97-99 Suburbans

[FellowTraveler]

Thanks for the tips. Excuse the novice questions. Fact is, I didn't realize this suburbaB]Highn had all the cooling upgrades already. I didn't see any codes in the glovebox. Beneath the glovebox near firewall reads 7/27/99 1B val60 52476834s so I assume this is a post may 99 burb. When I first bought it a couple or months ago the tstat would go up to 210 but after changing the tstats water pump and fan it will now stay two lines below 210. a new k& n air filter definitely let it breath better. Got a 4 inch diamond eye exhaust on and ordered a insight w a get probe. I have a brand new camaro and Chevy express van that I'm converting to a camper but I prefer driving the burb just wish it was a little bit peppier. And also realize that novody makes a good suspension lift kit for the 1999. They go up to 98 and pick up after 2000. I called offroad unlimited and who claim they get get any kit for any year and they said no to, so,etching about the transfer case. So I added new shocks and por15nd the underside seeing I wasn't going to be doing any lifting or suspension mods. I'm happy w it. I'll see if I can get some pictures up. Thanks again.

In my experience any radiator older than 10 years should be replaced, and if the Burb has the orange antifreeze dump it because it is extremely corrosive when air gets to it.

High coolant temps can be caused by a few things and on a diesel its worn injectors that could be the culprit especially since low sulfur fuels have entered the picture. After giving many fuel additive products a try I ended up using 2 cycle oil 1 to 2 oz per gallon of fuel to add lubricating properties to the diesel fuel it has almost the same burn rate and has allowed injection pump and injectors to last much longer. I rebuild my own injectors and have found the failure prone part is the nozzle assembly when using low sulfur fuel. Stanadyne has introduced a new injection pump assembly that has key wear parts modified and special hardening/coating process to increase life of pump using low sulfur fuel, I've not needed the updated unit while using the 2 cycle in the diesel.

The stock suspension is fine for 33" tires however some trimming of bumper end or using washers to space it forward on its mounts works too. 35"/36" can be used w/o any lift by using fender cutouts and flares Bushwacker comes to mind here.

Lacking in get up and go can be many things from timing/offset, worn timing assembly, weak lift pump (I use earlier lift pump from N/A 6.2/6.5 diesel it has almost 2x the pressure that the 1999 does) this helps greatly. The Post MAY 1999 6.5 td after certain mods to enhance VE for way more get up and go than you'll ever need, you want hot rod fast get a Cummins and you better have deep pockets because the question then becomes how fast do you want to spend.

 

[DoMiNiC1]

If you want Hot Rod fast get a Duramax and efi live. :ylsmoke:

This is a 2500 - with the 5.7...

Do you have some pics?

 

[Reeg]

Like I said, I like the 99 Suburban 6.5TD. Im just at the stage that I want to add power so that I have it when I need it but I dont want to bust up the engine after getting this far. Im just not sure whether the best next step is to get the 40 or 80 hp program from SS diesel or to get high output injectors. I get the feeling that I may be happy with 40 hp and that may be the safest way to go. As I mentioned it already has a 4 inch exhaust and I have the gauges and the cooling system has been upgraded? Any suggestions on programming or injectors first?

 

[chilliwak]

Nice:Wow1:looking `Burb ´you have there Reeq. Be carefull that you dont blow the motor up with too many performance upgrades... Cheers, Chilli.

 

[FellowTraveler]

What cooling upgrades do you have the HD clutch & fan blade from S&S or?
S&B makes a new and efficient air-box w/big air-filter allows some whopping increase in air available to intake designed w/help of Heath I use it and it works for me. I'm thinking S&S has a tow/ off-road tune @ 40+- HP and performance tune @ 80+- HP either will work and not strain a GM 6.5 td in good working order, oh, it's the torque that gives the get up and go the top dead center offset (TDC) would have to be adjusted too. With boost increase you'll need some charge cooling either an after-cooler (aka; inter-cooler) or high pressure water injection like RSR's system which is the only real high pressure system on the market. Then there is Walking J's turbo up grade that does not require after/inter cooler because it's designed efficiency not hot rodding. Keep in mind you'll have to monitor EGT's keep under 1k deg F, IAT's, ECT's, FTF, TFT,'s and on and on. Another item to mention is the turbo controller solenoid needs to remain connected always to ECM you just take the hose and loop it from one side of solenoid to other side if not running the factory boost controller reason is you will never be able to set top dead center offset with this circuit removed.

As always keep in mind any modifications you do on your 6.5 td are at your own risk!

 

[BurbanAZ]

their good trucks i havent had the later models, but ive had a 95, a 92, and now a 94. I had one with the 350, one with the 454, and no withthe 6.5 turbo diesel. I love these trucks and their solid and reliable with just basic maint. Also if you every have trouble finding parts. Rockauto.com is really good for parts, and if you get the LMC magazine or go to their site they have pretty much every part, nut, bolt, etc.. that you could need.

 

[Reeg]

I do have the HD clutch and fan blade (the entire cooling system upgrade) from SS. I looked into the S and B air box. It looks great but it says its for the GMC 99 suburban not the chevrolet 99 suburban. I thought theyd be good for both. Maybe Ill call them up. I installed the insight gauges yesterday and notice the temps on the intake easily go up to 200. I bet I can get the air temps down signfiicantly if that air box will fit. Otherwise, i saw a large ("K") box online which looks good. I bet that would do the trick.

Most importantly, I called up Heath Diesel this morning and put in an order for their performance upgrade. Yesterday the edge insight gauges came in and Im happy with those too except that I have to drill in the EGT probe which Im a little apprehensive about. The only thing I need is an inter cooler or mister (or whatever they call them) and I'm ready to barrell this baby down the quiet suburban streets of Montclair, NJ. Just when my neighbors were happy that i got rid of the beeper (reverse beep) that used go off at 6am in the morning as I pulled out of my driveway (this used to be a New York City Fire Chief Truck which explains the holes on the roof and in the front fender). I really appreciate all the help from the forum members. Some people on this forum really know their stuff.

 

[FellowTraveler]

I do have the HD clutch and fan blade (the entire cooling system upgrade) from SS. I looked into the S and B air box. It looks great but it says its for the GMC 99 suburban not the chevrolet 99 suburban. I thought theyd be good for both. Maybe Ill call them up. I installed the insight gauges yesterday and notice the temps on the intake easily go up to 200. I bet I can get the air temps down signfiicantly if that air box will fit. Otherwise, i saw a large ("K") box online which looks good. I bet that would do the trick.

Most importantly, I called up Heath Diesel this morning and put in an order for their performance upgrade. Yesterday the edge insight gauges came in and Im happy with those too except that I have to drill in the EGT probe which Im a little apprehensive about. The only thing I need is an inter cooler or mister (or whatever they call them) and I'm ready to barrell this baby down the quiet suburban streets of Montclair, NJ. Just when my neighbors were happy that i got rid of the beeper (reverse beep) that used go off at 6am in the morning as I pulled out of my driveway (this used to be a New York City Fire Chief Truck which explains the holes on the roof and in the front fender). I really appreciate all the help from the forum members. Some people on this forum really know their stuff.

Drill/tap for the probe at the "Y" section of the exhaust manifold on pass side just under the turbo turbine inlet it is an easy access through fender-well after removal of cover between chassis and fender-well.

As for parts on your Burb the cutoff is 1998 in most all parts books however there is issues even at chevy/gm on some parts.
SEE: http://usdieselparts.com/index.cfm/product/30124/sb-air-intake-chevy-65l.cfm

You have to have the injection pump top dead center offset adjusted @ dealer using the tech 2 if you do not have the tools yourself. Being that the factory settings are mild the diesel seems to lack power and is pretty quiet this timing adjustment is necessary and will make the diesel sound like a can of marbles with tune program it will wake up that diesel and perhaps your neighbors too (you have been warned). Heath will suggest top dead center offset for his tune, my top dead offset is 2 deg less than suggested because my gear drive timing set has the 2 deg built into it and I have the benefit of never having to change out timing chain ever again.

Another worth while item is the Fluid Damper balance r to prevent crank from failing, usual failure of crank is when the factory damper fails. You will need to replace the factory balance r anyway @ around 120k+- after fluid damper never again.

The transmission (4L80e) needs adjustments too and suggest "firm" as best suited for the upgrades you are undertaking, Heath will ask about that when you order the tune.

I can't see chevy/gmc being different under the hood if under the hood it looks like this there should be no problem, that's the S&B installed;

 

[Reeg]

From the look of your engine bay I can see that its the same as mine. No reason why the S@B air intake wouldnt work. Im ordering it. My air temps now run up to 190-200.
Funny thing, when i ordered the tune from Heath they simply asked for my vin number and what kind of upgrades i had done. THey didnt mention anything about timing or transmission. Maybe they'll send me an email or maybe I should just call them to make sure. And thanks about the EGR probe location. I saw some pictures on the location at the diese page and feel that with the proper tools I should be able to handle that (famous last words). The funny thing is that given that this is a 13 year old SUV that I bought without much research I've ended up making engine upgrades that I would never dream of doing on my duramax express. Working on this truck is fun. HOwever, the old saying "if it aint broke dont fix it" rings true. Dont want to get this program and then have everything run out of sync when the engine is purring like a kitten right now. I;m not sending in the old computer and keeping it just in case that reprogram gets me in trouble with the neighbors. I can just go back to the old one right? Or is there no turning back now? Thanks again. Anyway, the Sand B airbox is a must. Thank g-- the summer is almost over.

 

[FellowTraveler]

From the look of your engine bay I can see that its the same as mine. No reason why the S@B air intake wouldnt work. Im ordering it. My air temps now run up to 190-200.
Funny thing, when i ordered the tune from Heath they simply asked for my vin number and what kind of upgrades i had done. THey didnt mention anything about timing or transmission. Maybe they'll send me an email or maybe I should just call them to make sure. And thanks about the EGR probe location. I saw some pictures on the location at the diese page and feel that with the proper tools I should be able to handle that (famous last words). The funny thing is that given that this is a 13 year old SUV that I bought without much research I've ended up making engine upgrades that I would never dream of doing on my duramax express. Working on this truck is fun. HOwever, the old saying "if it aint broke dont fix it" rings true. Dont want to get this program and then have everything run out of sync when the engine is purring like a kitten right now. I;m not sending in the old computer and keeping it just in case that reprogram gets me in trouble with the neighbors. I can just go back to the old one right? Or is there no turning back now? Thanks again. Anyway, the Sand B airbox is a must. Thank g-- the summer is almost over.

Did I read correctly your air temps are 190 200, or did you mean engine temps? GM shop manual calls for engine coolant temps to be within the range of 185 to 220 deg F however the military manual for same 6.5 TD calls for engine coolant temps of 250 deg F as limit. Intake air temps (IAT) range 50 to 194 deg F which is the same range for the fuel temp sensor (FTS).

If I remember correctly Bill Heath does mod the transmission programming to go with the tune and mods you have already done, instructions will come with the new comp, keeping the old comp is smart I did and have never had the need to use it again. All the tune really does is increase the efficiency of your diesel along w/other mods done as it is de-tuned from factory.

Keep your EGT's under 1k deg F, boost @ Heath's recommended level. I suggest Car Code OBD2 data logger/device controller to use on lap top as it can allow you to set timing and other parameters as needed thinking the cost is about $125. US FRN's and only available in 32 bit only. Buy the factory shop manuals both sets for 1999 early & late.

The newer 6.5 TD's are real strong I'd not worry about the age of it either!

 

[Reeg]

I meant the air intake temps. Hopefull these will go down with the SnB Airbox I just ordered. The Car Code is OBD2 data logger sonds like a good idea. The edge insight ct i just got will give me warnings if my gauges go above a certain range (thanks for the egt range, hopefull i can get the other ranges, transm temp, etc). You said it also allows me to set the timing? I did order the factory manual set. Pretty dense stuff and references to specialized tools. I'm glad to hear the 99 suburban 6.5 was detuned and that the engine and trans can take it. I wish I could say the same for the Chevy Duramax Express. Its also detuned supposedly because the transmission wont take too much torque(a new word I learned). Thanks again, Regis. I have to find an early picture of this suburban. it was down to the metal and looked like a post-apocalypse bug out vehicle. i should have just put a coat of clear on it and called it a day. My neighbors would have definitely killed me them.

 

[FellowTraveler]

I meant the air intake temps. Hopefull these will go down with the SnB Airbox I just ordered. The Car Code is OBD2 data logger sonds like a good idea. The edge insight ct i just got will give me warnings if my gauges go above a certain range (thanks for the egt range, hopefull i can get the other ranges, transm temp, etc). You said it also allows me to set the timing? I did order the factory manual set. Pretty dense stuff and references to specialized tools. I'm glad to hear the 99 suburban 6.5 was detuned and that the engine and trans can take it. I wish I could say the same for the Chevy Duramax Express. Its also detuned supposedly because the transmission wont take too much torque(a new word I learned). Thanks again, Regis. I have to find an early picture of this suburban. it was down to the metal and looked like a post-apocalypse bug out vehicle. i should have just put a coat of clear on it and called it a day. My neighbors would have definitely killed me them.

I suspect your GM8 turbo is super heating the intake charge there are a few ways to totally fix this 1) Walking J A-team turbo upgrade, 2) an aftercooler (aka: intercooler) custom and can be big $$$$$, 3) RSR water injection is the most efficient and highest pressure water injection system out there and when it comes to water injection the higher the pressure the better period.

 

[Reeg]

Hi Fellowtraveler: I put in the air box and the air temps are generally down and dont go above 180 anymore but they do creep up every now and then. I was thinking about cutting into the fender and putting in a vent with a duct straight into the airbox but would hate to cut into the fender or let rain get in. I noticed that the space between the airbox opening and the fender runs along to the front grill and then sweeps down to two vertical slits. How is yours set up there. Also, what intercooler and where did you get yours from. I feel that this new airbox is keeping the temps down but the burb feels less powerful than with the the old large K and N filter. Maybe its all mental.

 

[FellowTraveler]

Hi Fellowtraveler: I put in the air box and the air temps are generally down and dont go above 180 anymore but they do creep up every now and then. I was thinking about cutting into the fender and putting in a vent with a duct straight into the airbox but would hate to cut into the fender or let rain get in. I noticed that the space between the airbox opening and the fender runs along to the front grill and then sweeps down to two vertical slits. How is yours set up there. Also, what intercooler and where did you get yours from. I feel that this new airbox is keeping the temps down but the burb feels less powerful than with the the old large K and N filter. Maybe its all mental.

The fender if factory will have a blocking plate just after the air box inlet best way to find if it does is to take filer out and feel in the opening and to the rear. The S&B is much larger than the old panel or cylinder filter and if you have the back panel removed you are just pulling in hot engine bay temps if you have a high temp issue. The S&B flow increase should be very noticeable if not you need to trace down why not.

Engine temps can sometimes be worn injectors and not a cooling system issue. When your IAT is at 180 what is boost level too high will super heat air charge, the fuel temp and engine coolant temp?

Is your diesel an "S" L-56 tune or "F-HD" L-65 tune, does it have a cat and if so is it clogged, egr valve or an air-mass meter? Any codes?

Charge air cooler/after cooler/inter cooler is $1,500+ a few diesel performance outlets still sell em, however IMHO the biggest bang for the buck would be the Walking J turbo charger up grade which will eliminate exhaust turbine back pressure and actually stuff more cfm into your diesel at lower boost pressure then Heaths program for this turbo, keep in mind this is not a hot rod mod its increasing volumetric efficiency.

 

[Reeg]

Heath chip

I think the air temps are now under control they don't go above 140 and usually stay around 110 specially now that things are colinf down. I don't know what program this car came with but I ordered the Heath chip and am just waiting for the hd fuel pump. I am worried about how to tell if I need to take to the dealer for the boost pressure. Now as always debating whether to take to mechanic to do this and instal a gauge probe for manifold or to attempr to do it myself. I'll look under and see if I can find a catalytic converter.