About a week ago, my wife mentioned that the heat was not working in our ’06 Equinox. (no overheating & no white smoke). I took it to 2 mechanics, one mentioned a clogged heater core, another mechanic is thinking head gasket.

When I got back, I reversed flushed the entire system with Blue Devil Flush. Might’ve flushed it too good, car is definitely showing signs of a blown head gasket now: white smoke & overheating after driving 30mins. I’m eventually going to replace the head gasket when the weather gets better in IL.

We probably drive 15-20 miles/day. Can I temporarily get by till March/April by using one of the head gasket sealers?

Has anyone used and/or recommend:
+ BlueDevil Head Gasket Sealer
+ BlueDevil Pour-N-Go Head Gasket Sealer
+ Bar's Leaks Head Seal Blown Head Gasket Repair

Thanks!

 

I'd confirm you actually have a bad head gasket first.

Make sure the cooling system is properly bled. It can be difficult to bleed. I recommend parking at an angle on a hill with the front right corner the most uphill to help air bubbles flow to the bleeder screw.
Make sure both radiator cooling fans are working. The connectors going to the fan motors often fail.
Replace the coolant lid if you haven't already done so. The coolant will boil prematurely (which produces air pockets/hotspots) if the cap isn't holding pressure. This is very possible on a vehicle this old.
I have no experience with leak sealers, but I've heard good things about the Blue Devil stuff.

 

K&N makes a good block sealer, but you have to run it in water, not anti-freeze, until it works.

 

I agree you should confirm it’s the head gasket - these engines can also draw coolant in from the lower intake manifold gasket.

Lisle tools has a head gasket testing kit #75500 - we use it at work and have had very dependable results. You can also rent a cooling system pressure tester.

As for sealers, I don’t recommend them because they can also clog up radiators and heater cores, but if you’re going to use one, whether or not it works and how long it lasts depends on the location and severity of the leak. We’ve reluctantly dumped them into cars at customer request and results varied from “didn’t last a mile” to “haven’t seen it since.”

 

While this is true, the intake gaskets very rarely fail in the 2005-2009 Equinox/Torrent. They use a unique design that's different from the other GM 3.1/3.4L engines which are notorious for lower intake manifold gasket failures. I also generally don't recommend the use of stop leaks/sealers because they often do more harm than good.

 

Please define “rarely” and “unique” because I don’t think there’s a 3.4 equinox in central Iowa that meets those qualifications!

You must be referring to the 3.6 and I’ll agree that they don’t usually have problems with lower intake gasket failures - however, they also don’t have coolant circulating through the lower intake, and they weren’t introduced (for the equinox, at least) until late 07/early 08. The OP said his equinox is a 2006, so it should have a 3.4 in it, so long as a previous owner didn’t swap it out.

 

I said they "rarely" fail because there aren't gobs of threads on here or other forums regarding intake manifold gasket failures with the LNJ engines. When you own the same vehicle for 12 years, you become pretty familiar with it's weaknesses and common problems. Common problems are easy to find with the help of Google. There's only one thread on this forum with pictures of what appears to be a lower intake manifold gasket failure on an LNJ engine, but the user didn't provide much context and never followed up.

I'm definitely referring to the 3.4L (RPO code LNJ) and not the 3.6L (RPO code LY7). I meant "unique" as in the LNJ engine uses different intake manifold gaskets than the 3.4L engine GM used in all the other models (RPO code LA1). The main difference is that the LNJ engine uses true, molded rubber valley seals instead of relying on RTV silicone alone there like the LA1 did. The gaskets for the LNJ engine only use RTV where the orange valley seals mate with the black plate gaskets (the cured RTV is visible in the OP's pictures). I've attached pictures below so you can see the difference. The top picture shows the intake gasket set for the LNJ engine (Mahle MS19377). The bottom one shows the intake gasket set for the LA1 engine (Mahle MS16259P).



_

 

I've used K&N Block Sealer on other peoples cars that didn't have the $$$ to do a head-gasket job. Trust me it works and won't clog up the radiator. You just have to flush out all the coolant and use straight water. Then you get the motor good and hot, Then add the K&N block sealer and drive it hot for 50 miles or better. After that you can flush the system and put the coolant back in. No one ever said the car ran hot or any indication of radiator plugging at all.And it did seal the head gaskets. Sure its not the best way to fix a vehicle, but if low on money for a proper head gasket repair this stuff works.

 

Definitely great advice. I noticed Harbor Freight has Combustion Leak Detector for $25.
Hopefully, this is the first and only time that I will need to use the Leak Detector!

 

I've been driving my 05 Nox for a year now since my first REDLINE hot outta nowhere, no warning or anything.. Thru my investigation I learned if the Head Gasket issue with these yrs. A few of my husband's friends looked at my car and suggested Bars Leak because of No white Smoke or other signs they Suggested the Bars leak and I've been exceptionally pleased with results. I my self don't drive many miles a month either so it is Perfect for What I need a car to do