High EGT's

[ropinfool]

Hey Doc, I am experiencing high egts with low power. High being 1100+. I have not touched the fuel metering screw yet, I have been tempted to turn it up due to the low power. I have no smoke to speak of. I could really use your help. I have not taken it to a shop yet but I think my vrv may not be adjusted correctly. Could this cause my problems? Thanks in advance. John

[britannic]

Where's your timing set at? Low power with high EGTs can be a sign of retarded timing, air intake or exhaust restriction, or a combination of these. The same can be said of timing that's too advanced, but it would be accompanied by obnoxious diesel clatter.

Presumably, this a new symptom for your engine, so did you change anything recently?

[ropinfool]

Hey britannic, my timing is about 1/16" towards the drivers side. I've been having this problem for about 6 months, but have just gotten to the point I can't handle it anymore. I installed the egt gage after my rebuilt pump and injectors so I don't know if I had a temp problem prior to that. I had a no power problem since I bought the truck 2.5 yrs ago. Since the rebuilt pump and injectors my power increased marginally. I really wish someone lived close who could drive it and tell me if I really do have a problem or if I'm expecting too much. I know I'm not expecting too much based on what Doc Lee has done to his. I just want to be able to pull that little hill along with everyone else. Eventually I'll have a boat and would like to be able to pull it also. Thanks again. John

[britannic]

I notice that you state:
I had a no power problem since I bought the truck 2.5 yrs ago. What diff. ratio are you running? Depending on that, the tire size you have may be part of the factor. The key to more power is removing exhaust backpressure and getting as much air as poss. into the engine, then more fuel can be burnt to generate those ponies! :D

In stock form, these engines don't put out a great deal of power or torque. When I first got mine, it was gutless until I fitted a turbo. Since then I have steadily made improvements, with the most recent being a 4911 pump, 6.5LTD injectors and a Mitsubishi TE06H wastegated turbo.

My final drive is 4.56 driving 32" tires. The next upgrade is a custom 700R4, which should improve the standing start with it's 3.06 first gear ratio and bring the cruise rpms down with the .70 overdrive.

[ropinfool]

I have 4.10's all around. Also have an Amsoil dual stage air filter with the intake silencer removed. I am running dual 3" pipes with super turbos all the way back. I priced a 700r4 installed, $2500. Too much for me. I tried to price a turbo since Banks is only about an hour and a half away but didn't get past the literature stage. But it'll probably be more than I can do. Thanks for your help, I really do appreciate it. John

[britannic]

Get your timing checked to be sure it's exactly right. You may be just suffering from not enough air, too much fuel and hot outside temperatures. The turbo will definitely help, especially with the mountains near you - there's no going back once you've tasted forced induction above sea level - it's the real thing!!!! :D :D

BTW, unless you get the timing sorted and ensure there's no other problems like air restrictions, blocked fuel return lines (causes retarded timing), restrictive fuel filter, leaking injectors etc., turning up the pump will just make your temperature problem worse.

[ 07-04-2003, 11:11 PM: Message edited by: britannic ]

[ropinfool]

Thanks britannic, I think I'll probably sell this baby once I get the a/c working again. I don't have the time or money to get it where I need it. Thanks again. JOhn

[Garand Fellow]

High EGT issue with me as well.

Just installed an Avant 6.2. (Timing gear drive, ceramic coated pistons and balanced rotating assembly). I had Avant do a run-in on it to make sure it was setup properly before shipping.

During engine installation, went with Banks Stinger intake/exhaust. Banks recommends a slight increase in fuel flow, so the installer cranked it up about 1/8 turn.

1. Good power, very little noise and quite a bit of black smoke. EGT up to nearly 1200 when climbing small hill with no load.

2. Talked with Avant. They said they "might" have set the motor up under the assumption that I was going to turbo it. (I'm not)and that they probably cranked the fuel up a tad at their shop. They suggested backing it off slightly.

3. We backed fuel off 1/8 turn. (The same amount we cranked it up when installing the Banks exhaust). No power, EGT still elevated.

4. Cranked fuel back up about 1/16 turn. Power back, smoke back, EGT still seems high. 850 at 65mph on level road, no load.

5. Emailed Avant.. no response.

Any suggestion would be appreciated. My installer thinks Avant might have the timing off.

[ropinfool]

Well I haven't had a chance to do anything yet, went out to install my new a/c compressor and my old bolts don't fit. I did talk to the only local diesel shop owner, he didn't much like this engine, he thinks it is just a characteristic of the 6.2. But after being on this forum for a couple of years I know others are doing much better. Oh and he wanted to do a compresson test and check the timing for $300. I told him I would do the compression test myself and maybe come back for the timing test. I'm not even sure he has the equipment to check the timing. Keep me informed on your progress and I'll do the same for you. Thanks, John

[gmctd]

High egt's can result from
1 placement of egt probe - manifold will be higher than pipe
2 more fuel than air - black smoke
3 and final drive ratio(s) - 4.10 will give higher egt than 3.00, 3.54, 3.73, etc at same mph

jd

[ropinfool]

Well this thing is fighting me to the end. I took the new compressor to get new bolts and when I got home I dropped it. Right on its face. Won't even rotate. Man I have terrible luck. Well I'm going to try and find a compression tester to rent, now will be a good time to do it. John

[arveetek]

High EGT's alone on a naturally aspirated engine can be normal. After reading many warnings on TDP about not exceeding 1200 degrees, I decided it was time to install an EGT guage.

My first trip out after installation with my trailer in tow, I nearly soiled myself! I was getting readings of 1300 degrees and above without full throttle! After doing some more reading and research, I determined that it was nothing to worry about. Since then, I have watched the needle go even past 1400 degrees for a short period of time on more than one occassion. I don't believe high EGT's hurt the n/a engines like the turbo'ed trucks.

I have put over 100,000 miles on my 6.2L with my foot buried to the floor for a lot of those miles. It hasn't failed me yet. I'll bet there's thousands of miles on this engine with over 1400 degrees EGT (measured at the driver's side manifold exit).

Once I get my turbo installed, then I'll be a bit more cautious of the temps. But then my temps should come down.

That being said, a low-power condition with black smoke and high EGT's is a sign of too much fuel, lack of air, or restriced exhaust, as was said. My truck runs with a lot of power, little smoke, and high EGT's.

Casey

[arveetek]

John, what's the elevation where you live?

Casey

[ropinfool]

I'm thinking I live just above sea level, the hills that I have to drive over are maybe 2000 ft, pretty steep though. The thing that confuses me is I have little power, I will drop down to 50 mph, no smoke, egt's climb quick and once they hit 1000 the water temp starts climbing quick also so I have to back out of the throttle. I wish someone who knew something lived close, I'd even drive a few hours, just to drive it and give me some kind of news. I love this truck, but am real close to selling it because of this issue. I am going to try and replace the rear main seal here shortly, with my luck the crank will fall out on the ground when I pull the pan. :eek: Thanks Arveetek and britannic for all the help.
John

[britannic]

It smacks of not enough air and too much fuel, which can be caused by:
</font> Timing (cam and/or inj. pump)</font> Injectors (worn)</font> Restricted air intake</font> Too much oil vapor coming across the CDR and being burnt</font> Restricted fuel return line</font> Air being drawn into fuel and throwing off the timing (remote possibility as there will be other symptoms)

Other areas to check are:</font> Binding brakes</font> Dry/seized bearings in any part of the drive train, including axles</font>
You're welcome to visit me, although I'm at least 6 hours from you.

[arveetek]

You're welcome to come visit me as well! But I'm more than just a few hours away.

In all honesty, I'd love to have your truck. I really wish mine was 4WD. The only thing I'd want different about yours would be to have an overdrive tranny.

Casey

[ropinfool]

Thanks for the info and offers arveetek and britannic. Where abouts in the sierra nevada? 6 hours may not be too long pretty soon. I still want to do my rear main first, well a/c first then rear main and somewhere in there have my timing checked and test my compression. I'm having a heck of a time finding a compression gage for a diesel, can't justify buying one right now. Anyway thanks again.
John

[britannic]

I'm near Auburn, CA, around 500 miles from you, so it may be a bit longer than 6 hours :D . You'd be more than welcome if you could make it!

[vcrtech1]

John,

Last time I drove over the hills from Temecula to Escondido on the 15 freeway, I was in third gear clutch locked (700r4) doing about 45-50 mph. EGT's were right at 850 - 900 (my limit). I was driving my 86 1/2 ton 6.2 suburban, 4wd, 31 x10.5 tires, 3.73, 89,000 miles, bone stock with the exception of gutting the EPR valve and disconnecting the EGR valve. Everyone in the suburban were not thrilled about going so slow with other cars whizzing by at 75-80 mph. What really bothers me is that I really have to lift my foot off of the accelerator to keep EGTs down. My 83 1/2 ton 2wd, suburban, 260,000 miles, does only slightly better. I believe it's due to the lower weight of the 2wd. In order to keep EGTs below 850, I'm typically the slowest on the road on pretty much any hill. That goes for both the 4wd and 2wd. I have yet to push either suburban past 900F. Engine cooling has never been a problem. On the other hand.... trans temps can really get out of hand especially in L.A. traffic, or going up slow steep grades with the clutch unlocked.

Pat

[ropinfool]

Hello All, Vcrtech - sounds like what I'm making except my egt's are around 1200 and climbing. I have 4.10's with 33 x 12.50 x 16.5 x 10 tires and wheels, 2.5" lift, turbo 400 trans. I am wanting to go back to stock height and narrower/possibly shorter tires. brittanic, thanks for the offer but I don't know if this truck would make it that far, I don't think it would survive the grapevine. A bit of good news for me though, I finally pulled the pan to change my rear main seal and no sign of cracks!! Yahooooo!!! The bad news is I broke an extension and socket trying to break free the main brg cap bolts. Off to sears and get me a 18mm 1/2" drive socket. Talk to ya'll later. John

[Motorbreath]

Hey Ropinfool;

When I changed my rear main seal on my '86 K20 about a year and a half ago I broke 2 18mm sockets trying to get the main bearing cap bolts off. I got myself an 18mm six point deep socket for an impact gun instead. It didn't split, and the six sided socket won't slip or strip a tough bolt like a twelve sided one will.

Regards, Erik.

[arveetek]

Pat,

I'm curious, why are trying to stay below 900 degrees? If I'd try to stay below that number, I'd never get anywhere. I can hit 900 to 1000 degrees on a flat highway in overdrive, if I'm heading into a wind. The recommended safety limit is 1100 degrees on a turbo'ed 6.2L. A naturally aspirated engine can go over that with no ill effects.

I've put over 100,000 miles on my rebuilt 6.2L, with many of those miles pulling a trailer at 1300 degrees for extended periods of time. My truck runs as good as ever.

Casey