CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

2007 Chevrolet TrailBlazer - failed intake valve

my 2007 chevy trailblazer hazs been diagnosed with a failed intake valve shop suguest engine replacement i am seeing a lot of videos on youtube of people owning trailblazers having the same issue im wondering if chevy has a recall for this problem and if they will fix it seems to me that this is a possible mechanical defect.

First, get a second opinion. Just tell the other shop what the symptoms are, NOT what the first shop told you.
But if it does require a new ( rebuilt/remanufactured) engine it may very well exceed the value of your vehicle.
As for recall, etc. extremely doubtful.

Please provide more details

a broken intake valve, which punched a hole through a piston?

burnt valve?

pitted valve seats . . . that is actually not uncommon for this engine family, which also includes a straight 4 and straight 5

4.2 liter straight 6, I presume?

Yes 4.2 straight six the shop said burned valve

The valve is shot, A new engine sounds extreme, new heads maybe 2 grand. I am on some websites and there is a rumor mid grade gas customers are less prone than regular grade, just a rumor, always used mid grade till we joined costco last year. 195k and no issues 6 cyl engine. Sorry for your troubles.

I’m not sure why that shop recommended a replacement engine

Sounds like the engine really just needs a complete valve job . . . or in the worst case scenario, a reconditioned head, which I believe are readily available on an exchange basis

There isnt going to be a recall on a vehicle that’s almost 12 years old . They haven’t even made that model since 2009 . This is not a common problem in fact this engine is pretty stout with a lot of people getting over 200000 miles without issue. I have the same engine and have 135000 on it still runs runs good .

It has 4 valves per cyl so it has 2 intake valves

TSB 16-NA-383 (May 10,2017) is for sticking/dirty valves on this engine, and p030X misfire codes. Carbon accumulates on top of the valves it appears. Googling might show you the document, or a dealership could print it out for you. It seems to be important to use gas w/ the correct gasoline specification (Top Tier), and GM has an engine cleaner for this problem too apparently. Not sure why a shop would recommend a new engine if there was only a valve problem. Popping the head and fixing the valve seems like it would be the less expensive route to a smooth runner.

1 Like

Are you sure that tsb applies to the Atlas 4.2L I6?

Not sure of anything, but from what I can tell it applies to the 4.2. A chevy dealership would know for sure.

Burned valves are usually caused by using the wrong gasoline, EGR faults, faulty ignition timing, etc.

You did not state how many miles are on this but you can forget warranty on a 12 year old car. A TSB is also not a Get Out of Jail Free card either.

Maybe a replacement engine was recommended because the current one with the bad valve has 400k miles on it.

Anything else about the engine? The mechanic may be looking for his “Boat payment” as they say or it could be a neglected engine and he sees no reason to fix it. Remember that sticky lifters from lack of oil changes can also burn valves. If he sees a sludge monster it might be better to replace it.

Most of the vehicles mentioned are late model with DI engines like 2018 Colorado for example. As far as I know, the Atlas does not have any history of carboned up valves and it would be strange to have tsb issued in 2017 for a vehicle not made in US since 2009. That’s why I asked…

but the Atlas does have some history of burnt valves and pitted valve seats

The bulletin mentioned applies to General Motors vehicles to address performance problems and intermittent misfires. The remedy in the bulletin is to perform a top engine cleaning. If the valves are leaking or burned it is probably too late to clean the valves.

BTW, it seems that some people get upset when a dealers service department offers an induction system cleaning.