Front end shakings

take it back to the workshop that did the work

leak somewhere
cooling fan slow to spin or not coming on
head gasket issue

Thermostat ?

post all signs of overheating.

1. dash guage
2. STEAM eruptions>?
3. AF (antifreeze ) leaks?
4. CHeck engine light sticks on running?
5. Scan tool shows way hotter than 200F? "ECT PID" parameter.
6. oil in the AF? cold you see oil floating in the neck of the rad cap off?
7. AF found on the A/T tranny dip stick end?
8. Loosing coolant (drops) all the time, Check rad directly cold.?
9. engine pings, (knock/detonation) ?
10. lost power. from engine.
11. shaking of engine. as it misfires.
12. car heater makes this odd gurgling sound?

those are the signs but. what about precondtions.
overheats only parked< and never moving fast>
yes, bad RAD fan, (or its controls)
over heats all the time>?
fan belt fell off or slips?
clogged, rad tubes. (inside)?
water pump bad, blades, rusted to nothing.?
thermostat died, as most do way before 10 years,,,,,,,
clogged system from not doing the 2year service.

WATER PUMP ON FRONT OF ENGINE HAS THE FAN SHROUD AND PULLEY ON IT.FOLLOW LOWER WATER PUMP HOSE TO RADIATOR AND HEATER BYPASS HOSE YOU CANT MISS WATER PUMP..

The first place would look assuming you have already changed antifreeze and replaced radiator cap is the fan clutch, try moving the fan when the motor is cool does it move freely? if yes then replace the fan clutch. If it is stiff then check that the radiator is not plugged with bugs or dabree if it is take it to a car wash and wash it out in reverse flow from the engine side out, be sure not to get electrical parts wet.If this does not fix your problem then you can check the hoses by removing them and see if they are separated if not then the next issue is the water pump or head gasket, the head gasket would be checked by using a gas sniffer at a garage to see if hydrocarbons are coming from the radiator, if not then your best bet is the water pump I hope this helps.

The waterpump on a chevy suburban can be removed once you remove the radiator fan.

1. Drain the coolant from the system.
2. Here is a way to remove the fan clutch withouy a fan clutch tool. The trick is to leave the belt on and tight.
3. Take a 1 7/16 inch wrench and put it behind the fan onto the big shaft nut attaching the fan to the water pump. P
4. ut it straight up and crack it counterclockwise with a hammer.
5. This should loosen the nut.
6. After that just spin the fan off and the rest is easy.
7. Make sure you clean the old seal off of the engine. It is small and easy to miss.
8. remove the serpentine belt.
9. remove the hoses connecting to the water pump
10. remove 4 bolts holding the water pump onto the block
11. clean the block of any old gasket
12. fit the new waterpump and new gasket.
13. connect the hoses to the pump.
14. refit the serpentine belt
15. refit the fan
16. refit the rad and cowling
17. fill it up with coolant.
18. Run the engine and check for leaks.

That is actually a pretty broad problem if you will. If it is overheating and you have coolant, wait til you have a day off, and when you do, pop the hood while it is still cold (sit over night) take the cap off of the radiator, and start the car. You will have to wait for a little while til it gets warm, but watch the coolant throught the top. If you see it flow, you may need a fan, or fan clutch. If there is no flow, then it will be basically isolated to your water pump, or your thermostat. Always replace the thermostat first just because you will need one at some point anyway, and that will tell you if you need a water pump

At least you have the 4 liter 6. Once you get all the **** out of the way its like replacing a W/P on an "old school" engine, very much like a Ford or Chevy straight 6. 1) Remove radiator top retainer (the metal U that looks like its the top of the radiator (#13 or 14mm sockets I think). 2) To completely get if off you also have to remove the grill (4-6 phillips screws), then 3) unbolt it from the tubular bumper retainers underneath the grill. 4) DO NOT remove the latch cable - no need. 5) Remove the top bolts holding down the fan shroud. Lift the shroud off its bottom "tabs" and push over the fan. 6) Using #10mm socket remove fan from fan clutch, then remove bolts holding fan clutch onto water pump pulley. 7) Pull out shroud, then fan, then fan clutch. Be very patient, lots of wiggling may be needed. 8) Locate belt tensioner on idler puller below the Power steering pump. Losen very little the pulleys center bolt (10mm), then use a 10mm w/entension to losen the pulley's tension (use counter clockwise/normal rotation to losen). 9) Draw a diagram of the belt routing - you will Never remember it correctly otherwise. 10) Tap the w/p pully and pull if off - do not hit radiator fins! 11) Drain the radiator (clockwise/right rotation opens petoc from factory radiators - counterclock used on aftermaket rads). 12) Remove lower raditor hose at radiator, then at pump (it will be a challenge). 13) Remove upper radiator hose from rad and from thermostat housing. 14) losen the Rubber heater hose from the metal hose screwed into the W/P. 15) Remove 4 bolts from W/P (13 or 14mm I think). The one at the 4oclock position is longer than the others. One is hidden at 6oclock.
16) Remove 2 bolts (14-15mm??) on bottom of Power Steering mount - these go through the W/P case to the block. You may also need to losen the top PS bolts so the PS Bracket can be loose at the W/P case. 17) Wiggle the W/P out from under the PS bracket. and pull off. (16b if needed, remove the upper idler pulley near the A/C unit.) 18) Remove the Thermostat (upper hose return) housing. Scrape off old gasket. Replace with 160deg or 190deg thermostat. Use silicone on gasket. 19) Carefully use a 17 or 19mm box wrench to remove the metal heater hose return line from the upper part of the old water pump. Coat threads with spark plug thread antiseize and screw onto new W/P. 20) Install new W/P gasket w/silcone, be careful to Not block the water holes. 21) Slide W/P under the P/S bracket and jiggle into place. Hand thread one of the top bolts to hold the W/P in place. 22) Insert the P/S bracket bolts and lightly tighten. 23) Jiggle W/P around and insert other bolts, start with the 6oc hidden bolt. Add remaining bolts and tighten to 25 or 250?ftlb (about 3/4 past socket-snug). 24) Tighten ALL P/S bolts. 25) Adjust metal heater pipe. Reinstall rubber heater hose. 26) Reinstall W/P pulley and Fan clutch, and upper idler if it was removed. 27) Thread NEW Belt on pulleys. 28) Tighten tension on idler. Tighten idler axle bolt. 29) Install lower rad hose. 30) Slide shroud over pulleys. 31) Install fan on clutch. 32) Clip shroud retainer bolt mounts back on top of radiator. 33) Install shroud. 34) Connect upper hose. 35) Reinstall radiator retainer. 36) Bolt retainer to Tubular bumper mounts. 37) Reinstall grill. 38) Wonder where the extra bolts etc are supposed to go. 39) Cuss - pray -cuss - pray. 40 ) sip some beer. 41) carefully inspect everything to ensure its back to the way it looked before (several pictures from a digital camera taken during the disassembly will help). 42) Close the rad petok. 43) Add 1 gallons of antifreeze. 44) Start engine and add another gallon of A/F. 45) Turn heater controls to HOT inside (no need for fan). 46) Water guage should show 180 to 210F. 47) Add 1 gallon of water. 48) Install New 18PSI rad cap. 49) Turn off engine and add water or A/F to overflow tank. 50) 1 hour later open Cap to see if level has settled. Add Water as needed to fill rad.

you can check if the water pump is working by feeling the top rad hose , if it is hot it should circulate into the rad and the rad should be hot at the top and cool at the bottom if the pump is faulty there will be no circulation of hot coolant into the rad. I suspect your head gasket might be blown if you are getting pressure built up in the rad. in that case you will need a new gasket and have your head skimmed

Normally, the fan will not spin at the same RPM as the engine. This is the purpose of the fan clutch. On the fan clutch sits a little thermal spring that engages the clutch to spin the fan at the same rpm as the motor when the motor gets hotter than normal.

Being able to hold onto the fan while the motor is running, is normal (not recommended, but normal).
You can test the clutch by heating it and then trying to spin the fan while the motor is off. If it is still easy to spin, you could have a bad fan clutch, or you didn't heat it enough. It is kind of a crappy way to test.

You not having cooling issues leads me to guess that your clutch is alright. But I don't know what type of climate you live it, nor do I know in what condition your clutch is.

They can actually be difficult to replace. Easy theory, but actually doing the job may be harder than you think. They are threaded onto the water pump pulley (just one big threaded stud). To remove you need to either be really crafty, or you need a wrench designed to hold the pulley in place while you loosen the clutch and fan assembly. No, the pulley drive belt is not enough to keep the pulley from turning (it will either slip or you will turn the crank of the motor).

Usually they are on there pretty tight! When I replaced my water pump on my truck, I could not remove the fand and clutch from the water pump while in the truck (I had to remove my radiator shroud and remove it all in one piece) then I had to weld the old water pump impeller to the casting to keep it from spinning then broke it loose with a 2ft breaker bar! Seriously.

Once you get the old one off, remove the fan and bolt it to your new clutch unit. Then thread it on the water pump.