Why is there coal under my valve cover?


Old 08-04-04, 07:06 PM
Visiting Guest
Posts: n/a
Unhappy Why is there coal under my valve cover?

Hi guys,
I'm new, but need some help before I unintentionally and tragically end a long line of automotive abuse.
My in-laws just gave me custody of a 93 Camaro Z28. The car suffers from several little problems that have arisen from neglect. I thought the worst was the non-fuctioning cooling fans until I peeped under the oil cap. Surprise! You know that crystalized buildup that is found under the intake manifold of an abused engine? Well my rockers and valve stems are about to drown in it. I pulled the dipstick and found more particles of the same stuff. The engine cranks, idles and throttles quite nicely, with good oil pressue and no overheating while on the move, although the temp rises in traffic, and the engine has to be shut off. It is a 5.7L/350 TPI with an Automatic tranny and has 132k on it.
I guess this is polymers from cheap and/or recycled oil. I've been advised to use everthing from Marvel Mystery Oil to kerosene to flush the oiling system, but i want as much input as I can get before I make a move.
The most ironic thing of all is that I grew up in the south and have listened for years about how great the "Camerra's" is. What's a Camerra? You know, a Zee Twinny-yate. Anyway, I've never looked twice at any Camaro past about 72, but when I drove this one home, I was overwhelmed at how responsive and tight the handling is. It needs more power, but definitely a fun car. And, hey, a freebie is a freebie, so if I have to rebuild the engine, I guess I will.
...and my brother does have that wickedly built 400 small block that he never has used...
Sponsored Links
Old 08-05-04, 04:32 AM
the_tow_guy's Avatar
Group Moderator
Join Date: Feb 2001
Location: SW Fla USA
Posts: 11,567
Given it's a freebie and if the engine rebuild is within your capabilities, that's the route I would go. At the very least you're looking at pulling the heads and the oil pan. Anything you use as an internal "cleaner" (and the results) are going to end up in the oil pan. If there's a product made that will clean up an engine as gunked up as you describe, I haven't seen it.

Don't sweat "cheap" oil; we use Sam's Club 10w-30 in our 350 Chevy- powered wreckers. Mine has 262,000 miles on it with 3000 mile changes.
Old 08-05-04, 05:46 AM
carguyinva's Avatar
Join Date: Nov 2003
Location: Shenandoah Valley
Posts: 1,147

...being a GM guy. anything you put in it to break up that crap will stop up the oil pickup screen and starve the engine of lubrication. you could remove the valve covers and clean the top end, i'd recommend using a vacuum cleaner so the crud doesn't end up in the pan...altho, i'd bet a dollar to a donut there is already some there.

heavy buildup usually is formed due to lack of routine maintenance AND not driving long enough to get the engine up to full operating temp. the oil gets contaminated with by products from the combustion process and if it doesn't get hot enough to boil off those contaminants, they cling to the cooled down metal surfaces inside the engine...keep doing this over and over for years and you end up with what you have.

if you are really considering an engine replacement, give consideration to buying a replacement engine from chevrolet...you may find that there are ALOT of things on that old 400 that won't match up and will require custom reworking. for example...your accessory brackets probably won't bolt up, your OE intake and fuel system won't fit those old heads.
Old 08-05-04, 02:27 PM
Desi501's Avatar
Join Date: Oct 2003
Location: Boynton Beach Florida
Posts: 2,207
As these guys have alluded to, once you have a sludge build up, there really isn't any safe way to remove. Don't even try any of those engine cleaners. You'll start a chain of events that will eventually seize that engine. Loosening that stuff up just makes it get caught in all the places you don't want it.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Display Modes