less psi, I'm assuming because everything is unrestricted it flows out easier. I've remedied the intake situation and the minder doesn't get sucked in now. However, I'm fighting egt issues. I'm running my lowest hp tune which I believe is 60 hp. I've even removed the chip totally and still running into egt's.

We pulled the camper about 500 miles this weekend, and I made about 7mpg... Used to be 10 or a bit better.

When I put it all together I ran a boost leak test and had no leaks that I could find. I've run the test several times since including just today. I can't find anything leaking except the sensor on the intake manifold bubbles just a tiny bit. How hard is it to locate leaks on the intake plenums? I sprayed it pretty good with simple green, and used a mirror in the few spots I could get access to see the bottom side of them. I'm just not sure that they aren't leaking where I can't see. Would they possibly leak more as the engine gets up to temp? Seems like when I first start driving, before everything gets heat soaked, that my boost is higher, and egt's lower.

What I've done that at some point along the way I thought for whatever reason might fix this,
1. changed oil, at first I thought it had helped but I think I just tested it with a trailer when it wasn't hot yet and thought it had helped
2. changed cps today and cleaned ebps tube and sensor,,engine might be a bit quieter, and it seemed better, but I was running empty.
3. tightened all the boots

Oh and another reason I wonder about the intake plenums, I keep finding the intake boot is oily, as is the first boot out of the turbo going to the intercooler. The top front of those two boots remain dry, I can't really figure out a directional pattern, but the other boots are totally dry, yes including the plenum boots. Last week I routed the ccv out the back, and cleaned up the boots, so the oil isn't coming from the ccv. When I run my boost leak test I think I can hear some air from the driver side, but it really just sounds like the air is moving through the turbo system a bit. I guess I should have plugged the ccv for the leak test. Should mention that the boots are 1 year old from Riffraff.

As you can tell I'm at a real loss here and I would appreciate some help. I'm pulling that camper a couple thousand miles in a few weeks and the trip will be miserable with the truck behaving like it is.

 

More air pumped means more PSI boost, plain and simple. Sucking in the filter minder means you are at least getting 20-25 PSI boost with a stock air box, and 30 PSI with an AIS. If the filter minder is pulling in and you're not getting that kind of boost, then you are loosing air somewhere. The plenums are a good place to look, but don't overlook a loose wastegate. Have you done the red line mod?

When I found my plenum leak, it would "fart". Meaning... the pressure would build to a certain point, then let go and not rebuild pressure. When I did my leak test, it made very little bubble activity next to the the 3" intake - but a leak is a leak. Changing to the billet intake plenums with the O-ring seal put an absolute end to leaks there, and my concern of a repeat.

 

As far as the AIS goes, I switched to a 6637 and the egt's were still present. I hated the sound of a hurricane under the hood, so I drilled the hole in the side of the AIS for the fender mod. Now it doesn't suck the minder in so it seems to me like it's getting enough air.

At this point I'm desperate enough to switch to the billeted o-ringed plenums, but time is short and they've been showing out of stock for well over a month. I'm not totally certain yet they are leaking. Since I've eliminated the ccv to the intake, does the fact that there is what must be a real fine oil mist present on the driver side mean that the plenums could be leaking? I've never been under plenums but I'm guessing that there is a source of oil there that could find its way out if there was a boost leak?

 

Time to do a compression test, a weak engine can cause high egt.

 

This is my fear. When my turbo went(6yrs ago), I have yet to find the missing "pop" in my trucks' step. Like the OP, only thing left to change out IS the plenums. Recently just added the bellows and still seeing same # results....feel your pain, bro. I'm in my egt gauges more than the road, and it gets tiring/old really quick.

 

Are you still running the OEM up-pipes? An exhaust leak before the turbo can skyrocket EGTs and drop fuel mileage.

 

No I have bellows. I have checked and there is no soot leaking anywhere.

 

Since the KC38R is new, I would not suspect any of the seals or rings in it are bad.

What process did you use to "clean the intercooler system out really well"?

Did you suspect there was a blockage or was this a shot in the dark in order to find the cause of the high EGTs?

As Rich said, a leak is a leak. The sensor on the intake is most definitely not your problem, but it certainly is not helping. I would seal that thing up and move forward.

Clearly all of your clamps are tight, or they would have blown off, but check them again.

You didn't mention what injectors you are running and how many miles are on them.

What was the PSI before the original turbo wheel upgrade, after the original turbo wheel upgrade and now with the KC38R?

How are you measuring boost, mechanical or electrical gauge?

Which KC38R housing did you get, the 1.0 or .84?

We will find the problem, stick with it and keep us posted as things progress.

 

I used simple green in the intercooler with water, multiple soaks and flushes. Cleaned out all the intercooler tubing. Did this mainly to clean any grit out of it since the old compressor wheel ate into the housing and presumably sent specks of aluminum through. I wanted to get as much as possible out so it wouldn't do any further damage.

I'll replace that sensor as it is the sensor itself leaking and not the threads. It's really small leak.

I've definitely checked all the clamps and tightened them up.

Stock injectors, 105,600 miles currently.

It was running 23-24 psi with the stock wheel and the ats housing. The billeted wheel for ported housing ran the psi up some, I tried not to push it past 25 because it was setting the check engine light. When it hit a shift it could shoot the boost number a couple and I saw 28 or so a time or two but I never pushed it to see what it would really do. Obviously it was enough as it blew that seal out. (I also wonder if higher psi made a leak in the sealant for the plenums, not that it shouldn't have been able to hold more) By the time I put the code eliminator on my psi was already running lower with that wheel, because the shaft seal was gone and letting things get nasty in there.

Right now conditions have to be just right to hit 25psi, and when it shifts the pressure drops pretty good, immediately.

It's a mechanical boost gauge. It reads pretty consistent with my air regulator when I'm running the boost test.

Got the .84 housing

Appreciate all the help I can get!

 

Whenever the turbo is R&R'd it's easy to misalign the baby's butt to turbo connection. That will cause a leak that spikes EGTs. To borrow Rich's term, I have that t shirt. Get a good look at the marmon clamp there to ensure it is aligned properly. Reach back there with the cell phone and get a few pics.

The 25 psi you're seeing kinda indicates against a leak there, but IMO it should be checked to rule it out.

 

David stole my idea...try what ^ he said.

 

I've looked back there from the bottom as well as I can and from the top with a mirror, I don't see soot so I'm guessing it's snapped in correctly?

 

I've been trying to find a Ford part number for that manifold air intake sensor. Anyone know it? I can get one down at Autozoo, prefer oem though.

 

I had mine on crooked for several thousand miles before I figured out it wasn't seated all the way. The clamp will still tighten down and look right...but it isn't. Biggest clue for me was the faint odor of exhaust coming in the vents when sitting and idling.

 

So what tune are you in when you see the high EGT's? Are you towing and a high HP tune? Higher then normal is normal with that type of usage.