Starting a few nights ago, I was leaving work and gavet he car gas, and it started coughing and misfiring and wouldnt accelerate. It was acting like it was running out of gas. First thought was that the fuel pump was dying. I pulled over and popped the hood and saw that fuel pressure is fine. There are no cracked or hoses popped off, no vacuum leaks, EGR is fine and all scanmaster numbers are fine. Every wire, ground and connection appears ok. Anyway, that night I just stuck it back in drive and drove home 30 miles and it seemed ok. But its sort of intermittent and happens usually from leaving a stoplight at low throttle...well thats the way it was and now its even misfiring intermittently at light throttle even at highway speeds. The coil packs are fine and all the plug wires are ok. The MAF signal seems ok and crosscounts are ok...lazy, but its been that way for awhile now. The TPS sweep is fine...no voltage drops. I poppe dthe lid off the cam sensor and its fine. I pulled all the plugs out and noticed number 6 was covered in oil and fouled. I stuck an old plug in and drove to work this morning. Ran great for about 20 minutes and started acting up again. Ill probably do a compression test next weekend, but the oil fouling wasnt so severe that it would foul the plug out in 20 minutes on the freeway. It almost acts liek it did when my positive battery cable was shorting out, but its fine. My turbo is in bad shape, but its been going bad for awhile. The thrust bearings are shot....but if it were oil from the turbo, all the plugs would look bad. Its just number 6 that looked suspect. I really dont think its plugs. Any ideas? At WOT or heavy throttle its fine. Its at light throttle that it starts coughing and misfiring and acting like its going to die.
Sputtering and coughing..
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Junior Samples
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brent
Worn valve guides and or seals
if its isolated to one cylinder, have you noticed any puff of smoke when you shut it down for say 10 mins then fire it up?
I know this car i got 2 months back with 2000 miles in 7 years, i got to replace a few umbrellas but nothing leaking through under load.. enough to cry foul anyway.
Or you have a little leakage which is burned off normally while under load but while its sitting at idle in Cali traffic it loads up plug which may have weak spark and cant burn it all... check #6 coil? or bad wire? check resistance on that also?
dunno just my old school chevy troubleshooting but im sure i'll hear of something new.
i love this car i bought but what a pain in the a$$
mike
Worn valve guides and or seals
if its isolated to one cylinder, have you noticed any puff of smoke when you shut it down for say 10 mins then fire it up?
I know this car i got 2 months back with 2000 miles in 7 years, i got to replace a few umbrellas but nothing leaking through under load.. enough to cry foul anyway.
Or you have a little leakage which is burned off normally while under load but while its sitting at idle in Cali traffic it loads up plug which may have weak spark and cant burn it all... check #6 coil? or bad wire? check resistance on that also?
dunno just my old school chevy troubleshooting but im sure i'll hear of something new.
i love this car i bought but what a pain in the a$$
mike
Thanks..yeah I ohm checked the coil packs and wires and they're fine. I do have the startup puff and always have. i think the rebuilt 4000 miles ago claim was BS when I bought the car. There were no signs of a recent rebuild anywhere. The heads had been done but the signs of a rebuilt block were nowhere to be found.
Junior Samples
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Ahh the rebuilt claim
Kinda like mine, although i bought from my chirocrackter he had the car built by so called V6 design team member here in Flint but after a few well placed calls i came to conclusion the guy is a legend in his own mind.
Still flipping quarter to decide if im going to re-rebuild motor this winter, that way if it fails i only blame myself.
goodluck on troubleshoot
mike
Kinda like mine, although i bought from my chirocrackter he had the car built by so called V6 design team member here in Flint but after a few well placed calls i came to conclusion the guy is a legend in his own mind.
Still flipping quarter to decide if im going to re-rebuild motor this winter, that way if it fails i only blame myself.
goodluck on troubleshoot
mike
I found a couple issues but I dont think they have much to do with it. About a year back I did one oil change with castrol dino oil and some lucas oil additive. 4000 miles later I popped the breather off and the whole top side of my heads were covered in the early stages of sludge and all carboned up. The upper part of the dipstick was all carboned up too. Real great oil! I threw some engine flush in and let it idle for 5 minutes like the instructions say and changed it out with synthetic like Ive always used. Seeing the condition of my heads I figured Id pop the intake tube off and check the turbo. It had like 1/16 of shaft play (thrust)...great. Then I pulled the plugs and noticed #6 was oiling up....figured, wonderful, so I have bad rings or a broken ringland, given every other cylinder is perfect. Well it never stopped wearing after that. I just checked my turbo and it has at least 1/8" shaft play...thats alot more than it sounds like. The blades are a hair away from hitting the housing. I think the turbo may not be getting enough oil. I give it gas and it falls on its face like its gasping for air. I think the turbo is actually dragging and stalling out from bottoming out...it cant spool up at all and get the air in the motor...gerat...and I dont even have money for an oil change and I need a new turbo and a rebuild...
jhanson1750
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the turbo dragging will not have the effect your speaking of. If it is (like mine was) it will either spool slowly or not at all. The processor reads the MAF to gauge fuel (many other sensors as well, I know). I would watch running with that much shaft play mine did the same thing. It seem to spool slower than some of my buddies so thats how I found it. Anyway the cold side wheel wore into the housing enough that the shaft could move and completely open the oil seal internally and dump oil into the exhaust side. Then there is the issue of the VERY VERY VERY fine alunimum dust from the contact that was injested by my motor. I cannot say it was the cause but my motor is currently at the machine shop due to a trashed rod bearing. I would check the valve seals at the very least. Good luck Jon Hanson
Its nice to hear from people who have experienced the same thing... Thanks!
Last night after fixing some things, I start it up to go home and the car will barely idle. I looked over everything and couldnt figure it out. In frustration I sigh and lay my hand on the intake tube..suddenly the motor coughs and tries to die. I let my hand off, and it runs smooth. I kept fiddling and tracking it down till I found one of the MAF wires is bad from being tweaked and bent too many times. I checked to see that its the MAF and its not..just the wires. This is severeal times now Ive traced a problem down to a wire with internal damage. This is one of the long term effects of high pressure washing your engine at the car wash. Those chemicals, and especially simple green, will corrode aluminum if not completely flushed...and there are alot of aluminum cored wires. It eventually dries out the insulation and cracks it everywhere, then the next time you clean it, the detergents get in the strands and slowly burn away at them until some sections are almost like a brittle powder. Use oil based engine cleaners!
Last night after fixing some things, I start it up to go home and the car will barely idle. I looked over everything and couldnt figure it out. In frustration I sigh and lay my hand on the intake tube..suddenly the motor coughs and tries to die. I let my hand off, and it runs smooth. I kept fiddling and tracking it down till I found one of the MAF wires is bad from being tweaked and bent too many times. I checked to see that its the MAF and its not..just the wires. This is severeal times now Ive traced a problem down to a wire with internal damage. This is one of the long term effects of high pressure washing your engine at the car wash. Those chemicals, and especially simple green, will corrode aluminum if not completely flushed...and there are alot of aluminum cored wires. It eventually dries out the insulation and cracks it everywhere, then the next time you clean it, the detergents get in the strands and slowly burn away at them until some sections are almost like a brittle powder. Use oil based engine cleaners!
To continue my diary log, I made a whole brand new MAF harness end and it didnt fix it. Its weird because last night I was very careful not to touch the MAF or tweak it in any way. I just barely touched and moved the wires around and it was stumbling. Now I grab the MAF and it tries to die....great. 3 months after selling my translator for 90 bucks with a new chip and now I need it. Got an Ls1 MAF at home and no use for it
Junior Samples
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Brent
Sorry to hear
although mine is running good it took quite a few hrs of troubleshooting the last couple of months to get it unlike my NA chevys such as the 61, rebuilt motor fired it up, couple of adjustments and havent dinked with it since.
it seems theres always somthing with these buicks but im not disenchanted yet...too fun to drive
keep chin up
Sorry to hear
although mine is running good it took quite a few hrs of troubleshooting the last couple of months to get it unlike my NA chevys such as the 61, rebuilt motor fired it up, couple of adjustments and havent dinked with it since.
it seems theres always somthing with these buicks but im not disenchanted yet...too fun to drive
keep chin up
