Intermittent problem, noticed mostly at low speeds, where car will buck or lurch forward. Most noticeable when accelerating after a slowdown, i.e. applying gas after coasting.
No check engine lights, oil & transmission fluid is full.
Car has 105K miles, tranny & coolant flushed every 30K, oil changed every 3K, tuneup w/plugs& wires @ approx. 93K, timing belt @ 70k.
This car is a gem, mostly driven on the highway that has been perfect until now.
The first 103K miles in boston, now in hawaii because of a job change.
I’m considering throwing money at it since I’m afraid of a total breakdown in this new locale where I basically have nobody to rely on. Things I’ve considered doing: replacing timing belt, transmission solenoid, computer sensor that controls tranny.
My suspicion is its tranny related but maybe not. Is there a way to check/set the timing on this car? I remember years ago using a timing light on my chevy.
This is weird, it will run perfect smooth in the morning and rough with lurching in the afternoon. Could be a total coincidence but it seems to run ok when its cool and not so when it is hotter.
Thanks for any suggestions/help. This is driving me crazy (no pun intended).
If the “tune-up” did not include a new fuel filter, I would replace it immediately.
If that does not help, something else to consider is a dirty or defective Mass Air Flow sensor (MAF). A failing fuel pump is another possibility.
I second VDCdriver’s recommendations and in regards to the MAF sensor make sure there is no vacuum leak between the MAF and the throttle plate in the throttle body.
You might also consider having a big box parts house such as AutoZone, etc. scan the car for codes. They will do this for you free so go ahead and clear that issue up.
(The reason I mention the air leak is that last year my Lincoln started exhibiting the same symptom; bucking and jerking after coasting, accelerating out of a turn, etc. The problem was a razor blade type cut in a 3" long breather hose. The cut (split actually) was unnoticeable but under acceleration the hose, which had softened with age, would change shape and the split would open up. Almost never found that one.)
Thanks for the help.
I’ve been told that this car does not have a traditional fuel filter but a screen like device inside the fuel tank that never need replacing.
I had not thought of the fuel angle before, good point. If the maf or fuel pump is the problem should I not have seen a check engine light with the appropriate code?
Your timing belt will have nothing to do with it.
In addition to the suggestions already noted, on the fuel system I would just add that the most straightforward thing to do would be to get a fuel pressure gauge on it. And on other matters I would add a test of the coolant temperature sensor. If it has a problem the computer might not “know” it when the car is warmed up and continue to keep the fuel mix too rich. (Thus it runs well cool but not so well when warmed up. It would be like leaving the choke on back in the days of carburetors).
Thanks for the help.
I just checked & there is nobody here in oahu that will do it for free. They told me it will cost 100.
This is all new territory for me. Is it possible that there could be diagnostic clues/codes available even though the check engine light has never come on?
There are codes that can be set but not trigger the light. But if it were me I’d not drop the $100 before doing other basic things (like those suggested). There’s nothing like spending $100 to find out nothing.
Actually for that much you can just buy your own code reader - but if you do be sure to get fully acquainted with its capabilities. A lot of the generic code readers will only read the kind of codes that come with the light being on (basic, generic emissions codes).
Thanks for the help.
I will keep your and the other suggestions in mind.
I moved to hawaii with no tools and do not feel comfortable working on the newer cars so I must rely on a mechanic. And I’m new here so I do not know where to go.
More importantly, this is an intermittent problem and I wonder if bringing it in is worthwhile. I did in fact recently bring it to a mechanic and of course the car ran normal. He said wait until the check engine light comes on and bring it in then. This to me is disturbing, waiting for it to escalate.
I imagine the hose mentioned earlier and maybe the maf sensor may be inexpensive fixes. Should I bring it in and have them replace those? Is there a way to test the fuel pump to see if it is the problem? Or is it in fact tranny related?
Not sure what is the most logical (and economical) next step to take.
I think you should be less worried about the “newer car” factor. If you have maybe a screwdriver, a small socket set (maybe), and a pair of pliers (maybe) you can check out the leaks (breather hose issue) ok4450 mentioned and clean your MAF sensor. If you have a digital multimeter (not expensive) you can check your own coolant temp sensor without much ado. The only way to check the fuel pressure is with a gauge. Mine cost me $40 - or that’s generally not a very expensive thing to ask someone else to check out.
Pop the hood and find the air filter box. Attached to that is the big black intake tube that probably has some other smaller hoses running from it. Its probably just clamped on with basic hose clamps (enter the screwdriver or small socket set). It will have some electrical plugs too. Just label those (though normally each thing can only plug in where it belongs), unplug them, pull that whole intake tube off. Its anywhere along there or the associated hoses that ok4450 is saying to check carefully for any kinds of splits, holes, etc.
Also inside of that is your MAF sensor (one of the things you had to unplug). You just pick up a can of MAF sensor cleaner at an auto parts store and spray down the little sensor wires. (A MAF sensor cleaning is cheap - a new sensor will be expensive). Inspect all of those electrical plugs that unplugged. MAF sensor cleaner is basically electronics cleaner - you could blow out all of those plugs with it just to give them a cleaning.
The transmission is actually a possibility. Given your description I’d be wondering about a torque converter lockup problem. If the car allows you to turn off overdrive (O/D off button?) - turn it off and see if that changes anything. If you don’t have a way to turn off overdrive try driving around in whatever setting is under the normal “D” (maybe 3; maybe a plain D without a circle around it). See if that does anything.