Guys, I don't post often just read others' posts constantly. I have searched the topic of miss and have been unsuccessful at fixing the problem. The first day I changed the fuel filter and used tectron; did not fix the issue. Second day, changed cap and rotor. Cap had slight carbon buildup on the contact patches. The car had considerable engine noise under 2nd gear deceleration; this noise decreased considerably at this point. Third day, changed plugs; the back pressure noise is nonexistent at this point (hopefully problem solved). Last night I checked all of the grounds wires and ingnition system connectors to verify that they are secure, they are. I have an O2 sensor that I am planning to install this weekend.

Now to the problem. When starting the car it has a rough idle but runs and drives fine while cold. As it gets up to operating temperature a slight miss develops. Example is crusing 65 mph 5th gear a slight but noticable power loss occures. A more noticable miss occurs when accelerating hard and is definitely more prevelant around 3200rpm. However, it does occur throughout the rev range. Any hints would be greatly appreciated.

One last piece of info. The engine and transmission have recently been out of the car for a transmission replacement. The car ran great before the process.

 

Vacuum leak or the ICV is sticking would be the next items on my list.

 

Thanks for the help and the quick reply. I appreciate the tip. I will search for a thread on check for vacume leaks.

 

Assuming nothing got "impacted" on the drop/reinstall....

What "kind" of "considerable engine noise" is it that you make mention?

May want to mist your ignition cables at night and see if you see any electrical anomolies....could be coil/ign cables breakdown or, of course, fuel-related issues.

Best!

Doyle

 

Check the CO reading.

 

As the engine warmed up it was almost like a ratteling noise. This would occure, while in 2nd gear and engine breaking. I was starting to think that the valves needed to be adjusted,but had no smoke and no loss of oil. The noise has stopped at this point, however you are probably asking for a reason, and your thoughts on this are greatly appreciated.

This car is amazingly clean, at this point there are no oil leaks at all and no smoking at start up or while running.

I checked the plug wires in the dark on Thursday night and looked for sparkes. On Friday I ran my hand over the wires looking/feeling for a shock. They look fairly new.

 

Thank you for the info. Noticed this one in the Chiltons manual and have it on the list. I think it requires a special tool that of course I do not have.

 

If there is no oxygen sensor, just a hole in the exhaust, then that would explain the noise.

Is the car a 3.2 or SC? Look at the engine running in pitch darkness. Look for shorts.

 

When we use the term "rattle", one generally looks to timing chain related matters...one can use various methods of isolating the noise to a specific location (stethiscope, wooden dowel, long screwdriver, etc)......valve noise is more of "tapping"..

Doyle

 

It's an 84 3.2.

 

3.2

The O2 sensor was present. spent this morning trying to get it out. The previous owner crossed the threads teribly. It is so bad I can't get the new sensor in. I am planning to borrow a Tap and attemp to fix in in the mornign.

 

Tapped the cat and installed the o2 sensor. The miss is cured. However, the engine is now much louder.
I don't mind a loud car and plan to install an exhaust, but is it normal to install an O2 sensor and the car gets louder?
I don't believe I loosened anything in the exhaust in the process.
Could a chain tensioner only be noisy when the clutch in engaged?
The car is running great and is surprisingly quiet at idle, but the noise may be the sign of a bigger problem that I would like to address before a catastrophic failure occurs. The dealer checked the clutch when the trans was out of the car and stated that it was ok. I have receipts from where it was replaced back in 2005.

 

Hi Mike,

I'm having some trouble following this,.......

Precisely, what got louder after replacing the oxysensor?

Exhaust noise?
Tapping sounds?
Rattling sounds?

Have you tried using a long-handled screwdriver as a stethoscope to locate the source of the sounds??

 

Thanks for the questions about clerification. I will work on getting a better description of the noise, this week. I attempted the screwdriver trick, but the car sounds perfect at idol.