Originally Posted by clm2112
Originally Posted by Hans
that is really bad. the coolant passage is blocked!!!???
While the buildup was bad, I thnk the two plugged up passages are the ones that dead end on the manifold flange. (On the 3800, only two of the four coolant passages in the heads match up with the crossover in the manifold)
Now, is Dex-Cool corrosive? When I took down my project motor, the cast aluminum rear cover was severely pitted where it seals the coolant passages in the block. Kinda like the Dex-Cool ate the aluminum,
That'* right, the plugs are at dead ends on the manifold.
As for pitting:
Even the junkyard LIM I picked up for my porting project isn't that bad:
I ground out all the corrosion with a brass wire brush. It was all within the limits of the gasket hole, so I figure it should be safe from leaking.
Finished the job; had to replace leaky valve cover gaskets, too (ain't that sickeningly stock engine pretty?):
I also found my vacuum leak; the vacuum boot on the TB has a slight split, so I stuck a hose clamp on it:
Now my LTFT'* scan at 0% to 3%, instead of the 7%-10% they were before.
The car is peppier, but that may have more to do with fixing the vacuum leak. In any case, now I know I'm not moments from LIM disaster!