98 gt miss....I'm at a loss
04-19-2011, 10:41 PM
#1
2nd Gear Member
Thread Starter
Join Date: May 2010
Location: Georgia
Posts: 239
98 gt miss....I'm at a loss
last week I blew the heater hose, and replaced it but it got sensors and plugs/wires wet so the car wouldn't start, so I unplugged everything that got wet and it ran fine after that.
Thursday I noticed that when I started the car after work it missed for a few seconds but went away, then it did it again on Friday, so Friday night I pulled the plug wires again and left the hood open over night [it was garaged] Saturday it did it every time I started the car up as I was doing a lot of running around, it sat for about 2 hours and it did it the worst and it took a good 5 minutes for it to stop missing. then it sat for another 2 hours and when I started it back up it would not stop missing the entire time the car was on, and it does this now the entire time the car is running, the rpms also bob up and down.
Sunday I changed all 8 spark plugs and all the threads on all 8 were wet with coolant on the threads, before I replaced them I sprayed brake parts cleaner in the boots and plug holes. when the car runs it sounds lopey and the rpms rev up and down slightly, also there is a small amount of smoke mostly coming from the passenger side. when the car goes down the road it pulses like you step on the gas the let off over and over.
I had a mechanic friend look at it and he said there's water somehow getting into my combustion chamber, but not through the head gasket [no water in oil] it threw a code for egr circuit malfunction, not one for a misfire. he said he doesn't understand why it sounds lopey. he also said could have a coolant sensor bad and IAC and he suspects that the intake gasket is leaking and water is getting in through the intake valve, and the coolant level is slowly going down.
anyone have any clue whats wrong with it? or is my friend right and I need to change the egr sensor IAC and intake gasket?
short clip of the exhaust lope and you can kinda see the rpm fluctuate:
http://youtu.be/8ecBATuLhPA
Thursday I noticed that when I started the car after work it missed for a few seconds but went away, then it did it again on Friday, so Friday night I pulled the plug wires again and left the hood open over night [it was garaged] Saturday it did it every time I started the car up as I was doing a lot of running around, it sat for about 2 hours and it did it the worst and it took a good 5 minutes for it to stop missing. then it sat for another 2 hours and when I started it back up it would not stop missing the entire time the car was on, and it does this now the entire time the car is running, the rpms also bob up and down.
Sunday I changed all 8 spark plugs and all the threads on all 8 were wet with coolant on the threads, before I replaced them I sprayed brake parts cleaner in the boots and plug holes. when the car runs it sounds lopey and the rpms rev up and down slightly, also there is a small amount of smoke mostly coming from the passenger side. when the car goes down the road it pulses like you step on the gas the let off over and over.
I had a mechanic friend look at it and he said there's water somehow getting into my combustion chamber, but not through the head gasket [no water in oil] it threw a code for egr circuit malfunction, not one for a misfire. he said he doesn't understand why it sounds lopey. he also said could have a coolant sensor bad and IAC and he suspects that the intake gasket is leaking and water is getting in through the intake valve, and the coolant level is slowly going down.
anyone have any clue whats wrong with it? or is my friend right and I need to change the egr sensor IAC and intake gasket?
short clip of the exhaust lope and you can kinda see the rpm fluctuate:
http://youtu.be/8ecBATuLhPA
Last edited by stangcoupe1970; 04-20-2011 at 09:20 AM.
04-19-2011, 11:15 PM
#3
6th Gear Member
Join Date: Apr 2006
Location: Las Vegas
Posts: 5,010
The only way that coolant would get to your cylinder wall is by pushing is way through the head gasket. Now I know you said there is no coolant in oil. Is there any bubbles on the dipstick and is there oil in the cooling system?
04-20-2011, 11:34 AM
#7
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
Here's another scenario--when the heater hose blew it sprayed coolant all over, including into the spark plug wells. When the OP pulled the plugs the coolant ran down into the cylinders (and wet the plug threads as they were removed).
Then, as brake cleaner is a terrible thing to spray on plugs and wires another ignition problem was created.
What I would do would be to blow out the plug wells with compressed air and once again pull the plugs. Then while they are out wipe the plugs wells dry with a shop cloth, and do a compression test to rule out (or in) a bad head gasket.
Next blow out the plug connectors on the wires with air, spray them with WD-40 (Water Displacing, formula 40) and blow 'em out again.
Assuming the compression check comes out OK put it all back together and see how it runs; if the compression is bad then it's time to dig further...
Then, as brake cleaner is a terrible thing to spray on plugs and wires another ignition problem was created.
What I would do would be to blow out the plug wells with compressed air and once again pull the plugs. Then while they are out wipe the plugs wells dry with a shop cloth, and do a compression test to rule out (or in) a bad head gasket.
Next blow out the plug connectors on the wires with air, spray them with WD-40 (Water Displacing, formula 40) and blow 'em out again.
Assuming the compression check comes out OK put it all back together and see how it runs; if the compression is bad then it's time to dig further...
04-20-2011, 02:15 PM
#10
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
My point is that spraying the brake cleaner would not fix the problem, it probably just continued i--brake cleaner if for cleaning brakes, not ignition system components...