Engine knock perhaps - 2.3L ?

[soldier989]

I've noticed what sounds like valvetrain rattling on cold mornings, or if I've not driven it for a couple days. This goes away within a few minutes.

What I just recently noticed, is what sounds like bottom end rattling/clattering, under acceleration/load. It's slight, and only under certain conditions, which I'm trying to figure out those conditions. I almost always drive with my windows down until winter, and can hear it bounce off a concrete curb or wall I drive past (I dont think it would be heard with windows being up). Since I primarily drive in the city, my RPMs are constantly changing, so it's been heard possibly in 2nd/3rd gear (7MT), maybe around 2k RPM. It's not constant, if I hold an RPM I never hear it, it's challenging to replicate and occurs after being warmed up.

Not concerned at the moment, but I do think it sounds like a detonation issue, and thought this was a good place to make note.

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[SNOWOLF]

I would think it is normal for it to go away once it is to operating temperature. If it is a waste gate rattle, once it builds up pressure, and heat, the rattle goes away.......and what does heat cause.....expansion.
Mine does the same exact thing.....seems to be normal. I have 2100 miles on the odometer now, and since it has been really cold out it is more noticeable.

 

[andyman7931]

I'm just getting caught up in this thread. I have the same issue of engine knock when the engine is not fully hot, seems worse now in cold weather. Has anyone had any luck at a dealership getting this resolved? I'd like to approach the service department with as much info as possible to make their job easier.

 

[Lil Red Broncette]

I'm just getting caught up in this thread. I have the same issue of engine knock when the engine is not fully hot, seems worse now in cold weather. Has anyone had any luck at a dealership getting this resolved? I'd like to approach the service department with as much info as possible to make their job easier.

Since I originally posted this, my one Bronco that wasn't exhibiting this started to do so when cold but not as bad as the first. The one I wrote about initially started to do it less. So both about the same now just sort of between the extremes.

My dealer has told me this is normal as well as others have been told the same. I found a technical article that explained some issues with direct injection engines that suggested this could be inevitable when cold. I did post a link to it someplace in this thread. At this point I accept it as normal to a degree even though I think they could avoid the issue with the right programming.

 

[MC1313]

I'm just getting caught up in this thread. I have the same issue of engine knock when the engine is not fully hot, seems worse now in cold weather. Has anyone had any luck at a dealership getting this resolved? I'd like to approach the service department with as much info as possible to make their job easier.

It’s going to be one of those situations where you will have to show them exactly the condition. I would recommend setting an appointment to rode test with a “shop foreman” park your Bronco at the dealer the night before and then go there the next morning for your appointment and that way they will hear it when it’s stone cold. And make sure they document the correct complaint under “what conditions” it is happening.

 

[MC1313]

This is probably the best explanation of what is happening (watch this from the 7:47 mark and it explains) small engine pre ignition on direct injection engine . Either way this is still not good or even normal to allow it to happen.

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