Good morning to everyone. Last year, for several months, we had a check engine light that was pointing to one of the oxygen sensors. The car would hesitate and shake a little bit under load or acceleration. Because of life and other things, I put it off and then finally had it replaced about six months ago or so. A nephew of mine, who is a big Acura fan, confirmed that a bad sensor would cause hesitation and shaking because of the way that monitors the oxygen and then delivers fuel and air for acceleration. Anyway, even with the new oxygen sensor, it’s still shaking a little, but not like it did when the sensor was bad and there was an engine code.

now, two weeks ago, we were getting transmission issues, and come to find out that the heat exchanger on the radiator broke and the transmission fluid was going inside the coolant and drain from the transmission. We only drove the car a handful of miles, because of the shut down, we weren’t driving much anyway. The mechanic fixed everything and didn’t indicate any issues when he test drove it, but he doesn’t know the car as well. I’m just trying to figure out if maybe the sensor I used wasn’t as good as it should be or there’s another issue to look at.

thanks
Mark from North Alabama

 

Hi Mark!

Great that radiator breakdown got fixed. Any details on the fluid used and number of drains&refills done? History of pressure switches replacements would also be nice.

re: oxygen sensor, if you have or get an OBD2 wireless device and a smartphone tool, you can graph the O2 voltage while accelerating and post it here (maybe dashcommand or torque depending on the phone type).

considering that the shaking was noticeably reduced but not eliminated by a new sensor last year and radiator/fluid replaced after failure two weeks ago, you may be searching for a mechanical issue now, could be located between road surface and engine.

easy to check possibilities for starters:

CV joints are known to cause shaking under acceleration.

Deteriorated engine or transmission mounts could easily match symptoms too.

Tires can be inspected visually for uneven tear. Btw recently with current reduced driving conditions for extended periods, I found a single front tire with ~25 psi causing shaking under acceleration (the other three were normal at my chosen 40psi level).

Hth

 

Always check the cheap stuff first like fuses and battery/battery terminals for corrosion loose connections. Check all colors and consistency of all fluids. Also did you check all hoses for cracks or connections on the hoses to make sure they were not leaking? Plus the exhaust has two oxygen did you replace both?

 

New tires too, and they wouldn’t shake just under acceleration.. the thing is, it never shook until the code for the O2 sensor, so I always associated the shaking with the sensor.

sounds like I need to check other things.

 

Did not replace both. Never thought of that. Good idea.

 

Which o2 sensor did you replace? The downstream sensor only monitors for emissions purposes, and will not have any effect on how the car drives if it goes bad (although it may throw a P0420 code). If you replaced that, then any change in feeling in the car is unrelated.

The upstream sensor, just behind the turbo, monitors air/fuel ratio in the exhaust and the car uses that to adjust fuel trims as needed so that the actual ratio meets what is expected for any given condition. Those rarely go bad, but definitely possible. More often there is a leak in the intake or exhaust side that is skewing the numbers (an intake leak in the hot side may cause the car to run lean, a leak in the cold side may cause the car to run rich).

Also worth checking the spark plugs, air filter, etc. Ultimately anything that controls air, fuel or spark can contribute to what you're experiencing.

 

I think it was downstream and I had a code.other than that, i wouldn't have replaced it. As I said, I am ALMOST for certain the car was not shaking until the sensor code went off, but that could have been a coincidence. I appreciate all the replies. By the way, its an 08 RDA with 160k miles on it. The dealer in Chattanooga we bought it from replaced the turbo before selling. It was a one owner vehicle bought there for a trade-in....

I will explore all. The wires and plugs sound reasonable.

Thanks

 

Ok, it’s one of those days. Took it out this morning for an errand and smelled antifreeze. Saw steam so headed back to house which was only about 78 miles away. Check the engine temperature and it never changed the whole drive home. Pulled it in the garage and noticed coolant leaking from near the middle of the car so behind the engine. Because of the fact we’re having company over and I was already cleaned up, I couldn’t get under there too much and get dirty. Could it be coming from behind the turbo charger? I’m assuming there’s a coolant return back there somewhere.

 

yes, turbo has coolant running through. Sounds like you may have lost pressure as well, suggest not driving it until thoroughly checked and fixed, especially that the car is on its second turbo and recently replaced radiator.

Note one of the thin rubber coolant lines from the back area seems to connect to the throttle body via a metal intermediary called "pipe install", located between the engine and the air filter box, reported to be easily broken if rusted, check it out as well

enjoy the remaining part of the weekend!

 

Seven to eight, not 78. Yes, no driving until fixed. I don’t know why it broke a week after the radiator fixed. Any correlation or just bad luck??

 

Possible correlation would be pressure rising with coolant operating temperature, blowing out through weakest spot: first rusted rad connection, second towards back of engine after radiator eliminated its weak spot.
Now its up to you to eliminate the speculation by finding the leak/leaks and having them fixed.
Consider replacing thermostat, fan relay and fan sensor at bottom of radiator, its cheap at this time in case it did/cause a short overheat before steaming/leaking.
Make sure to pressure test the cooling system before driving again.

hth

 

well, the temperature never got high today. I “turned on” the temp gauge and it never got past 30%, which was odd, because when I got home and looked at the coolant reservoir, it was practically empty and then when I finally open the radiator after it cooled, I couldn’t see anything. However, the thing is still dripping seven or eight hours after I parked it. I got underneath it and could see way up to the top of the motor on the back side, that it was dripping from something but can’t see from White. I’m a take it back to the shop at worked on it and have them look at it further.

So, it wasn’t overheating, hot coolant was just filling out the back of the motor and causing the steam that I and the smell. So back to my original question a few post back, does this leak in the back of the motor or possibly around the turbo charger, has anything to do with the repair that was done. When they leak check the radiator, did the pressure in the system, possibly cause a weak spot in the cooling system? I have no clue. This is above my knowledge level.

 

for the future, if pressure containment is lost, the water/coolant above 100C would immediately boil expanding 700 times and become visible like steam, vapours or air pockets can or will PREVENT PROPER ENGINE COOLING quickly leading to spots within the engine that could reach much higher temps, while the reported dashboard temperature will likely still show only 7 bars="normal" operating temperature for the coolant, not the engine.

Did you actually drive 7-8 miles of slow driving, maybe @20 mph with steam gushing for 20'?

maybe consider testing the engine compression too before committing to any course of action

 

Thats fair and I understand. The car ran well and I am hoping there was no damage to the engine due to driving and the steam was not gushing, but a slow trickle. I did drive slow. Now, the coolant is still leaking from the engine, even now. By the time I got home, and an hour or so afterward, about a gallon or so dripped on garage floor, so I assume that I didn't lose that much driving back. It is out in the driveway waiting for the tow truck.

 

Finally got the car back last week. The mechanic had it for 4 weeks. They replaced a rubber hose going into the turbo. Still need to work out the shaking issue. Going to replace the upstream O2 sensor and go from there.

 

👌
I know how relieved you must feel!

Slightly off topic, my son had recently high fevers, sneezing and throwing up, muscle weakness, a lot of shaking, tylenol worked right away, and took up to four weeks to get two negative test results for the new bug. We werent told anything what if anything was wrong. Still some uneven controlled movements... probably from too much time spent not going to school...
We are also still searching for the bug, or whatever it is...