Fuel filter causes tranny bump?

[Chad K]

Hi all,

My wife took her 2001 pontiac montana in for a tranny bump

and the service tech replaced the fuel filter and said that can cause the prob.

Something about insufficient fuel causing the oxygen sensor not to read

right.

Remember I'm getting this second hand from my wife (I love her dearly) who

thinks all vehicles fall into basic categories, trucks vans cars and suv's.

Does this sound possible? (the fuel filter causing the bump, not her categories)



thanks

new Chad

 

[scott degroot]

If the vehicle is running lean, I assume they think this because they replaced the fuel filter, and also has a trans shift issue the #1 cause for this on a GM is a is a dirty or faulty mass airflow sensor. I have also seen alot of plugged cats on the 3.4 that will cause a lack of power and then when they shift they shift hard.

 

[JohnM LowryJr]

We had a 1999 Montana. At or just about 110,000 miles. We felt a hard I mean a hard bump when changing gears. We took it to cottmon trans. shop to fix. Had to be repaired. Bump stayed after the repair. Then the tranny was replaced with a core and it to had the bump or hard shift still. Then the tranny went out all together. Replaced with another core tranny again but still had the bump afterwards? then when we would put it in gear and we had to wait on the tranny to catch up with us. So we traded it for a Honda Van!

One of the guys that I work with had a newer Olds van(same as the montana van) started at the same time with the same problem. He owns another kind of van. the tranny for the GM van are not that good. Search the web for troubles on the van.

If the fuel filter was the problem then we wasted over 30,000.00 for the repair. Van 28,000 + 2,000 on repair of old van????

 

[Chad K]

Thanks for the replies.

My wife's van is just over 100,000 miles.

The bump seems to start after you drive for a bit and everything is warmed up.

It will also now whine when it down shifts.

Am going to try to clean the maf as soon as I can.



Thanks again

new Chad

 

[scott degroot]

Thanks for the replies.

My wife's van is just over 100,000 miles.

The bump seems to start after you drive for a bit and everything is warmed up.

It will also now whine when it down shifts.

Am going to try to clean the maf as soon as I can.



Thanks again

new Chad

Hate to say it but it sounds as if you may be needing a trans...the whining noise kind of gives it away...although it's definitive it is a good clue that all i snot well inside of the trans.

 

[Chad K]

l1tech,

I figure it will come to that. The van is a 2001 which would make

the replacement tranny cost as much as the van is worth.

But I guess that is still alot cheaper than buying a new vehicle.



new Chad

 

[Richard L]

It sounds like the dealer is blowing smoke.



They probably know the tranny is going out or what the fix is, but they can milk more money out of you if they say it's a part that is not covered under the warranty,,,like a fuel filter.



The trick to avoid this kind of scheme is to insist that you get your money back if the part they replaced does not fix the problem. They will never do that if they are nor sure that the part is really causing the problem.



I was common for a dealer to tell a customer that they needed a tune-up for any bad sensor or problem that caused rough idle, poor mileage, etc. If you let the dealer write down "Tune-Up" on the workorder, you are stuck. Do not agree with the service writers best guess diagnosiss, and make sure they put down your complaint exactly as you described it.. If what ever they do does not sove the initial problen, then they cannot charge you for the parts because they did not fix the problem.



That is why you are paying a premium price for the certified technicians, so they will run the proper test and diagnose the cause and fix it. This is a big problem with warranty work since the Manufacturers do not pay the high rate, so they either do quick, sloppy work, or they know what the problem is and they want to bulk up the bill with a few non-warranty parts or services.



An to answer your question. No, I don't believe that the fuel filter/Oxygen sensor will cause a transmission bump. If the filter is clogged at normal fuel deliver, the Oxygen sensor will aske for more fuel but if the filter is clogged it cannot deliver more fuel. That would not cause a single bump, but an irratic bucking of an engine that was starved for fuel.



...Rich

 

[Chad K]

Thanks for the reply Richard L.



My wife went to visit her mom in Illinois so I will ask her how it's

running later tonight.



I like your idea of having the shop write down exactly what I say

the symptoms are.



new Chad

 

[D Potts]

Not saying that the Tech is right but:



After teh recent "Traction Control Teaser" thread I have had a bad...like worse than ever tranny bump.



TODAY, after I had the Hi-flow cat's installed and the o2 sensor bungs moved futher back in teh Y-pipe....the tranny bump is mysteriously gone!?



Not sure why this is, in fac I did not give it a second thought till after I read teh above post!?

hhmmmmm food for thought!