Some Chevy Colorado and Chevy Silverado owners with the TurboMax 2.7L four-cylinder gasoline engine under the hood may notice reduced heater performance. This issue could be the result of a twisted coolant hose or incomplete machining of the heater core feed pipe port. Now, GM has identified what can be done to address the issue.
The poor heater performance issue can affect units of the Chevy Colorado and Chevy Silverado 1500 pickup trucks equipped with either the turbocharged 2.7L I4 L3B gasoline engine or the turbocharged 2.7L I4 L2R gasoline engine, including the 2023 through 2025 model years.
According to GM, the issue lies in restrictions in the coolant flow. If coolant flow is restricted, the heater core (which warms the air for the cabin) will not receive get enough hot coolant, leading to poor heater performance.
The coolant flow issue could be the result of a twisted or kinked coolant hose, or an improperly positioned hose. GM recommends that a technician first check the coolant hoses to ensure they are in the correct position. In some cases, the hose might twist about two inches above the hose clamp, which is not visible until a mesh cover is moved.
If the hoses appear fine, the technician should next check the heater core feed pipe, in particular around the exhaust manifold outlet pipe T fitting. When the engine is warm, the feed pipe should be near the same temperature as the engine. If it’s not, it may indicate a problem with the machining process during manufacturing, leading to a blockage.
GM recommends letting the engine cool down, then disconnecting the heater core coolant feed pipe at the exhaust manifold outlet. Next, the technician should inspect the spigot connection for any blockage. If a blockage is found due to an incomplete machining process, the exhaust manifold coolant outlet pipe will need to be replaced.
Comments
It amazes me that things like this dont get caught in assembly.
mistakes happen, it amazes me when they find the problem….
I’d just like a better photo (…maybe in-focus) of the issue.
Back in the day they used to have franken cars on the lots where they would run out of a pair of red seats or a pair of blue seats, so they would stick everything together and just sell it. I’m not complaining about a twisted hose, after all, that’s why warranties exist.
Cheapest parts from lowest bidder and questionable quality control. This beat goes on across all brands. Sad for the new vehicle prices being paid.
I’m thinking that that is the same issue that that the 4 cylinder Diesel Duramax has.
Engineering issue.
This is not the first time they’ve had problems with too short, and poorly routed, hoses bending and kinking.
After engines leave the engine plant they go to the assembly plant where they are “dressed”.
This includes installing all of the brackets, pulleys, belts, hoses, wiring harness, starter, alternator, Etc.
Only after that do they try to stuff the engine into the chassis. On a lot of these smaller, front wheel drive / all wheel drive, vehicles the engine and drivetrain are together and stuffed into the chassis from below. They have followed the Japanese in perfecting the art of putting 5 lb of $h-t into a 4 lb bag. This is why I use the word stuffed. That is plain to see from just opening the hood. Some automotive repairs require the shop to drop the entire engine and drivetrain assembly from below to gain access for a repair.
Employees don’t just slap components on anyway they feel like it. Those hoses would have had a mark on them to line up with the mark on the fitting coming from the heater core. If the hoses then kink that is a result of poor engineering design.
My ’24 Colorado definitely does NOT have this issue.
It’s heater is hot and fast….
Well here we go, they’re in hot water again!
i saw what you did there
My 2019 4cyl. Colorado heater gets toasty as fast as the coolant does.
My ‘23 Colorado has been in the dealership shop for the last 2 weeks for a heater core replacement which they seem to be having a hard time finding. During a recent cold snap is when I discovered the problem. I would let the truck warm up 5 to 10 minutes and then drive to work. Some mornings it would blow cold air for 6 miles and suddenly turn hot, other days it would be warm immediately. Service mgr. said one side coming out was hot and the other was cold and technician said there was a blockage. Glad it happened under warranty at 28k miles.
Sounds like a blend door problem, not heater core.
My 2023 Colorado was having the same issue not getting heat. I find out my coolant reservoir was empty. The reason was because upper hose connection gasket or o ring was leaking. I replaced it with a cat o ring problem resolved. I saw the video on YouTube.
So much for quality control
When I had my 4cyl Silverado, I noticed the heat was never as strong as any other vehicle, even my GFs little Mazda blew hotter air. I took it to the dealer and the claimed it felt fine, but the truck never warmed up properly either.
Sucks now that I got rid of the truck they’re just finding this out now
“it may indicate a problem with the machining process during manufacturing, leading to a blockage”
Is GM going to have a special policy for this? “Yeah it was made wrong, but your truck is past the 3/36 warranty so sucks to be you” won’t make customers happy.