Normal EGT?

[ISX]

Truck rolls too easily to have a brake dragging, although I will check each wheel. I will suggest some hypothetical reasons for my problems and tell me if I am crazy. I will also try to load a cruising video, not on a hill. Exhaust turbine is damaged in turbo, causing it not to spool very well unless large amounts of heat/exhaust flow hit it. Intake turbine seems fine with little to no end play. New injector/s is bad, not creating an effective spray pattern/ dribbling fuel. ( in my 24 valve I had a bad injector/s that caused huge amounts of black smoke under load, no power, and no boost- changed injectors and vast improvement in power and milage) is my reasoning behind this Could the fuel plate being all the way back be doing something causing load? Could exhaust manifold be plugged? Could timing being too high/low cause this? I seem to have had several issues after timing change, could too much timing cause high EGT. I may be paranoid, but I requested the timing change at the diesel shop to 15 degrees, when I got my ticket it said "incease timing 15 degrees per customer request", I questioned the shop manager about this and he said it was only taken to 15 degrees. I then had the timing checked at another shop who checked it with timing light attached to the #1 injector line, they never pulled the injection lines, they said it was at 15 degrees. The truck does have a lope when dropped into gear when cold, no lope once warmed up just a little. Could valve lash being out cause this? You were pushing like 2 psi at 500 degrees, I don't build practically any boost until 600 degrees. I can also be running along at 55 at 600 degrees with 4 PSI, hit a small hill, go up to 700 degrees and not have boost change at all. What do I need to take loose to see the exhaust turbine to inspect it? Sorry about dragging this on, but I really appreciate the insight.

The timing thing is really the only thing that seems to be the culprit. My turbo shaft is actually brand new so it spins a little better than usual. Over time they get a little oil coking on them and it might not look like much but when you talk about something spinning 100,000RPM it starts to really have an effect. Not too much but down low it seems to spool better. Set your valves a little tighter, such as 0.017 exhaust 0.008 intake. The thing about timing making it have issues is what really interests me. Is the EGT issue the only symptom that happened after the timing was changed? The fuel plate limits fuel, I have NO plate/starwheel/anything and I run cooler than you.. That stuff is more of a "governor" for fuel. They actually have NO function on the truck itself if you drive it sanely. The AFC is there only when you have less than 5psi of boost, it limits the fuel so you don't smoke up the road. After 5psi it assumes you have enough air to burn all of the fuel, so it gets pushed back, past the fuel plate, to which point the fuel plate becomes the limiter. It again is only used if you are really getting on it, but it is more there to control power so you don't burn up a stock clutch or ruin the stock automatic trans. In other words, it has no effect on everyday driving EGT's, it just stops the fueling to prevent too much power. Tell me more about the symptoms that changing the timing had.. Its really the most viable culprit at this point. I have had the timing way out of range and it had similar effects.

[texas503]

The issues I had after the timing change were not huge, but noticable. White smoke at idle. Greyish smoke when getting on it.Harder starting cold, even like 50 degrees, truck would try to die just after starting. (This has improved somewhat with new injectors.)Lack of low end power, and I had not started tinkering with starwheel before timing change, so power difference might be even bigger if I had. (Has improved somewhat with new injectors.)Engine is alot louder, does not have the smooth 12 valve sound. Has a valve rattle sort of sound.Exhaust (unburnt fuel) smell in the cab when parked idling, or at a red light. If I put my nose right to the exhaust at idle it kind of burns my nose and eyes with the unburnt fuel, I don't know if that is normal- wasn't with my 24 valve.I did seem to get more top end boost after the timing change, but looking back at it, the negatives have not been worth it. The only reason I did it was, with the 24 valve, the "timing box" that I had on it made a huge difference in power, but I now know it is like comparing apples to oranges. I did not gain any real power that I could tell, and did not improve fuel mileage noticeably.I just checked the brakes, no drag what so ever.

[ISX]

The issues I had after the timing change were not huge, but noticable. White smoke at idle. Greyish smoke when getting on it. Harder starting cold, even like 50 degrees, truck would try to die just after starting. (This has improved somewhat with new injectors.) Lack of low end power, and I had not started tinkering with starwheel before timing change, so power difference might be even bigger if I had. (Has improved somewhat with new injectors.) Engine is alot louder, does not have the smooth 12 valve sound. Has a valve rattle sort of sound. Exhaust (unburnt fuel) smell in the cab when parked idling, or at a red light. If I put my nose right to the exhaust at idle it kind of burns my nose and eyes with the unburnt fuel, I don't know if that is normal- wasn't with my 24 valve. I did seem to get more top end boost after the timing change, but looking back at it, the negatives have not been worth it. The only reason I did it was, with the 24 valve, the "timing box" that I had on it made a huge difference in power, but I now know it is like comparing apples to oranges. I did not gain any real power that I could tell, and did not improve fuel mileage noticeably. I just checked the brakes, no drag what so ever.

This whole time you have been saying it runs perfect and barely smoked but the usual bit when you floor it... That thing is way advanced on timing, just like I suspected. When the timing is advanced really far, it is set up to be efficient at high RPM, and in your case it sounds to be over 20* advanced. The low power will suck, it will smoke, it will have no boost, it will knock like a 24V... It has no efficiency down in the lower RPM. At cranking RPM you might as well forget about it starting because the engine is cold and it is injecting way before the piston hits TDC so there isn't near enough heat built up yet. Ideally the engine should be around 0* while starting, maybe 8* idling, and around 14* at 2000RPM, maybe 20* at 3000RPM. You advance it because the engine moves so fast that you are trying to beat the fuel delivery delay so that it detonates right around TDC, hence the reason you have to keep advancing it for higher RPM. Sled puller trucks running over 4000RPM are running into the high 20's* with timing. The injectors being bigger spray a little bit bigger droplets which take longer to absorb heat and combust, retarding timing (helping out your overly advanced situation). Did the timing light guys mark TDC on the damper or put timing mark tape on it or did you not get to see it? I'm just wondering if they just "told" you it was at 15* to get your money, cause that thing is way too advanced. A true 15* setting would make the truck start fine and it would really be just a tiny bit different than stock. Here is mine when it was over 20* on a 56F morning start..

http-~~-//www.youtube.com/watch?v=DLfiWV2Tg7g

[texas503]

Well in my defense, it does run O.K., but I guess it takes quite a bit to make a cummins run badly.The damper was marked before the timing light guys checked it, so they just used that.Why would advanced timing cause high EGT's? Is is just because it can not build the correct amount of boost. I am going to have timing reset to stock which is, I believe 14 degrees if I am reading it right on the badge. I won't be able to do it until next week, will let you know.I thought you were running 14.5 degrees of timing, and I now see 13.5. Is that right?Thanks

[ISX]

Well in my defense, it does run O.K., but I guess it takes quite a bit to make a cummins run badly. The damper was marked before the timing light guys checked it, so they just used that. Why would advanced timing cause high EGT's? Is is just because it can not build the correct amount of boost. I am going to have timing reset to stock which is, I believe 14 degrees if I am reading it right on the badge. I won't be able to do it until next week, will let you know. I thought you were running 14.5 degrees of timing, and I now see 13.5. Is that right? Thanks

I wasn't really trying to chew you out..just saying those subtle things are the things were the things we needed to know.. Any cummins not running top notch is a cummins with a problem.. so any little thing is a clue. Though having had my timing way advanced I do know what you mean by it runs OK. As for the timing deal, you had high EGT's mainly during low RPM. What really advanced timing does is shoot in the fuel really early, way before the piston has reached TDC. Well at low RPM, there is a relatively long amount of time between the injection and TDC. This means the fuel ignites before TDC and is actually trying to turn the engine backwards since it is blowing up while the piston is still trying to come up (compression stroke). This effect is actually part of why advanced timing causes the louder knock. But at low RPM, this is horribly inefficient and causes high EGT's because you need more fuel to drive the truck and overcome the wasted power. When the truck is cold, it doesn't start because it is shooting the fuel in so early that the piston hasn't gone up enough to create enough heat from compression, so it doesn't ignite. My timing is at 13.5 yes. I think. Either that or 14.5 I can't remember. I hate losing low end power and startability. You being in texas I would set it more at the 14.5 mark. On a side note, overly retarded will have a similar reversed effect. It will start up so fast that you won't believe it. Have low end power like you won't believe. And be the doggiest thing in the world over 2000RPM to the point that the only thing that changes when you floor it is the EGT gauge.

[texas503]

Well thanks for the help, I will let you know how it turns out. I had not thought about too far advanced timing actually causing the engine to work harder at low RPM, makes sense though.Thanks again.

[Rogan]

my egt probe is post-turbo (previous owner-installed) and towing @ 55, I carry 6-700*F..

[texas503]

Well I had timing reset, but EGT are about the same. I have better low end power and a little better boost on the low end. Idle sound is a lot smoother and starting is easier. EGT will still rise 100 degrees while cruising without boost changing at all.I am happier with truck now even though EGT are still high and power isn't what I had hoped.

[ISX]

I would like to tinker with that thing. It's hard to explain all the things on here plus without driving the thing it makes it all the harder. There are several things in the ppump that all play a part with how it runs. How did they reset it anyways?

[texas503]

In all honesty I did not ask them how they did it, I am assuming they used the timing to locate stock timing. I can call them. I know the previous owner installed a 3gsk, could he have installed it wrong, causing this issue?

[ISX]

Everything that has to do with the injection pump (other than timing) would have no effect on EGT. I can see a lot of arguments coming from that but fuel is fuel. I don't care how or when it gives you fuel, when you push on the pedal, it's going to give it more fuel. So if the timing is right, I would look at other things. But what!? Valves, injectors....

[texas503]

Well thanks for all the help, I have to run the truck pretty extensively for the next month or so, after that I will check valves and maybe pull the injectors and have them all pop tested. I will let you know. Valves aren't hard to do are they? I have done a 24 valve but not a 12 valve. Maybe I should check your videos. Will let you know.Thanks

[texas503]

Well I checked the valves, some of the exhaust valves were a little tight though, don't know if that would make a difference. I did not adjust anything tonight, just ran out of time. I was confused a little by your easy way of adjusting valves, by reading your write-up things were not working like I thought they should, but after realizing that you were turning the engine the correct direction and I was turning it backwards with the alternator, I realized my mistake. Would you recommend setting them, when I have time, to 0.018 and 0.008? Seems like you said that would spool better. Also, I was thinking, if the exhaust valves were too tight, would that cause them to open a little too soon, thus decreasing burn time and power and increasing EGT? Or does the cam prevent that?

[Mopar1973Man]

Intakes valves are good between 0.006 and 0.015 inches.Exhaust valves is good between 0.015 and 0.030 inches.

[texas503]

Does anyone know if these problems I am having could be related to accidently getting 155* marine injectors as opposed to the 145* injectors I was supposed to get. Did some towing yesterday, about 6k lbs. I was running 700-900 degrees running 55-60 on the flats. Once I hit a hill, it would climb to 1,000 which I wouldn't let it get over. I was really only running 15 PSI boost at that. Alittle disappointing.

[Rogan]

What turbo are you running?Sent from my SPH-L710 using Tapatalk 2

[Mopar1973Man]

Experience of this last pull with the RV...Cruise set at 55 MPH, Edge Comp set at 5x3, RV275 Injectors, and I could climb over mild grade in 5th gear. Now the 2 larger grades I would shift down to 4th gear and rarely did I get to 1,100*F. The weather was cool 45-60*F on both trip to and from.

[texas503]

HX 35 turboDid some pulling last weekend, 16 foot GN with 4 horses, firewood, hay and some gear. As long as I kept the RPM around 2000 EGT were O.K. about 800 degrees or so. As I dropped it into OD in Lock-up, EGT would climb pretty good if going up hill. There was a decent grade on the FS road, but I had it in 1st climbing about 5-10mph and EGT were up to about 900 degrees. Pulled well though.

[ISX]

HX 35 turbo Did some pulling last weekend, 16 foot GN with 4 horses, firewood, hay and some gear. As long as I kept the RPM around 2000 EGT were O.K. about 800 degrees or so. As I dropped it into OD in Lock-up, EGT would climb pretty good if going up hill. There was a decent grade on the FS road, but I had it in 1st climbing about 5-10mph and EGT were up to about 900 degrees. Pulled well though.

EGT is determined a lot by air flow and the temperature of the air. In 1st gear you saw 900F because the intercooler wasn't getting any air through it. I'm sure the fan helped but nothing like when you go 70mph. RPM is also something that helps because it not only gives you more leverage (such as the leverage 4.10's give you) but it also pumps the hot air out. I also pull stuff at 2000+, no EGT issues whatsoever.

[Mopar1973Man]

I'm sure the fan helped but nothing like when you go 70mph.

Sorry can't be done with my rig. 2 problems.

[*]Idaho state laws limits towing speed to 65 MPH period.

[*]ST trailer tires are designed for a maximum speed of 65 MPH. Most RV tire blow outs occur at 65 MPH and above.

So I'm stuck at lower speeds.