I am trying to get this car of mine into tip top shape (2000 Pontiac Grand Am SE). Ive been experiencing this problem where the rpms will jump while the engine is under a high load. If i apply more throttle, the problem goes away.(as shown in the video)
In the youtube video below, I am going up a 5% grade. This will happen at slower speeds, but i will need a significantly steeper grade of around 25-30% ...
[URL] ....
I have an 2001 Ford Escape V6 3.0, about 130,000 miles. When the engine gets under high load and low RPM, before downshifting, it will shudder (misfire?). Local shop couldn't reproduce it, but they thought it might have to do with slightly cracked vaccume hose, which they gouged me to replace. No improvement. Next they wanted $700 to replace Valve Cover Gaskets. I decided to become a mechanic and learn how to do that one myself. Sure enough, there was a little oil dripping onto one plug. I replaced the gaskets and all 6 spark plugs successfully. Still didn't fix the problem though.
Symptoms will occur reliably when driving at 45-50 MPH with the transmission in overdrive (1500 RPM), and I begin a slight incline. The vehicle will kind of chug forward (feels like sporatic misfires) in overdrive, getting down to 1200 RPM before deciding to downshift. Generally, I can just give a little more gas to force downshift and avoid the nasty-feeling misfires. Some days, however, it is much worse, and will misfire at idle, and make me feel like I have to treat the gas as an on/off switch to keep the engine from dying. (It has never actually died.)
During a really bad day, I got a flashing check engine light. I did not check codes in time - they've all cleared.
I now have an ODB2 reader logging real-time data. All I can do is prove the conditions that cause the symptom: high engine load at low RPM is the recipe. Nothing seems to show a cause... I may just not know what I'm looking at :-/ . I haven't monitored long enough to record a 'bad' day.
I've read about ignition coil issues on this engine, and weather might explain why this is worse some times than others. However, I wouldn't expect that to be load dependant.
Most of the time it feels like the transmission just isn't shifting when it's supposed to, but on the bad days it seems more than transmission related. When stopped at a light in Drive, this can still occur.
I have a '07 Sonata GLS with the 2.4-liter Theta engine and the 4-speed automatic. It has 52k miles on it and has always been serviced regularly. It's been a pretty decent car but is starting to feel a little tired, most notably the worn/bouncy suspension.
Anyway, the other day I was driving down the highway and gave it a little gas to pass a slower car. Doing 60 MPH it downshifted to 3rd (~2000 to ~3300 RPM) and I thought I heard a noise in the engine bay, but I wasn't sure. I ended up needing more power so put it to the floor and as it kicked down to 2nd at ~5000 RPM the rattly noise got a lot more pronounced. Driving around normally I don't hear it but any time I put it to the floor (merging/passing) I will hear the rattle. I can also hear it if I lock it in 2nd gear and give it full throttle up a hill at low speed, like you might do with a stick shift.
It seems like it only does it under load because if I rev it to ~4000 RPM in park in the driveway, there's no noise, even at full throttle. I know the V6s had tensioner issues but I haven't heard much about the 2.4s. I'm not super concerned as it is still under warranty but what might be wrong with it as this is my first Hyundai vehicle, especially in case the dealer can't replicate it.
I have an 06 with 105000 miles. Since about 95000, I've been starting to get what sounds like a fuel knock with medium-high load on the engine. Thought it was carbon at first, but a few applications of Techron didn't clear it. Higher octane does seem to solve it.
Do the knock sensors go bad on a Prius? What's the proper way to diagnose the knock sensor on a Prius? (can't exactly bang on the block with a wrench at idle and listen for fuel adjustments on a car that doesn't idle).
I am having overheating problems at high speed/high rpm/under load. The only codes ive gotten are EGR dpfe (0401). Truck is 99 f250 with the 6.8 new egr valve, dpfe, new coolant, new thermo, new sensor under manifold. I blew 90 lbs air pressure thru the egr lines, big and small, they were clear.
So whats left? I never hear my fan clutch......should I? I've had other trucks and the fan roared when first started for a few seconds, and then again when you were hot...they really roared.
Is it possible for the egr port where it goes into the throttle body to be plugged? guess I should've checked that when I had the egr off. Would an aux. fan be a waste of time?
This is pulling a 3500 lb camper trailer up moderate hills.
I recently installed a 42 DD DP in my 2012 CW Golf R. I have noticed that under high load (mostly down shifts) that something is knocking under the car. It is a single bang sound and only happens under high load. I did the DP install myself and I have since done a quick check to see if the exhaust is loose. It is not. I have checked the Drive shaft and all the bolts are tight. I suspect it is the exhaust hitting something but I don't know what.
View 5 RepliesJust took off the throttle body of my 2002 GT to clean it. Had all of the sensors off (IAC, MAF, TPS). Put everything back together and it fired right up but immediately went to 3000 rpm and acted like it would keep climbing.
Thought I was very careful putting everything back together. Obviously the throttle is open but there is no play in the throttle cables. Could it be a sensor?
My 2003 Chrysler is making a strange "whirring" noise. It is shaking a bit and there is occasionally a knocking noise near the rear driver's side tire. What the problem could be?
View 4 RepliesI replaced the thermostat in my 2000 3.1L Grand Prix SE yesterday. I had to remove the throttle body to get access to it. After putting it all back together, my car now idles around 3000rpm in Park or Neutral. It drops to around 2k when driving which is still a little high. I can definitely feel it taking off faster and it seems to buck a little bit here and there while driving. I did hear a loud hissing sound when I first started it up right around the throttle body area. I don't hear the hissing sound anymore, though. It justs sounds like it's running a lot harder. So my question is, would a leak around the throttle body (I did not use a new gasket and it's possible that the gasket wasn't properly seated) cause these symptoms? On the plus side, my car seemed to heat up super fast!
View 2 RepliesOne day, I was on the highway and my Pontiac's speed started dropping. I looked at the temperature gauge, and the temperature was really high. I flushed the coolant system, and changed the gasket. Also the mechanic said that the oil might be leaking after they changed the oil. I paid like $700 for something that has nothing to do with the problem (I paid for a spark plug, ignition wires, fuel filter, and an oxygen sensor). After they changed the oil, oil started leaking all over my driveway, which didn't happen before. It also looked like coolant was leaking out. None of this happened before I got my oil changed with these guys.
After I changed the gasket, the car was running smoothly. But today, the same thing happened again, and I don't know if it's the thermostat, or water pump, or oil leaking, or coolant. The mechanic always suggests to fix something that doesn't have to do with the problem. I don't have much money on hand, so I need to only fix what has to do with the temperature rising, and I need my car to run.
For the techs in here, I have a data logger (AutoTap) and the symptoms are low idle and sometimes it runs rough idling and driving. It had me thinking the fuel pump was going out. That is not the case. I did get into part swapping mode so I have new plugs and coils and new VCTs all in the last 24 hours. The engine has 85K miles on it (rebuilt ford long block), truck had 150K. I'm not sure what parts were replaced when the longblock was replaced but I'm guessing the 02's are original.
Data that looks odd to me in the Autotap real time data logging is this:
- STFT Bank 2, goes from 10-15% and climbs till its over 300% and then the truck goes into Open Loop due to an error (per the Autotap) but it never says what error and the CEL never lights. Idle goes up when its in open loop and then after a minute or two it will drop back into closed loop.
- Fuel pressure never drops below 37
- Idle will drop to 250rpm
- Engine load at idle is 25%?! With AC on and idling (at 550rpm) engine load is 42%? Seems high no?
Nothing else other than the STFT Bank 2 and the high engine load seems out of miss. No misfires, codes, etc. What else should I look at?
Other background/patient history:
- Alternator #3 was installed 2 weeks, It replaced alternator #2 that went in 4 months ago to replace the original alternator (144K miles). Both died and caused low voltage/battery dying symptoms and verified by volt meter.
- FPDM was replaced proactively 8 months ago just because I don't want it to break down when I'm towing my race car.
- I have not tried cleaning MAF, EGR?, IAC, nor have I replaced O2s. The only thing that leads me to believe MAF might need cleaning is the load?
I just changed my fuel filter and now I am having issues with the idle/accelator. When I get the car going to a speed of 40mph for example, I let off the gas and the speed barely drops. Then when I went down a side street about 20 mph, I let off the gas and the car just kept going. The idle was initally high, but then dropped down to it's normal 800rpm.
The only thing I touched under the hood was releasing the pressure from the fuel pressure regulator before the fuel filter change. I just removed the idle control unit and cleaned it but that didn't work.
2001 Pontiac Grand Prix GT/3.8L
I've noticed, maybe a handful of times in the 5k miles I've owned the car, that the engine will rattle excessively for maybe 30 seconds or so on a drive. This only happens during high load/low speeds and I think after the engine has been off for at least about 10-15 minutes. It doesn't happen on start up, only after the car is warm, but hasn't been using the engine for a bit. I'm thinking this is fuel enrichment (really rough running) because the cat has cooled.
View 6 RepliesMy 2003 Chrysler is making a strange "whirring" noise. It is shaking a bit and there is occasionally a knocking noise near the rear driver's side tire. What the problem could be?
View 1 RepliesOn my way home late at night, my tachometer started jumping a little, and the engine was rough. Then after another minute the lights dimmed and the engine died. It wouldn't start again. The next morning, it started right up, and it seemed fine. Drove it to the mechanic, he took it for a drive on the freeway, then after he got off the freeway it died again and had to be towed. The error code on the computer is P0326- Knock Sensor. I had the same sensor activated a couple of years ago, and my awesome mechanic (we have since moved far away, so I don't have access to the same guy) gave the engine a tune-up and replace the spark plugs and everything was fine (well, for two years). The car has been idling rough, and the intake manifold may be warped. Could the intake manifold cause this? Distributor?
View 3 RepliesI have a 2001 Ford Escape, and since the colder weather set in it is tacking below 1 and 'jumping' when idle. When accelerating and/or once the heat gauge has reach midway, the car is fine. I added a bottle of gas additive to the tank 3 weeks back, but the problem persists. The engine light is on but no code is registering.
View 2 RepliesI'm getting a weird code on my engine it's p1298 which is electric load detector circuit high input and I'm also getting 3 misfire codes but the car runs great what can I do to fix these.
View 10 RepliesSo basically I thought it would be a great idea to degrease my motor from the top down.... After washing I start it up and drive down the road to head abunch of misfiring under heavy load or high rpm's.
My problem is that the misfiring won't throw a code. I then proceeded to buy a new ignition coil (thinking this was the problem) but with no code to go off which cylinder was bad I just switched the good ignition coil into each cylinder and starting it.
Up each time. None of them seemed to make it better. Also the injectors all seemed to be good. So what to do ?
2002 Ford F-250 5.4l
2000 neon automatic. My wife was complaining about the rpms jumping around when on the highway going about 65mph. The rpms are around 3000 and jump very slightly up and down and you can hear the engine tone change when it happens. Checked tran fluid and it was low about 3/4 of a quart and added some fluid, changed spark plugs and wires and the problem is still there. Doesn't happen all the time. She says it seems to only do this if the car has been sitting for a few hours or longer. There is an code for the downstream sensor which needs to be changed.
View 2 Replies2005 Honda Civic which has been pretty reliable up to this point. Had all the suggested maintenance services up until the most recent which just passed. Last oil change and inspection: Early November.
Last month:Went to start up the car and it basically went all blinky with power. But after letting it sit for a minute or two, it started up just fine. This happened three times. On the third time opened up the hood and found corrode on both polls of the battery. Scrubbed and cleaned the posts and connectors. Had the battery tested and it was just fine. After that no problems or occurrences. Only things that lingers in my head is that perhaps the driver door window rolls down slowly (thought the motor was going out and would have to replace soon) and the headlines would slightly dim and waver at times, but not consistently.
Now:Just got back from vacation and car has been sitting about two weeks. Mostly in weather below freezing, but in a garage. Went to start up the car and the starter would rev but the engine would not turn over. Battery seems to be good still. Jumping did not work either.
I'm pulling the engine to overhaul. I've borrowed a hoist and think I'm ready to lift the engine out, but I don't know how to strap the engine to the hoist. I first thought of using the brackets with the eyelets bolted to each head and bought chain and hooks. But I had to remove the rear bracket so I could remove the rear exhaust manifold so I could remove that darn rear engine-transaxle bolt. (That really bites because I want to have the exhaust manifolds on when dropping it back in.)
Are those brackets intended for lifting the engine? If so, I could reinstall the back bracket and give it a go.
Searched the internet for info but didn't find much. Did find a 3800 being lifted with two straps completely under the engine.
Also, the engine-transaxle joint hasn't cracked open yet. I'm guessing it's because they're stuck after 198k miles and will eventually separate. But I did not find one of the engine-transaxle bolts mentioned in the 98 FSM: front lower (#1). I don't see how I could have missed it ; maybe the 99 doesn't have it?