Cadillac P0171 P0174 Cause Found

A large vacuum leak between the intake manifold and the throttle body causes two leans codes to set on this 2001 Cadillac DeVille.

[@chsbadsly]

Im so glad to find your video, even the other one on my exact car, corolla 2004. Thank you for your input I can't wait to try it out!

[@carywollenweber4484]

Thanks Daniel, nice for you to share all that with us. Before I used carb cleaner or starting fluid, but brake cleaner is the best and, of course a scan meter, listening and watching where the vacuum leak is. The throttle body seal is notorious for vacuum leaks. -We all appreciate it. 😀

[@sunbow45]

Very informative! Thank you for uploading the video!!

[@redneckpower394]

Quick question. I have been watching your videos for a while now. And I have seen that you have worked on GM, Ford, and Chrysler products. All of which were still under factory warranty. So I am wondering how this is possible since each vehicle would go to the dealer for warranty work, how is it you are able to work on each one?

[@petworld9727]

Nice video! I appreciate the info...Thanks for helping me find that leak... Now i got to pull the intake off to get to the throttle body coupling boot/gasket... Quick question... How would you take off the idle pulley on a 04 cadillac deville? I can't get my hand or socket/boxend wrench in there... I need some advice on how to attack this

[@namnug69]

Legit AF! Sprayed brake cleaner in the same spot and white smoke came out of the exhaust. Don't know how to say this but, I love you.

[@akob8169]

I got the same problem how did u fix N how much it cost u ?

[@namnug69]

@@akob8169 you have to replace the intake plenum boot. At least that's what fixed mine. The part cost about $30 and it took a couple of hours. I followed a KZbin video step by step with no problems. When I removed the old one it had a huge hole which was the vacuum leak.

[@ryanwilliams9854]

​@namnug69 I put a new starter on my 01 deville an replaced that intake plentum with a new dorman one an its not getting a tight seated seal an causing my engine light to come on an its running crappy

[@jonathangrubbs2329]

Hello Daniel have you noticed any more over all power in your new motor compared to your old one?

[@JohnathanLee8702]

I believe I got this same problem after getting OEM coil packs, boots, and spark plugs. Problem isn't fixed after all that need to try this out thanks for posting this trying to get my car back right soon.

[@ChevySS1968]

Excellent vid, thanks very much!!!!!

[@daveconway8833]

@1:50 that first line you disconnected. What is that? My 2000 deville has it plugged with zero hose coming out

[@stevensapyak7971]

7.14.16. Those plastic upper plenums have caused a pleathora of headaches for owners!......i.e......GM 3100/3400 & the venerable 3800. If you change the lower intake manifold gaskets to the metal framed ones, & flush the infamous DexCool from the cooling system, you will go along way towards an extremely long lived engine. A very informative video! 👍🏽👌🏽😎

[@zuone3573]

Sorry.bit confused. So dexCool bad for northstar? Or should i use Dexcool only for my showroom condition 96 deville.with 90k on it.

[@stevensapyak7971]

@@zuone3573 11.14.20. The original DexCool®️is touted to last 5yrs/150k miles....it is A marketing ploy by GM™️,to make their vehicles appear to cost less to maintain over a certain amount of time for the owner. It doesn’t work out that way in the real world! If you go no more than 3yrs/50k miles you will be OK with using DexCool®️, but I just change mine with the mixes with any type of antifreeze, and change it every 2yrs/30k miles. If you look in side of your coolant overflow tank and it looks grungy and not orange colored, it’s past time to drain and flush your radiator and cooling system.

[@wyvern4588]

Such a nice engine when it's running right, a total nightmare when it isn't. For shame GM.

[@nathanaellensch2894]

its not even gm. its a cadillac with a northstar

[@amberlynn6914]

Wyvern Cadillac is owned by GM.

[@nathanaellensch2894]

But gm didnt build the motor now did they

[@wyvern4588]

Nathanael Lensch I don't know if you are playing stupid or genuine stupid, GM designed and made this engine for Cadillac- GM's high-end luxury line of cars.

[@nathanaellensch2894]

cadillac is owned by gm. they still build their own motors. gm does not build them. cadillac does. gm builds chevy gmc and buick only

[@davidjames666]

THANKS!! I shall use this to find the leaks in my rusted out brake lines

[@rajachampatiray3398]

No you shall not

[@alaskanjammer]

So you say it is between the manifold and throttle body...so is that not a throttle body gasket that needs replacing?

[@MitchGrooms]

GREAT VIDEO

[@keenanhatley7184]

will this problem come with a little smoke ocassinally from under the hood and over heating

[@markbouldin6513]

If I'm remembering correctly my 98 Aurora with 4.0 Northstar had a backfire valve under the plenum, kinda like a spring loaded butterfly valve and easy to locate on my engine as the leak caused it to whistle........ I love the Auroras have two of'em and made the 98 with 305k miles a parts car for the 96 with 60k miles.... Honestly couldn't afford to maintain the Auroras if I had to pay someone to repair them! I'm a novice/parts changer, I have the "3" GM repair manuals and real mechanic's on the web to help so Thank's..... Love the cars but they're maintenance nightmare!

[@jamesbrettwhite7821]

Thanks for sharing 👍

[@mrkongsimr]

If a car has any leak can that cause it to become sluggish sometimes ,like in heat ?? Thanks !

[@flatboat67]

whoever changed that throttle body wasnt paying attention

[@brianmoore5498]

i have the same exact craftsman scan tool how do you go about getting dynamic date while the engine is running? thank you in advance ( if you have time) and also I am a big fan of your videos. take care!

[@user-ny7yr7fk8i]

Whats the scan tool model?

[@josephpacelli3691]

Are these Devilles with the Northstar engines known to have those vacuum leaks mine is a 2003

[@AhPhoey]

Good video.

[@claytondeeds5812]

Need to invest in a smoke machine snap on makes a good one. Find vacuum leaks super fast

[@REPAU]

what was the part called to replace?

[@UPRR-nq6uj]

Thanks Cool Video

[@scottrudner8834]

Nice video.

[@FredyInjecar]

Thank you i just found the same problem

[@jasonmorales997]

Which scan tool do I need

[@federicovasquez8709]

Thanks man!!!!

[@davidjames666]

What a beautiful car. Someone needs to take it out, and drive it hard to get rid of that carbon rap. Notice no spark plug wires as the coils are on top of the plugs. I have a 1996 Northstar in my showroom Deville. Hope they change the coolant every 4 years to keep those headgasket threads healthy

[@user-mf4ic7wb5u]

So instead of removing the manifold can we just remove the throttle and replace gaskets? Or whatever it was that was affecting that side.?

[@user-mf4ic7wb5u]

I’m just saying which would be easier/lass work

[@jwlindem1]

Good job.

[@dakeda2024]

its odd it still drives without missing … my 96 DEVille had the 1074 codes . and the prob turned to be maf even though I cleaned it and it wasn't a direct maf code but that was the prob.... it was still the bad piece .20 plus years old ... I ws thinking the intake gasket changed that .. the plenum boot are notorious ..im glad I don't have one on the 96//.the engines are great without the codes … learn alittle on diagnosing it is a must ..you will narrow the prob down ..I hate to just throw parts after parts not having a clue . just do a little internet research ect..//

[@tjy3388]

I've seen multiple of these boots fail

[@alexlanders6369]

My only issue with the video is .... why would you order and install a maf sensor that was recommended by a part store with out running diag and proving or eliminating that as a probable cause?? I mean part slingers rarely even get me the correct part even when you give them the engine code or vin number. Why leave that to chance?

[@My-Pal-Hal]

Well. That particular part covers an Extremely Wide Spectrum of GM Products. So concerning that particular part. It's probably correct.

[@wendystark7413]

what is that replacement part called? Please help... That's what is wrong with my 95 cadillac eldorado

[@mariovillegas90]

wendy stark kinda of late but plenum duct.

[@wendystark7413]

Mario Villegas thank you. I finally found one on Amazon.com

[@scottdaugherty1696]

pcv leaking?

[@brianmoore5498]

i have used an unlit propane torch to do this. when rpm increase you are near the leak.

[@fukkawi]

Brian Thanks I'll give it a try. Finally, Finally, found a vacuum leak that causes rough idle and stuff that 2 mechanics missed. Can't wait to try the propane torch test.

[@zakkrick]

This the same my friend that is an auto mechanic told to do too to find links

[@CarsandGuitars100]

I found the problem, it's a Northstar V8.

[@68camarorsss33]

The Laughing Philosopher *and guest lol so true!!👍

[@keaganbutler7924]

The Laughing Philosopher *and guest they aren't even bad engines

[@albertoleon4754]

Where are you located ?? Honestly if I have an issue with my car I rather have you look at it cause this mechanic shops I don't trust at all or my dealer

[@edwardmyers1746]

Alberto Leon i think texas

[@albertoleon4754]

Edward Myers darn!! I'm in California

[@albertoleon4754]

Gryazev-Shipunov I've been having issues with my car where it jerks when accelerating I've had this issue since I purchased it no engine light is on I've taken it to the dealer and they said they can't find an issue and nothing is wrong. They told me it's normal but the jerking is so strong at times it throws you back and fourth on your seat at times I really need help I have no clue what's causing it and I don't want to be spending money if I don't have to

[@taredrickmiller861]

check motor mounts

[@ANGRYSHOCK]

Cadillac DTS PURGE VALVE CODE. misfire, lean. Now it's crank no start.. The stalling is after fuel pumps turn on and humms.

[@mikeperry3284]

Why dont you just use something like carb clean or starter fluid? That would run cleaner, right?

[@TheWallyjp]

yes you can, but brake clean does not leave a residue

[@DanielJaegerFilms]

You're right, it would run cleaner, but unlike brake clean, it will leave a residue on other engine components while spraying for the leak.

[@johnnyg5476]

Brake cleaner dries out seals and should not be used to detect leaks. Carb cleaner and or starter fluid would be a better option.

[@reweydewy]

common issue on the Northstar 4.6

[@cyrysvonnachtseite4546]

I have an Eldorado. I have to do this job every 2 years. The mice. Chipmunks and squirrels get into the valley pan where the starter is and chew the wiring and rubber plenum boot. So when it’s starts to idle rough or a screaming high idle. That’s the problem. I Bitch to the neighbors to stop feeding the rodents.

[@RicardoPCGamer]

is it me or does it sound like that engine is lightly knocking?

[@aaronjones8341]

you're not the only one

[@RyGuyLikesFrenchFry]

Mine makes the same odd sound.

[@edwardmyers1746]

Ricardo The Computer Wizard its part of gm so youll hear the knocks like a chevy engine and it is a 32 valvue 4 values for 1 cylinder so there is alot of moving parts

[@geminijtwa29]

Mine make that noise too...

[@genegeneish]

If its cold you get a little ticking. Once valve train and pistons warm a little, noise goes away. Ive got 140k on my third n*. And its one of the cleanest eldos you'll see.

[@FrenchValleyAirport]

Burn that engine down

[@cyrysvonnachtseite4546]

The rodents luv to gnaw on that plenum between the throttle body and intake manifold. Had to do mine twice so far. I just turned 70,000 on a 01 Eldo

[@BigBoy4005]

that godawful rubber boot between the coolant crossover and the manifold wasn't one of the better design changes GM made to the N* in 2000. The earlier design with the TB mounted directly to the intake was better (had coolant hoses to the TB to prevent icing). Somebody probably changed the starter, by the book, and tore the boot; it's best to unbolt the 3 throttle body bolts and slide the manifold straight up with the plate and boot still on it.

[@TATTDIS]

Does the intake manifold have to come off for that? I've been having horrendously high idling lately.

[@BigBoy4005]

@@TATTDIS depends upon the year; prior to 2000 it does not

[@Adam-bw4lw]

why not use water??

[@abyssunderground]

If water enters the engine that's bad, very bad. If it gets into the cylinder you can destroy engines very easily because water doesn't compress or burn. Not to mention the issues it might cause with electronics if they get wet.

[@Adam-bw4lw]

abyssunderground yeah but that amount of water arent hurting an engine(no hidrolock),you dont have to get water over the conectors:)))

[@abyssunderground]

Perhaps not in small quantities, but water also wouldn't affect the readings he was using to diagnose the issue since it doesn't burn.

[@Adam-bw4lw]

abyssunderground but in the other end you hear the engine changing rpm when you hit a vacum leak:)

[@cebruthius]

Tool Guy, more like Cocaine Guy

[@bobcaracappa8597]

Dan it don't take long to fix n u can make some money for your toys buddy

[@order9066]

How many keyboard warriors would have figured it out? Nice troubleshooting!

[@stevenmoss9836]

first

[@makingbakersfieldgreatagai9203]

I hate CADILLACS

[@filthyanimal874]

MAKING BAKERSFIELD GREAT AGAIN, all homosexuals hate Cadillac’s.