07 suburban 5.3L misfire and white/grey smoke

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Leadfoot31
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Joined: Fri Dec 13, 2013 4:32 am

07 suburban 5.3L misfire and white/grey smoke

Unread post by Leadfoot31 » Fri Dec 13, 2013 4:52 am

hello I am new to forum and of course I got a question. I have a 07 suburban LT 4x4 5.3L vortec motor. I was driving and it started to miss fire real bad. I checked scan tool got a code for cylinder#7 misfire. I unplugged coil pack at top engine didn't stutter like when I pulled the other plug ins. so I figured that was the problem went ahead and replaced all 8 plugs, wires, and #7 coil pack. still has a miss and now scan tool says multiple misfire. also now it smokes real bad a white more greyish smoke when accelerating. I also noticed a lot of oil/water residue at the oil fill tube and when I took air inlet hose off it had the same milkshake like residue on the little hose that connects to hose assembly to valve cover under coil pack on pass side. And at the bottom of air duct hose in the black plastic could hear water when I shook it. I turned it upside down and water came out like dexicool color. I also have 150,000 miles on this vehicle and this is the first time to do plugs. I also noticed it uses 3 quarts of oil between 5,000 mile oil change I am using amesoil. I haven't really seen an collant leaks but I have my vehicle serviced at a shop and I don't no if there adding coolant or not. This one has stumped me hopeing I can get some help with this problem any suggestions thanks

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mastertech
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Joined: Fri Dec 13, 2013 11:39 am

Re: 07 suburban 5.3L misfire and white/grey smoke

Unread post by mastertech » Fri Dec 13, 2013 11:44 am

Pull the dipstick for the oil. Does it look like a milkshake? Do a compression test on cyl 7. Since you have a scanner are there any codes coming up besides misfire?

Leadfoot31
Posts: 6
Joined: Fri Dec 13, 2013 4:32 am

Re: 07 suburban 5.3L misfire and white/grey smoke

Unread post by Leadfoot31 » Fri Dec 13, 2013 9:51 pm

I checked dipstic and oil looks fine no milkshake. water reservoir coolant looks good also. gonna try this weekened to check compression will see what I come up with. you don't think it could be a injector problem with the bad misfire. also got a throttle positioning code but that always comes out on codes replaced tps about 3 times in 2 years. but when it goes out the suburban will eather die out or have a high rev. also the traction control warning light on dash came on since this started. ill clear codes and truck will start and start misfiring and nothing shows up on dash but a few minutes later check engine light will start flashing and traction control will start flashing and say that it is turned off.

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mastertech
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Re: 07 suburban 5.3L misfire and white/grey smoke

Unread post by mastertech » Fri Dec 13, 2013 9:56 pm

Does the truck have active fuel management? Does it tick when first started cold? Reason im asking is we had a 2008 suburban that had a misfire on cyl 6 and it was the afm liters.


TPS is serviced with the throttle body

Leadfoot31
Posts: 6
Joined: Fri Dec 13, 2013 4:32 am

Re: 07 suburban 5.3L misfire and white/grey smoke

Unread post by Leadfoot31 » Fri Dec 13, 2013 10:58 pm

when you first start it it stumbles bad then kinda has a rough idle but when you accelerate to about 2 grand on rpm's it runs normal can barely feel misfire then when you let go of throttle it acts like It wants to die but just runs rough. it doesn't start smoking till you run it for about 5 or more minutes then it starts to fill garage up with white smoke but if you give it gas it turn almost grey to like black. it dripps water out of tail pipe but it has always done that. also when its iddleing the light inside suburban flickersan headlights to. I don't no about the fuel system. its never given me any problems before just took it out to store and started to hesitate then as I accelerated it would smooth out. and no it doesn't have that ticking sound. just a rattle when you turn off the suburban in the intake hose area.

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mastertech
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Re: 07 suburban 5.3L misfire and white/grey smoke

Unread post by mastertech » Sat Dec 14, 2013 9:49 am

Any other codes coming up?

Leadfoot31
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Re: 07 suburban 5.3L misfire and white/grey smoke

Unread post by Leadfoot31 » Mon Dec 16, 2013 3:22 am

ok now that I start it at cold it does have a ticking noise when first started I also found out cylinders 1,3,5,7 are missfireing. it doesn't smoke till at close to operating temp then it starts to smoke white at idle and when you mash the gas it belchesh out grey white smoke. its getting worse with the misfire at idle.

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mastertech
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Re: 07 suburban 5.3L misfire and white/grey smoke

Unread post by mastertech » Mon Dec 16, 2013 10:56 am

Ok
AMF Cylinders are 1, 4, 6, 7 So you may be able to rule that out. First thing I would do is a compression test on all cylinders. If you have any low numbers add a teaspoon of oil to that cylinder and see if it improves. If it does then the piston rings are bad. If not then the valves maybe sticking. Then you will need to perform a leak down test.

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carriedi
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Re: 07 suburban 5.3L misfire and white/grey smoke

Unread post by carriedi » Mon Dec 16, 2013 11:44 am

1,3,5,7. so all on one bank? check your bank one O2 sensor operation. also check your bank one cat. If your Os sensor has died it will mess with the fuel on just one side. Is it possible that your misfire has damaged the cat for that side? Hook up to a scanner and see what the engine is doing when your problem is happening. look at the O2 sensors for the bank side. pre-cat and post cat.
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