High EGTs at idle
 

First of all, I would like to say, hi, I'm new here. Been a member over on the TDR for several years now, thought I would come over and check this site out. I also have a problem.

Whenever I fire up my truck, EGTs jump almost instantly to about 400 F. This has been going on ever since I put in the pyro, before all the mods. Also, when I go to shut her down, no matter how long I wait, EGTs will NEVER fall below 450-500 F. My operating EGTs are also high. Very mild acceleration will net me 800-1000 F unloaded. Crusing EGTs at 70 mph, 5-8 psi of boost is 800-1000 F unloaded. If I get in it, I see 1200-1300 F in about a second. Also, going up a mild hill, I can see 1200 F at 45 mph unloaded even with OD off and TC unlocked.

I figured it might be a problem with the pyro, so I sent it out to autometer to have them look at it. They said it was fine and also shipped me a new wiring harness with probe. I also checked for torn intercooler boots, etc., for somewhere were boost could escape, everything looks alright. Although, my thoughts are that it wouldn't really be a boost leak because it wouldn't effect my idle EGTs since I shouldn't be making boost at idle?

Any ideas??

:humm: maybe your intercooler is clogged up with crap from the blow by tube...if you turn off you a/c will it drop down to 300-400 range at shut down

Mmmm...interesting...never thought about the intercooler. How could I clean all that out? Also as far as the A/C thing goes, that is with it off. With the A/C on, it won't go below 600 F!

my brother in laws truck was doing that but i found his exhaust brake was sticking blocking exhaust. i didnt see were you had ex brake but make sure your exhaust is free.

the best way to clean the IC is to take it and the radiator out of truck and power wash it just dont get super close and blow a hole thru it with the water pressure...and like Pap said make sure no part of you exhaust is clogged

Well, I have no exhaust brake. I'll check the exhaust, but when I put the pyro in, I still had the stock turbo/exhaust, so everything's been replaced. I'll take the IC out and wash it this week. I still have the fuel heater bowl in the truck. Could an air leak into the fuel system cause high EGTs??? :humm:

How is your idle? I know when my truck would idlw at 900-1000 RPM I would get teh same thing

check for any boost leaks, and I assume you put the pyro before the turbo?

Are your ddp dv's full cuts?

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your sure timing is still at 17*?

My idle is generally low 700-800 RPM. I've had it higher, still the same problems. I'm building a rig to test for boost leaks. Pyro is pre-turbo. DVs are not full cut. DDP claims 20 more hp, less smoke, less EGT over 191s.

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As for timing...pretty sure it's still at 17. I set it, and then checked it a week or so later when I thought I was having hazing issues, still dead on. Might check it again, just to be sure.

there 022's then

I would recheck timing just to make sure, have you checked the easy stuff like air filter and exhaust for restrictions?

what washers did you put in when you swaped the injectors?

The washers I used were whatever came with the injectors.

air filter?

Not sure my brothers 12v runs about 300 deg at idle

400* is a warm idle. i set about 300-325. check the air filter check in and exiting air flow

Are you running straight exhaust or is the cat still on? If the cat is still on it might be clogged so you might try a delete pipe or a temp removal to see if this helps. What gets me is jumps high as soon as you fire the truck.

The air filter is a K&N kit, looks pretty clean. I may start it up and let it idle without the filter just to see if that would help. Exhaust is a straight pipe all the way back to the stacks, and it feels like I'm getting good flow out of both of them while the truck is running.

check you valve lash?

Hadn't even thought of that. I'll do that and see what comes of it. Thanks!

I hope thats it my next guess is cam/ lifter issue

ya thats wierd mine is at 250 at idle started when cooling down i have no problem hitting 250 again to klill the truck

Well, I'm gonna head over to my shop today, I'm gonna check the air filter/exhaust for restrictions, check/adjust my valve lash, and mess with my starwheel and AFC housing a little bit.

the afc and starwheel are not gonna help your hot idle issue

Someone suggested the AFC thing to me, and it made sense when he said it, but now that you mention, it makes sense that it wouldn't too.

the acf will make a difference when you hit the pedal but not at idle ... how was your valve lash?

I know that when I bought my EGT gauge it was matched to the thermocouple. I wonder if you have the right thermocouple to gauge setup. I know the vendor sent you another but how did you check to see if it was somewhat accurate. You could always bring some water to boil and put the thermocouple in the boiling water to see what the gauge reads should be 212. This is not for complete accuracy but should be close.

some one may have put something in each of your stacks, bot enough to keep it from running, but enough to cause restriction. just a sugestion. hope ya get it figured out. u didnt cut the excess off of the pyro line did you?

Unfortunately, didn't get to the valve lash today, a buddy conned me into doing his brakes so he could pass inspection. Gonna get to it tomorrow.

Relay93: Good idea on the boiling water thing, never thought of it. I'll have to give that a try too.

Stacks look clear, still blow out plenty of smoke. I also left the 100 extra feet of pyro probe wires intact.

100 feet?

Im sure it was about 200 feet he is just being modest

Yep, you got it! Ok, maybe I was exaggerating a little. :w2:

did you just hook up that pyro

No, I put it in a few years ago, sent it off to autometer, and reinstalled it about 6 months ago or so.

So, checked the valve lash today. Couple of the exhaust valves were a little loose, so I tightened them up. Started up the truck, pyro jumped to about 200 and then went up slowly to a little over 300. Drove it around, all my operating EGTs seemed about 100 degrees or so lower. Parked the truck. Let it idle for about 10 min...won't come down below 450. Took the air filter off, no change.

Did you send the gauge and the thermocouple probe or just the gauge?

I would check the lash again if its off I would pull the push rods and make sure there not bent then I think your gonna have to check the cam/lifters.

I sent just the gauge in, but when they sent it back, they included a brand new probe as well.

I was thinking it could be a bent pushrod. I take it to check them, I'm gonna have to take the rocker pedestals off? Also, while checking the lash, I noticed that the rockers kinda slid back and forth on the pedestal shaft (I think that's what it's called). Is this normal?

I thought the lifters were solid? I guess I don't understand the bent push rod other than not enough lift of the rocker to operate valve properly.

yes you have to take the pedestals off to get the pushrods out. with the head bolts and that other little bolt the pedestal should not move and the rocker arms should move a little side to side but not foward and back.

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the lifters are solid but if there wore your not gonna get as much lift as you should.

thats right, if you don't have the right amount of lift your not getting air therefore running hot

Dave where is the EGT probe installed? Could the probe be installed to deep and resting on the exhaust manifold? Do you know anyone with thermal scanner to see if you have one cylinder that is hotter than the other?
Just some more thoughts and easier to check.

Good Luck.

I would think if it was not getting enough air on the intake side would cause that cylinder to be rich. Would one bent rod cause that much heat?

So, the rocker arms have play back and forth like, towards the front and back of the truck, but they don't move from one side to the other. What type of lift should I be getting at the rocker arm on the pushrod side? Like if I put a dial indicator on it to verify lift? Also, since the lifters are solid, I take it the only way they would go bad is if they are just worn down. Is this the same for the cam lobes as well?? Thanks for all your input so far guys! I appreciate it.

I have no idea where his is installed but mine is right before the turbo twords the rear 3 cylenders ( because they run hotter then the front 3). I used a heat gun and shot my manifold to make sure there about the same.

The reason I think its a pushrod/cam issue is because he set the valves and made everything better, ran it and I slowly got worse thats why I think when he rechecks the lash its off again.