Thread: Smoke test help for 3800 series 2 engine running lean, HELP PLEASE

I've googled,youtubed and searched EVERYWHERE! I cannot find a vid or pic of WHERE to put the hose w the smoke into my 3800 series 2 engine to run a smoke test. I am NOT a DIYer and i am NOT engine savvy. With that in mind here is my problem.. i have been running lean since January and cant figure out whats wrong but i know it's a oxygen leak. I have the tools to do a smoke test but have NO IDEA where to put the tube the smoke comes out of into my engine to make sure it goes all the way thru the system to tell me where if any there is a oxygen leak. So here is a pic i found on google images w yellow and red writing on it so PLEASE ignore that i circled in blue where i want to hook up the smoke tester too and have learned this is called the throttle body? If i run a smoke test thru this spot will it hit the entireeeee system? If not could someone PLEASSSEEEEE circle in blue whereeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee EXACTLY to put the ****ing hose into. I am not good at stuff w out indepth pictures vids or explanations thus why i am posting here and now. PLEASE HELP ME!

I have replaced my MAF,MAP,Fuel Pressure regulator,main oxygen sensor on back of engine, and fuel pump. Nothing has fixed or helped.

I literally just need someone to say hey hook up the smoke machine to this spot and show me exactly where thisss spot it so pleaseeeeeeeeeeeee help me if u can please!!!!!!!!!!!!

My car is 2001 grand prix 2dr. If theres isn't a random air leak in the system then it's either my EGR Valve,Charcoal canister or its components or my fuel filter.

Thanks!

So nobody on here knows where to insert smoke test tube into engine to run a smoke test on here? Seriously? Maybe i posted in the wrong place?

could someone please move this to the general grand prix discussion?

You could hook it up there, that nipple is behind the throttle body blade so it would fill the entire upper intake and so on.

If you post the check engine code(s) we may be able to lead you in a better direction. FYI, that copper colored accordian pipe from the intake to the EGR valve loves to crack in hidden places and cause issues. Vacuum leaks can be a pain to track down sometimes, especially if you're not super familiar with where to start looking.

Originally Posted by FordMan77

You could hook it up there, that nipple is behind the throttle body blade so it would fill the entire upper intake and so on.

If you post the check engine code(s) we may be able to lead you in a better direction. FYI, that copper colored accordian pipe from the intake to the EGR valve loves to crack in hidden places and cause issues. Vacuum leaks can be a pain to track down sometimes, especially if you're not super familiar with where to start looking.

codes i have...

p0107
p0125
p0128
p0302
p0336
p0420
p0442
p0751
p0757
p1404 this says next to it "Closed Position performance"
p1811

i have no cat convert and am straight piped. My thermostat still works just fine.

Ok, let's sort through these.

p0107-click the link--> P0107

p0125- Check the connection to your coolant temp sensor. Replace sensor if wiring is good. temp sensor is under the t stat housing, bottom of the lim

p0128- related to P0125

p0302- misfire on cyl 2- check the plug wire.



p0336- crankshaft position sensor- check the wiring harness that goes down to it. Sometimes it can get chaffed and cause issues.


p0420- Catalyst System Efficiency Below Threshold (Bank 1)this is likely due to no catalytic converter on it

p0442- Small EVAP leak- clean the seal on your fuel tank filler neck where the cap goes, and clean the cap seal. If it persists, replace the gas cap.

p0751- there's a malfunction with the shift solenoid “A” shift circuit. Most commonly, this is because of low transmission fluid, dirty transmission fluid, or a clogged transmission filter. If changing the flud/filter and properly filling the transmission does not solve it then you would have to likely replace the solenoid.

p0757- This transmission code usually points to needing a rebuild, but here is some additional info on it:

GM had a TSB on this a few years ago and basically said to pull the valve body and clean it but that wasnt a guaranteed fix either and was just what the bulletin said to do unless there were damaged or severly worn or scratched valves which I doubt.

A stuck 2-3 shift valve will cause this but something caused the valve to stick and that something had to come from somewhere inside. A small amount of debris in the trans is common to see but for there to be enough to make a shift valve become stuck it would cause other valves to have issues before as the shift valves have pretty stout springs on them and Im not sure I have ever seen one stuck in these transmissions. Does the car feel like it is starting in the wrong gear? Does it shift through all of the gears? Is it worse hot or cold? If you clear the code will it come right back-if the trans is acting up all the time it should.

p1404 this says next to it "Closed Position performance"- EGR valve issue- I would remove just the EGR valve and clean it as bet you can (search the web for good how to's) and then do the following relearn procedure on it:

the pintle position must be relearned either via tech 2, or the following: (this goes for attempts at re-learning with the old, and learning new, if it's replaced)

disconnect EGR valve plug.
with key on, clear SES light/code.
immediately turn off key, so code does not reset.
plug in EGR valve plug.
turn on key.

p1811- max adapt/long shift- another tran code further pointing to the possibility of a rebuild:

click the link--> P1811 max adapt, long shift

I read somewhere that the car could be in "limp mode" from the trans code. But when the car started doing this it was the end of december and absolutely FREEZING outside. I know the coolant censor isnt my prob i did the crank shaft censor just over a yr ago and never cleared the code. Sometimes i'll start right up and have zero issues and it's like the car is fine again but only til i turn the car off and then back on. I had a trans go on me in a different 2001 grand prix gt and when it did that it would just keep me stuck under 25mph and i couldn't ever get past 30mph til i got it rebuilt. So i figured if it was something with the trans that would be happening. I have had the car 10yrs as of next month and have never had to do anything to the trans but it has had a slow trans leak since i bought it and it only leaks while the car is driving it never leaves spots on the driveway or anything like that. I always keep my eye on the trans fluid and figured since the car is running hot its burning up my coolant and trans fluid so i figured thats why trans was being weird. I can still go thru all the gears fine and hit the expressway n all but at 50-60mph my entire front end/where the trans is will shake but after 60mph its stops and before 50mph it doesn't shake at all either.

Is there a way for a trans shop to test anything on my trans w out having to drop the trans or everything that has to be done w the trans include dropping it? If the trans is the problem im gonna have to get a new car cuz its already got 200k on it and has a power steering issues i can't fix unless i spend 1k on it. So between those to problems i guess im getting my 5th grand prix.

Would or could a shift kit fix this problem? If so would a trans shop be able to do this under $1k you think?

Have you ever changed the trans fluid/filter on it? If not you could try that. A trans-go shift kit could alleviate the 1181 max adapt shift issue. You could try disconnecting the electrical plug on top of the transmission, cleaning both sides with electrical cleaner spray and reconnect and see what you get.

The shake at 50-60mph could be a front wheel hub, cv axle, or both. My brothers 01 GT had both axles get so bad it was shaking the dash. I just installed 2 new hubs and cv axles and all is smooth again.

What power steering issues do you have? The only super expensive thing is the rack. All other stuff is cheap and easy.

A trans shop should be able to hook a scanner up to it and command/cycle those shift solenoids I would think. I would call and ask first to be sure that is even possible on an 01.

If the boots are leaking, then you need a new rack. Do-able on your own if you have jackstands. There is a how-to here. It's not fun, but not super complicated either. If you look down at the steering shaft boot on the drivers side of the rack and see a wire coming from it then you have Magnasteer, so make sure you get that type as a replacement. It was an option.

Changing just what fluid is in the pan along with the filter is NOT going to kill a trans. What could kill it is a "flush". Put it this way, I've NEVER done a flush on any of my transmissions just pan drop/filter change and they survive just fine. My current trans has over 300K on it and it's just getting flat worn out due to age, not neglect. And no, I'm not always nice to it. For the price of 6 quarts of fluid and a filter it would be worth a shot.

On the hard start, if you turn the key to "ON" but not start for a few seconds, and then start it, does it fire up quicker? This lets the fuel pump prime the system. If the fuel filter has never been changed then I would do so. Could throw a fuel pressure gauge on it to check as well.

If you're not tuned for not having a cat, then it's always going to run rich. IMHO, I'd find a downpipe with a cat and get in in there. A ZZP one would work and would eliminate the stupid crush bend in the factory pipe. I actually have a used one out of my brother's 01 GP sitting here in perfect shape with the downstream O2 in it.

The coolant temp issue sounds like you may have failing lower intake manifold gaskets. They will seep and burn off coolant slowly with no signs of external leaks. Search LIM gasket repalcement for GM 3800. Plenty of pic/info there. A known issue on these engines. Easily fixable. The temp gauge bouncing around says there is air in the system somewhere.

If your exhaust is glowing red then you are running way too rich. Getting the cat back on there would likely help that issue. If you have a scanner that can read live data that would help read fuel trims.

When was the last time it got a new set of irridium spark plugs and plug wires? Often ignition issues can present strange behavior on these engines.

I just googled lower intake manifold gasket symptoms and that sounds like exactly what is happening literally. And because of that is whats creating the trans issue as well because i am running hotter then usual. I am gonna have a shop check the LIM gasket n see if its bad and if so replace that seal. All of these things started happening at the same time to its probably this throwing everything off so if i get that fixed w improvement then i will swap the trans fluid if its still acting weird. Thank you sir!

I will say this, take a look at the "front" of the engine (the pulley side). If you can follow where the lower intake meets the front head and you see a BLACK gasket edge then you have the stock plastic gaskets and they are junk. Were then, and even more so now. Get them out. Even if it does somehow show an aluminum edge, replace them. Pretty sure the aluminum gaskets didn't come around until late '02.

Here is the proper relacement set for the LIM job. I've used this kit on 5 other 3800's and never had another issue.

More Information for GM GENUINE MS006

This will also be the perfect time to flush the cooling system.

thanks. yeah i figured if i ever figured out what the problem is and i get it fixed then i would get the coolant flushed ASAP! Tomorrow or tuesday i will find out more and once i do i will report back with my findings! Thank you again and again and again!!!

​Mechanic came by today and im leaking coolant from upper intake gasket everywhere and some from lower. So gonna replace those and thermastat and see how car runs after that. I will report back next week. Thanks for all the help!

I'll pass on some info that is pertinent to the UIM/LIM job that I always use. It's the bolt tightening pattern and torque specs for the LIM and UIM. Follow those and you'll be good.

UIM bolt sequence.gif


limtorque.gif

Note on this pic- the #5 bolt is the unmarked one under #11. I have used 15 ft/lbs with no issues. Also, use thread sealant on all the LIM bolts so they don't wick oil. I want to say that the lower intake bolts are 3/8", if you use a 10mm likely you'll round the heads when torquing.

Just look up LIM gasket replacement on here and there is plenty of info on it. One BIG tip I will say is do NOT let any coolant get inside the valley when removing the lower manifold. Suck out as much as possible through the t-stat opening and keep it level as possible when lifting off the block.

Some will likely make it's way there regardless, so before you reinstall the lower manifold it is standard practice to wash the valley down with 2 quarts of new oil and let it drain. Once that is done, drain the oil pan and refill with fresh oil BEFORE starting the engine again. Once running again, let it just idle and circulate everything. Then do another full oil change (filter and oil). This will ensure that no coolant gets into bearings and causes you to loose the engine.

Intake job complete and i have power behind pedal again! Car isnt over heating or getting hot anymore either but my radiator and cap are done for so i am gonna get a new cap and just drive the car our til it dies and in the mean time look for a new 99-03 GP GT. Thank you all for all your help and info i literally wouldnt have a functioning car without your help. In the future i will post my new problems here as ive been viewing this forum for over 10 yrs! Love everything about this place! Thank you all again and again and again!!!!!!

You're welcome. Glad to hear it's back proper again.


A radiator change isn't that hard on these cars. Hell, I've swapped mine in about an hour. The only suck part is removing the clips for the transmission lines without loosing the dang things, lol. Radiators are cheap. If you've gotten this far, fix what's left and sell it while it's still running good or it'll likely end up in a junkyard for such a silly reason. I know money is tight but since the rest of the system is clean now, changing the radiator would make it damn near brand new all the way through the system.

Could it be something to do with my exhaust causing this? Ever since this had been happening underneith my car sounds diff/doesn't sound like it usually does... i have a straight pipe but it sounds like right before where the straight pipe is there is a gap or hole maybe idk i haven't been able to lift the car up to look or had it on a hoist but it sounds completely different. Figured id mention this just incase it sparked a memory for someone.