Page 272 of 488

L 
WATER 
IN 
FUEL 
If the light  comes on at any other time,  use this  chart.  This  light  also  should 
come  on  briefly when 
you  start  your  engine, 
as 
a check.  If it 
doesn’t,  have  it  fixed 
so it will  be there  to 
let  you  know  if you 
ever  do get  water  in 
your  fuel. 
If you drive  when  this warning  light is on, you  can damage your 
fuel  injection  system  and your  engine. 
If the light  comes  on  right 
after  you refuel, 
it means water  was pumped into your  fuel tank. 
Turn 
off your  engine  immediately.  Then, have the water  drained 
at once. 
“WATER IN FUEL” LIGHT  CHART 
Problem  Recommended  Action 
Light  comes on intermittently.  Drain water from  fuel  filter. 
Light stays on: 
1. At  temperatures  above  freezing. 
2. At temperatures  below  freezing. 
3. Immediately  after refueling - 
large  amount  of water possibly 
pumped  into 
fuel tank.  Drain  fuel  filter 
immediately. 
If no 
water  can be drained  and  light  stays 
on,  see  your  dealer  for  assistance. 
Drain  fuel  filter  immediately. 
If no 
water  can be  drained-water  may 
be  frozen.  Open the air bleed  valve 
to  check  for  fuel  pressure. 
If no  fuel 
pressure  is  present,  replace the  fuel 
filter. 
Fuel  tank  purging  required. See 
your  dealer  for  assistance. 
6-6 
ProCarManuals.com 
     
        
        Page 274 of 488

NOTICE: 
If there is water  in  your  diesel  fuel  and  the  weather  is warm  or 
humid,  fungus  and  bacteria  can  grow  in  the  fuel. They  can 
damage  your  fuel  system.  You'll need  a  diesel  fuel  biocide  to 
sterilize  your  fuel  system.  Your dealer  can  advise 
you if you ever 
need  this. 
If your  fuel  tank  needs  to  be purged  to  remove  water,  see your 
dealer  or  a  qualified  technician.  Improper  purging  can  damage 
your  fuel  system. 
Running Out of Fuel  (Diesel Engines) 
If the  engine  stalls and you think that you've run out of fuel,  do this: 
First, open the fuel  filter  air bleed  valve. 
Briefly crank  the 
engine  and have 
someone  watch the 
bleed valve.  If there  is 
air, then  you are 
probably 
out of fuel. 
To restart your engine: 
I. If  you're  parked  on a level surface, add  at least two gallons of fuel. 
However,  if you're  parked 
on a  slope,  you  may  need  to add up to five 
gallons  of fuel. 
2. With  the  air bleed  valve open,  turn your ignition key to START for 10 
to 
15 seconds  to crank  (but not start) your engine.  Wait one minute 
between  intervals 
of cranking  to allow the  starter motor to  cool. 
Overheating  the starter  motor could  damage it. Keep  doing this until 
you can just see some  clear fuel at the air bleed  valve.  (If,  during  this 
step,  the  engine  starts, turn  the ignition  off  and close the valve before 
restart.) 
6-8 
ProCarManuals.com 
     
        
        Page 275 of 488

A CAUTION: 
Diesel  fuel is flammable. It could start a fire if it  gets  on  hot 
engine parts.  You could  be burned.  Don't  let too much  fuel flow 
from  the air bleed 
valve, and  wipe  up any  spilled  fuel  with a 
cloth. 
3. Close the air bleed  valve. 
4. Turn the ignition key to START for 10 to 15 seconds  at a time until 
your engine  starts. 
Fuel  Filter  Replacement  (Diesel  Engines) 
If you want to  change  the fuel  filter yourself,  here's how to  do it: 
A CAUTION: 
Diesel  fuel  is flammable. It could  start a fire if something  ignites 
it,  and  you could  be  burned. Don't  let  it get  on  hot engine  parts, 
and  keep matches  or other  ignition  sources away. 
First. drain  any water  from the filter  following  the procedure for  draining 
water listed  previously. 
Your  vehicle's  engine  should  be  off until the end 
of the  following  procedure. 
1. Apply the parking  brake. 
2. Take off the fuel tank  cap.  This releases  vacuum in the tank. 
3. Unscrew and 
remove the ring 
nut from  the top 
of  the 
filter head. 
6-9 
ProCarManuals.com 
     
        
        Page 276 of 488
7. 
8. 
9. 
10. 
4. Lift the element 
out 
of the  filter 
head. 
5. If  there is any dirt 
on the  element 
sealing  surface 
of 
the filter head, 
clean 
it off. 
6. Line  up the 
widest  slot in the 
top  of the  new 
element  with 
the 
widest key on 
then top of the 
filter  head. Push 
the  element  in 
until the mating 
surfaces touch. 
Replace  and tighten the ring 
nut to the top of the  filter  head 
With 
the air  bleed  valve open,  turn your  ignition key to START for 10 
to 15 seconds.  Wait one minute  for  your  starter to cool. Do this until 
you can  see  clear  fuel coming  from  the air bleed valve. 
Close  the air bleed valve and replace the fuel cap. 
Start  your  engine  and let it idle  for  five  minutes. Check your 
fuel filter 
and  air bleed  valve for leaks. 
6- 10 
ProCarManuals.com 
     
        
        Page 292 of 488

Air Cleaner 
To avoid the possibility  of  un-filtered  air being drawn into the  engine, make 
sure  the air cleaner cover 
is on straight  and  the wing nuts are properly 
tightened.  If there 
is an arrow  on the air  cleaner  cover, it should point  to the 
front of the engine. 
Refer to  the Maintenance  Schedule to determine  when  to replace 
the air 
filter. 
See  “Scheduled Maintenance  Services” 
in the Index. 
A CAUTION: 
Operating  the engine  with  the air cleaner off can cause  you or 
others  to be burned.  The air cleaner not  only  cleans the air,  it 
stops flame  if the  engjne  backfires. 
If it isn’t  there,  and the 
engine backfires,  you could  be burned.  Don’t drive with it 
off, 
and be careful working on the engine  with the air cleaner off. 
I NOTICE: I 
If the  air cleaner  is off, a backfire can cause a damaging  engine 
fire.  And,  dirt can easily  get  into your  engine,  which  will  damage 
it.  Always  have  the air cleaner  in  place  when  you’re  driving. 
To remove the air cleaner filter on a gasoline  engine  or  a 6.5 liter naturally 
aspirated  diesel  engine, turn the wing nuts  to the  left.  Remove  the cover  and 
change 
the filter. 
6-26 
ProCarManuals.com 
     
        
        Page 293 of 488

To remove the air  cleaner  filter  on a 6.5 liter turbocharged  diesel  engine, 
first  remove  the rubber  elbow.  Remember  to observe the caution  about 
turbocharger  blades on the rubber elbow. 
Then, unhook the 
cover  retaining  clips 
and  push  the rear 
of 
the cover  toward the 
engine. 
Automatic Transmission Fluid 
When to Check  and  Change 
A good  time  to  check  your  automatic transmission  fluid  level  is  when the 
engine 
oil is  changed.  Refer to the Maintenance  Schedule to determine 
when  to  change  your  fluid.  See  "Scheduled Maintenance  Services'' 
in the 
Index. 
How to Check 
Because  this  operation  can be  a little difficult, you may  choose to have this 
done  at your 
GM dealer  Service  Department. 
If  you  do 
it yourself,  be sure  to follow all the  instructions  here, or you could 
get 
a false  reading  on the  dipstick. 
NOTICE: 
Too much  or  too  little  fluid  can  damage  your  transmission. Too 
much  can mean  that  some of the  fluid  could  come  out  and  fall  on 
hot  engine  parts  or  exhaust  system  parts,  starting  a  fire.  Be \
 sure 
to  get  an accurate  reading  if  you  check  your  transmission  fluid. 
6-27 
ProCarManuals.com 
     
        
        Page 350 of 488
Service  Replacement  Part  and  Filter 
Recommendations 
- Gasoline  Engines 
Engine 4.3L 
VTN Z 
Oil Filter  PFS2 
Air  Cleaner 
A 178CW 
Filter 
PCV  Valve  CV789C 
Spark 
Plugs* .CR43TS 
Fuel Filter  GF48 
1 
Radiator  Cap 
RC36 
5.0L 
H 
PF12183- 
A348C 
cv774c 
.CR43TS 
GF48 
1 
RC36 
5.7L 
K 
PF1218q A348C 
cv774c 
.CR43TS  GF38 
1 
RC36 
+Four  Wheel  Drive  Vehicle 
- use a PFS2  oil filter 
Wse AC  copper-cored  resistor type spark plugs 
Service  Replacement  Part  and  Filter 
Recommendations 
- Diesel  Engines 
Engine 6.5L 6.5L 
VIN P S 
Oil Filter  PF1218 
PF1218 
Air  Cleaner  A644C 
A 1236C 
Fuel  Filter  TP 
1006  TP 
1 006 
Surge 
Tank Cap  RC33  RC33 
7.41 
N 
PF1218 
A348C 
cv774c 
.CR43TS  GF48 
I 
RC36 
6.51 
F 
PF1218 
A 1236C 
TP 
I006 
RC33 
6-84 
ProCarManuals.com 
     
        
        Page 360 of 488

If your engine has more  than one  emissions  classification, the classification 
is determined by the Gross  Vehicle  Weight  Rating  (GVWR) of your  vehicle 
as shown  on  the Certification  Label.  See “Loading  Your  Vehicle” 
in the 
Index. 
Once  you’ve determined your  engine type and, 
if necessary, emissions 
classification,  you’ll need to  decide which  of  the  two schedules  is  right  for 
your vehicle.  See Definitions  for Maintenance  Schedule 
I and Maintenance 
Schedule 
I1 following. 
Schedule  I Definition - Gasoline  Engines  With  Light  Duty 
Emissions 
Follow Maintenance  Schedule I if any  one of these  is true for your vehicle: 
iII Most  trips are  less than 5 to 10 miles (8 to 16 km). This  is particularly 
important  when outside temperatures  are  below freezing. 
0 Most trips include  extensive idling (such as frequent driving in 
stop-and-go  traffic). 
You operate your vehicle in dusty  areas  or off-road  frequently. 
0 You frequently  tow a trailer. 
Schedule 
I should also be  followed if the  vehicle  is  used  for  delivery 
service,  police, taxi, or other commercial  application. 
Schedule I Intervals - Gasoline  Engines  With  Light  Duty 
Emissions 
Every 
3,000 Miles (5 000 km) or 3 Months,  Whichever Occurs First 
Engine Oil and Filter  Change 
Chassis  Lubrication 
Drive Axle Service 
At 6,000 Miles (10 000 km) - Then  Every 12,000 Miles (25 000 km) 
Tire  Rotation 
Every 75,000 Miles (25 000 km) 
Air Cleaner Filter Inspection, if driving in dusty  conditions 
Front Wheel Bearing Repack 
(or at each brake  relining)  (2WD  Only) 
7-4 
ProCarManuals.com