Hi Guys,

A couple weeks ago I had a flat on the way to work, so took it to the nearest Firestone to replace both fronts. Long story short; they put a larger tires on than needed 40/19s instead of 35/19s.

It caused the VDC OFF and Slip lights to come on - and the car wasn't starting correctly so after digging around on here I checked the tire sizes and last week took it back to the shop. They switched the tires for free (as they should) and the lights went off but I'm still having irregular issues starting the car.

If I understand the mechanics, the change in the rolling radius upset the speed sensor, causing the cam sensors to be out of whack, hence the lights coming on? Seems to make sense to me...

My question then is, should they have re-aligned / reset the cam sensors to fix the problem? I've checked the battery and the starter motor seems fine as when it does crank it's fine and healthy.

Rob

 

You really don't understand the mechanics of the VDC system. There's NO connection between the wheel speed sensors and anything causing "the cam sensors to be out of whack". The problems you're having with starting the car is a completely different and separate issue than anything having to do with tire size.

 

OK I'm confused. So there is no correlation between the rolling radius of a tire and the speed sensor on the car?

It seems unlikely to me that the car goes into the garage for two tires, and comes out with warning lights on the dash and problems turning over without any of them being related. Especially when changing the tires back to the old rolling radius removed the waining lights? Guess it could all be coincidence though.

Could leaky cam sensor seals cause the issue starting? They need replacing apparently.
Only other thing that needs replacing that I'm aware of is the valve cover gasket as it's leaking but I can't see why that would cause intermittent ignition.

 

Two separate issues. The word "coincidence" exists for a reason, and this is one of them.

 

OK, cool. I'm not disputing the fact it could be coincidence hence why I used the word.

My question again, is what could be causing the intermittent ignition issues. Battery check was fine. Spark plugs and coils are brand new. It's just not turning over one minute and then try it a few times or leave it a while and it starts perfectly.

 

I suggest getting the code(s).

 

i agree with spike....

 

Only code I'm getting is in pending. random misfire cylinder 4. That could be the one that's leaky but could that cause it not to start?

 

it usually number 6 that gets the oil in it.... the coilpack could be going bad though

 

Just drove home from work and didn't get any codes this time. No pending or logged. It's getting harder to start though. It seems to be starting fine once the engine is warmed up though.

 

How did you know that you "didn't get any codes?"

Questions:
1)When do you test for codes?
2)How do you test for codes?

 

I've got an odb2 Bluetooth tool that connects to my phone. I used the torque app to check while I was driving and after I stopped the engine.

 

Explain more about the starting problem
Slow to crank
Cranks for 5 seconds before it fires
Etc etc