So I have a friend that has a manual 1999 Chevy Truck with 5.3 vortex engine that was replaced because the cam sensor burned up distributor cap and pretty much chewed up the engine. Replaced the engine, distributor, and numerous parts.
Now he says he has a misfire on number 6 cylinder and the truck idles and runs weird.
Well here’s his link tell me what you think.
Tomorrow I’m going to start pulling the harness to see if he has a short some where down line to the cam sensor.
Any input is grateful he’s been chasing this issue for a while now and he uses this truck for his business
thanks guys
Are you saying that this is your friend's truck in the video?
Wow. I'm a huge fan of Ivan Temnykh and I'm hesitant to critique his diagnostic abilities because he's so good.
But what the heck, I will on this one because I don't understand some of the diagnostic logic he's using here.
Typically, an intake manifold gasket leak is larger when the engine is cool. As the engine warms up and parts expand it closes up.
But here. Ivan says that when the engine cools down the misfire diminishes. That's not a characteristic of an intake manifold gasket leaking.
He also states that "the misfire is more prevalent after the truck has been running under heavy load and then cools down a little". The truck should be able to maintain a stable operating temperature under all loads so I'm not sure how it "cools down a little". Either way, again, that's not a characteristic of an intake manifold gasket leak either.
But it's easy to Monday Morning Quarterback this thing because Ivan edited the video to tell us that he made the wrong call. That's another thing I like about him.
Even though he made the wrong call on the cause of the problem I don't think you should throw out the baby with the bathwater. He identified what's happening here he just blew the call on the cause.
The #6 cylinder has an air:fuel mixture issue and not an ignition related issue. (so it may not be helpful to troubleshoot ignition related issues just yet)
Here's another thing which I'd give more consideration to.
The spark plug comparison between the cylinder #4 spark plug and the cylinder #6 spark plug in the video. (#6 is in the foreground).
If somebody told me that this engine had good/equal compression on all cylinders and showed me this screenshot I may comment that #6 looks like it's running rich. Maybe not always, but sometimes.
I'd start running down reasons for that.
That's my 2 cents but if your friend has any way to get the truck back to Ivan he should. Ivan doesn't blow it very often and he told your friend that he'd figure out what's going on here without any additional diagnostic charges. I'd bring it back to him and let him have another bite at the apple. I have a feeling that with Ivan, this time it's personal
Yes that’s my friend’s work truck. He wants to take it back but the towing bill would be expensive. However I told him to he needs to let the guy finish what he started. I was just hoping to get other’s opinion on what could be happening.