abs+traction control MIL problem + plenum leak ??

[Spykem4e]

Hello everyone!

I have two questions regarding my 05 3.6l cts with almost 100k miles. I asked on the caddy forum but I want advise from other people too and I lost all the trust on dealers since my car is out of warranty, they just want to switch all parts of the car even if the car runs o.k.

First:
Last falls, during one entire day I had the exact same problem has yesterday. And yesterday, instead of snowing here in Montreal, it was raining (I hate the weather here). I'm a sales rep and I work in my car all day long and suddenly, TC + ABS Mil went on + Service Brake Assist on the DIC. This time I said to myself, go to the dealer without cutting off the engine because they need proof! I went at the dealer, showed them the christman three in my car, they plugged the tech2 and there was NO CODE. No one knows why or what is going on. It only happened when its raining (1 out of 10). I think its a bad sensor or bad sensor wire + humidity = MIL but the dealer couldn't find the problem and asked to take my car for a run with tech2 plugged for about an half hour or so to try figuring pout witch wheel speed sensor if faulty ???? but not today, only next month, too busy for them! Wheel speed sensor? Why? Which one? (They dont know) The problem only occured 3 times in a year and a half so if it was a faulty speed sensor, wouldn't be all the time? I want your opinion on this.


Second:
Last november (2008), I was too busy (big contract) so I left the car at the dealer (big mistake) and asked them to test the car and fix stuff that need to be fixed because in one week from then I was going to Baie James (a long long run) for work. They said, everything was good and asked me if I did changed my spark plugs. I said yes. They asked me about the upper manifold gasket (plenum gasket) if I put the new one. I said what new one? They told me story about an old gasket wasn't good enough blah blah blah so they changed the gasket (dawm, I was out of the province). 3 days later, I picked up my car and it runs great! Since december, I did saw something that I never saw before:

-there's the plenum and just under the plenum, there's the black plastic top of the engine where the coil seats etc (it covers the entire top of the engine). On the plastic, there is some kind of grease or oil. It doesn't accumulate but its like greassy (its not coming from the coil). I can't figure out if its oil or not because the dealer did put some di-electric grease on each coil saying it was better than doing nothing at all. So maybe it the di-electric grease melting? If there's a leak in the plenum gasket, shouldn't the idle or acceleration would be reduced? Is there oil suppose the escape from the plenum?

For oil consumption, maybe 200-300ml in 1500 miles (always been like this) Is doesn't smell oil burn or anything. The car runs fine, accelerate very good, no choking etc.

Any advice is more than welcome.

Mark.

 

[aquariuscsm]

My gfs 1998 Olds 88`s traction control/abs lights have been on for a long time now. Idiot light or actual mechanical problem I wonder?

 

[Brian Barnhart]

The TC/ABS problem could be due to a bad wheel sensor ($$$). If there is significant play in the wheel bearing assembly that could be the problem.

However, the problem can also be caused by a poor (or broken) connection. On my '01 Chevy Venture I traced the problem to corrosion in the wheel sensor connector (near the wheel). I cleaned the tiny metal connector receptacles and terminals and the problem went away for about a year. When the problem reoccurred, I traced the problem to the wire itself. Turns out water wicked up into the wire and caused significant corrosion. I actually replaced the last three feet of wire leading to the wheel sensor and the problem has not come back (yet).

In the case of my van, the problem was in the right front sensor. Unfortunately a rather expensive diagnostic tool is required for GM’s ABS systems. The cheap scanners don’t cover the ABS. It helped a lot to know which sensor/wheel was causing the problem. The mechanic that ran the diagnostics for me told me that he's seen quite a few GMs with wheel sensor/wire corrosion problems. It's also worth mentioning that in my case the wire was so corroded (even three feet back), that soldering a new section of wire in was extremely difficult. HTH.

 

[Spykem4e]

tks.

Yesterday night and today its been very dry outside and with another 200 miles today, nothing wrong on the car, so I guess, just like Brain said, could be the wire with the contact of the water grounded itself. I'll try to find which one now but even with their GM computer Tech 2, they could not found the problem with a wheel speed sensor or abs sensor. Tech2 said everything was fine! So the dealer was just guessing and would want me to change a wheel sensor and see if it helps at my cost. If its not one wheel, try the other one etc. I dont want to pay a lot for not curing the problem you know.

And what about the plenum, any idea? any symptoms if it had a leak from the gasket?