Question about 1994 GMC Sonoma

1 Answer

Radiator leaks at drain plug. I have a 1994 GMC Sonoma 4.3L truck. Recently after flushing the radiator and refilling it, coolant leaks at the radiator drain plug. It does not have the type of plug that gets removed all the way, it turns and pulls out partially. The o-ring appears fine, but if the plug is not meant to be removed completely, I'm not sure how I could replace it anyway. I love this truck, it's the first vehicle I bought on my own and keeping it in good running condition is a sense of pride for me (plus I am unemployed and I can't keep having my ex-husband do repairs). Does anyone have any suggestions? I'm a little new at doing stuff on my own, but this doesn't seem to be all that complicated, I just can't afford a new radiator, is there any thing I can do to stop this leak? Something I may have overlooked?

Posted by on


1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • GMC Master
  • 959 Answers

The plug is replacable.. you need to squeeze the tabs together to remove it fully though... Think old school clothes line pin...

Posted on Sep 30, 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 expert 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 repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (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:

2 Answers

How to drain coolant

They do clog up and will not drain. You probably found the drain. Pull the lower radiator hose. If you have access to air and can shoot it up in the hole. This might help you problem.

Jul 08, 2015 | 1997 GMC Jimmy

2 Answers


Not sure what you mean by "using a small amount of water." Are you having to refill the coolant? If you are losing coolant, it's either leaking on the ground or leaking into the combustion chamber. Either one of these will cause overheating.

Aug 04, 2017 | Cars & Trucks

1 Answer

How to change radiator drain plug

Simply loosen the old one in the radiator to let the coolant run out. After the radiator is empty, pull the old drain cock out of the radiator and install the new one. Tighten the new one up firmly and refill with coolant. Let the engine run to reach normal operating temperature and check for leaks.

Jul 09, 2014 | 1991 GMC Sonoma

1 Answer

Coolant leaking from 1994 Sonoma. Is not near the water pump or radiator, but more towards the back of the block. What might it be?

It could be a heater hose, an intake manifold gasket, or a rusted through freeze plug. You must "look" to see where the leak is originating from.

Jan 02, 2012 | 1994 GMC Sonoma

1 Answer

Coolant level ok no leaks new 195 deg. thermostat still very little heat from heater defective heater core?

I am assuming your vehicle has the pink antifreeze called Dexcool. This is the recommended coolant for all late model GM cars and trucks. This coolant tends to form a pasty sludge in the cooling system which can lead to overheating and/or plugged up heater core. Try flushing the cooling system with a good aftermarket product such as prestone radiator flush. First thing to do is drain all the pink coolant, then add the radiator flush and fill with plain water. Run the engine according to directions on the flush container. Drain the radiator again and refill with plain water. Run the engine for a few minutes and drain again. Keep repeating this until all the pink antifreeze has been eliminated. Fill the system with 2 gallons of green antifreeze. Make sure the antifreeze container says it is compatible with aluminum engine parts. Hope this helps. If it does, then you won't have to replace the heater core.

Dec 16, 2010 | 1999 GMC Sonoma

1 Answer

How do I drain the coolant in a 1998 GMC Sonoma?


Open the bonnet of your 1998 GMC Sonoma, look under the radiator, you will see a hose/pipe coming out of the radiator going into the engine of the 1998 GMC Sonoma. Remove the hose and the coolant will drain.

You will see a screw holding the hose to the engine, get a screw driver to loosen the screw so that the hose can be easily removed.

After draining, pour more water into the radiator to flush out the coolant entirely from the radiator.

I hope this helps.

Good luck.

Nov 24, 2010 | GMC Sonoma Cars & Trucks

1 Answer

Draining old coolant how does the drain plug work on radiator can'nt get it to move.

it works like any tap ----anti clockwise to open it . if you cant get it to move , remove the bottom radiator hose .

May 04, 2010 | 1994 GMC Sonoma

2 Answers

I have a coolant leak in the back of the block of my 1994 gmc sonoma. i'm not sure if it is the freeze plugs or the o-ring. wat can i do to stop the leak, or seal it for a while until i can afford to get...

If the leak is not to bad, you can add 3 table spoon of common kitchen table black pepper. The pepper will plug up the hole and when it's time to clean up, it's just a simple flush and the pepper will not plug up any water passageways. Try not to use any radiator stop leak, they end up restricting the water flow and your going to have to use radiator flush to get it all cleaned up which can also damage the heater core creating more work for you. Good luck and hope it's a simple fix once you have some time. Keep me posted.

Feb 09, 2010 | 1994 GMC Sonoma

1 Answer

Changing antifreeze in a 2001 GMC sonoma

you can remove the lower radiator hose on the bottom of the radiator. **remember to let the vehicle cool before working on**, as coolant burns are very serious and difficult to remove quickly with water. make sure that you collect the old coolant, it will need to be disposed of properly [not into the ground] and take a water hose and place it inside the top of the radiator to flush the system . once the system appears to run clean of all coolant , replace the lower hose and refill as desired. once full, crank the vehicle with the radiator cap off and continue to fill. this will allow the water to flow and release any air pockets that may be in the system. once full and constant flow is assumed, replace the radiator cap .

Nov 11, 2009 | 2001 GMC Sonoma Extended Cab

1 Answer

What should I do to clean out my radiator in my 1994 Merc Sable?

locate drain plug on bottom of radiator and drain coolant then flush with water till clean. close drain and refill will Peak green 50/50 fluid

Apr 09, 2009 | 1996 Mercury Sable

Not finding what you are looking for?
1994 GMC Sonoma Logo

375 people viewed this question

Ask a Question

Usually answered in minutes!

Top GMC Experts


Level 3 Expert

76848 Answers


Level 3 Expert

1311 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22246 Answers

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

Answer questions

Manuals & User Guides