02-19-2012, 04:38 PM
Join Date: Feb 2012
4.0L I6 Rough start/idle after cylinder head repair!!!
Hi all, I am at an absolute dead end on this one. I have a slow ignition crank with a rough/shaky idle with low rpms (around 4-500 idle) and it acts like it wants to stall only when I am decelerating to a stop once in motion, not so much while idling (down hill braking drops rpms to 200 or just under). No CEL
A little about my vehicle and back track to when and why im having this awful engine problem:
-1999 Jeep wrangler sport TJ standard transmission
-just over 114,000 miles odometer, 40k miles I've added since purchace
-engine is a AMC 4.0L I6
-i have had some issues with it having high heat in the past but never to the extreme of "overheating"
I had the radiator and all the connecting hoses replaced when i noticed the issue of my jeep getting too hot, during the summer months it was gitting hotter than normal and i wanted to/could afford to do preventative maitenance work with the cooling system. The radiator was old and rusty due to long use and old age i figure but replaced it anyway.
This most recent "overheat" happened about 2 and a half weeks ago sitting in traffic headed home, I was not minding my temps too much because it had been replaced recently, but sure enough I look down and the coolant guage is just about to hit red. First i threw the heater on until pulling into the nearest lot and shut off the engine. It was steaming a bit at this point but not pouring smoke like i've read in many other "blown head gasket" posts. I let it cool until i could touch the hoses and valve cover safely with my hand then (and i know, foolishly) drove it home babying it and heater full blast. It cranked and started normal and the ride was smooth as before but it did get just about to the red on the coolant guage again.. smoke and steam from under the hood and tail pipe when i pulled in the driveway, shut it off and let it sit for 24 hours. The culprit was a lower radiator hose clamped too tight causing a slow leak. As many could guess unfortunatly my head gasket was fried. But thats not my issue here. No CEL still
After "Overheating" I replaced:
-head gasket of course along with all the other gaskets in the set
-pulled the cylinder head off, machine shop resurfaced and "Magnaflux"
-pulled the spark plugs and put new ones in
-threw some new spark plug wires on
-pulled off the distributor cap and cleaned with attitude
-put on a new engine oil filter with engine oil
-flushed radiator to be safe and check for leaks (found none)
-last but not least cleaned the engine and compartment until it shined
(so i could see if and/or where any other leaks or failures would exist)
Head gasket and major work was done with the assistance of my mechanic friend who is ASE certified and has done most if not all work on my Jeep.
After all was said and done Jeep ran well and started without much crank time at all. The engine ride was back at normal and the idle was spot on. I drove it around the neighborhood 4-5 times about 5 miles each trip before i noticed another issue.
When i started it the crank time became longer each time with that slowing sound of giving up. It still cranks on the first try but its longer and slower. Also when in idle there is an obvious roughness to it, more so like a shaking of the engine when looking under the hood. I tried everything within my short knowledge and experience with mechanical work.
Parts I replaced trying to troubleshoot the issue (in order from first to most recent)
-i pulled the spark plugs to see what they would tell me (fuel or gasoline was present on all, more on #1 and less on each as i went down the line).
-i first drained the engine oil and swapped filter again
-idle air control valve replaced (old one was dirty but seemed good still)
-fuel injector for cylinder #1 (was told it was a leaky injector causing my issue)
-i tried seafoam in the gas tank at 1:1 ratio ounce per gallon, just over a quarter tank in all
-throttle position sensor TPS
-pulled the throttle body off and cleaned
-i also tightened the screw that the accelerator bracket sits on a half turn so that my idle would be a bit higher (gas pedal wire connects to the bracket that sits on this screw, not sure what the actual name is)
After all that the problem still persists, I had my mechanic friend do a double check to see if a fix was obvious or even possible. With no codes and no CEL He said there was nothing wrong with the jeep. So now I begin to online search only to find many problems similar and almost no solutions. Currently I can smell a new smell from the engine compartment after bringing it to running temps. It cranks longer and slower still with a start on first round, the idle when cold and warm is rough and shaky. During acceleration i can feel minor hiccups or stumbles. When coming to a stop once in motion with foot on brake it seems to want to stall on me. I feel i have done almost all i can and fear any mechanics outcome (price) but its looking expensive either way... I AM STUMPED AND NEED ANY HELP I CAN GET!!!!!
As of friday i broke down and took it to a garage, last resort. Main mechanic said $100 for diagnosis. He then called and was positive my cylinder head was the source of issues or one of many in that area. quoted $300 to get into it and compression test as well as other test. He concluded that cylinder 1 had 0 compression
-cylinder 2 had 50
-cylinder 3 at 75 and the rest were good to go
He also gave me a quote of $1500 for total service and labor now telling me that i need a "valve job" on my cylinder head, the head gasket and total labor plus diagnosis. My question now is WHAT DO I DO? is there anything i CAN do to fix the issue, if not HOW DO I GO ABOUT HEALING MY JEEP. I dont want to pay the 1500 but will if proven needed. ALL IDEAS AND ESPECIALLY SUCCESS STORIES WELCOME WITH THIS ISSUE. Thank you for reading my book of a post and for any and all responses. jeep it real.