Chevy S10 bog problem (Long)

[RickB]

A friend of mine suggested I post this here. I didn't know you guys existed. I have been posting on Harley sites for years.

 

I have a 99 S10 XR2 with a 4.7 V6 4X4 overdrive with all the bells and whistles. It has 75000 on it now.

I have had a bogging problem with the thing since I got it. Last summer It got worse so I did a complete tune up. Plugs, cap, rotor, wires, fuel filter, cleaned and recharged the K&N filter which was very dirty because the previous owner never did it. I thought I got it but NOT.

 

Symptoms:

Cold starts fine. When put into gear it hesitates slightly for the first 100 yards or so then operates in a normal fashion.

Warm restarts: This is where the MAJOR problem surfaces. If I pull into a bank, a fast food place or anywhere else that the pu sets turnoff for any amount of time up to cold engine. It restarts fine but as soon as I put it in gear and give it gas it bogs. It I try to pull into traffic and hit it or feather it, the bog scares me. I am afraid of getting rear ended. I do not shoot into small spots but wait for a clear spot in traffic where a normal running engine would have no problem merging. I have tried pulling the shifter down into low and sometimes that helps but the bog is still there. And it usually takes around 100 yards to clear up. Then it runs better.

 

Steady speed - Driving down the road at a steady speed of something above 40 MPH. The motor seems to very in RPM even with the cruise set. Not much but a noticable amount always.

 

This has been a problem for almost since I got it. I have had it into a shop once but the mechanic told me .... ready for this...."They all do that!". The mechanic is my Son in law and I don't want to offend him.

 

My plan is to call him tonight and give him one more chance to fix this SOB. It that don't happen it will be going down the road and I will trade it for a newer PU.

 

It is to a point that it is dangerous to drive at times. I really don't know when this problem will pop up and scare me.

 

Any Ideas?

[GM-Tech]

This has been a problem for almost since I got it. I have had it into a shop once but the mechanic told me .... ready for this...."They all do that!". The mechanic is my Son in law and I don't want to offend him.

 

They definitely don't all do it. And by the way, it's a 4.3, not a 4.7.

 

It needs to be driven with a scanner on it to monitor the various parameters when this happens. Otherwise, you're really just guessing. Could be the TPS, fuel pressure, MAP, MAF, etc., if you want to guess at it.

[jamey777]

I have a 99 s10 4x4 w/ 4.3 vortec v6 and it does the same thing. Sometimes when i mash the gas it acts like it bogs down. Now I was told that the EGR valve was bad and either needed replacing or cleaning. I took it off and cleaned it and it ran real good for about a week, then it went back to running bad. I'm going to try cleaning it one more time really good and see if I get any better results. It's almost like the trucks not getting the gas that your sending to it. Keep me posted. And good luck.

[RickB]

I have a 99 s10 4x4 w/ 4.3 vortec v6 and it does the same thing.  Sometimes when i mash the gas it acts like it bogs down.  Now I was told that the EGR valve was bad and either needed replacing or cleaning.  I took it off and cleaned it and it ran real good for about a week, then it went back to running bad.  I'm going to try cleaning it one more time really good and see if I get any better results.  It's almost like the trucks not getting the gas that your sending to it.  Keep me posted.  And good luck.

 

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Exactly! I figured if I posted here I would find someone else with this problem. EGR you say? I might just run and get a new one and install it.

[FryZ71]

The 4.3s are known for EGR probs. Might want to run a bottle of that Seafoam top end cleaner through it..get all that carbon buildup out of there.

[Shadowfax]

Defintely sounds like the egr valve. My dads 95 GMC 2500 did the same exact thing and we replaced the egr and it worked fine after that.

[jamey777]

Before you go out a get a new one try cleaning it out first with some carb cleaner, but hold it upright when you do it. And use the seafoam to end cleaner. The EGR cost around 150 to 200 bucks.

[RickB]

I have been playing around with cars and trucks for lots of years. But not recently. Which brings me to ask a dumb question.

 

Where exactly is the EGR valve located?

Do I need to remove it to clean it?

 

 

Thanks from the dummy.

[jamey777]

on the 4.3 v6 it is right on top on the front of the intake. It is round and has 2 bolts holding it on with a wire cluster plugged into the top. It's very visable and easy to get to. If you look up the EGR valve at a parts web site like Auto Zone or such you can get a good look at it and know what your looking for. Remember to clean it with CARB cleaner and to hold it upright because it is an electronic device. You might want to get some SeaFoam Motor Cleaner (Napa Stores) and use it first. Go to SeaFoams web site to get directions on how to use it.

[RickB]

on the 4.3 v6 it is right on top on the front of the intake.  It is round and has 2 bolts holding it on with a wire cluster plugged into the top.  It's very visable and easy to get to.  If you look up the EGR valve at a parts web site like Auto Zone or such you can get a good look at it and know what your looking for.  Remember to clean it with CARB cleaner and to hold it upright because it is an electronic device.  You might want to get some SeaFoam Motor Cleaner (Napa Stores) and use it first.  Go to SeaFoams web site to get directions on how to use it.

 

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Thanks I will be doing this when the weather gets above freezing! Maybe tomorrow.

[RickB]

Thank you to the fine people here. Your suggestions were right on the money. My problem was if fact the EGR valve. I tried cleaning it but that did not help. So NAPA auto parts supplied the replacement and the bogging and hesitation problems are gone.

 

Thanks you again

RickB