Minor Sludge On Bottom of Rad. Cap with RMI-25? Stumped on noise also?

[Tim Cucci]

My car is making some bad under hood noise and I was looking into a possible blown head gasket. When I looked in the rad. I found a sludge build up on the bottom of the rad.cap and some sludge debris floating on top of water and RMI mix. The radiator and engine have less than 1200 miles on rebuild.

Can oil actually get into the rad. from a blown head gasket and cause this or is this just the surfactant working in the RMI?
I do not have the milkshake in the rad. or the oil pan just minor floating sludge type debris in rad. Oil is clean.

The noise I am hearing goes up and down with engine rpm's at over 2800 rpm and sounds like an exhaust leak or rocker arm rattling. Can't hear anything abnormal at idle or up to 2800 rpm.
I am stumped. Any suggestions?

Tim

 

[Chris McDade]

Tim,
What you see on the radiator cap is normal. That is just the RMI doing it's job. Don't worry it's normal.

 

[Steve Wood]

Like Chris says....normal behavior for RMI...keeps stuff in solution rather than letting it settle out in the system and become a deposit. Just overflow the radiator a bit and let the surface stuff wash out.

As far as the noise, hard to say....trial and error search....use a stethoscope and/or hose and try to locate area where it is coming from. Make sure brackets on IC are tight, check exhaust leaks, converter bolts, inspection cover, a/c compressor bolts, interference between idler/tensioner pulley and a/c compressor clutch, etc.

 

[GNX]

Water pump going out? Check with S.scope around that area. Shield around the flywheel loose....vibrating?