Just bought 97 Suburban, Now What, Help!

[dieselrealtor]

After a long search I have purchased a 97 SLT, Mexican built with 83k :D . Have very little service history but looks to be in great shape.

Any suggestions on "Must Do" maintenance, "Should do" & "Would be a good idea to do" maintenance?

Also, any suggestions on improvements for longevity?

I feel like a kid who just got the red rider bb gun. :D

[rjschoolcraft]

Is this a diesel Suburban?

[dieselrealtor]

Hi Ronniej,

YES it is, do you have the green one?

[rjschoolcraft]

Yes, mine is Forest Green with rear hatch.

[markrinker]

Congrats on your purchase. If it were my vehicle, and with 83K miles, I would verify the following:

1) Check engine light on? If it is - even intermittently, pull the codes (explanation of how elsewhere on the website) or get it to a dealership and find out why. Don't wait.

2) Call dealership with your VIN and have them pull up history. Find out if there are any open warranty campaigns you qualify for, or if any warranty work was done to this truck.

3) Fuel filter. If you don't have good maintenance history, I'd do this right away. Cheap insurance against plugged injectors and stressing your injector pump.

4) Air filter. Again, cheap insurance. There are lots of aftermarket solutions (like K&N) that can be washed, oiled and reused. If you perfer to stick with OEM, plan on changing it every other oil change or more often under dusty conditions. Turbo diesels need gobs of clean, unrestricted airflow!!!

3) Oil, lube, filter. Self explanatory. With no service history, I'd do all fluids, including both diffs, transfer case, and complete transmission flush with new tranny filter. Cheap insurance. My lube shop even does the power steering box!

4) Proper turbo wastegate operation. At idle you should be able to gently pull and move the acuator, and have it return to its normal position under vaccuum. Inspect vaccuum lines from pump to solenoid and solenoid to actuator for cracking or routing issues close to hot surfaces. Your exhaust should not be black, even under loads. At the most, you should see grey smoke with your foot in it. At idle or cruising, you should not see black smoke in your right hand mirror. If you do, your wastegate actuator system is not likely functioning properly, or other problems need to be addressed.

5) Replace thermostats with either OEM GM parts, or diesel specific units (high flow) sold at www.heathdiesel.com (http://www.heathdiesel.com) or www.kennedydiesel.com. (http://www.kennedydiesel.com.) If you intend to do serious towing, you might also consider one of the performance fan/clutch packages. Keeping your 6.5L cool is probably the most important key to longevity.

6) Verify proper OEM fan clutch operation. Might need to do this on a warmer day, towing something, while running A/C. You should hear the 'roar' caused when it engages at or about 210-220 degrees.

7) Before winter, verify soundness of batteries, block heater, hoses, belts, etc.

Have fun!!!

[dieselrealtor]

Purchased last night, took for the LOF this morning, used Shell Rotella 15/40.

Any recomendations on best oil & gear lubes?

No check engine light on.

will work on getting info from the GM dealer

[sturgeon-phish]

After I bought my truck I put the amsoil synthetic in the trans and the motor. Improved fuel mileage. Liked it so well I'm using it in my '03 Avelon and as soon as the motor breaks in, it's going into my '04 Civic.

[CareyWeber]

Place a second hose clamp on where the hose from the CDR goes into the intake by the infront of the turbo.

Clean all battery cable ends (both ends of each cable).

Clean all ground cables too (both ends of each cable).

Do the Dr Lee battery bolt fix/upgrade too.

Carey

[dieselrealtor]

With all the gasser trucks & cars I have had in the past, I have been a stickler about changing every 3000 miles.

If I run the Amsoil or another synthetic, how often does it need to be done, best & worst case?

[rjschoolcraft]

I run Shell Rotella T 15W-40 in the summer and Rotella T Synthetic in the winter. I do oil changes about every 5000 miles or so. I put a lot of miles on in a very short time, so I don't change the oil on as short of an interval as some others.

I would also grease all of the front suspension components promptly, then do them about every other oil change.

[markrinker]

I also run Shell Rotella. Since I burn approximately 1 quart per 1,500 miles while towing, I change oil, filter and OEM air cleaner every 10K miles, which has been about every 6-8 weeks lately.

My preffered transmission interval is approximately 25-30K, diffs/transfer 50K, coolant every 24 months.

[dieselrealtor]

I think I may start with the gauges (sounds like I need them no matter what), then look air filter options & cooling system upgrades.

Any recomendations on gauges?

[rjschoolcraft]

Lot's of folks sell gages. The Banks gages I have were actually made by Isspro.

[Shuck]

Hmm... long oil change intervals on a diesel make me nervous. Unless one has a high-bypass filtering system. the problem with diesels is that the oil fills up with soot and really can't hold much more after about 3-4k miles. I would almost wonder if the guy who burns a quart per 1.5k miles might be making it worse by not changing it for 10k miles. If you run a lot of miles, perhaps some high quality synthetic and a bypass filter system would be right for you.

I used to have a 91 K1500 with a 6.2 in it and it would only burn oil after the oil had about 2k miles on it and was really black.

When I first got my 6.5TD suburban, I put Rotella 5-40 synthetic and a Mobil1 filter on it every time. Oil got just as black just as fast. So I started using the rotella 15-40 and a regular filter in the summer. From November through March I use the 5-40 Synthetic but still just use a regular (decent quality) filter because the Mobil1s are $15 compared to $6 for a Bosch premium - both use synthetic fiber technology instead of paper.

I'm no expert, that's just my experience. Some of it comes from my mechanic's opinion, others from my own learning. This is really a topic that many people have many opinions on - so I don't claim any knowledge above anyone else on the subject.

[markrinker]

With a fresh quart going in every 1,500 miles, my thought is that the filter can handle 10K worth of highway miles. If it were dusty condtions, I'd have probably cut it to 5K miles.

I'm driving 750+ tommorrow, so I'll drop the oil this afternoon and try a 3K oil change interval to see if the oil consumption stops - thanks for the idea and observation about 'soot loaded oil'.

Sometimes I still revert to gasser mentality. (I've had a few high miler 'beater' gassers that only got filters changes for the last few years of their life, due to high oil consumption!)

Unloaded, the truck doesn't use oil at all. Currently, 40-50% of the miles are loaded. It seems like consumption is directly proportional to load, which makes sense given the turbocharged engine.

[rjschoolcraft]

The Rotella is very good at handling soot. I now have over 204,000 miles on the truck and over 139,000 on the engine. So far, I've seen no adverse effects of running longer change intervals. If I were doing this properly, I'd do oil analysis and put on a bypass filter system. Haven't gotten to that yet.

[Turbine Doc]

I posted this at "the Place" some tips for the new to 6.5 owner feel free to add in what I may have overlooked or how you might do it differently

Common Question what can I do to make more power with my 6.5

While not an expert I'll pass along what has worked for me and what I've learned from others RATDOC, GMCTD, JK, Bill Heath you out there Thanks for all the help.

1st question you have to ask yourself is what is your goal, power or speed, I'll list what I've done for power/longevity. Speed to me is best left to gassers, yes you can build a fast Diesel but at what cost in the long term, beat it up and it won't last. If you are here on the 6.5 forum you have an "old truck" 6.6 DMAXes are current offering since 2001. How much life do you figure you have in a higher mileage vehicle, not only has your engine been stressed but so has the rest of the running gear. Unless you have done a complete top down rebuild/inspection of the whole truck speed is going to cost you in the long run.

Before plopping down bucks get smart, visit other Diesel sites to see what works there running feud aside; there are some good folks at TDP, another good place to start is www.banksdiesel.com (http://www.banksdiesel.com) they have a lot of good education on the site. Power from a Diesel is tied to airflow which is why turbo and in really big engines turbo/supercharging is a necessity, while you are making power you also want to keep combustion temps under control to keep the engine from self destructing.

My truck safely pulls 12K which is a lot for a L56 K1500.

1st thing I did was to install a free-er exhaust Banks 3.5" cat back system, this reduced backpressure and lowered exhaust temp, the factory down pipe gets replaced with a mandrel bent one, factory pipe look like it had been run over by our truck. Other vendors out there for this system check around, Banks was pricey but at the time I did not know better. free flowing air filter was also part of that kit Amzoil or K/N your choice another site had a pretty long study end result was Amzoil had better result but K/N wasn't far away in my opinion.

The L56 EGR engine upper intake needs hogging out it has (2) 3/8" wide x 3" long slits beside the EGR tower that the engine breathes thru, I removed the excess with a shortened metal cutting jig saw blade to reduce mess that would come from a air or dremel grinder. make sure it's hospital clean before reinstalling, don't feed the engine metal chips it can't digest. Also replace "donut gasket" ring that sits between upper and lower intake that seals EGR port/tube, hard to see under the soot but its there. I left a little webbing 180 deg apart to add support to the center tower.

Later 6.5s OBDII with electronic IP have problems with PMD/FSD overheat relocate on remote heat sink ASAP if you can't afford that, at a minimum remover plastic "Turbo Power" dress up cover to allow more flow across PMD.

Gages, not enough can be said about importance, if you are a data nut like me more is better, boost & EGT at a minimum, trans if you are frequent towing

Do no more mods than exhaust restriction removal without them!!!

You need to know when to back off Max EGT post turbo location 1000F.

If pre 97 truck and will heavy/frequent tow consider up grade to dual H2O thermostat and HO 130gpm water pump, better fan clutch.

Boost control allows fake out to PCM IAT so boost stays in longer, factory PCM program backs out boost when you need it most, max boost without Intercooling in my opinion 10 psi will explain later. Mechanical WG controls are available for mechanical IP and WG trucks

Remote bypass oil filt setup, on K (4x4) series IMHO a necessity just to get access to the filter, stock adapter does not allow easy access, bypass filt has second element for better filtration plus extra oil helps reduce operating temp from more oil to be cooled and passive cooling as filter bodies are in cooler air stream location than under engine.

Manrel bent left to right bank cross over corrects same problem as turbo down pipe, stock one is crushed and not as free flowing.

Once you get improved air flow, then you can think about more fuel from a chip or a reflash, without flow it's like the old Potato in the tail pipe you are capped/limited at what you can flow.

What follows next falls under the let you concience be your guide category. Modification of emissions equipment is against the law, as you can see from my sig I'm L56/65. I am able to convert to legal mode when I'm not off roading as I would never knowingly break a federal regulation.

Gutting the cat, several ways to skin it remove all together, bore a big hole in the catalist media with a Fosterner bit, knock all guts out and weld pipe in the shell, or have a removable "test pipe" that can be swapped for the cat; which is what I do when I'm finished off roading and cat goes back on

TDC offset whole pages on that one I'm at -1.3 not sure what it gains in the whole scheme of things supposed to be crisper throttle and fuel econ at -1.94 some dissent at just right number -1.94 too aggressive for some, I'm in it for the long haul which is why I settled on -1.3 better than GM -.25-.75 but not tromping on the engine too hard.

As for more fuel I tried a reflash computer, but either the one I had was not right or it isn't much better than the late model L65 PCM program to warrant the extra expense $600 reflash vs. $125 boneyard PCM. Try the boneyard PCM you need a core for the reflash any way if you want to keep your stock one for any reason . I have a 1999 L65 PCM from a 3/4T van with the 76mm fuel curve vs stock 63mm L56, this also allows mte to put a blank flange shim under the EGR valve so I don't flow EGR when off road. L65 PCM does not look for baro, EGR, or MAF.

My MAF gets replaced with a piece of 3" PVC so I'm not restricted by the "honeycomb" of the MAF. I leave all sensors wired so there isn't a potential of "electronic noise" getting induced to the PCM through an "open ended" device not properly grounded. Mecanically baro and EGR solenoids are disconnected only vaccum is to waste gate actuator.

I carry both PCMs I can be back to L56 mode in about 15 minutes, its also handy to go back to stock for troubleshooting, and complying with law of the land

Last mod to the engine was Intercooling, http://myweb.cableone.net/tbogemirep/ this reduces charge air temp from the turbo, as air is compressed it gets hot so while going faster brings up boost, the temp also goes up. to about 350 non IC . Add fuel and combustion temp goes up, water temp is up, run hard enough and long enough and you will melt down pistons or overheat the engine.

The intercooler knocks back the heat to allow you to use the power still available in the engine without doing damage. It doesn't add power per sei just lets you use more of what you have on tap safely. For a non towing truck the benefit probably does not justify the expense, just my opinion don't flame me for it.

Now that you are making more power you gotta stop, GMs braking leaves a lot to be desired. I upgraded my wheels to 3200 lb rated wheels, am running cross drilled rotors with high performance pads front and shoes rear, new stainless lines on order, and will be upgrading to a K30 booster.

New extra support in rear springs www.activesuspension.com, (http://www.activesuspension.com,) I had my trans rebuilt at 68,000 and HD clutch packs installed, added 25K electric trans cooler. I am looking for a good 3/4T or 1T single wheel complete suspension.

Eventually I'll go to a 18:1 block, 300 hp injectors and IP, and bigger turbo.

Whew did not mean to be so long winded but that is quick low down as I see it for power mods and a way to go about it in steps. You DMAX guys that moved on add your knowhow please or set the story straight where I might have it wrong.

That was what I posted at the Place, since I wrote that I added Bill Heath's Turbo Master & 2.0 version reflash PCM, JK's Hi pop injectors.

[ 06-18-2004, 11:22 AM: Message edited by: tbogemirep ]

[dieselrealtor]

What I am hoping for is longevity, most of my driving will be without towing. We will pull a camper approx 30-40% of my annual mileage, but it will be mostly all at once on a cross country trip.

I really appreciate all the advice, I have gleaned some info about oil filter bypass setups, is it worth it? :D

[Turbine Doc]

Yes on the bypass setup, especially on a 4x4 so you can get to the filt, very difficult to access in stock location for that alone a plus IMO.

2nd filt adds more oil to total system(more to heat up), reduces soot & contaminants in oil(I had been changing my dino oil every 3500mi, oil sample results said in current contition I could double that interval) I run Rotella or Delo 15-40

You also get some passive cooling from cooler non engine bay air blowing across filt bodies.

I'm at 86K mi mine has been installed since 38K

[rjschoolcraft]

Check out my post 6.5 Performance (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=006650) for the power upgrade issue. Every one of my upgrades has made the truck run cooler (egt and coolant) so will give me increased life. Gotta love it.

[dieselrealtor]

Thanks to everyone for your insight & experience.

Ron, I was just looking at your impressive stats, do you have any upgrades that you have "outgrown" that you are looking to sell?

[rjschoolcraft]

No, not at this point. Sorry.

[moondoggie]

Good Day!

Mark Rinker on 17 June, 2004 02:35 PM: [i]

[Turbine Doc]

Brian,
Check with Greg at www.lubespecialist.com (http://www.lubespecialist.com) , that is where I got mine, IIRC $9 for prepaid bottle , send sample to lab and you get back result in email.

Running my bypass kit my sample result at 81k Mi said I could double my change interval from 3500 mi to 7000 mi

[dieselrealtor]

Now that I have driven a tank, mostly in town I am getting about 14 mpg, this is a little less than I was hoping for, but very acceptable (my 95 blazer 4.3 doesn't get much better & it is just a wannabe truck). tongue.gif

One thing that I have noticed, waiting for the "wait to start" light to go off, even when hot the engine cranks for about 1-3 seconds before firing up. I don't know if this is normal or something that I should look into, hopefully someone out there can give me some pointers.

All of the help so far has been priceless, I have learned so much in such a short period of time. :D

[rjschoolcraft]

Moondoggie mentioned this to me a while back:

The electronic trucks rely on a crank sensor to determine proper injection timing relationship (the way I described this is way over simplified). It is conceviable that the crank might need to turn one complete revolution before the reference signal is read, depending on where the crank stopped after the last shut down. That could cause some delay in start-up.

The idea seems to have merit to me.

[dieselrealtor]

Ron,
you think this may be the normal operation of the crank angle sensor?

[rjschoolcraft]

Yes, there seems to be a variation in the crank time on mine. Sometimes it starts very quickly, sometimes it cranks a little, hot or cold. I think it has to see that pulse from the crank pickup to orient itself before doing anything else.

[dieselrealtor]

Had my first scare. I thought that the voltmeter was showing a little low, (my 95 blazer does the same thing, normal).
Arrived at my appointment yesterday morning, the gauge was below 12 volts, ok this ain't normal, left it running (in the boonies & skeptical about getting a jump).
Appointment over & on my way back, it shifts into 3rd then immediately shifts back down to 2nd, won't upshift, voltmeter around 10 volts, thought low system voltage, trans went into failsafe, try to get back to town, progressively lost power till meter showed about 9 volts, got out when I got back into celphone coverage, shifted battery cable, slightly loose & engine went up in rpm, started charging.

Took it home & put it on the trickle charger, cleaned battery cables & re-installed.

Good end to what was just a little scary at the beginning. :D

[dieselrealtor]

Oh, since this, it has not cranked as long before starting.

[rjschoolcraft]

Check this out! (http://www.thedieselpage.com/members/batterm.htm) I did this mod and it really helped my cranking speeds.