issue The trouble begins, no start

[brendon444]

Dealer, said gm has no fix for the flapper valve all they are doing is wiring them open.

[TJay74]

Take the truck to an exhaust shop, have them weld the valve open. I did that from day one on mine, plus the valves are notorious for rattling over time. That valve takes up a huge amount of space in the exhaust tube, it has a half dollar weight on the backside that is prob 1/2" thick. I had mine cut out last week when I had the Magnaflow muffler put on.

[mzodarg]

Take the truck to an exhaust shop, have them weld the valve open. I did that from day one on mine, plus the valves are notorious for rattling over time. That valve takes up a huge amount of space in the exhaust tube, it has a half dollar weight on the backside that is prob 1/2" thick. I had mine cut out last week when I had the Magnaflow muffler put on.

TJAY,

I'd really be interested in any details you could provide on your exhaust (either here or PM me). I'm also in Oklahoma and will travel up to OKC if necessary.

 

Mike

[brendon444]

What is the point of this valve? Is it strictly for sound or does it serve a purpose.

[mzodarg]

What is the point of this valve? Is it strictly for sound or does it serve a purpose.

I'm guessing here: I would say it's for back pressure when the engine drops into V4.

 

Mike

[Jon A]

So you guys are sure this is the problem? If so that's great as it's an easy fix (I'll be removing the valve entirely pretty soon after delivery). But it surprises me somewhat that the valve being closed would prevent the engine from turning over at all (click, click) vs just making it turn over more slowly.

 

I guess in the next couple months we'll know if any of you who fix the valve have the issue happen again.

[brendon444]

So you guys are sure this is the problem? If so that's great as it's an easy fix (I'll be removing the valve entirely pretty soon after delivery). But it surprises me somewhat that the valve being closed would prevent the engine from turning over at all (click, click) vs just making it turn over more slowly.

 

I guess in the next couple months we'll know if any of you who fix the valve have the issue happen again.

 

The problem with the motor not turning over is not exhaust valve related but when the truck cranks but does not start it has been the exhaust valve.

[Jon A]

OK, so there are two separate issues regarding starting in cold weather? Is there a known cause for the "click click" problem yet?

[brendon444]

OK, so there are two separate issues regarding starting in cold weather? Is there a known cause for the "click click" problem yet?

"Just an update the dealer said my problem was likely caused by to much grease on solenoid connector for the starter which confirms what another was told by different dealer and it should go away after more starts and it has seemed too so far"

 

Truck would not turn over and just click dealers are saying that was the problem.

 

Next problem is tho my truck wont start with remote start when its -30 only when warmer or engine warm. Starts perfectly with key. hmm when I really need it.

[Jon A]

Ah, I missed it. Thanks.

[TJay74]

The valve is for sound only, the spring is super light weight so there is no way it is there for performance.

[pclay]

Yes, it was -25 a couple of days ago and mine remote started with a large cloud of black exhaust smoke. The less than 2 minutes later shut off. I then tried to start the truck from the cab, which failed. It cranked but would not start. I suspected water in the gas but the fuel level was over 3/4 tank. 30 Minutes later the truck did start but now will not remote start at all. I have a scheduled trip to the dealer Friday. This problem sounds different that what others have been reporting? My truck actually tries to start but won't fire up and later will actually start.

[Jon A]

Did you check to see if the flapper valve was stuck?

[pclay]

Well, the Check Engine Light went off so I delayed taking the truck to the dealer. This morning it was -31 and the truck started OK but with the check engine light on. I drive 30 minutes South and to a Grocery. Upon exiting 10 minutes later the truck would not start. Towed to the dealer and waiting to hear from the dealership. Also new problems, power steering stopped working and the heater blower makes a loud motor sound (almost like an outboard motor)

[SLESierra]

The valve is for sound only, the spring is super light weight so there is no way it is there for performance.

The valve is to slow the exhaust during idle to heat the catalyst more efficiently. This is to comply with ULEV is what I was told. Easy fix is open it and put a water clamp around it and tighten the clamp so it is in the open positiion.