i have a 96 tahoe with a 6.5. does anyone have any arguement for or against eliminating the EGR function on the vehicle? has anyone tried this? any methods of eliminating the EGR would be appreciated. also, i have noticed that when i put the truck on cruise control, it drops off boost when it doeseent need the power. any comments on that issue? thanks alot guys

Turbine Doc has done this on his tahoe and could say more than me. My personal opinion is do it.


www.dieselplace.com/forum/forum_posts.asp?TID=1138&PN=2 (http://www.dieselplace.com/forum/forum_posts.asp?TID=1138&PN=2)

QM,


Not a Tahoe I did it on my K1500 truck, but it should work on the Tahoe as well

to the best of my knowledge all half ton gm's using the 6.5 including tahoe's, yukon's, and suburban's have the " s " vin code engine with EGR. I recentlly converted my 95' tahoe to a non-EGR lower intake from and " f " and a hand built custom upper intake w/ 3" opening. This setup is working excellently for now as it is in an "R&D" phase. Before this conversion I had pulled the vacuum line from the EGR and plugged it. The truck ran much better this way as compared to stock and about 80% of the smoking durring acceleration went away.

Mattsparacio,

didn't the SES light come on when you pulled the vacuum line?


GH

Mattsparacio,

didn't the SES light come on when you pulled the vacuum line?


GH



As long as the wires are still plugged in and it has vacuum to the sensor, it won't know it is plugged.


If you take the hose off and put a ball bearing in the hose, (needs to fit tight) you can plug the hose back on and the EGR will be disabled.

i also replaced my "s" manifold with an "f" lower and upper. the upper has a flat plate where the egr would go so i left the egr operational so no codes are set but when it moves it doesn't acctually do anything except look legal. when i removed the "s" manifold it had literally .25" of soot throughout. not to mention the upper "s" that had almost closed itself up.

Hi,

I've never expected that being so easy, since it's illegal to do (here) :) --- Can any damage result from a non-working EGR? Airflow is increased, I think, so more air has to squeeze through the exhaust ... Turbine Doc mentioned somewhere that, on heavily modified engines, the EGR could get lifted off the intake.

BTW, the FSD-cooler I've got is mounted on the upper intake, and I think I should take it off and move it to a cooler location. When doing so, I can take a look at the intake and clean the soot out from the upper part, so there. Cleaning the lower part might do worse rather than any good, as the soot could get into the engine where I don't want it, at least not that much all at once :)

What's the best way to get the soot out? When using a wire brush, tiny parts of the wires could break off the brush and eventually remain unseen, getting into the engine later on ...

The gaskets should be replaced, but it won't be easy to get a new set ...

How much torque should I apply to the bolts that fix the upper intake and the EGR when putting things back together?


GH

Gaskets can be made out of suitable hi-temp gasket paper; but if old ones are still intact Hi-temp (red) silicone RTV will seal them again, 23 Nm or 17' lbs is what is in my 98 manual for torque. Edited by: Turbine Doc

T/Doc,

making you own gaskets is a good idea, thx! The intake has once been open when the FSD-cooler was mounted, and some read liquid sealant was applied at that time.

Maybe the sealant has glued things together now, so I'll get some gasket paper before I'll open it :)


BTW, I happen to have bought a camping trailer today, so I'll do some towing in the future ... I'll get it on Thursday and can upload a picture of it then :)

when i had my 97 6.5TD tahoe, i first disabled the egr system by using a #6 panhead screw stuck inside the vacuum line to stop it from working. it fixed the problem, but it did give me a MIL light on the dash. i lived with it until i had to do an e-test. then i fixed it better. i took a piece of 1.5mm aluminum and made my own solid gasket for the egr valve, and took the dash apart and removed the MIL bulb from the cluster. it caused no problems with performance or fuel economy so i left it like that.

Mattsparrio, I think it was says,


to the best of his knowledge all 1500 6.5's came with an egr?


Including the 8 lug models? So what abt 2500 models were they exempt from this Kaulifonion sludge?


Still trying to learn these things before I sell our trusty 93 k1500 5.7.


Thanx, Gbenhttp://www.dieselplace.com/forum/smileys/Ermm.gif

My 6 lug 2500 has an egr on it.

the "s" is for soothttp://www.dieselplace.com/forum/smileys/Big Smile.gif

Stopped up is more like it soot can't get out, most 1500s & some 2500 depending on destination are "emissions friendly" engines, those with light duty rating mostly are S engines a 6 lug 2500 is considered "LD" also both the 1500 & 2500 LD have a shorter box beam tube cross section in the frame, which is why the HD 2500 is about 1-2" taller than the LD 2500 even though both have 16" wheels.


I found this the hard way when installing my IC, a LOT less room to plumb it under the crank/engine front LD vs HD; I had to replumb and route under pan to fit it in.Edited by: Turbine Doc

pfloy, what diff ratio & what rpm do you see at 65-70? 16 tires?


Quantum, thanx for link to the thread, had been looking for it.


TurbineDoc, thanx for the write up it has done wonders for my ego, ego, ego! Could never get into the 6.5 info over at dp although I've come across people with them over the years that had lotsa miles & swore by them.


And pfloy if you don't mind using your thread here a couple more ques?


In the 6.5's, did gm ever build it with an intercooler? Sense thanx to all we'll be more focused on looking for a suburban 8 lug 2500 what ratio is most common? And we'll hope for a 3.73 that will put tq & rpm in the mileage range with the 4l80 od. Most heavy pulling will be hooked upto the dmax anyway. Did most of these come with gl80 diff?


Thanx Guys, Gben

GB,


No factory IC for the 6.5, 3:73's are good compromise for pwr vs econ, I get 16-17 running 75-80mph, above that falls off 15 or less depending how far above 80 I run. Hauling 12K trailer load, at 70 I get 12-13mph, no G-80 in mine I don't think G-80 as common as one would hope.Edited by: Turbine Doc

T Doc,


Just abt same mileage we get with dmax but, "how far above 80 I run" comes standard with these machines & occasionally minutes supercede the ecnomics of fuel.


In the pre 97 models what can be done to bring the cooling system upto par? And did caping the egr show a noticable gain in lower temps under loaded config?


Thanx, Gben

I've done so much stuff I've forgotten what did what. For pre 97 upgrade to 97+ dual H2O thermostat & 130 GPM waterpump, for max cooling you can go all out and do some of the stuff in the thread QM is linking to aboveEdited by: Turbine Doc

Thanx T Doc,


For getting us upto speed on the cooling. Of all the things abt any truck I can't stand one to get over temp. The 98 xj Cherokee sometimes would creep over the line on hot days just sitting in traffic with the a/c on at which time I'd reach over & flip it off for a minute or two. This just didn't set too well with my little wonder lady so I ordered the electric flexalite from summit to cure the problem. But while waiting for the fan to get here I put 1/4in spacers betwix the hinges & the hood & it did so good I almost sent the fan back.


But by doing both it will scat up the mountains with 4klbs tied behind it with nooo probs.


Never buy a wife a Burban, she started that stuff agn last nite & looks like I'll need to buy a good diesel sub before I can sell Hers'. Ohwell....http://www.dieselplace.com/forum/smileys/Disapprove.gif


Thnx agn, Gben

GB,


In addition to the H20 mods a bypass oil filtration rig gets the filts to where you can get to them, plus adds a little extra cap & some passive cooling from air flowing across the filter bodies.


A Deraile trans cooler can pull some heat; more fluid to heat up, the electric fan cools the trans oil so the radiator has less heat to pull from the trans. Then add a deeper aluminum trans pan that is finned or ribbed for more fluid and some more passive cooling thru the pan surface.

T Doc,


The list grows & the plot thickens.


Will try to show what has appeared on the other thread.


Thanx, Gben