Check to see if the hoses are collapsing.

 

He has told me that the heat comes and goes. Sometimes it's warm, other times it's cold.

 

 

Would the water pump contribute to the fast "overheating" within the 10 minutes?

 

04 Inti.. shoud he have the car on and then disconnect the hose?

 

You can do that but use caution. The coolant has isn't water and will heat above boiling. The safer way would be to have the car be cool ... remove the Radiator Cap ... Have a Shop-style Thermometer to measure the temp of the water in the Radiator. If the Radiator begins overflow before the Temperature of the contents of the Radiator is below that of the overheating engine ... You pretty-much KNOW its the Pump ... because the Engine will heat opening the Stat and letting coolant from the Radiator get pumped through the system.

You can also PROBE the Water Pump and "Listen" for the Impeller trying to move the coolant. If the noise coming from the Pump Housing is strictly Rotational and you don't detect a fluid movement ... that Water Pump is shot and needs to be Replaced.

Judging from what has been discussed in this thread, so far, I'd say you should replace the Water Pump and Stat. I'd put a Stat in there as cool as you can go without causing a problem of running NOT Hot enough.

You might want to replace the Belt too, because its a good preventive maintenance job and you'll have to remove it anyway to get the Old Pump off that block. Always use a new Gasket when doing the Pump Job ... and add some High-Temp Sealant of prevent the Gasket from leaking.

 

Okay. My friend who owns the car sent me an email of EVERYTHING in detail.. if anything is repetitive, I apologize.

Delayed start up, engine makes a grinding noise once running. every 5 seconds engine makes a [/align] [/align] knocking noise, can be felt through the steering wheel. Car idles extremely rough, [/align] [/align] occasionally the service engine light will blink when it idles harder. The rest of the time [/align] [/align] the service engine light will remain on but not flicker. Had a diagnostic done, multiple [/align] [/align] misfires, bad 02 sensor, bad intake manifold seals. Changed out the seals to fix the problem [/align] [/align] of pressure leak and coolant and oil mixing. car frequently overhealts from a cold start up, [/align] [/align] engine not hot, possibly a bad sensor? Have not yet flushed radiator or changed new oil. [/align] [/align] Exhaust spits out sweet smelling smoke. Asked dealership to check head gasket, did a leak [/align] [/align] pressure check, checked out good. When car "overheats" Engine wants to accellerate on [/align] [/align] occasions. Majority of the time the speed and power is put into GIMP mode, so i cant go [/align] [/align] above 2,000 RPMs. The overtemp used to bounce around without hitting the "hot temp" now once [/align] [/align] it overheats it usually stays that way until i restart it. Ive also noticed when car is [/align] [/align] running hot it looks like the Reservoir is bubbling, Either its extremly hot, or the engine [/align] [/align] is spitting it back into the reservoir. Not really sure. Above 4,000 RPMS, car runs [/align] [/align] extremly rough, engine misfires and knocks, unsure to the cause.[/align][/align]

 

Your problem of coolant and oil mixing is serious. That could mean a blown head gasket or a crack in the cylinder head. That you see the overflow bubbling confirms its overheating do to the problem you have.

A typical scenario begins with a problem like the water pump or thermostat and because the problem was not corrected they ballooned into a costly repair. Once the engine overheats the Aluminum Heads would be prone to cracking ... causing the coolant and oil to mix. Pull a rocker cover and see it the inside is coated with a ugly, creamy substance ... a combination of oil and coolant. If you have creamy material buildup inside the covers ... then, you need to start worrying about permanent damage done to the engine s a result of the overheats. The heads can't withstand too much of an overheat without cracking across where water-jacket is brought closer to combustion chamber. And, you need to look for a fracture across the top of the combustion chamber in the area that separates the two valves.

If this problem spread from being a water pumo to damage from operating the engine in a superheated condition ... the repairs are going to be labor intensive and costly. You may be looking at replacing your cylinder head(s) plus cooling system parts as well.

The clue you provided about seeing the overflow tank gurgling is pointing to serious trouble. I hope its just a pump but I have a sneaking suspicion it could be worse, now.

 

sounds very much like a head gasket / cracked / warped head to me too

 

We bought an OBD II Scanner and here were the reports.. I apologize for the lengthiness of this

Report#:1
Report Date:1-6-2008 (3:08 PM)
Vehicle Year:1999
Vehicle Make:Chevrolet
Vehicle Model:monte carlo
Vehicle Engine Size:3.1L
Vehicle VIN:
Vehicle License Plate:
Vehicle Mileage:
Stored:
P0131O2 Circuit Low Voltage (Bank 1, Sensor 1)
P0301Cylinder 1 Misfire Detected
P0420Catalyst System Efficiency Below Threshold (Bank 1)

Pending:
P0420Catalyst System Efficiency Below Threshold (Bank 1)
MILON
MisFire MonitorComplete
Fuel System MonitorComplete
Comprehensive Component MonitorComplete
Catalyst MonitorComplete
Heated Catalyst MonitorNot Supported
Evaporative System MonitorComplete
Secondary Air System MonitorNot Supported
A/C System Refrigerant MonitorNot Supported
Oxygen Sensor MonitorComplete
Oxygen Sensor Heater MonitorComplete
EGR System MonitorComplete
DTC for which Freeze Frame was StoredP0301
Fuel System 1 StatusOpen Loop
Fuel System 2 StatusNot Supported
Calculated LOAD Value36.08 %
Engine Coolant Temp51.80 °F
Short Term Fuel Trim - Bank 1-0.78 %
Long Term Fuel Trim - Bank 10.78 %
Intake Manifold Absolute Pressure22.44 inHg
Engine RPM2621 rpm
Vehicle Speed Sensor15.53 mph
Air Flow Rate Mass Air Flow Sensor7.00 lb/min
Absolute Throttle Position35.29 %
Automatic Transmission Problems:
Check Engine Light:
Driving Conditions When Problem Occurs:
Driving Habits:
Engine Quits Or Stalls:
Engine Temperature When Problem Noticed:
Problem First Noticed:
Gasoline Used:
Idling Conditions:
Peculiar Smells:
Problem Occurs:
Problems Starting Vehicle:
Running Conditions:
Strange Noises:
Weather Conditions When Problem Occurs:
Transmission Type:
Describe The Problem:
Previous Repairs:

Problem Found:
Repair Performed:
Related Technical Service Bulletins:
Repair Time (hours):