Thread: I think I have a cam? Help. Lol

Soooo long story short I've had this car almost a year now. It has had a p0300 misfire code since day one. Idles very rough but drives like a new car when going down the road. The only time it doesn't have the lobing "camming" sound is the first 30 seconds after cold starting it. Basically I start the car and as soon as the PCM turns the climate control on I'll hear the ac compressor kick on and it starts idling like it's cammed. My mechanic thinks it has a cam but I want to know 100% what's going on with it. I have replaced the spark plugs, wires, and checked literally everything for misfires and vacuum leaks and check and replaced all gaskets. I've been at a stand still and it's frustration. I'll put some videos up if anyone wants to try and help lol. Basically my question here is what's the easiest road to go down to find out if the cam is stock or aftermarket. Even if I took it apart how would I know? The car is a 2000 GTP 3800 supercharged L67


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I'll post a video as soon as possible

Good chance that it is cammed. Pop the oil cap and see if you can see if the valve springs/retainers/seals are different (titanium retainers, yellow springs, or blue seals) That'd be a great indication that someone has messed with the valvetrain.

Only way to be 100% sure is to pull the motor, and either pull the cam (lots of work) or pull the rear cover and see if the rear of the cam is scribed like so



See how the cam has got the cam specs on it?

Ok thank you that actually helps a lot, I have a bunch of mods almost ready to go on the car but I don't want to mod it without knowing if it's cammed or not for tuning reasons and all that. Is it very difficult to take off the rear cover to look for any specs? The car had a cold air intake on it when I bought it also the valve cover gaskets and grommets were all new so I know someone had those off at the least.


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Not really difficult but you have to pull the engine out to remove the rear cover iirc.

Sounds like a lot of work lol.


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Is there a lot to mess up if I continue to mod the car without finding out first?


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You do have to pull the motor. First time probably takes about 4-5hours to get the motor out. A little longer to get it back in. Once you've done it a few times, you can go from it running, motor pulled, issues fixed (my case broken flex plate) and back in and running in about 6-7hours.

It's really not that hard to do. If you take the hood off (4 bolts) you gain a lot more space for the hoist.

But like Slick said, it's not hard to pull the cover and check, it's just getting to the cover.

easiest way is to yank a valvecover, pull a rocker and put a dial indicator in the end of the pushrod and read the cam lobe lift and compare

why has no one suggested checking boost levels? he is on a 3.5 pulley. someone with similar mods should be able to compare boost pressure to his at a specific RPM. a cam will lower boost pressure. by any chance what kpa or psi are you seeinng?

I've already replaced the iac, But I'm getting around Maby 8 spiking 10 psi under full throttle


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What's kpa?


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kilopascels - measurement of pressure like PSI.

Ok


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Pull the valve cover, look and see if anything is different (Blue seals, different retainers) and if you really want to know pull a rocker and put a dial indicator in the end of the pushrod and read the cam lobe lift and compare to the stock lift.

whats your vacuum like at idle?

That seems like a pretty good idea, I'm new to the pushrod thing. So which part exactly do I measure with the valve cover off?


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Just check your vacuum. Stock should read around 18-22. If your cammed most likely you will be around 15.