Vibrating Highlander, Rattling Explorer, Oil Leak, Used Car Dud?

Q: I have been experiencing a vibration on my 2012 Toyota Highlander since I purchased it used about 2 years ago. The vibration has started to get just a bit worse and now there is a slight vibration that changes when I take a turn. About a year ago the car was in for service and the tires were rotated and the vibration felt better. Now I just had the oil changed and the tires rotated again the vibration and noise are terrible. Do you know of any problems with the 2012 model that I can address with my dealer?  

A: I checked AllData, the technical database that I use and didn’t find any bulletins that would address a vibration. Since the vibration changed when the tires were rotated, I would suspect the problem is still related to the tires/wheels. The simplest solution is to see if the dealer as a test, can swap a set of wheels and tires from another vehicle. If the vibration and noise improve, the issue is related to the tires. Then at that point a technician will need to carefully inspect each tire and wheel for a problem.

Q: I have a Ford Explorer that is making a rattling sound that seems to be coming from under the car of the driver’s side. It has been in service two times in the past month and both times the shop jacked up the car and looked around but didn’t see anything. It is just a noise not a vibration, but it does seem to be getting worse. Any idea what I should do?

A: There are plenty of parts that can wear on your vehicle and make noise. Some of them are; coil spring insulators, sway-bar links, exhaust system, steering gear intermediate shaft and the lower ball-joints. Some of these parts are easy to check, others require a trained eye to spot a problem. The best method to check for a problem after a road test is to put the vehicle on a drive on style lift. This way all of the pressure and weight stay on the tires and suspension. On a frame contact lift, the suspension hangs and can mask worn parts.  

Q: I consider myself a pretty competent backyard mechanic, but I have a problem that I can’t seem to find. I have a Chevy truck and there is an oil leak and I have washed down the engine to look for the leak but can’t seem to pinpoint it. I have checked the oil sender, valve covers and intake manifold and can’t seem to find the source of the leak. It is most certainly engine oil and not power steering or transmission fluid. Do you have any suggestions?

A: In a shop you would add a dye to the oil and then run the engine a bit and shut off the lights and using an ultraviolet light look for traces of dye. Back years ago, before these time savings gadgets we would clean and dry the engine and sprinkle talcum powder around the suspected area. Then let the engine run and if there is a leak, you can easily trace it in the powder.

Q: I just recently purchased a Ford Taurus from a police auction but now I’m concerned this great deal is not that great. I was checking all the fluids and it appears as if there is oil in the antifreeze. When I asked someone more knowledgeable than me, they suspect a cracked block or head gasket. There is no warranty, so I’m stuck with the car and now I’m thinking of junking the car or buying a used engine for it.  What would you do?

A. The first thing to do it determine the actual problem. You can buy or sometime rent a “block-check” kit from an auto parts store. This kit will tell you if you have combustion gases in the coolant. The other more common possible problem is the oil is actually transmission fluid and the transmission cooler that is internal to the radiator is leaking and allow transmission fluid to mix with the coolant. Spend a little time to determine that actual problem, before jumping to drastic conclusions.  

John Paul is AAA’s Car Doctor. He is an automotive expert who has been writing and talking about cars for more than 30 years. He also hosts the Car Doctor radio program on WROL radio in Boston. Email John at jpaul [at]

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