1997 Sunfire 2.2L 3Spd Trans.
Recently (all within last 5-10K mi) replaced: plugs, wires, coil packs, fuel filter, timing chain and tensioner, IAC, MAP, TPS and not to mention the rest of the maintenance fluids and filters
Loud ticking noise coming from the driver side of the motor sounds like in the head (#4 far as i can tell). Anyways the car idles very rough and on the bottom end acceleration sucks but after about 3k rpm it smoothes out. Driving on the highway is not an issue, but the throttle seems VERY touchy. Stalls from time to time at red lights if in Drive gear.
As I said it has new plugs, wires and coils so spark is strong. New fuel filter and I have swapped all the injectors around and noticed no change. Compression is around 130psi and leak down test showed good also. I can either pull the spark plug wire off or go through the scanner and disable the #4 injector, EITHER WAY the engine smooths out and picks up idle. Short Term Fuel Trims are -20s.
I have removed and checked all pushrods, the two out of #3 are very slightly bent but Im not replacing those until I figure out what the hells going on with #4. All others look good, rocker arms torqued down to 22ft/lbs.
Any help here would be appreciated as I am stuck
Have you put a vacuum gauge on it?
The last one I had that ran like yours does, the valve springs were shot, would flucate rapidly 5-15hg at idle
- 2004 Cavalier - 124k, owned since new
no, that I have not done. Is there a way to go about checking the vacuum on one particular cylinder?
Get a compression tester, or barrow one. Thats the best way. it sounds like u have a bent valve. Didn't you have your timing chain snap not too long ago? If so, then your piston slapped the valve, and bent it enough to cause problems. There are interference motors, so if the push rods are bent, then it means that ur valves are probably bent too. Best bet, pull the head off, and look you will see damage on the valves.
Sneezy -
I have done a compression test on the cylinder in question, also a leak down test which test for leaky valves.
I know we do have some pushrods on a different cylinder that are slightly untrue but not enough to replace them now when thats not even the one giving me issues.
So let me make sure im understanding you. You did a compression test and a leak down test, and both showed ok? And on cyl 3 you have some pushrods that are slightly bent, but nothing major. Am I correct so far??
Edited 1 time(s). Last edited Wednesday, December 22, 2010 7:29 PM
Sorry just read the whole post. I see u said the cylinder is at 130psi, how much was the varience between the other cylinders?? Should be no more then 5%.
Sneezy - Yep your good so far. thats where i am at to this point
all compression was within 5 - 10 psi
Ok, and when you pull the connector for the injector it actually causes a improvement in the engine?? I now am thinking its the injector or spark plug, or wire in that CYL. Try this, take the wire and plug out of cyl three, and put it to cyl 4 and move the stuff from 4 to 3. Make sure you put back the wires in the correct spots on the coil packs. Then start it and see if 3 is dead, if not, then your injector is bad. Thats the only other thing literally thats left.
Mike, he said he swapped the injectors out.
To the OP, install a vacuum gauge and observe the readings at idle and at 2500rpm, post the results
- 2004 Cavalier - 124k, owned since new
Ahhhh, I didnt see that. Okay, well Im officially out of ideas now lol Goodluck, Im following this to see where it goes.
Since you have a scanner that tells you fuel trims, can you look at injector pulse. if so is it good???
I will get back to the scanner and testing next week.
When #4 loses either spark or fuel the car picks up idle and smooths out some, the backfiring seems to quiet down some also.
Injector pulse width isnt really revelant in this case
What equipment are you using for a leakdown test......some brands arent very good to use
- 2004 Cavalier - 124k, owned since new
Small update with good news and bad news.
Well start with the bad, Christmas Eve I get a call from the girl saying that she has what she thinks is coolant spraying on the windshield as she drives and says she can smell the sweet smell of it burning under the hood but the temp gauge shows good. She makes it home from work and I go out to take a look and the damn plastic tank on the driver side of the radiator split right open. Talk about throwing salt in a wound heh...so now on top of it running like @!#$, it pisses out coolant.
Good news is, I went to the junk yard today and found a 96 cav with 140K on it, immaculate inside and out. Someone had already snagged the radiator but when I looked up I saw a fresh head staring at me. Has to be too good to be true so I pull the valve cover off it and everything is sparkling! Valves, springs, retainers you name it its new. Even had 1500 mi before the next oil change was due. The outside of the head doesnt have a speck of dirt or oil or anything on it at all and still bright silver so its either new or its been recently rebuilt. Either way I just came home with a hell of a steal
Well see if the fresh head can get things running right and if so, I will be making the journey to another junk yard to pull a radiator on Tuesday when Im off again.
My main question is do I want to use the pushrods and rockers out of the new head or out of my old head? as I know your supposed to keep them all together in order.
I would grab all the new stuff as much as possible. Grab the rods from the other engine. And as far as keeping them in order, you can, and technically your suppose to, but I lost track of them before, and it didnt matter. And take the rockers out of the new head and use those. BUT remember, you will need NEW head bolts, since the ones holding the heads down are Torque to Yield, meaning single time use. So along with a NEW head gasket, you will need NEW bolts. Don't make the mistake of re0using the old head bolts from either engine. Goodluck.
got the new head in tonite... running MUCH better.
now time for the radiator troubles...
Good job. Least now u know it was in the head.
If I get time this week Ill strip it all down and see if i can determine if there was a bent/burnt valve or just a weak spring there on #4.
I want to thank everyone whos been following this and helping out!
