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04lss

$1200 tahoe question thread

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Hi Folks, 

 

Ive had my 1200 dollar 1999 Tahoe for a few days and i have some questions about it. I figured I would just create a thread for all of them instead of spamming the forum. 

 

1. when the truck gets warm there is a hesitation at part throttle. It gets worse on a steep hill. We found water in the gas when I changed the fuel filter. My initial reaction is that the water is to blame, but why is it only when the truck gets warm? Could this be indicative of it going Closed loop, and a bad o2?  
2. There is an odd noise at idle. the best way to describe it is that it sounds like the squeal a blower fan makes at low speed when it is on its last leg. Its coming from the engine bay. Its not loud. any ideas what i should check?
3. What is unacceptably low oil pressure at idle? if i can trust the gauge (not sure i can since half of them are incorrect) I get 5-10 PSI at idle, and around 20-30 at cruising speed. (when warm) Should i be concerned and looking to replace the oil pump, or should i just leave it? I added some Ceratec to help keep things protected.
4. I cant seem to get confirmation one way or the other. Does the engine need to be removed to replace the oil pump?

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1,how long has it been sitting?water in fuel rusts the lines and debris ends up in injectors,restricting flow,other,yes,a possible lazy,bias 02,a scanner would confirm

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I don't believe it was sitting. it was being daily driven until about 2 weeks before i bought it, and the guy who was selling it drove it around a bit during those two weeks. 

I have torque and HPT I can probably scan to o2 voltage with either of those. I also know that it has -4* of cam retard, and it saw 4* of KR when i gave it wot from first. 

Ive been getting a code for Catalytic converter efficiency on bank one.  Maybe i have a clogged Cat?

 

I noticed that hitting the gas off the line it moves pretty well for a second then as the revs climb it pulls back the power it starts this around 2k. 

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Ok,how much fuel in tank? just thinking it might be wise to run thru what's in there with some drygas,try to get rid of the water before looking at data to close?

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I'm just going to address #2 and #3, OP on #2, the slight squeal in the engine bay, I would check the serpentine belt and tensioner pulley. On #3, what appears to be low oil pressure, first check with a mechanical gauge to verify those numbers. You didn't say how many miles this Tahoe has on it, but if those numbers are correct, you're getting into the lower range of what I think is acceptable oil pressure. As long as you're not getting any consistent lifter tick, I would think it would be safe to drive for awhile as long you don't drive it like you stole it and for $1200 maybe you did!

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3 hours ago, riverbanks said:

Ok,how much fuel in tank? just thinking it might be wise to run thru what's in there with some drygas,try to get rid of the water before looking at data to close?

It had a full ish tank. I put two bottles of ISO heat in it after about 80 miles. Is that what you mean by dry gas? If not, what should i be adding. Right now ive got 220 miles on the current tank of gas. All my gauges are wonky, but i got some stepper motors and hope to replace them tonight or tomorrow. 

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1 hour ago, garagerog said:

I'm just going to address #2 and #3, OP on #2, the slight squeal in the engine bay, I would check the serpentine belt and tensioner pulley. On #3, what appears to be low oil pressure, first check with a mechanical gauge to verify those numbers. You didn't say how many miles this Tahoe has on it, but if those numbers are correct, you're getting into the lower range of what I think is acceptable oil pressure. As long as you're not getting any consistent lifter tick, I would think it would be safe to drive for awhile as long you don't drive it like you stole it and for $1200 maybe you did!

The truck has 252k miles on it. The engine is very quiet when warm. Almost surprisingly so. At least since the engine flush and Ceratec. I do know the cerpaintine belt needs to be replaced i can hear it chirping, but that is a different noise. I plan to replace that belt tomorrow. 

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On the question about the catalytic converter/exhaust restriction, you can use a pressure gauge in place of the oxygen sensor to measure upstream pressure:

 

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Sent from my iPhone using Tapatalk

 

 

 

 

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