High RPM's low acceleration

DAHLIA.SWAN

MEMBER
1997 HYUNDAI EXCEL
1.5L
4 CYL
2WD
AUTOMATIC
188,851 MILES

My problem is when I accelerate on level ground, up hill, from lights the rpm's hold up to 2500 to 3000. Only way to gain more speed is to let go off accelerator and then re push accelerator to gain more speed, but rpm's go straight to 2500 and 3000 and slowly get up to speed sometimes revs goes over 3000 when only at forty km's sometimes even 20 km's. It is like I am forced to let go off accelerator as car is straining rpm's do not freely rev up and down more so get stuck at high revs and low acceleration car will lose power going up hill sometimes only going twenty km's up a hill with revs of 2500 to 3000 revs. Car revs high when taking of from stop position when I need to take off faster from lights so it takes a while to gradually gain speed whilst constantly letting go of accelerator and re pushing it to gain higher speed, when car is at speeds of sixty going on seventy or eighty even hundred it stays on 2500 but sounds like it is not meant to so every now and then I have to drop speed a little in case it is revving too high for long periods of time.I have changed fuel filter 02 sensor, timing belt, air filter, thermostat and thermostat gasket, power steering belt, spark plugs, and leads, oil filter, water pump. I have had a transmission service a general yearly service. I have put fuel injector cleaner through. I have sprayed carburetor cleaner through the solenoid hose. I have done diagnostic test checked for any leaks in hoses or worn hoses. I have recently noticed a very potent sweet smell coming out of exhaust when car is running or just started not sure what that is either the transmission service that I had done was a flush. I have also noticed a bit of yellow on one of the spark plugs although they were brand new not sure if it has anything to do with it. I do not know what else to look at other then the solenoid valves head gasket ECU sensor. Can anyone help me as I am just really stuck and I been researching and changing stuff on the car for about two months now, spent so much money. Thanks in advance.

5 Replies

CARADIODOC

MECHANIC
33,752 POSTS

By now you should have figured out that replacing random parts is the most expensive and least effective way to solve a problem, especially when you are working in every part of the car except the right one. It will cost you less to have a mechanic look at it and diagnose the problem properly. From what I can follow on your description, it sounds like the transmission is slipping. One potential cause is low fluid level. That is easy to solve, but continuing to drive the car like that is going to totally destroy the transmission. If it is indeed slipping, the clutch plates will have been seriously overheated. That will occur in as little as a mile or two if the slippage is bad enough.

You could also have a simple failure of the transmission to up-shift to the next higher gear. Flushing the fluid can break loose some debris that can get caught in a shift valve or plug a shift solenoid. If it is staying in the wrong gear but not slipping, that is very hard on the engine. Your mechanic will start with a test-drive to determine exactly what is occurring and he will figure out the best course of action.

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Wednesday, September 14th, 2016 AT 3:53 AM

AYAEGBUNAM OCHEI

MEMBER
2 POSTS

My car is a nissan quest 2007, Automatic Transmission, It takes off well in the morning, but after some 1 mile or so it will not change to the next gear and will start crawling, no speed. But the amazing thing is that it speeds on R and on L but not on D. Can someone help me with a suggestion please.

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Monday, October 29th, 2018 AT 8:00 AM

KEN L

MASTER CERTIFIED MECHANIC
42,960 POSTS

It sounds like a input shaft speed sensor is going out but to be sure. Here is a guide to help us run the codes:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Here is the location of the sensor below.

Check out the diagrams (below). Please let us know what you find.

Cheers, Ken

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Monday, October 29th, 2018 AT 9:58 AM

AYAEGBUNAM OCHEI

MEMBER
2 POSTS

Admin, thank you for the response but my check engine light is not displaying. What I forgot to tell you last time was that I first changed the front shock, apparently they gave me a wrong shock an altima shock that couldn't even lift the car from the floor so I returned it and they gave me something that is now the same size with the one I am changing but after fixing it the movement of the car changed, its like something is not allowing the gear box freedom, I went back to the mechanic he drove the car and said there was no problem and one day as I was moving slowly to a junction I heard a big slipping noise, as if the gear stick or a rope previously under stress just unhooked, and since then, when I drive it doesn't change from D and after a little while it RPM will be far higher that the speed, it will be crawling. So I parked it and stopped using it but I need it back on the road, I appreciate your keen observation and professional approach, to diagnosis. I am quite grateful. Please see if there is any further guide you can give me.

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Tuesday, October 30th, 2018 AT 10:46 AM

KEN L

MASTER CERTIFIED MECHANIC
42,960 POSTS

It sounds like you have a plugged catalytic converter which will cause excessive back pressure not allowing the transmission to shift. Here is a guide to help check it:

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

Even though the check engine light is not on we should run the codes anyway.

Please run down this guide and report back.

Cheers, Ken