Foamy Residue In Coolant Reservoir

[acflye]

I recently experienced my 92 ls-400 running hot...upon examination I found antifreeze coming from around the sensor on the reservoir. I also had a crack in the corner of the reservoir next to the sensor. I went to add antifreeze and noticed a foamy residue in the reservoir and was wondering how to clean that out or is it possible.......is a radiator flush worth it?....would a crack in the reservoir cause my vehicle to run hot and I also hear alot of bubbling inside the reservoir when I shutoff the engine.........thanks for your input....

[bsouth123]

I recently experienced my 92 ls-400 running hot...upon examination I found antifreeze coming from around the sensor on the reservoir. I also had a crack in the corner of the reservoir next to the sensor. I went to add antifreeze and noticed a foamy residue in the reservoir and was wondering how to clean that out or is it possible.......is a radiator flush worth it?....would a crack in the reservoir cause my vehicle to run hot and I also hear alot of bubbling inside the reservoir when I shutoff the engine.........thanks for your input....

is it milky white? If so, you have oil mixing in with the antifreeze....

[Robert Young]

Also check to see if you have foam forming when the engine is running. That is unfortunately a pretty sure sign of head gasket failure.

[SKperformance]

I am not sure with the year but is the cap on the reservoirs part of the pressurized system? If so the crack is causing the coolant to over heat.

[LEX4]

"but is the cap on the reservoirs part of the pressurized system? "

Yes it is, and the resevoir needs to be replaced. If it were my car I would flush with water then mix up 50/50 mix of distilled water and Toyota Antifreeze and refill and watch the color. If it does not stay red then it might be time to let someone check for combustion gases in the coolant. :P