help me out here, very odd problem

[taseal]

last night I was driving home, and I felt my car had an odd vibration. i was on the highway, so it was hard to tell, but I knew something was up... I get near home and i'm at a light, and my car feels like its cammed. its idling perfect (i mean RPM/surge wise) but there is constant vibration. I give it gas, and it gets worse, but the car goes. at 1st I thought it was some kind of missing. I hoped it would go away the next day.

next day comes, I start up the car, and its the same thing....

so whats happening is that the car's engine is very rough throughout all RPMs, but she does drive. all the power is no longer there. I have lost about 30-40% power. on idle it feels like I have a cammed domestic car (feels like my old trans am with 112 lobe separation on the cam with 1/10 of the power lol) when you go, the vibrations get worse, and lessens again. you hear this puff puff puff noise from the muffler (like its leaking)

I'm afraid its mechanical related (like valvetrain). I thought it could be the cat, or simple as a vacuum leak.

any ideas what i'm talking about? what can it be?

[taseal]

i did the stomp test, nothing came up :( plus wouldn't the light be on if i had somethign worthy of stomp?

I had been flying my ass off lately, so tomorrow (well today) is my day off, I will check today, I just wanted to see if someone would say 'dude I know EXACTLY WHAT YOU ARE TALKING ABOUT! its xxxxx' lol

[taseal]

ehhhh, how did my reply end up being post 2, that was in reply to shogun

[vince]

Have you checked for leaks in the boot that runs from the airflow meter to the throttle body, especially in the ribbed area between the ribs?

Are there any vacuum hoses that are loose or broken enough to leak?

vince

[shogun]

any ideas what i'm talking about? what can it be?

errrh..., well, why do you not open first the hood and check if something visible loose or broken?
I have no X-ray eyes ;)
Do a stomp test, instructions on my website below.

[KenB]

motor mounts, symptoms sound similar to what mine did when a motor mount went bad.

[taseal]

i checked under the hood, everythign seems in place. I'm thinking it might be a sensor now, because car is SOOO sluggish off the line (I have to floor it to move next to a kia which is just like leaving a traffic light) but once like 2,000 RPM hits, it starts to pick up back to normal power.

so I doubt it can be motor mounts, i've lost power.

[Bob in San Jose]

I would suspect the Cat may be bad and causing backpressure. This would explain the loss of power and the strange exhaust noises.
HTH
Bob

[RobPatt]

if you're hearing that noise...?

else not firing on all cylinders?
broken rocker arm? (has happened)

BTW how old is your timing belt? (it didn't let go...obviously...but)


last night I was driving home, and I felt my car had an odd vibration. i was on the highway, so it was hard to tell, but I knew something was up... I get near home and i'm at a light, and my car feels like its cammed. its idling perfect (i mean RPM/surge wise) but there is constant vibration. I give it gas, and it gets worse, but the car goes. at 1st I thought it was some kind of missing. I hoped it would go away the next day.

next day comes, I start up the car, and its the same thing....

so whats happening is that the car's engine is very rough throughout all RPMs, but she does drive. all the power is no longer there. I have lost about 30-40% power. on idle it feels like I have a cammed domestic car (feels like my old trans am with 112 lobe separation on the cam with 1/10 of the power lol) when you go, the vibrations get worse, and lessens again. you hear this puff puff puff noise from the muffler (like its leaking)

I'm afraid its mechanical related (like valvetrain). I thought it could be the cat, or simple as a vacuum leak.

any ideas what i'm talking about? what can it be?

[ahlem]

Turn the car off. Wear gloves. Pull one plug wire at a time, start the car and see if there is any difference. If no degradation when the plug wire is pulled you may have located the problem cylinder. Also, check the cap and rotor. On s-14 motors this symptom can occur before the rotor cuts loose. You can also read your plugs to see if something is going on.

[taseal]

Turn the car off. Wear gloves. Pull one plug wire at a time, start the car and see if there is any difference. If no degradation when the plug wire is pulled you may have located the problem cylinder. Also, check the cap and rotor. On s-14 motors this symptom can occur before the rotor cuts loose. You can also read your plugs to see if something is going on.

yeah, I did the 1 plug at a time thing.... I thought that it could be the cat, but power does come back at higher RPMs, its just there is NO power down low...

if it was ignition related I think the power wouldn't come back at high RPMs

so right now what seems to be happening is car has a rough 'idle' (at any speed, just keeping RPMs) and about ~50% loss of power at low RPMs, it comes back at higher speeds.

I'm not too sure how old the timing belt is, its something I thought could be going bad. I honestly just have been putting it off because it seems like it involves alot of work lol

[Podmore]

The "puff puff" noise from the exhaust and loss of power would tend to indicate a valve problem (burnt or sticking). Then again, pulling the plug leads should normally identify which cylinder was affected. As for then getting normal power at higher revs, this is the hard bit to explain. If it was plugs or leads, it's not a self-healing problem even with an Italian tune-up.

[Ross]

Sounds like an ignition miss to me. The puff, puff is when the miss occurs.
Ignition wires, cap and rotor and the cylinder identification wire are all suspect.

[RobPatt]

didn't mean to distract w/the timing belt comment... the thing's not gonna cause what you're describing... but if you don't know when it was put on... soething to consider doing...

otherwise, you may just feel like it's ok when up at RPM 'cause you don't notice it..but I'd vote w/others about ignition/firing related...else valve (hence my rocker arm note)... take a look at your plugs... can even get a grease pencil or something and make a mark on each exhaust mani to see if/which isn't getting hot... but guess you did that w/the pulling the plug route... maybe you have an airflow/vaccuum leak (intake boot? or idle valve issue)....


yeah, I did the 1 plug at a time thing.... I thought that it could be the cat, but power does come back at higher RPMs, its just there is NO power down low...

if it was ignition related I think the power wouldn't come back at high RPMs

so right now what seems to be happening is car has a rough 'idle' (at any speed, just keeping RPMs) and about ~50% loss of power at low RPMs, it comes back at higher speeds.

I'm not too sure how old the timing belt is, its something I thought could be going bad. I honestly just have been putting it off because it seems like it involves alot of work lol

[taseal]

The "puff puff" noise from the exhaust and loss of power would tend to indicate a valve problem (burnt or sticking). Then again, pulling the plug leads should normally identify which cylinder was affected. As for then getting normal power at higher revs, this is the hard bit to explain. If it was plugs or leads, it's not a self-healing problem even with an Italian tune-up.

at worst, that is what i'm thinking...

burnt (or sticking) valve: head job = $1,000 :(

[taseal]

didn't mean to distract w/the timing belt comment... the thing's not gonna cause what you're describing... but if you don't know when it was put on... soething to consider doing...

otherwise, you may just feel like it's ok when up at RPM 'cause you don't notice it..but I'd vote w/others about ignition/firing related...else valve (hence my rocker arm note)... take a look at your plugs... can even get a grease pencil or something and make a mark on each exhaust mani to see if/which isn't getting hot... but guess you did that w/the pulling the plug route... maybe you have an airflow/vaccuum leak (intake boot? or idle valve issue)....

I'll pull the plugs and see whats up, i did pull the wire on each one at a time, and it was still acting the same way

[taseal]

damn, I just called a place, they said if its 1 or 2 bad valves, they'll fix my head for like 350, the whole thing will be around 650.

I was thinking about a grand to do the whole head..... I could probably take the head out myself, (weekend project eh) so its not as bad as I thought (altough the damn car cost me 700 bux lol)

i guess I just need to make sure my head IS the problem before anything, and not the cat, or ignition