"Contaminated Fuel Rails"

That was the diagnosis by my local Chev dealer even though it SEEMS to run perfectly. I brought it in to find out why I can't get 4th gear. They claim it is a common problem on these around here. A mechanic friend and I will be tackling it this week. Anyone heard of or experienced this?

My question is how does a contaminated fuel rail keep it out of 4th gear. Wouldn't it just run crappy in all gears..?

BUT what is it "contaminated" with? water? scale? And how did they diagnose this?

They hooked it up to their diagnostic computer. The service tech also called and talked to Chevy...they had a tsb on it as well. Could be water or dirt or.... My friend that will be doing the work has had success in the past with cleaning out rails and even injectors. The dealer would have wanted to sell me all new replacement parts. Apparently there was enough of a mis-fire (perhaps worse before I got the car) to trip the code or whatever it does. I bought it with a check engine light and flashing "hold" light on as well as some other issues I have already solved.

thats a much more "relevant" explanation to the diagnosis than just not going into 4th gear..

http://www.acdelcotechconnect.com/pd...echConnect.pdf Page 4 in this PDF talks about it.

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Originally Posted by wiseguydave

That was the diagnosis by my local Chev dealer even though it SEEMS to run perfectly. I brought it in to find out why I can't get 4th gear. They claim it is a common problem on these around here. A mechanic friend and I will be tackling it this week. Anyone heard of or experienced this?

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If it "seems to run perfectly", what are you complaining about and why did you bring it to your local Chevy dealer?

Is this a manual or an automatic transmission?

It is an automatic. Won't shift into 4th gear. It was a repossessed car I bought "as is".

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Originally Posted by wiseguydave

It is an automatic. Won't shift into 4th gear. It was a repossessed car I bought "as is".

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An Aveo has four forward gears plus torque converter lockup. The torque converter works as part of the automatic transmission system. The lockup acts similar to a fifth gear or overdrive on automatic transmissions. On an Aveo, the torque converter doesn't enter lockup until about 45 MPH. When it does, it actually feels like a shift: you will notice a drop in RPM to about 2000. If the engine is cold, the TC will not lockup at all until it reaches operating temperature.

The torque converter itself is a separate component from the transmission itself. You may have a bad torque converter or a problem that is preventing it from entering lockup mode. Car dealerships know little about automatic transmissions and usually subcontract the work to transmission shops. I suggest you take it to a transmission shop and let them diagnose it.

Thanks Thyme...we probably have multiple issues. The thrill of the hunt :) BTW...I only have 3 gears at present...and it runs about 3200 RPMs at 60 mph if I recall right. Still gets me 27 MPG which is twice the mpg of the vehicle it is replacing :)

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Originally Posted by wiseguydave

They hooked it up to their diagnostic computer. The service tech also called and talked to Chevy...they had a tsb on it as well. Could be water or dirt or.... My friend that will be doing the work has had success in the past with cleaning out rails and even injectors. The dealer would have wanted to sell me all new replacement parts. Apparently there was enough of a mis-fire (perhaps worse before I got the car) to trip the code or whatever it does. I bought it with a check engine light and flashing "hold" light on as well as some other issues I have already solved.

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If you would like for me to research the VIN to see if there are any special coverages, open recalls on the vehicle, I would be glad to do. Please private message me.

Vanessa
GM Customer Service

THanks Vanessa! :) Will do.

Cleaning the rails did not do the trick. Doing a crankshaft re-learn procedure did :)