Cramer said he's worried about what's happening with three stocks- Volkswagen (VLKAY), Glencore (GLCNF) , and Petrobras (PBR). Cramer made the comment on the floor of the New York Stock Exchange while answering viewers' Twitter questions Friday. Volkswagen is embroiled in an emission scandal and is changing its leadership, commodity company Glencore's stock has been sliding all this week, and in regards to Petrobras, Cramer said he believes if oil prices don’t go up, the company will have to do a debt restructuring. He said those are bigger worries than a possible Federal Reserve rate hike, which Cramer said he'd like to see by year end. He doesn't want to see the Fed raise rates in October due to concerns about China, but Cramer also said that Nike's (NKE) earnings made him feel better about the Chinese consumer. Cramer's second question was from a viewer who wanted to know if an investor already owns Caterpillar (CAT), should the stock be sold or held, in light of this week's news. Cramer said Caterpillar’s earnings power is much lower, and he would feel more comfortable if the company’s stock was trading in the 50’s. Send your twitter questions to @JimCramer using #CramerQ.