1996 3100 SFI V6 Engine Problems

[montecarlols]

Hello, I bought my first car back in June of 2010 (96' Monte Carlo LS) it has the 3100 SFI V6 L82. One of my lifters knocks really bad when the engine is cold. Now that it is winter in Michigan the lifter knocks really really bad when i first start it up. I let my engine warm up a good 15 minutes before I go to school and leave school. What should I do about this lifter?

Another problem is my engine is hesitant when at time when I give it gas it doesn't want to go over 3000 RPMs. I then floor the engine and it finally down shifts and takes off. My dad said that it could be the fuel pump no supplying enough fuel pressure. I had problems with the fuel pump back in the summer. I ran the car out of gas (stupid me) and i think I killed the fuel pump. What should I do?

If someone could answer my question's I would be really happy. I would like to fix this car, it's a great first car and It's paid off. I'm currently saving money to pay for fixing the engine. I can post a video of the knocking lifter if needed, and the hesitant engine if needed Thanks!

-Joshua

[Jonpro03]

Are you sure it's lifters making the noise? It could easily be the notorious piston slap.

[montecarlols]

I know its not the pistons, its extremely loud, I know what pistons slap sounds like. this lifter knocks louder then the engine. But What should I do about it?

[Azrael]

If a lifter goes bad there's not much you can do for it besides pulling the intake manifolds off and replace it.

The hesitation sounds like a sensor issue. At full throttle the computer ignores some sensors and relies on pre-determined values. There's a good chance it's the O2 sensor if it's old. If not then find someone with an OBD II scanner and see what your computer sees.

[montecarlols]

So to fix the knocking lifter I have to replace the cam shaft push rods and the heads? Would that fix the engine then? My cars cat converter has been cut off so would that affect the O2 sensor a lot?

[bszopi]

So to fix the knocking lifter I have to replace the cam shaft push rods and the heads?

No, you just have to replace the lifter, as well as any gaskets taken off in order to get to the lifter (lower intake manifold gasket and up). Cam, pushrods, and heads should all be fine.

[montecarlols]

But wouldn't the cam shaft lob get warn off I've only owned this car for 6 month who knows how long its been like this. I've had people recommended me to replace the cam shaft. ALso have any of you ever had problems with fuel pumps? I think mines going to go out. What would recommend for cheap / good fuel pumps?

[bszopi]

Its a roller cam, so unless something went drastically wrong, there should be no wear at all on the cam.

[montecarlols]

Okay so I just have to replace the lifter then. I guess in order to figure out about the engine hesitation is to get a hold of my neighbors OBD II computer then.

[bob442]

make sure you replace the lower intake manifold gaskets with the felpro upgrade steels

[pocket-rocket]

If your fuel pump were the problem, the car wouldn't take off the way it does after a while. Reason being is the pump wouldn't be able to keep up with the fuel demand of high rpms. Now if it ran fine on anything under 3k rpms but ran like crap at 3k+, then I would be thinking ignition or fuel delivery. But since it takes off fine after you punch it I wouldn't consider the fuel pump, or really any other part of the fuel system at the moment.

I do agree with Azrael's comment of the O2 sensor though. Most of the time no one bothers to change them, and the computer does ignore it at WOT. How many miles is on the car? If you do decide to change it, get the upstream one. The rear one mainly monitors the cat and isn't used a lot in fuel management.

[montecarlols]

Well the car has 85,500 on it. And i jsut discovered last night my intake manifold gaskets are leaking like a bitch. Coolants leaking out from the top over the engine and drippnig down onto the starter and then onto the ground. I go threw a whole tank of coolant within a month. Felpro i heard is the best.

[60dgrzbelow0]

FWIW... I read something recently encouraging about "Marvel Mystery Oil" that many have touted as the means to dissolve plugged up and recalcitrant flat tappet hydraulic lifters. The idea here was to substitute one quart or litre of your regular motor oil...for one of the Marvel Mystery Oil. Run the vehicle for only a few hundred miles with normal driving...and then change out the oil at the same ratio of one to whatever number of quarts the engine is designed for. When you change the oil...you should notice an enormous amount of blackness to the oil...this is apparently a normal outcome because the Marvel Mystery Oil is supposed to loosen all the old gunk and carbon coating the inner surfaces of the engine. This is a good thing if it happens to yours because in all probability, some of that crap was dislodged from the innards of your lifters. Repeating the procedure after that is recommended and you should see some improvement in engine performance by then. If not, you can always fall back on the manual repair. In the early designs of the Cadillacs...they had a built in Marvel Mystery Oil venturi-like glass jar device that was piped into the carburettor plenum to siphon small amounts of the stuff into the fuel/air stream and provide top engine valve lubrication. So the stuff has been around a long time and proven itself capable of solving many lubrication "Mysteries". It might be worth a try before doing the mechanical tear down.

[pocket-rocket]

Seafoam works wonders too. That and Marvels is the only thing I personally will add to an engine besides oil. I've had Seafoam take an engine that didn't even have enough compression to start (carboned rings sticking to the pistons) and allow it to start and run in the driveway. Granted it didn't have enough compression to actually move the vehicle, but that engine was notorious for too tight of ring gaps and rings freezing to the pistons after carbon formation causing severe oil consumption (1qt every 1k miles was perfectly acceptable in a problem free vehicle according to the dealership...)

[montecarlols]

Ok i have a Huge problem now. Coolant is leaking into my heads....i check my oil and coolant every week so it just started happing within the last week or so. What do I do?