Question about 1998 GMC Sierra

1 Answer

A/c blow very cold air just dont blow enough ,its like a vacum line is closed or clogged

Posted by on


1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 20 achievements.


    An expert that got 10 achievements.


    An expert that got 5 achievements.

  • GMC Master
  • 17,130 Answers

You would have meant that the blower is not effficieent to blow the cold air well into the cabin.? If so then the blower is faulty.A clogged filter in the blower will not recirculate the air from within and will be dying down.
So get teh blower filter fitted at the intake of the blower unit to be taken out and dusted with high pressure air. This must be done periodically and and AC car is most recommended to be cleaned on the inside and not run with windows down on dirt/dusty tracks, as all the dust accumulating will clogg on to the filter and will even give a bad smell.
Also if possible clean the fan blades, the vents and also the cooling coils accordingly to your access.
I am sure this must solve the issue.

Posted on Aug 31, 2010


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya Mechanic can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repair professionals here in the US.
click here to Talk to a Mechanic (only for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Replaced thermostat heater blows warm for a few minutes and then cold for a while then hot again and then cold??

Check vacume lines on heater boxes under dash doors on your heater box are opening and closeing check the vacume lines on engine also sounds like a vacume leek

Nov 21, 2010 | 2005 Dodge Stratus

1 Answer

2002 Dodge Caravan - A/C not blowing, blows a little cold air when pressing on gas pedal, stops when not moving

Sounds like there is a vacum leak
Check the vacum line coming from the intake to the firewall this should be a small black line

Jul 12, 2010 | 2002 Dodge Caravan

2 Answers

Ac seems to come on but air not blowing through the vents. the fan is working. i can hear it but nothing comes through the vents. you can feel some cold air coming from behind the dash.

Check for a broken vacume line under the hood find the vacume canister should be eather on the right or left side under the fender its a black round ball shaped with 2 hose's one in one outif the line is not attached or is leaking then you do not get any air

Apr 09, 2010 | 2002 Chevrolet Tahoe

1 Answer

2000 dodge neon that blows cold air all the time

hi, you could probably start by bleeding the air out of the radiator, thats not to hard and is easy to narrow out,
if the heater core is cloged you could try flushing it out, you could take both heater hoses off at one end and stick a hose in and check if there is flow through it, if there is good flow then check all vacume lines etc... if you know where the right line is you could try and overide it by borrowing a vacume line from somewhere else or bloing into the hose to see if anything changes...

Feb 11, 2010 | Dodge Neon Cars & Trucks

1 Answer

1997grand voyager is blowing cold air new thermostate water pump and the raditor and heater core has been back flushed it started blowing hot air again then went back to blowing cold air again

I would look for a vacum leak on the control valve for the heater. There are 2 lines from the radiator leading back to the firewall. One has a control valve on it that should be vacum controlled. When you back flushed to the heater core you may have forced this valve open temporarily. The control may have low vacum or insufficient vacum to open a stuck valve. The good news is you can actually manually open this valve and tie it in the open position which will at least temporarily solve the problem. Check your vacum lines for leaks and check the valve to make sure it isn't sticking.

Jan 21, 2010 | 1999 Plymouth Grand Voyager

1 Answer

1998 Jeep Wrangler not blowing hot air. Fan is blowing cold air. Suggestions?

your heater hose or heater core could be plug, or your flap that opens inside of the heater housing may not be opening like it should. It operates off a vacum line, check all your vacum lines going into your heater housing.
good luck

Dec 09, 2009 | 1998 Jeep Wrangler

1 Answer

Blowing hot air all the time

There is a door that opens to the heater core.When the vacum control in the dash gets old the diaphram gets to flimsy to close one port so it puts vacum to all ports.Therefore there is not enough pull to engage the vacum motor to move the trap door.Change the switch in the dash. Check to make sure that there isn't an obstructing object in front of the door before you buy a new switch

Jun 02, 2009 | 2000 Chevrolet Blazer

3 Answers

A/C blowing hot air, I'm testing your talents because so far this site has done me no good

Run the OBD diagnostic with the ATC self test feature. I bet you'll find a faulty blend door or motor....accordianman PS Three Pounds??!!?

Jul 28, 2008 | 1994 Chrysler Concorde

Not finding what you are looking for?
1998 GMC Sierra Logo

Related Topics:

65 people viewed this question

Ask a Question

Usually answered in minutes!

Top GMC Experts


Level 3 Expert

77202 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22265 Answers

Ronny Bennett Sr.
Ronny Bennett Sr.

Level 3 Expert

6927 Answers

Are you a GMC Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides