00 5.7L, Misfire, Vacuum Leak, White Smoke
May 16th, 2014, 3:02 PM
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00 5.7L, Misfire, Vacuum Leak, White Smoke
Grandfather has a 00 Express 1500, 5.7L, 161k miles
Recently its been running worse than usual. Its been sipping coolant for quite some time. It has had vacuum leak codes for quite some time, he has been ignoring it, however, the last time I drove it id had enough.
Whats been done, other than oil changes:
30k ago, dealer replaced ECU and distributor/ cap
1K ago, I looked into the vacuum system, to pass emissions, replaced fuel canister, and found one of the lines going into it had burst, replaced it. I also replaced both cats, and the two pre cat O2 sensors.
After this the engine light went out, but came back on 1500 miles later.
Read the codes last night
P0171 system lean bank 1
P0174 system lean bank 2
P0300 random misfire
P0307 cyl 7 misfire
The white smoke. When it starts, exhaust is colorless, if it idles for 2-3 minutes, the smoke turns white, and the white color goes away only after its properly warmed up after a drive. I have videos I will attach later.
It also idles a bit higher rpm until its completely warm, at a light, when engine is cold, you can feel the car wanting to move forward in D when I have the brakes applied.
Running lean bank 1 and 2: I assume this is a vacuum leak related issue? Any culprits i should replace immediately?
Misfire: 1st order of business is to replace spark plugs and wires. Anybody have other misfire related parts? I don't think a distributor and cap the dealer replaced would fail after 30k miles.
Final issue, oil pressure. No matter how hard I get on the gas, it never goes above 60, and at idle sits at 20, sometimes on a really hot day goes to 18. He runs 10w30 conventional.
Any input would be greatly appreciated.
The mechanics he uses are absolute hacks and charge 90 an hour. I am very comfortable with a wrench so have decided to give this pile a go.
Recently its been running worse than usual. Its been sipping coolant for quite some time. It has had vacuum leak codes for quite some time, he has been ignoring it, however, the last time I drove it id had enough.
Whats been done, other than oil changes:
30k ago, dealer replaced ECU and distributor/ cap
1K ago, I looked into the vacuum system, to pass emissions, replaced fuel canister, and found one of the lines going into it had burst, replaced it. I also replaced both cats, and the two pre cat O2 sensors.
After this the engine light went out, but came back on 1500 miles later.
Read the codes last night
P0171 system lean bank 1
P0174 system lean bank 2
P0300 random misfire
P0307 cyl 7 misfire
The white smoke. When it starts, exhaust is colorless, if it idles for 2-3 minutes, the smoke turns white, and the white color goes away only after its properly warmed up after a drive. I have videos I will attach later.
It also idles a bit higher rpm until its completely warm, at a light, when engine is cold, you can feel the car wanting to move forward in D when I have the brakes applied.
Running lean bank 1 and 2: I assume this is a vacuum leak related issue? Any culprits i should replace immediately?
Misfire: 1st order of business is to replace spark plugs and wires. Anybody have other misfire related parts? I don't think a distributor and cap the dealer replaced would fail after 30k miles.
Final issue, oil pressure. No matter how hard I get on the gas, it never goes above 60, and at idle sits at 20, sometimes on a really hot day goes to 18. He runs 10w30 conventional.
Any input would be greatly appreciated.
The mechanics he uses are absolute hacks and charge 90 an hour. I am very comfortable with a wrench so have decided to give this pile a go.
May 16th, 2014, 10:35 PM
#2
White smoke is water.....head gasket? Pressure test the coolant system. If your loosing coolant, then maybe engine compression is pushing it out.
I would switch to high mileage oil. I did and saw an increase in oil pressure and less oil loss over the 5000 km interval.
Lean fuel mixture could be caused by any of the engine control sensors. Camshaft position, crank position, throttle position....etc. Have the van checked for codes at a shop. Those had held units are hit and miss.
Random misfire.....check for corrosion on the 8 points in the dizzy cap, and the tip of the rotor. These vans require a cleaning of them every 6 months or so.....cheaper that replacing the cap and rotor, but if you do keep and clean the old ones for later.
Replace the spark plugs if they are older than 80k. Make sure they are iridium. Not platinum. Plug wires if needed...up to you. I found the cap and rotor issue was my culprit.
May as well do the post cat 0s sensors too. They send info to the computer about how the system is running.....I would always do all 4.
I would switch to high mileage oil. I did and saw an increase in oil pressure and less oil loss over the 5000 km interval.
Lean fuel mixture could be caused by any of the engine control sensors. Camshaft position, crank position, throttle position....etc. Have the van checked for codes at a shop. Those had held units are hit and miss.
Random misfire.....check for corrosion on the 8 points in the dizzy cap, and the tip of the rotor. These vans require a cleaning of them every 6 months or so.....cheaper that replacing the cap and rotor, but if you do keep and clean the old ones for later.
Replace the spark plugs if they are older than 80k. Make sure they are iridium. Not platinum. Plug wires if needed...up to you. I found the cap and rotor issue was my culprit.
May as well do the post cat 0s sensors too. They send info to the computer about how the system is running.....I would always do all 4.
May 16th, 2014, 11:50 PM
#3
agree on most of the suggestions
fix the misfire first...
any pressure build up in the cooling system? cooling system pressure check is a good idea.
engine compression check may be in order also to check the head gaskets. definitely check cyl 7 if the ignition system checks are all ok.
yes, a vacuum leak could cause the lean condition. to confirm a vacuum leak check the fuel trim at idle and 2500 rpm. if its adding fuel at idle +20%,but drops back in spec +/-10% at 2500rpm your lean condition is a vacuum leak. If the system is lean at idle and 2500rpm, it is not a vacuum leak.
cam and crank sensors will not cause a lean condition. a misfire will, however the fuel trim monitors will not run if a misfire is present.
do not replace the rear 02 sensors. they are not used in fuel metering...rather to verify convertor redox reactions.
fix the misfire first...
any pressure build up in the cooling system? cooling system pressure check is a good idea.
engine compression check may be in order also to check the head gaskets. definitely check cyl 7 if the ignition system checks are all ok.
yes, a vacuum leak could cause the lean condition. to confirm a vacuum leak check the fuel trim at idle and 2500 rpm. if its adding fuel at idle +20%,but drops back in spec +/-10% at 2500rpm your lean condition is a vacuum leak. If the system is lean at idle and 2500rpm, it is not a vacuum leak.
cam and crank sensors will not cause a lean condition. a misfire will, however the fuel trim monitors will not run if a misfire is present.
do not replace the rear 02 sensors. they are not used in fuel metering...rather to verify convertor redox reactions.
Last edited by tech2; May 16th, 2014 at 11:59 PM.
May 17th, 2014, 9:01 AM
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thank you both for the replies
in terms of oil, i was thinking of switching to 10w40 for the summer months all together
coolant system pressure, seems fine, if the engine is running, I shut it off, I can remove the cap immediately, and don't feel any air rushing past my hand, i don't have a coolant system pressure tester, but could get one
With the way it smokes, could it be a intake manifold gasket, and not a head asked? nothing is getting into the oil
I terms of distribute replacement, am I going to see a differences, granted I get everything else sorted, by purchasing one of the MSD or JEGS performance distributors? How about high performance plug wires? Only reason I consider it is we tow a small sailboat with it a couple 100 miles twice a year, an could use all the help we can get.
Vacuum Leaks: Before doing the fuel canister and replacing the ruptured hose, the engine light was on all the time. Now it is on and off, is this why it leads you guys to believe its one of the sensors?
In terms of ignition system checks and fuel trim readings, as well as checking sensors. Are there any scanners I can purchase that are not a fortune that would help me determine this? There are GM Tech 2 scanners for roughly $350, or more sophisticated universal OBD2 scanners like the equus units for under $200.
I am used to working on VW/ Audi products, and have a reverse engineered cable that hooks up to a laptop where I can diagnose everything like a dealer.
Is there a higher end hand held scanner that would let me test sensors? or is hooking them up to a multimeter easiest?
I have new O2 sensors for the rear sitting in the box, rock auto sent me the incorrect ones when I was doing the cat converters, I will put the new ones in the same time I fix the rest of these problems.
in terms of oil, i was thinking of switching to 10w40 for the summer months all together
coolant system pressure, seems fine, if the engine is running, I shut it off, I can remove the cap immediately, and don't feel any air rushing past my hand, i don't have a coolant system pressure tester, but could get one
With the way it smokes, could it be a intake manifold gasket, and not a head asked? nothing is getting into the oil
I terms of distribute replacement, am I going to see a differences, granted I get everything else sorted, by purchasing one of the MSD or JEGS performance distributors? How about high performance plug wires? Only reason I consider it is we tow a small sailboat with it a couple 100 miles twice a year, an could use all the help we can get.
Vacuum Leaks: Before doing the fuel canister and replacing the ruptured hose, the engine light was on all the time. Now it is on and off, is this why it leads you guys to believe its one of the sensors?
In terms of ignition system checks and fuel trim readings, as well as checking sensors. Are there any scanners I can purchase that are not a fortune that would help me determine this? There are GM Tech 2 scanners for roughly $350, or more sophisticated universal OBD2 scanners like the equus units for under $200.
I am used to working on VW/ Audi products, and have a reverse engineered cable that hooks up to a laptop where I can diagnose everything like a dealer.
Is there a higher end hand held scanner that would let me test sensors? or is hooking them up to a multimeter easiest?
I have new O2 sensors for the rear sitting in the box, rock auto sent me the incorrect ones when I was doing the cat converters, I will put the new ones in the same time I fix the rest of these problems.
May 17th, 2014, 9:35 AM
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videos of smoke at idle: after start up, smoke is seen after 2-3 minutes of idle, goes away after a drive when its warmed up, notice how at idle its not a steady stream of exhaust gas, but theres almost a rhythm to it.
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January 18th, 2016, 9:39 AM
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YES!
2 years ago now, I think.
Texted local machine shop on a Wednesday that did my Audi engine block machining years ago.
Luckily, they had a slow week the following week. I assumed it was intake gasket, as it had never been done, so had one shipped amazon prime, a felpro, with new bolts.
Tested coolant system, there was a leak.
Since it had so many miles on it, before we did any work, they did a compression test, all good.
Coolant System:
Intake manifold gasket, was shot. that was replaced
Coolant Hoses: the lower coolant hose was a warm summer day from bursting, you could pinch it with a pinky, and I could teat open like a bag of chips.
Water pump: looked to be in bad shape, put a new one in.
Tune up:
While everything was out, we did plugs and wires. They mentioned the distributor cap could be the culprit of the misfire, so I got a new MSD unit.
Fuel injector: This is probably the issue for your misfire. There was a TSB chevy released about this.
They switched injector design from one injector, to a unit with 8 tiny injectors, look it up. It sits inside the intake manifold, so you will have to split the 2 halves.
They soda blasted the intake manifold clean while they were in there.
Buttoned everything up, and needed to replace the throttle position sensor.
Towed my 24 foot sailboat like a champ a week after the service.
Couple months after the service, I started running 10w40 conventional in it, as it would get hot on summer days, cuz of the intake gasket leak.
I continue to run 10w40 in it, just let it warm up a bit on cold mornings.
at 175k miles at the moment
2 years ago now, I think.
Texted local machine shop on a Wednesday that did my Audi engine block machining years ago.
Luckily, they had a slow week the following week. I assumed it was intake gasket, as it had never been done, so had one shipped amazon prime, a felpro, with new bolts.
Tested coolant system, there was a leak.
Since it had so many miles on it, before we did any work, they did a compression test, all good.
Coolant System:
Intake manifold gasket, was shot. that was replaced
Coolant Hoses: the lower coolant hose was a warm summer day from bursting, you could pinch it with a pinky, and I could teat open like a bag of chips.
Water pump: looked to be in bad shape, put a new one in.
Tune up:
While everything was out, we did plugs and wires. They mentioned the distributor cap could be the culprit of the misfire, so I got a new MSD unit.
Fuel injector: This is probably the issue for your misfire. There was a TSB chevy released about this.
They switched injector design from one injector, to a unit with 8 tiny injectors, look it up. It sits inside the intake manifold, so you will have to split the 2 halves.
They soda blasted the intake manifold clean while they were in there.
Buttoned everything up, and needed to replace the throttle position sensor.
Towed my 24 foot sailboat like a champ a week after the service.
Couple months after the service, I started running 10w40 conventional in it, as it would get hot on summer days, cuz of the intake gasket leak.
I continue to run 10w40 in it, just let it warm up a bit on cold mornings.
at 175k miles at the moment
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January 23rd, 2016, 8:34 AM
#9
From personal experience... if your intake gaskets are bad and have dumped coolant in the oil... - just have the engine completely rebuilt using AFTERMARKET gaskets & parts. At a minimum - do a lower end rebuild when the gaskets are replaced as water in the oil is going to eat your bearings up.
I had no clue about this VERY common gasket failure issue when mine went out and ended up with not one... but two used engines after the original engine failed with the same intake gasket problem. Even then we had to do the intake gaskets and a bottom end rebuild on that (second) replacement engine as well. Could have just installed a performance crate motor for about the same overall expense given the downtime, shop labor & multiple repairs. Far cheaper to just rebuild it now or install a remanufactured engine.
It's not like the old days when you could pick up a used GM engine in the boneyard & go... Don't waste your time if there is any coolant muck in your oil - rebuild it (or if you rely on the van for your income just replace the vehicle with something dependable.)
I had no clue about this VERY common gasket failure issue when mine went out and ended up with not one... but two used engines after the original engine failed with the same intake gasket problem. Even then we had to do the intake gaskets and a bottom end rebuild on that (second) replacement engine as well. Could have just installed a performance crate motor for about the same overall expense given the downtime, shop labor & multiple repairs. Far cheaper to just rebuild it now or install a remanufactured engine.
It's not like the old days when you could pick up a used GM engine in the boneyard & go... Don't waste your time if there is any coolant muck in your oil - rebuild it (or if you rely on the van for your income just replace the vehicle with something dependable.)
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