Plastic Engine Cover

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

FATrabbit

FATrabbit

10 Year 15 Year 20 Year
Joined
Sep 8, 2004
Threads
19
Messages
152
Location
San Antonio, TX
05 with almost 100K on it.

In cold(er) weather, while the truck is idling in drive with the brake fully depressed (like at a stop light), the plastic cover on my engine vibrates wildly and makes a very loud noise. I have watched under the hood while my wife stayed on the brake and the vertical edges of the cover are moving so fast I can barely see them! This has only started happening recently and it seems to only happen if the temp is <50 deg F.

Is this cosmetic or is there something more serious I should be concerned about?
 
Take it off. The vibration will be gone and it won't hurt a thing...
 
I think I have the same problem - doesn't do it at start up and not after completely warm but somewhere in between. Interesting thing is that I can shift into neutral and it will stop. Seems to have some correlation (in my case) to the temp and the rpm's as shifting to neutral kicks up the rpm's slightly and it stops.
 
That much noise and vibration does not seem right. Mine does not make any noise. I would check for what is causing the vibration.

And you may be the first to discover the purpose of that cover, warning device for engine vibration. :D
 
That's a lot of engine vibration. Obviously, most engines are not going to run as smooth when cold as they are once they reach operating temp. I would check the little things first like engine mounts or a broken plastic engine cover mount allowing it to vibrate. Then once you have confirm that it is nothing bad, take the cover off find a more useful purpose for the thing. Just a thought...
 
obviously not normal if it makes a very loud noise.
As stated above, likely something wrong with the cover mounts. Possibly higher vibration than normal by engine, but much less likely I would think. Do you even see the engine vibrating?
 
BamaHeel said:
I think I have the same problem - doesn't do it at start up and not after completely warm but somewhere in between. Interesting thing is that I can shift into neutral and it will stop. Seems to have some correlation (in my case) to the temp and the rpm's as shifting to neutral kicks up the rpm's slightly and it stops.
Click to expand...

Mine is also related to the RPMs. As I mentioned, this only happens when the car is in drive, but idling. Sometimes at lights, I will shift into neutral to stop the noise. Also, I know that the noise is the cover because I can physically hold it and it will stop.

I have no problem with just ditching the thing but I am trying to allay any concerns about actual engine vibration, as mentioned in other posts.

Once it gets cold enough here in South Texas (almost 80 today!) again for the issue to rear its head, I will check the cover mounts and try to quantify how much the engine is vibrating.
 
I doubt that it has anything to do with a change in engine vibration and more about the harmonic changes in the plastic since it only happens in colder weather. When cold, the plastic is stiffer, and therefore would have a different harmonic than when warm...
 
I've had this on my 98 LC since I bought it at 108K 5 years ago. The cover has just deformed slightly over the years due to the heat cycling, and some of the foam on the underside has deteriorated as well. So those two combined allow it to vibrate and make contact with another part of the engine, and thus the noise.

You can get rid of the noise by just tugging on the cover in one direction when you bolt it down. My noise comes from the front drivers side edge making contact. Or buy a new cover or just remove it :).

Rich
 
that engine plastic cover has foam underneath on each side, mine was vibrating until i replaced both foams.. no more vibration since then.. check yours to see if you still these foams...
 
Engine vibration when warm and foot on brake. Check coils you must have some misfires i had the same issue 3coils acting up
 
I get the concern about "engine vibration" from others, but I've seen a ton of people complain about this exact thing and it happened to me as well; super loud banging noise that scared the crap out of me. Took off the cover and instantly gone. No noticeable issues otherwise. I really don't think you need to read too far into all the worry from everyone.
 
Remove the Cover and glue on a small piece of Foam on the inside where the cover touches the Oil Cap.
You should see the imprint where the factory had the foam. Happened on my LX470 too and toyed on
whether to just remove the Cover or fix it.
 
You must log in or register to reply here.

Share this page

Back
Top Bottom