Higher than normal EGT's

[PVanderlugt]

Hi Guys, Pete here in NW Ohio,
Haven't been around in a while, but I still have my good old trusty '02. Have 185K miles on it by now, and really no major issues, other then trying to stay ahead of the rust.. Truck has RV275 injectors, an old Smarty on level#3, Goerend build transmission and an Airdog fuel pump set at 15psi..all these upgrades have been on the truck for 125000 miles with no issues.
So the problem I have now is that my EGT's are about 100-150 degrees higher then what I am used to seeing, and the boost is a couple pounds lower then usual, in relation to Throttle position. I used to almost never see 1000 degrees (no load) and now can hit 1100-1200 pretty easy.. My first thought was intake leak, but I made an adapter and pressure test with shop air, but all is fine with 30 psi test.. also did a propane sweep of the intake system (presume it runs a vacuum at Idle), all seems tight.. Turbo intake wheel is nice and tight.. no codes stored..
The Turbo is a rusty mess, and I know the wastegate has not moved in several years, but I can control max boost with the foot pedal pretty easy... Removing the Turbo, the elbow and the downpipe is going to be a major project if needed.
Anyway, any thought on what can cause a sudden rise in EGT's??,
One Other thought I had was, Maybe an injector that is not spraying quite right? and the fuel is still burning on the way out the cylinder, causing the higher temps?
Or maybe the EGT probe burned off, not sure if this would cause a high or low reading?
T wheel in the turbo burned off? really haven't done anything or ran any high temps.. very seldom tow, and mostly highway miles to work..
Problem is, like said, everything is a rusty mess (thanks ODOT) and trying to get stuff off, means stuff is going to break...
Anyway, would appreciate any thoughts and suggestions on what could possibly cause this..
Thanks for your time
Pete

 

[KRSmitty]

Done an upgrade to your Smarty lately?

Had a Smarty Jr. on my '07...after doing an upgrade I noticed my EGT's jumping up around 100* over normal. It took me around a year to figure it out. Even setting the tuner back to stock did not help. I had to got get the ECM reflashed before the EGT's went back to normal.

 

[PVanderlugt]

Well, managed to get the turbo off without breaking anything, a little patience goes a long way!!
Compressor wheel and T wheel in good shape, very little play in the bearing.. Wastegate was indeed frozen in the closed position, but managed to get it freed up, overall looks to be in good shape.
EGT probe looks good, But I will get a new one anyway.. I guess I will swap injectors next, see if that does any good..
Couple of questions,
Is the hardware on the turbo anything special? need some new bolts for both the downpipes and the exhaust elbow, Can I use stainless or some plain old grade 8?
Can the Injection pump go out without throwing any codes? any way to check?
What would be the symptoms of a faulty injector? I only have a little higher EGT's no smoke or other symptoms..
Thanks
Pete

 

[KRSmitty]

I assume no on the smarty upgrade?

 

[PVanderlugt]

Done an upgrade to your Smarty lately?

Had a Smarty Jr. on my '07...after doing an upgrade I noticed my EGT's jumping up around 100* over normal. It took me around a year to figure it out. Even setting the tuner back to stock did not help. I had to got get the ECM reflashed before the EGT's went back to normal.

Had the Smarty set on #3 10 years ago and never touched it again, all the other upgrades at the same time, have had "0" issues since engine wise.. This issue started out of the blue without anything precipitating it..
Pete

 

[KRSmitty]

Had the Smarty set on #3 10 years ago and never touched it again, all the other upgrades at the same time, have had "0" issues since engine wise.. This issue started out of the blue without anything precipitating it..
Pete

Just to make sure we are on the same page. When I say upgrade...I mean a software/firmware upgrade to the Smarty unit itself.

 

[PVanderlugt]

Just to make sure we are on the same page. When I say upgrade...I mean a software/firmware upgrade to the Smarty unit itself.

Nope, Smarty is as the day I got it from Bob, back in '06... no updates in any way..

 

[KATOOM]

What brand are your gauges? I would have suspected a faulty pyrometer or thermocouple first since that happened to me years ago. EGT's were higher than normal under the same loads. My pyro is electric through an amp box and after testing to identify the culprit, I replaced the box and the thermocouple. But you mentioned the boost is also lower relative to the increase in EGT. That would have me thinking that there has to be a boost leak somewhere. But if your leak down test is good then that's odd.

An injector could cause an increase in cylinder temperature but with a laser temp tool you would be able to identify the hotter running cylinder. I'd definitely try that before pulling perfectly good injectors.

Also, if you did decide to pull the injectors then definitely dont pass up a compression test just to be doubly sure.
That said, have you ever checked the valve clearance? If not, thats something you should do at usually around 150k miles.

You could also check the exhaust manifold for cracks since that will reduce drive pressure. Not sure how much it would show up on a boost leak test though...

 

[PVanderlugt]

Thanks for your reply Katoom,
My gauges are Isspro, and a Thermocouple EGT probe is on order.. It was on the list of things to replace.
Taking the Turbo off was not a total waste of time, since I have been meaning to "unstick" the wastegate anyway and was a good way to check and inspect things, the Turbo itself, and the Compressor and T wheels look great.. Bearing has minimal play in it.No cracks or other exhaust leaks noted around the manifold area
I did just make an 2nd adapter to check for boost leaks, and there are none at 35psi.
Plan is to put the turbo back on, put in the new EGT probe and go run it for a bit, see if anything changes.. this will give me an opportunity to check the exhaust manifold temps for possible injector issues. If no change, I will pull the valve cover and get the injectors out, see if anything obvious. This will be a good time to do a compression check and do a valve inspection and clearance check(never been done).
To me, everything screams intake leak, but I sure don't see any, Intercooler hoses are nice and dry, no oil leaks from the turbo.
Will come back with more info and/or results
Thanks
Pete

 

[KRSmitty]

May want to try a ECM reflash...what fixed mine. But, it was due to different reasons it sounds like.

 

[PVanderlugt]

Well, thought I would report back,
I did check the individual exhaust ports with an IR temp gun, and they all read pretty close, what leads me to believe the injectors were doing OK, at least at idle.
Ended up replacing the thermocouple style probe for the Isspro Egt gauge , and that fixed the problem of my high temperature indications. Was kinda weird the way it failed, it would indicate almost correctly at idle, but started reading increasingly much higher as the temps went up. Not sure about the boost, seems normal now, and reads pretty close with what the OBD2 reader shows..Maybe it was my foot taking it easy with one eye on the pyro.
Anyway, Turbo wastegate all freed up and working again, probe was only $50.00 from Geno's, did get the stuff to do a valve clearance check, things seem to be under control again.
Pete