CamaroQueen85

I have an 02 Camaro 3.8L automatic with only 71k miles. I am the 2nd owner and this car has been kept in pristine condition inside and out. In the 4yrs I have owned him I have replaced the rear-end, a/c, timing belt, and most recently(1-2months), the catalytic converter and fuel pump. Now I am experiencing a random surge/loss of acceleration around 40mph but the rmp continues to increase. It also happens on the hwy if Im going 60 and nail it, it surges around 70-75mph. If I let off the pedal briefly and nail it again it stops surging and flys. It only starts doing it when Ive been out running errands for a few hours. And twice Ive heard a grinding noise during the surge when I didnt let off the gas and tried to nail it instead to see if that would work better..it didnt. All oils and filters (engine and transmission) have been recently changed and are done regularly by my husband. I believe I may have a pinhole leak in a radiator hose somewhere because its slowly loosing coolant when the engine is off. We do not see a drip anywhere though. I was told by a friend that if the radiator is low or empty it will make the clutch plates hot and that will cause surging...? Is this true? Or could it be something else..like a shitty fuel pump job?? Any and all help will be greatly appreciated.

Lup

Power brake the car. Put car in drive, left foot on brake and right foot on gas. Take up to about 2,000- 2,500 rpm. If the engine cuts out it stumbles, you need new spark plug wires. Don't buy the super cheap ones

Kyle

hrcslam

Sounds like it's time for a transmission rebuild. What did the trans fluid look like when it came out (when he changed the fluid)? Odds are the trans fluid was pretty dark. That dark was reminiscences of clutches. Those were keeping your trans working right. Now that they are gone, you have additional clutch pack clearances. That will take more time for the clutches to engage, slipping them, making them wear faster.

This is actually very common in conventional automatic transmissions. If the trans fluid doesn't look new, DON'T swap it. Leave it u til the trans fails. It will last longer that way.

Ask me how I know......

CamaroQueen85

Ok, thanks. I will try that in a bit and post the results.

CamaroQueen85

It was already surging before the swap..it started surging a day after my cat & fuel pump was fixed. That is what prompted the trans fluid & filter change. Yes it was slightly dark.

MMWS6

I would start with a fuel pressure regulator connected to the rail and then taped to your windshield. Get it out and see what that pump is doing when this happens.

hrcslam

If your rpms increase but your speed doesn't, it's a transmission issue. Is that what you mean by surging?

CamaroQueen85

Well, it's more of a lack of power/inability to receive an adequate amount of fuel when I nail it around 40 or 60. It will sound like its picking up and the rpms will steadily increase but it won't go faster until I let of the pedal for a sec then nail it again. It's not jerking or slamming into gear so a friend said it could be the clutch plates getting too hot when my radiator is low on coolant...?? Is this possible?

CamaroQueen85

Ok. I put it in drive pressed the brakes and revd it. I think Im hearing a slight popping/knocking sound from under the hood on the driver side. I hear it while its accelerating and while I'm letting off the gas. But I've never heard this while driving! I'm not sure if that's a normal noise I'm hearing but I'll record and post it later today.

hrcslam

O.k, so it's not surging. It's doing the opposite of surging? It's bogging?

When it bogs, then you lift and floor the throttle again do the RPM's jump (like it's downshifting) when you start to accelerate like normal again? Or does it stay at the same RPM's but accelerate normally again?

CamaroQueen85

Yeah bog would probably be a better term. When it's boging the rpms increase but speed does not. When I let off the gas rpms drop along with the speed and increase like normal when I gas it again. And it doesn't happen every time I drive. Only every 50-100 miles or so.. like somethings getting hot or clogged every so many miles or hours of driving.

hrcslam

When the rpms rise, but the speed doesn't how much do the rpms rise? Does it always happen in the same gear (as in when you hammer it, does it only happen when it drops to 2nd)?

Bogging would be if the car doesn't really accelerate, but the rpms match the speed they are supposed to be at. Lack of power, usually due to a rich condition.

Surging would be when the rpms jump more than they should and is usually accompanied by a surge in acceleration without throttle input.

What you are describing is a slipping clutch. Usually that gets worse, auto or manual, over time. I'm assuming you are in an auto. That can be caused by a valve body issue (solenoid usually) or your clutch packs going bad. Not all codes will illuminate your check engine light, and because this is intermittent it probably wont. Hook up a code reader and see what codes are stored. A bad solenoid will store a code, a slipping clutch pack wont.

FireBreathinLS1

Check your fuel pressure first. If it's fine then change your plugs and ignition wires.

CamaroQueen85

Then it's definitely a bog! The rpms go up and down with speed like normal but it won't fully accelerate until I play the off/on game with the gas. When it happens it's always at 40mph when I stop at a light and take off or when I'm on the hwy doing 60 or so then try to haul *** around someone. The rpms go up the way they're supposed to but it stays at 40 or 65 till I let off or press it harder(that causes a grinding sound sometimes). I will take it to autozone this morning and see if I get a code. I got a feeling it's gonna be those clutch packs. I'll post the results and that video when I get back.