Burnt intake plenum and tb?

[bigfred1123]

Hey, I just bought a 04 gt and have bought a couple small items and one of them was a bbk 70 mm tb. When I was installing it I noticed the inside of the old tb and the plenum looked to be burnt, is this normal?

 

[bigfred1123]

Also I changed the plugs out with some fresh motorcrafts and this is what they looked like. Do they look fine? The car has 75000 miles on it.

 

[squeak93]

It's likely carbon build up. Wipe it out with a dry rag and leave what won't come out. MOST throttle body's have a coating of something (can't think what its called, hell it may not have a name, I'm getting old), anyway, tb's have a coating on them that if you clean it off, it will screw with the idle. If the stuff is oily, then ur pcv valve could be messed up/clogged and causing oil to seep up into the intake system. easy/cheap fix if that's the case.

 

[squeak93]

oh, btw none of ur pics worked and it wants me to sign in to view them. I'd suggest using a site like photo bucket to share pics as it's very forum friendly. Remember that any time you change your plugs in any mod motor car, the engine must be stone cold or you risk spark plug blow out and stripped threads.

 

[bigfred1123]

 

[bigfred1123]

 

[bigfred1123]

 

[bigfred1123]

 

[bigfred1123]

ok i hope the pics work now. But you can see the tb is like coated in alike a oily black sludge, also the spark plugs had the same thing.

 

[Noobz347]

Looks like you're getting oil in the intake. Check Replace your PCV valve.

 

[trinity_gt]

What you are seeing is perfectly normal. It's a mixture of oil vapor and mist from the PCV system and exhaust gasses from the EGR system It's harmless and nothing to be worried about.

Don't bother cleaning the TB or plenum.

The plug looks normal too in terms of some oil on the threads. However, the electrodes from this angle look a little rounded and the plug gap a little large. Get some new OE plugs. Make sure you properly torque the plugs when re-installing them.

 

[bigfred1123]

Yesterday, i replaced the spark plugs with new motorcrafts, did an oil change, and changed the fuel filter and put in a new air filter. Is there anything other maintance items i should do since i just got the car and i have no records of what has been done to it? Im just trying to cover all the bases.

 

[bigfred1123]

Soo i shouldnt be concerned about the oil in the intake? Or should I buy a new pcv, btw it has a little bit of a wierd idle; it stays always at 750-800 rock solid but it was a constant quiver and this is with no ac or other items on.

 

[trinity_gt]

Soo i shouldnt be concerned about the oil in the intake? Or should I buy a new pcv, btw it has a little bit of a wierd idle; it stays always at 750-800 rock solid but it was a constant quiver and this is with no ac or other items on.

The PCV valve won't change the amount of oil vapor entering the intake. This is a function of everything from engine blow-by to oil temperature to viscosity etc etc. The PCV valve is simply there to close off the system at idle to prevent a vacuum leak-like condition that would affect idle quality. If you're really concerned about oil in the intake look up what are known as "catch cans" or "oil separators."

What I see in your pictures raises no alarm bells for me in terms of oil in the intake.

I'm not sure how to read "constant quiver" in terms of idle quality. Does the check-engine (aka malfunction indicator light or "MIL") come on or flash at all? Does the car have aftermarket cams?

 

[squeak93]

I would agree that the amount of residue in the tb/plenum are more than acceptable. A new pcv is cheap insurance but like stated the only way to get rid of most of the residue is to get an oil separator.

 

[bigfred1123]

The constant quiver or lite steady shake at idle is like the feeling of a mild cam. I just bought the car and have no idea whats been done to it. But i do have to say i've had 3 gt's; an 01, 03 and now an 04 and this is by far the most heathly one of them all. It just seems different, but it shows no sign of stalling or anything and the idle is steady as a rock at like 750-800 it just has a wierd lump. I would thinks its a cam but there wasnt anything else modded on this car, it was all stock; unless someone took off all the bolt-ons before they sold it? I just would like to know if anything else would cause a idle distortion like that?

 

[bigfred1123]

also if I did a egr delete wouldnt that be just as good as getting a oil catch or no?

 

[trinity_gt]

Don't do an EGR delete. There's no real benefit to it and doing so can actually increase the likelihood of detonation at part-throttle operation such as cruising down the highway. In addition, if you live in a state with emissions inspections you'll likely fail NOx emission testing.

 

[darkside03gt]

also if I did a egr delete wouldnt that be just as good as getting a oil catch or no?

Your EGR has NOTHING to do with oil or anything of the sorts. It stands for exhaust gas recirculation. That tube that connects to the valve is connected to your exhaust so it wont do a damn thing for oil. If you want to do a cheap oil seperator do the home depot mod and call it a day. If you want something nice get one from JLT.