Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

A Service Your Engine Soon question

I have a 2000 Infinit I30 with 56,000 miles. A couple of weeks ago the Service your Engine light came on (along with Slip and TCS lights). Now just the SEL comes on, but on occasion the other two lights come on as well. I took it to Firestone to diagnose. The results were vague. The mechanic said that one of the valves had a bad solenoid. But, it did not show which valve in the diagnostics. So his suggestion was to replace all six at a cost of $1200.00. I asked him what’s the worst that can happen he said that it will run rough. It runs fine, but the light does make me nervous. I already paid $105 to have it diagnosed, so what do you think I should do.

I would strongly suggest that you have it diagnosed by another shop. Having one bad valve should not result in the replacement of all of the valves–unless the shop owner has a boat payment coming up. An independent shop that specializes in foreign cars is likely to give you a more accurate assessment, but in any event, you will then have 2 diagnoses to compare.

Also, you should be aware that your car is probably using more gas than usual when that CEL/SEL light is illuminated, and it is likely putting out a lot more pollution than normal, so I disagree that the only downside is a rough-running engine. Additionally, if the current problem is causing some unburned gas to wind up in the catalytic converter, you can wind up with some REALLY expensive repair costs.

Your not telling much. What kind of valves? connected with a solenoid,will make the car run rough. Using Firestone to diagnois and repair a Infinity makes me feel uneasy.

Thank you very much for responding. I do not want to add polution, I was coming from a financial point of view. I was concerned by the last part of you reply regarding the catalytic converter. I am looking for symptons, are there any?

My option would be for me to take it to my Infiniti dealer. I would have to pony up another $150 for a diagnosis, plus an expensive repair. But they are honest (used them before).

Not being very technical myself, he pointed to the 6 cylindars in my engine

Many auto parts stores will check your car for error codes.  They come out in the format [P0123] and some will do it for free. Check around. 

Post the results back here and we can offer some more informed advice.  A few things about the results you paid for, just don't quite sound right.

The combination of service engine, slip and TCS seems to be related to traction control. It could be an anti-lock sensor which the traction control also uses. My Intrigue has seperate service vehicle and service engine lamps. Sometimes the SV lights with the ABS and PCS lights. If you have the seperate lights it could be 2 problems. I am just guessing and others might correct me.

It is interesting that you mentioned traction. The first signs was during a snow storm, when I was trying to get up a hill. I noticed as my wheels were spinning the SLIP light came on. It was soon after that one day SEL, TCS, and SLIP came on. Now only SEL. But as I said, a couple of times I will have all three on. But, the next time I do start the car, only the SEL is on.


First, run don’t walk away from Firestone for any diagnosis. The I30 did have coil pack problems and that will throw various codes that can be confusing. My son’s same model did the same and I suggested that the O2 sensors (heated, and there are four)may be responsible, they measure the O2 in and out of the converter and will make adjustments to the engine control system, maybe even putting it in limp mode. I finally got him the shop diagrams and to the change the correct sensors and it cleared up…not the coilpacks. but the delay can ruin a convertor and create cold running problems at start. And I strongly suggest the OEM or equivalent O2 sensor (yeah they cost a little more)

Thanks. I did notice today (early morning on west coast and at 30 degrees), while driving both the SLIP and TCS lights came on, along with the Service Engine light. When I got it into my garage and restarted the engine, only the Service Light went on. Perhaps this is a tempurature thing. I will take this to the dealer in town. They are reputable plus quality, but pricey.