horrible mpg and weird idle drop

[PProph]

Walker

 

[gmcman]

I will try to get the video tomorrow. When idling naturally it took longer to heat up but you could see it stabilizing around the .600 area. When i was driving at a steady 50-60 MPH after about 5 miles I was keeping a steady .530-.535 ish. This would change if I coasted or accelerated, sat at a light for a couple min, but once at cruise and been holding that speed and steady throttle, i would get back into the mid .500's.

My cat has 206K miles and is likely not as efficient but the voltages are steady after awhile.

How does it run when you use WOT above 4K? does it pull to 6K or does it take awhile or struggle to accelerate? Just trying to see if your cat is partially clogged.

 

[Gerbil21]

I will try to get the video tomorrow. When idling naturally it took longer to heat up but you could see it stabilizing around the .600 area. When i was driving at a steady 50-60 MPH after about 5 miles I was keeping a steady .530-.535 ish. This would change if I coasted or accelerated, sat at a light for a couple min, but once at cruise and been holding that speed and steady throttle, i would get back into the mid .500's.

My cat has 206K miles and is likely not as efficient but the voltages are steady after awhile.

How does it run when you use WOT above 4K? does it pull to 6K or does it take awhile or struggle to accelerate? Just trying to see if your cat is partially clogged.

well ive only done wot once and it felt pretty good not entirely shure about the rpm since i got a bit worried about the dam 1-2 shift after that it felt like there is a dead spot in the pedal where nothing really happens until you really hit wot (the car is still pulling but just not revving and flying down the road) then the car starts to pull but i was running out of space so idk but i will see if i can test it agin getting it up to 4k then wot. im pretty shure i was just feeling the dam throttle management

 

[gmcman]

Here's a video of driving after about 5 miles of warm up. I will get another with MAP but it stays pretty much in the 500's with a light load. After my first stop the road somewhat went on a downgrade and there wasn't much fuel in the fire so to speak. I think my cat is getting worn since the warm up takes a little longer but at a highway cruise it does it's job.

It's hard to measure the efficiency at idle, it will cool off a little and the numbers will creep up a little. Best is to test it at a good highway cruise.

I'm still very curious about the backpressure and I did a test on mine comparing the Walker Quiet-Flow to the stock and I had very little backpressure...I think under 1 PSI, 3PSI is pretty high for stock.

I wonder if also your PCV hose is partilly clogged on the drivers side of the intake. Be careful removing it as it's a molded hose and will crack especially with age.

You also stated you have no vacuum at the port on the intake? Was this where the fuel pressure regulator goes or the one I showed you with the arrow? The one with the arrow may or may not draw vacuum with the SWB models, mine happens to pull vacuum.

Your MPG's are horrible and should be at least 15 on the highway and likely closer to 18 in stock form.

Have you checked your intake manifold bolts? Use a 10MM on a 1/4' drive and be careful as they only require 89 inch pounds, not foot pounds...at least check them for being tight.


You still need a wet/dry compression test.

https://www.youtube.com/watch?v=ysaWcI52NS8&feature=youtu.be

 

[Gerbil21]

Here's a video of driving after about 5 miles of warm up. I will get another with MAP but it stays pretty much in the 500's with a light load. After my first stop the road somewhat went on a downgrade and there wasn't much fuel in the fire so to speak. I think my cat is getting worn since the warm up takes a little longer but at a highway cruise it does it's job.

It's hard to measure the efficiency at idle, it will cool off a little and the numbers will creep up a little. Best is to test it at a good highway cruise.

I'm still very curious about the backpressure and I did a test on mine comparing the Walker Quiet-Flow to the stock and I had very little backpressure...I think under 1 PSI, 3PSI is pretty high for stock.

I wonder if also your PCV hose is partilly clogged on the drivers side of the intake. Be careful removing it as it's a molded hose and will crack especially with age.

You also stated you have no vacuum at the port on the intake? Was this where the fuel pressure regulator goes or the one I showed you with the arrow? The one with the arrow may or may not draw vacuum with the SWB models, mine happens to pull vacuum.

Your MPG's are horrible and should be at least 15 on the highway and likely closer to 18 in stock form.

Have you checked your intake manifold bolts? Use a 10MM on a 1/4' drive and be careful as they only require 89 inch pounds, not foot pounds...at least check them for being tight.


You still need a wet/dry compression test.

https://www.youtube.com/watch?v=ysaWcI52NS8&feature=youtu.be

I do have that cap and it dose pull vacuum sorry if i wasn't clear what I meant was I don't feel vacuum at the port on the resonator where the pcv hose goes to, the pcv hose is good and is not old and rotted the worst thing it has is a small crack but it dose go through it, I have sprayed tb cleaner through it and made shure it wasn't gumed up and did the same with the resonator. I will try to make a vid tomorrow of live data aswell, i will also drive it with the pcv hose off of the resonator and see if that makes a difference on the o2.

One other thing, how is a compression test done on this engine?, for changing plugs it says to do it with cold engine so would I do compression check cold too? I have no experience with aluminum heads so idk also should I just use 5w-30 for the wet test?

 

[gmcman]

Which pvc hose are you referring to? The large curved one going into the valve cover? The vacuum is drawn from the molded hose in the middle of intake on drivers side, pulled from the valve cover, this draws filtered air from resonator.

You just don't want to pull the plugs from a hot engine. I pull mine cold or after maybe a 30 sec warm up, this can loosen tension on threads slightly since the head has expanded.

Spraying the PCV hose isn't going to affect your O2 readings, can't imagine anyway.

 

[KNBlazer]

Which pvc hose are you referring to? The large curved one going into the valve cover? The vacuum is drawn from the molded hose in the middle of intake on drivers side, pulled from the valve cover, this draws filtered air from resonator.

You just don't want to pull the plugs from a hot engine. I pull mine cold or after maybe a 30 sec warm up, this can loosen tension on threads slightly since the head has expanded.

Spraying the PCV hose isn't going to affect your O2 readings, can't imagine anyway.

I too pull plugs cold, however, I have pulled one hot with no problems.. I had used anti-seize though prior to installation...

 

[Gerbil21]

Which pvc hose are you referring to? The large curved one going into the valve cover? The vacuum is drawn from the molded hose in the middle of intake on drivers side, pulled from the valve cover, this draws filtered air from resonator.

You just don't want to pull the plugs from a hot engine. I pull mine cold or after maybe a 30 sec warm up, this can loosen tension on threads slightly since the head has expanded.

Spraying the PCV hose isn't going to affect your O2 readings, can't imagine anyway.

Just making shure but are you talking about the I6? I only have one vacuum hose it goes from valve cover to intake resonator and is short

Also I meant that since I sprayed it I know its not kinked in the inside also I said I should take off pcv hose and see if there is a difference since I get blue smoke from it and that maybe effecting the mixture

I too pull plugs cold, however, I have pulled one hot with no problems.. I had used anti-seize though prior to installation...

Ok I will probably have to do it tomorrow because I have to go out and rent the tester but I have to go somewhere tonight so it won't be cold In Time

 

[gmcman]

You should not be getting blue smoke from that hose, that's a suction hose.

Check the molded hose on drivers side of intake, it's a booger to get off but go slow. That's your vacuum supply to the crankcase and pulls through the valve cover through that short curved fat hose you are getting smoke from.

 

[Gerbil21]

You should not be getting blue smoke from that hose, that's a suction hose.

Check the molded hose on drivers side of intake, it's a booger to get off but go slow. That's your vacuum supply to the crankcase and pulls through the valve cover through that short curved fat hose you are getting smoke from.

http://www.gmpartseast.com/diagrams/large/56S/air-intake-system-ts0323501.png


Number 8 is the only hose I know of where exactly is the one you are talking of?

Also as far as I know there is just one hose that pulls crankcase gasses out and that is the short fat one. Also why wouldn't there be smoke coming from there? The hose is to vent out gasses which would be the smoke I see.

 

[gmcman]

The air goes from the air filter into the resonator, then exits the bottom of resonator through that short fat hose into valve cover. Then into crankcase and back into intake just above valves.

Between the number 3 and 4 intake runner there's a molded vacuum hose. This pulls air from crankcase into intake.

Number 6 in pic if the pic will download from my phone.

 

[Gerbil21]

The air goes from the air filter into the resonator, then exits the bottom of resonator through that short fat hose into valve cover. Then into crankcase and back into intake just above valves.

Between the number 3 and 4 intake runner there's a molded vacuum hose. This pulls air from crankcase into intake.

Number 6 in pic if the pic will download from my phone.

Thanks for explaining it for me I will check that hose

 

[Gerbil21]

Well the hose looks good from the outside I really dont want to take it off since its in a bad spot. Dose that hose normally go bad?

 

[gmcman]

You should not be blowing smoke from the other end. That hose supplies vacuum, I would start there. Don't crank it off with pliers, turn it and pry gently. It's a dealer item

 

[Gerbil21]

Ok well I will try to take it off idk why they put a clamp on the hardest side when there's not alot of space to get to it

 

[gmcman]

While you're at it, check all the intake manifold bolts.

 

[Gerbil21]

Any tips on how to get off that clamp?

 

[gmcman]

Lol...the clamp should lock in place when fully opened. I take some silicone or light dab of oil and that helps.

 

[Gerbil21]

Lol...the clamp should lock in place when fully opened. I take some silicone or light dab of oil and that helps.

I already spayed it with wd-40 the problem is that I can barley fit pliers in there

 

[Gerbil21]

Ok I found my needle nose channel locks and got it out

 

[Gerbil21]

Would you happen to have a part #

 

[Gerbil21]

Ok the # is 575660 for the hose and it comes with a new clamp for $9

 

[Texan]

I have never had a problem with mine, but could the vacuum port in the head be
clogged up with gunk? Could you spray carb cleaner into the port to unclog it?

 

[KNBlazer]

Ok the # is 575660 for the hose and it comes with a new clamp for $9

12575660

I have never had a problem with mine, but could the vacuum port in the head be
clogged up with gunk? Could you spray carb cleaner into the port to unclog it?

Chances are it's not clogged, stick in a screwdriver gently and feel for resistance, thus determining whether there is or not gunk in there... I'm thinking if a PCM flash doesn't fix your problem, you might have internal damage...

 

[Gerbil21]

Chances are it's not clogged, stick in a screwdriver gently and feel for resistance, thus determining whether there is or not gunk in there... I'm thinking if a PCM flash doesn't fix your problem, you might have internal damage...

Well I did just finished it and did both I stuck a 1/4" screwdriver in there and sprayed tb cleaner

 

[gmcman]

I would start the engine and see if the intake is drawing vacuum where the hose attaches. If it is, and the hose is clear, then we need to find out why you are blowing smoke from the other end.

Where the large fat hose attaches to the valve cover under the resonator, with the engine running, there should be a strong suction there.

If the hose is off, and you hear a pressure release when you pull the dipstick, then you have some blockage somewhere.

Sorry, you should have vacuum at top of valve cover when the molded hose between the intake runner you just removed is in place.

 

[Gerbil21]

I recorded some live data and will post later also I will try both of what you said later since neighbors started cutting grass and I won't be going out until.they finish since the winds blowing that stuff everywhere

 

[Gerbil21]

I recorded some live data and will post later also I will try both of what you said later since neighbors started cutting grass and I won't be going out until.they finish since the winds blowing that stuff everywhere

had to go out so i will test for vacuum first thing in the morning along with compression test if its not broken like the last one i got from autozone loaner tools, also is there any reason why i shouldn't just replace the hose with a regular vacuum hose? i know its not molded but i don't see the point in paying $20 for the o.e part and i will have to wait for it in the mail, or i could just use a elbow and two pieces of vacuum hose right?

 

[gmcman]

Yes, you could use whatever, not sure how much vacuum it sees so a thicker hose would be better.

I was thinking maybe even a small coil with each end about 90 deg apart.

A 45 with two short pieces will be neater.

 

[gmcman]

Easier to reply being on a PC.....There's alot to check and the smoke bugs me....I wonder why it's happening.

Also, have you checked your MAF sensor or cleaned it? I'm pretty sure the 05 had one.

The fact you're mileage is practically cut in half is a big deal.

Could be many things...

restricted exhaust
leaking injectors
vacuum leak
worn rings
incorrect fuel pressure
ignition timing way off


Use the vacuum hose at the base of the throttle body for your vacuum check.

Very curious to see the results.

 

[Gerbil21]

Easier to reply being on a PC.....There's alot to check and the smoke bugs me....I wonder why it's happening.

Also, have you checked your MAF sensor or cleaned it? I'm pretty sure the 05 had one.

The fact you're mileage is practically cut in half is a big deal.

Could be many things...

restricted exhaust
leaking injectors
vacuum leak
worn rings
incorrect fuel pressure
ignition timing way off


Use the vacuum hose at the base of the throttle body for your vacuum check.

Very curious to see the results.

im guessing there is something wrong with the resonator since there is no vacuum so im trying to piece together a intake but i find im finding autozone's website to be not helpful. so far i found a 3" flexible intake that i can use and its only $20 http://www.autozone.com/autozone/accessories/Spectre-Black-air-ducting/_/N-25h5?itemIdentifier=422454_0_0_

all i would need is a vacuum connector and a vacuum line to go from the valve cover to the intake any idea what size hose i would use? also i need to find out the size for the vacuum hose between the intake manifold.

as to what you said (i have no maf 06+ got them)
1.how does your exhaust at the tailpipe feel? also as far as i know everything is o.e on the car so i wouldn't be surprised if the cat is going even thought the reading aren't that bad, there is no smell, sound, or codes

2.if they were leaking i would of smelled it in the oil i have been 1k since oil change

3.there are not many hoses on this car and im shure all are o.e also i will change the manifold one tomorrow which was cracked but not bad and i could try spraying brake clean on the intake with the engine cold and starting it up. if there was a leak i would hear the change in rpm

4. i hope not but hopefully compression test tells me otherwise tomorrow

5.idk how that would happen other that a fault in a different system (vacuum leak) since i have a return less fuel system and pressure is constantly changed

6.idk how also since its cop (unless something is effecting it) and would be changing all the time but a look at the plugs tommorow will be a good indicator of something wrong

also thanks for the info on where to check vacuum.

 

[gmcman]

Can you post some pics of the setup you have and point to the problem areas?

The resonator is a fairly simple device...just a formed baffle and since the incoming air is filtered, that's what enters the valve cover.

 

[Gerbil21]

Can you post some pics of the setup you have and point to the problem areas?

The resonator is a fairly simple device...just a formed baffle and since the incoming air is filtered, that's what enters the valve cover.

(i updated post)

well if it adds some sound it would be worth it

 

[Gerbil21]

Timing & rpm
Timing & load

 

[gmcman]

Have you checked the screen in your MAF meter?

 

[Gerbil21]

Have you checked the screen in your MAF meter?

I don't have one also would a filter on the valve cover be ok

 

[gmcman]

Can you post a pic of your engine bay?

 

[Gerbil21]

 

[gmcman]

I'm not too familiar with the 05 but what is the large almost 2 inch Dia hose coming off the intake boot just after the air cleaner?

 

[Gerbil21]

ok so i just finished the compression test and i got

cylinder 1 200 psi
cylinder 2 180 psi
cylinder 3 190 psi
cylinder 4 190 psi
cylinder 5 195 psi
cylinder 6 190 psi

i pulled all spark plugs

they all took around 16 cranks to get to there max
the battery was 12.22v after i finished

the tube coming off the intake is for the a.i.r pump