MY COOLANT KEEPS EVAPORATING AND TEMP NEEDLE GOES ALL THE WAY UP. I HAVE FLUSHED THE RADIATOR AND CHANGED THE THERMOSTAT.I DONT KNOW WHAT MY NEXT MOVE SHOULD BE. WHAT DO YOU THINK. SOMEONE TOLD IT COULD BE DEHIDRATION AND MY HEAD GASKET MIGHT BE BAD.
if you dont see antifreeze leaking anywhere,its the head gasket,check your oil dipstck,the antifreeze is probally mixxing with the oil as it leaks thru the gasket and will give the oil a milky white color on the dipstick,if you start to see white smoke from the exaust then its leaking into your exaust port,either way head gasket and change as soon as possible,you dont want it in the oil cause you can seize the motor
Posted on Jul 08, 2008
Have a Yukon when started idles very rough, revs up to 2K rpm, and almost stalls to the point where cylinders are dropping out. Idle is up and down up and down, seems to improve as engine heats up. Code reader says 'Lean Bank 1, Lean Bank 2.' No other codes present. Changed fuel filter, air filter, cleaned MAF with special solvent from parts store. Did not help. Note: filled gas tank up to 3/4, problem not as evident, but still there. Help!!!!! Is it the fuel pump???
i now for a fact that it is the egr valve . carbon balls in side you have to take it of and clean them out
Posted on Apr 18, 2009
SES light is on and the pcm codes of P0171 and P0174 popped up on the OBDII. Replaced the MAF sensor, reset the the PCM and drove it. Sure enough the SES light came back on. Tested and the same two codes pop up. Whats next? 2002 GMC Yukon denali
Could also be fuel filter, pressure, vacuum leak, etc. Check these two articles out, they should help too - http://www.obd-codes.com/p0171 and http://www.obd-codes.com/p0174
Posted on Dec 21, 2008
I've checked the system pressure in the A/C and it's fine, also the rear A/C blows cold like it should, but my front A/C blows only warm air..the fans work like they should I'm just not getting any cold air. Any help would be great. I look forward to your answers!!
Here is a TSB (Technical Service Bulletin) for your vehicle for loss of temp control.
File In Section: 01 - HVAC
Bulletin No.: 01-01-39-007
TECHNICAL
Subject:
Loss Of HVAC System Mode and/or Temperature Control
(Reroute Wiring Harness)
Models
1999-2002 Chevrolet and GMC C/K Pickup Models (Silverado and Sierra) 1999-2002 Chevrolet and GMC C/K Utility Models (Avalanche, Suburban, Tahoe, Yukon, Yukon XL, Denali) 2001 GMC Sierra C3
2002 GMC Sierra Denali
2002 Cadillac Escalade, Escalade EXT
Some customers may comment that they cannot control the HVAC system modes and/or the temperature. These concerns may be intermittent.
Cause
There may be poor terminal contact and/or bent terminals in connectors C206 (RPO C68 automatic HVAC controls) or C296 (RPO C60 manual HVAC controls). Excessive tension on the wires due to the wiring harness being miss routed in the instrument panel carrier may cause these conditions.
If the warranty campaign is over i am sure they can or may have in the system on how to correct the problem.
Good luck and hope this helps, keep me posted if you need help on to the repair procedure.
Posted on May 26, 2009
help my 2005 denali is overheating, replaced thermostat and water pump and problem persists I haethe truck at GMC and they belive there is air in system or head Gasket needs to be replace can you please advise
Start it cold with rad cap off, and heater on high heat, and let it run until you see increased flow in radiator, indicating thermostat opened & engine reached operating temperature. Rev engine slightly every once in a while and hold it there for 10-20 seconds, just to help purge air better/faster. Watch rad flow again, and wait until you see increased flow 3 or 4 times. Then top up coolant in rad to an inch or 2 from top of rad, and put cap back on. Top up return bottle to appropriate level on bottle & then try it again. If it still heats up, get back to me. Does it overheat at all times? Rad fan is good i take it?
Posted on Jul 18, 2009
2002 gmc yukon denali rough idle, low idle about 500 rpms on cold starts or when air is turned on
Clean the trottle body & Check spark plugs.
Posted on Feb 14, 2010
where is the coolant temperature sensor located in a 2003 yukon denali awd 6.0. thanks in advance
Follow the top radiator hose to where it meets the engine. This is known as the thermostat housing, the sensor will be either screwed into that (also look on the underside the housing) or within 4" of the housing.
It is the standard place for that sensor as it is the hottest water point of an engine.
Best regards
Lloyd
Posted on Dec 15, 2009
have no power to the ac compressor. all fuses and relays are good i i used a jumper wire on the ac low pressure switch and still no power at compressor it has front and rear ac with automatic control 2002 gmc yukon denali
SOUND LIKE AC COMPRESSOR CLUTCH COIL IS OPEN.ITS GETTING POWER YOU HAVE A OPEN COIL CIRCUIT.
Posted on May 27, 2010
will a bad mass air flow sensor stop a car from starting
Yes,but they seldom fail
I would look a lot of places before that
If it is unplugged it won't start,if you have ducting
or air filter cover loose, it won't be able to adjust for
air flow.
You can not test it yourself
You need a scanner or back probe it with a scope etc,
who has that knowledge
Do you have any check lights or codes?
Need more vehicle history & current issues leading up to
the no start!
Posted on Dec 03, 2010
need diagram of drive belt assembly for 8.1 liter gm
Hello! Here is the diagram of the drive belt for an 8.1L...Guru..saailer
I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867
Posted on Jan 02, 2012
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