Someone help me troubleshoot this problem please

[FFORMULA78]

I figured maybe its not the engine that’s the problem so maybe someone can give me an idea about what the problem might be. It’s a 1994 Firebird Formula with 124K miles on it.

The car starts right up every time, it has never once not started right up. I don’t get any jerking from the car. The rpms while in drive & at idle are stable. It has never stalled out and I never felt like it was about to stall out or anything. Transmission seems to shift pretty smooth. Im not getting any lights or anything except when the coolant was coming out.

Only problem it has is this. I definitely notice a loss of power from when I first bought the car a couple months back. When I accelerate either from a dead stop or while going around 45 mph, the car starts to vibrate in the 1500 rpm through the 2000-2300 rpm range. From a dead stop, the vibrating does not stop until about 3000 rpms. While going at higher speeds(40+), the vibrating stops around 2300 or so rpms. Sometimes I feel like the vibrating is coming from the engine bay, and other times I feel like its coming from my tail pipes or near that area.

The only other problems happened when I was being stupid 2 times. Its an automatic and I dropped it into (3) instead of (D) and clicked on that (performance transmission) button and ran the car really hard. The same thing happened both times. It started spitting coolant and I could notice a loss in power. I wont be doing that again.

Other than that, the car seems to be running fine. I was going to swap engines but im just not sure it is needed. Any help would be great.

[loser]

Re: Someone help me troubleshoot this problem please

i just woke up, but just scanning over it, it kinda sounds like a tranny issue. like its not downshifting, 1500RPMs is kinda low, more so for us v6's than your lt1, but still.

when your going 45 and step on it, does the car downshift?

do the rpms go up but your speed not? ( tranny slipping )

is the car modded at all? i have some vibrationg around 1500-1600 rpms becuase of my exhuast, i cant feel it, but i can hear it.

you said when you ran it hard, it started spitting coolent. we need to talk about this a little more. where was the coolant coming from? the radiator cap? how hot was it out? how long did you run it hard? how hot was your engine? do you know what your coolant level was before?

when a car overheats, the pressure inside the system gets greater than the rating on the radiator cap, and pushing some coolent out to relieve the pressure. do your fans kick on around 210*? does the car heat up normally? or really slow? or really fast?

sorry about all the questions, the more we know the better.

[FFORMULA78]

Re: Someone help me troubleshoot this problem please

i just woke up, but just scanning over it, it kinda sounds like a tranny issue. like its not downshifting, 1500RPMs is kinda low, more so for us v6's than your lt1, but still.

when your going 45 and step on it, does the car downshift?

do the rpms go up but your speed not? ( tranny slipping )

is the car modded at all? i have some vibrationg around 1500-1600 rpms becuase of my exhuast, i cant feel it, but i can hear it.

you said when you ran it hard, it started spitting coolent. we need to talk about this a little more. where was the coolant coming from? the radiator cap? how hot was it out? how long did you run it hard? how hot was your engine? do you know what your coolant level was before?

when a car overheats, the pressure inside the system gets greater than the rating on the radiator cap, and pushing some coolent out to relieve the pressure. do your fans kick on around 210*? does the car heat up normally? or really slow? or really fast?

sorry about all the questions, the more we know the better.

1. When im going 45 and step on it, the vibration stops, it picks up really well, etc. Basically the car feels like it should.

2. RPM's never go up while my speed stays the same, no slipping that i can notice anyway.

3. You said you have vibrating around 1500-1600 rpms because of your exhaust, i think(im not sure tho) that i might have a similar thing going on with my car. I have a K&N & flowmasters exhaust. It was on the car when i goit it and i dont know if it is damaged or what not. I did notice this past weekend that either something under the car or a muffler is making a vibrating sound. Not the kind of car vibrating i referred to earlier, but im just telling you about the muffler because maybe it is damaged and its a small part of the overall problem(possibly)

4. When i ran it hard, it wasnt spitting coolant. It was smoking a little this past time and my mechanic was at my house. I think the temp got to around 260 or so, it is usually around 210 - 240, the fan comes on and it goes back down. It does not heat up too quickly, i'd say as normally as any other car ive owned. But this time it got up to around 260+ before it went down. He took off the coolant cap, not the reserve bottle) and when i turned my car on, it would gush out. We saw that a hose had a hole in it, probably from over heating so we replaced the hose. Then we put coolant in and while my car was on @ idle, the coolant would come out.

We put a whole bottle of coolant in plus refilled the bottle with water about 7 times and it still kept coming out. The coolant light was on at that point as well. I decided to just keep filling it up with water if needed the next week or so until i could take it back to the original mechanic to fix it but, I ran the car easy for a couple of days and it is running alright now. No coolant light, no overheating, etc. It just has that damn annoying vibration and maybe its just psychological but it feels like a loss of some power. Or maybe im just scared to run it really hard at this point at higher speeds. i am certain ther is a lower end power loss though, that is certain. Top end, maybe not.

You ask a bunch of questions, i give you a bunch of info. :wavey:

Thanks tho, it made me think it through entirely to give you a better picture.

[CDNFB]

Re: Someone help me troubleshoot this problem please

Here's my take on it all.

1) the vibration that you are hearing is from the catyletic converter. The insides are loose and vibrate in certain RPM ranges. It can be very loud and annoying both inside and outside the vehicle.

2) You have the beginnings of a head gasket leak. With the engine under load the cyliner (with the leak) is pumping gases into your cooling system causing a displacement of the coolant (coolant comming out) and a vapor lock (your high temps). As the leak progresses and gets worse, you will begin to leak coolant into the cylinder and white smoke will start to appear in the exhaust,
and/or
coolant will begin to appear in the engine oil. When coolant starts to mix with your engine oil, your engine will be on it's death bed unless you fix the problem ASAP.

[FFORMULA78]

Re: Someone help me troubleshoot this problem please

Here's my take on it all.

1) the vibration that you are hearing is from the catyletic converter. The insides are loose and vibrate in certain RPM ranges. It can be very loud and annoying both inside and outside the vehicle.

2) You have the beginnings of a head gasket leak. With the engine under load the cyliner (with the leak) is pumping gases into your cooling system causing a displacement of the coolant (coolant comming out) and a vapor lock (your high temps). As the leak progresses and gets worse, you will begin to leak coolant into the cylinder and white smoke will start to appear in the exhaust,
and/or
coolant will begin to appear in the engine oil. When coolant starts to mix with your engine oil, your engine will be on it's death bed unless you fix the problem ASAP.

Damn, thats exactly what i did not want to hear but im glad i did. Thats what my mechanic friend told me almost word for word but i was hoping he was wrong. How is this fixed? Just the guy needs to fix the heads properly? Could this be caused by a cracked engine block as well or is this just a head thing? F%#* ME. Thanks for the information, tho.

[CDNFB]

Re: Someone help me troubleshoot this problem please

Cracked heads and blocks do cause these symptoms, but the trend with these cars is that it's only a gasket failure. Having said that, it is wise to do a detailed inspection of the heads when you have them off when your changing the gaskets. Look for cracks and warpage, but you probably won't have those problems and it will only be gaskets.

[FFORMULA78]

Re: Someone help me troubleshoot this problem please

Cracked heads and blocks do cause these symptoms, but the trend with these cars is that it's only a gasket failure. Having said that, it is wise to do a detailed inspection of the heads when you have them off when your changing the gaskets. Look for cracks and warpage, but you probably won't have those problems and it will only be gaskets.

im taking it back to the original mechanic tonight. if he is able to fix it and you are right, i owe you big time. next time you come to south florida, drinks r on me

[CDNFB]

Re: Someone help me troubleshoot this problem please

Florida eh....! Mighty tempting. That's where my 99 FB comes from. Built in Canada, shipped to Florida, then brought back to the land of the cold and ice!! (poor thing)

Anyways....good luck. I hope you don't get soaked $$$$wise. Some mechanics charge an awful lot to do that job, which inspires a lot of people on this forum to tackle it themselves.

[FFORMULA78]

Re: Someone help me troubleshoot this problem please

Florida eh....! Mighty tempting. That's where my 99 FB comes from. Built in Canada, shipped to Florida, then brought back to the land of the cold and ice!! (poor thing)

Anyways....good luck. I hope you don't get soaked $$$$wise. Some mechanics charge an awful lot to do that job, which inspires a lot of people on this forum to tackle it themselves.

well, its a whole big story but this guy fixed it originally for a maroone dealership and it is kind of warrantied through "the word of a car sales manager". Seems kind of scarry but so far the sales mgr. has been cool. i think i can bring it to him one more time before he starts *****ing and says enough is enough. we'll see man. thx again

[FFORMULA78]

Re: Someone help me troubleshoot this problem please

How easy is it for my mechanic to replace the gaskets. How much labor time are we looking at there? I might just give that a shot. I went to the mechanic yesterday. Seems they are out of business sort of. Their building has been shut down by the city for being unsafe and there is no timetable for when they will be up and running again. Oh well, live & learn i guess :)