Sometimes, a very violent problem can turn out to be something very basic. Within one week, I had two of these issues show up at the shop. The first was a 1997 Toyota Camry LE with a check engine light on. The Toyota owner told me that, besides the check engine light, he needed front struts. Since the Toyota is 29 years old, I told the customer, “Let’s find out what the check engine light is first before taking on other work.”
Once the Toyota was in the shop, we connected the scanner and pulled codes. The car had four codes P0300 random multiple misfires, P0304 misfire cylinder #4 current, P0304 misfire cylinder #4 History and P1135 Air fuel sensor heater circuit (bank 1 /sensor 1) History. The P0304 was the code that triggered the check engine light. Because of that, the first thing we did was a compression test. All four cylinders were between 185 pounds per square inch (PSI) to 210 PSI. Since we have to remove the spark plugs to perform a compression test, we checked them. The spark plugs were extremely worn out. We then suggested that we replace the spark plugs and test drive the car. The customer gave us the OK to replace the spark plugs, but then reminded me about the struts.
After the spark plug replacement, we cleared the codes and test drove the car. This is where things got scary. When the car got over 30 mph, the front end started shaking violently. Now I know why the customer wanted us to check the suspension. We had to drive the car back to the shop right away as it was not safe. The shake was so bad I thought a control arm or possibly a tie rod was about to fall off the car.
Once the car was on the lift, we looked at the suspension. The front and rear struts were soft, but not blown or falling apart. The control arms and tie rods were old, but were all fastened properly and had no movement. For a moment, I scratched my head. Could it be a tire? I then spun the wheels on the car and checked to see if one of them was wobbling. I could not see a wobble. I then called the customer and told him what I was feeling. I then sold a tire balance. All of the tires were out of balance. Not severely, but out of balance. We then moved the best two tires to the front. Once the tires were on, I test drove the car again. The car drove great and did not shake.
The second car was a 2013 Volks-wagen Beetle that came in for normal service. During the normal service, we found the front struts blown and some uneven tire wear. We suggest replacing the front struts, rotating tires and alignment.
After the work was completed, we test drove the car. Going straight and turning left, the car was fine. Yet if we accelerated from a stop and turned to the right, the car would shake violently for about 100 feet. The technician did not remember this from his original test drive. We brought the car back to the shop and checked the work. Everything from the front strut work was correct and did not have a problem. We then figured that one of the tires that was rotated from the back to the front must be out of balance. We removed the front two tires and checked them. Both tires were perfectly in balance.
Once again, I was scratching my head. We then spun each front wheel by hand on the balancer. While we were spinning them, we placed our hand on the tire tread. The tire that was on the right front had no irregularities. The tire on the left front had a small bump that you could feel with your hand, but not see. It was almost as if the tire was coming apart on the inside. Since that tire was on the left rear before, we moved it back there. We then moved the left rear tire that was on the left front back. Before installing the left rear tire back to the left front, we checked its balance. That tire was out of balance. We then balanced that one tire and installed all three back on the car. After that, the car drove fine – left, right and straight.
We found that the tire we had moved from the left rear to the left front, with the irregularity, was causing a vibration when the car turned to the right. This was occurring because there was more load on the right front tire than the left front tire during an acceleration to the right. I know, I know – that is a lot.
Normally, I would not write an article on something so basic, yet it was just unusual to have such acute cases come in days apart. In the end, this just reminds us how important it is to perform tire balances, tire rotations and wheel alignments.
Matt Pataky owns Sunnyvale Foreign Car Service, 15 Pioneer Way, Mountain View. For more information, call (650) 960- 6988, email [email protected] or visit sunnyvaleforeigncar.com.
