2000 - 2005 deville 4.6 vacuum line hose pcv valve fuel regulator hose elbow replacement random misfire code WHY WHY WHY is it so hard to find replacement Vacuum hose to Air intake?

[Love-Hatemycaddy]

ON the 2000 - 2005 Base 4.6 NS Deville and I know this has been brought up many times b/c its so common for the rubber boots to the Vac lines around and **sigh** "UNDER" the Air Intake Manifold to rot out and start leaking? I want to remove my Air intake and replace my Intake Gaskets AND mainly replace the 2 main Vac Hose (and PCV Valve while Im at it) that connect to the Intake Manifold INCLUDING the little rubber 90 boots. I swear for as common as the random misfire problem at Idle these leaking Intake Vac Lines are FAMOUS for causing and yes I can hear the Vac leak in mine and if  my top connecting elbows are rotted then one would expect the same once I remove air intake. 

Anyway is there part numbers for the Intake lines I want to replace and if not WHATS Best way to go about replacing them. I live way out in the country so once I start removing my intake I want to be 1000% sure I have the right vac hose replacement parts b/c its a very long trip to the nearest parts store to play the '"I hope this help section piece does it" game, lol

Thanks guys, BTW 1st time poster but I have read a few threads long before signing up about other issues, thanks again...

 

 

I bet somebody could make a killing on Ebay making a full parts kit  with Intake Valves, Vac Hoses, elbows, PCV valve, etc. to fix this common problem, lol...

[barczy01]

On the 90 degree elbow I use the end of a spark plug wire,works great. Otherwise I use 3/8 hose

[BodybyFisher]

Some parts are strictly only available at the dealer.  I would try them or visit a scrap yard.

Try this

Http://www.car-parts.com

 

[KHE]

The rubber coupler rots over time but I have not noticed any posts for the other components you mentioned.

Why are you replacing the intake gaskets?  They typically do not go bad.  Have you tested them by misting them with carb. cleaner while the engine is idling?

[Logan]

2 hours ago, KHE said:

The rubber coupler rots over time but I have not noticed any posts for the other components you mentioned.

Why are you replacing the intake gaskets?  They typically do not go bad.  Have you tested them by misting them with carb. cleaner while the engine is idling?

I thought the same thing. He may be thinking the wrong hose. The large rubber piece (red circle) in picture goes bad at the bottom....the intake juices collect at the bottom and rot it out. It can look perfectly fine from the top side. 

[Love-Hatemycaddy]

The rubber coupler rots over time but I have not noticed any posts for the other components you mentioned.

Why are you replacing the intake gaskets?  They typically do not go bad.  Have you tested them by misting them with carb. cleaner while the engine is idling?

 

Yeah I know they dont but I figured at 16$ for the full set that surley couldn't hurt. And no I havnt tested anything yet with Carb Spray but I Can clearly hear a leak and see clear (very bad) Rot on the 90's connecting both Intake hoses and would like everything to be new if I can b/c I have grabbed a few used lines out the Local Junkyard that even tho they looked pretty good at first that after closer inspection I see cracks appear on the 90's when I press on them a bit which even if they do work for now then next question will be how long and again like the intake Gaskets "Why Not" go ahead replace them to make sure the repair will last with us planning to keep the car for awhile.

Thanks very much for commenting back. All you guys have been great so far...  

[Love-Hatemycaddy]

I thought the same thing. He may be thinking the wrong hose. The large rubber piece (red circle) in picture goes bad at the bottom....the intake juices collect at the bottom and rot it out. It can look perfectly fine from the top side. "

 

Thanks for pointing that out b/c I do hear a leak at the rubber Intake but at 1st inspection didnt see anything jumping out at me tso I didnt think to check the bottom of it due to the top looking so good and as soon as I get a minute to look and check it I will Let you guys know if that is rotted at the bottom as well. 

Car runs great with no misses at all once you give motor any bit of throttle so Knowing cars a bit like I do Its most likely a leak in a line or Intake hose mentioned that is the best (And Cheapest) bet at fixing the Multi-misfire code on my Scanner.

 

Thanks again to everybody that posted responses and Im glad that you guys have given me a couple more simple things to check and or repair the problem...

Tho Im very Busy I will be checking this thread for anymore help and post as soon as I get back under the hood to let you guys know how it turns out...

 

[Love-Hatemycaddy]

I have a unstripped 2000 Deville for parts (got it super cheap, shocking it has a blown head. Im sure many never heard that happen to the famous NS before, lol joking of-course.)

I think it was 2003 and correct me if Im wrong that Cadillac changed the motor a bit so tho some parts work like the power steering pump I will be taking off it soon that a lot of things are slightly different on the "In proved" 4.6 NS Engine in my 2005. Jury still out for me as I have owned 4 devilles with the NS motor from 97 till my 2005 now and 2 of them blew a head Gasket the 1st time they ran hot from water pump failure on one and Radiator separated at plastic end caps on another. Both times I shut the car down right away when car showed it was hot on gauge display and had it towed to be repaired and both times it was the end of the car as it was cheaper to buy another used one then make the head repairs that happened from running hot. I love Cadillac's (every since I was a kid and have owned so many over my life I cant even give a number off top of my head of how many I have over the years, lol) and really love the power of the NS motors with out having to know the employees of every Gas station in the city that my older devilles did before the 4.6 NS came out. So I really hope this one holds up much better and so far it didnt blow a gasket when my water pump belt came off from the Idle pulley bearings going bad  2 weeks ago so so far so good. Was extremely happy the heads held up so far.

[KHE]

20 hours ago, Love-Hatemycaddy said:

I thought the same thing. He may be thinking the wrong hose. The large rubber piece (red circle) in picture goes bad at the bottom....the intake juices collect at the bottom and rot it out. It can look perfectly fine from the top side. "

 

Thanks for pointing that out b/c I do hear a leak at the rubber Intake but at 1st inspection didnt see anything jumping out at me tso I didnt think to check the bottom of it due to the top looking so good and as soon as I get a minute to look and check it I will Let you guys know if that is rotted at the bottom as well. 

Car runs great with no misses at all once you give motor any bit of throttle so Knowing cars a bit like I do Its most likely a leak in a line or Intake hose mentioned that is the best (And Cheapest) bet at fixing the Multi-misfire code on my Scanner.

 

Thanks again to everybody that posted responses and Im glad that you guys have given me a couple more simple things to check and or repair the problem...

Tho Im very Busy I will be checking this thread for anymore help and post as soon as I get back under the hood to let you guys know how it turns out...

 

Usually, when the rubber coupler rots through, the P0171/174 lean codes for both banks.  Have you verified the coupler is bad?

[BodybyFisher]

20 hours ago, Love-Hatemycaddy said:

I have a unstripped 2000 Deville for parts (got it super cheap, shocking it has a blown head. Im sure many never heard that happen to the famous NS before, lol joking of-course.)

I think it was 2003 and correct me if Im wrong that Cadillac changed the motor a bit so tho some parts work like the power steering pump I will be taking off it soon that a lot of things are slightly different on the "In proved" 4.6 NS Engine in my 2005. Jury still out for me as I have owned 4 devilles with the NS motor from 97 till my 2005 now and 2 of them blew a head Gasket the 1st time they ran hot from water pump failure on one and Radiator separated at plastic end caps on another. Both times I shut the car down right away when car showed it was hot on gauge display and had it towed to be repaired and both times it was the end of the car as it was cheaper to buy another used one then make the head repairs that happened from running hot. I love Cadillac's (every since I was a kid and have owned so many over my life I cant even give a number off top of my head of how many I have over the years, lol) and really love the power of the NS motors with out having to know the employees of every Gas station in the city that my older devilles did before the 4.6 NS came out. So I really hope this one holds up much better and so far it didnt blow a gasket when my water pump belt came off from the Idle pulley bearings going bad  2 weeks ago so so far so good. Was extremely happy the heads held up so far.

The head bolts were changed in 2000 and 2004, we have heard some 2005s have had the problem but the failure rate seems lessened.  

I don't tend to feel that a bad water pump or plastic end tanks caused a head gasket failure, not that it matters a failure is a failure, but remember that the engine was supposedly designed to run 50 miles with no coolant, shutting down cylinders and pumping air.   My guess is that the head gasket failure exposed other issues, keep in mind that the head gasket failure superheats coolant and it boils raising the cooling system temp and pressure quickly. 

[Love-Hatemycaddy]

Yes I did check it and you was exactly right its rotted out and I will need to replace it and yes I have the lean codes...

Thanks...

 

 

[KHE]

The intake needs to come off to replace the coupler.  The shop manual states that replacement is not required unless the gaskets are damaged.  I've had the intake off my STS about four times over the years and the gaskets were always fine.  It's OK to replace the gaskets but it isn't necessary.

Removing the intake sounds like a terrible job but it is really straightforward and takes about 20 minutes.  Make sure not to miss the vacuum line near the power steering pulley - the nipple on the intake is hard to see and it is easy to overlook that line.

[Love-Hatemycaddy]

Thanks and I have no problem with turning wrenches and have much better then average tools for a guy thats not a mechanic at trade but I am a big DIY guy and to me a huge part of doing things yourself is that good tools make a HUGE difference and I figured that when I was looking at it lastnight b/c I seen know way to get to it from the throttle Body Assembly side at all so Ill be jumping...

 

Now all that said I have a NEW BIGGER problem that is all my fault for messing with as I was pulling off all my vacumm lines and replacing anything with signs of cracking and wear and I got this "WONDERFUL IDEA" sarcasm greatly intended to remove my I guess what is the fuel pressure regulator atop my fuel rail and car is running like complete Garbage since I put it back on. Sigh I know I know (I feel stupid enough already) but any clues on how to I guess to gett his go back on correctly and what do I do to get my cars fuel pressure working right again. Didnt even know I messed it up till I drove after I posted lastnight as car cranks fine but runs as if not getting proper fuel pressure at all. Jerking and jumping when I try accelerating with my iand DRINKING gas like 454 BIG Block with a Huge Holy Double Pumper carb trying to power a  Monster truck down a drag strip (for those that dont get that it pretty much like drive with a huge hole in your gas tank, 

[BodybyFisher]

There is a trick with the FPR.  It is possible to not get all of the parts out when removing the old FPR, I cant recall the detail, but it might be an o-ring.  Someone witl stop in and add to this thought.

Do you have a fuel pressure gage?

[Love-Hatemycaddy]

Yes somewhere in my shop, I will have to look. and both the O rings came out fine and stayed in there grooves on the regulator it self. But to me when I look down in to regulator housing the bottom fuel line connecting to the underside looks a bit crooked, I wonder if that matters. I have another assembly that looks to match off my 2000 Parts car and other then it having a blown head Gasket my parts car runs perfect So if I did mess up anything I do have replacement parts at hand. I guess tho I should go ahead replace the regulator since its out and I screwed crap up to begin with. Thanks again for the help you have been on point so far with so much.

[BodybyFisher]

I would check the fuel pressure.

Have you disconnected the battery to get the system to do a relearn?  You had lean codes, the system.would adjust air/fuel trim to compensate for the.lean mixture.  If you didnt delete P codes you may be seeing an engine that is running based on lean compensation that slowed the idle.  If you have not cleared codes clear them.

I would also pull the IAC and clean it and the port.

Do you have any P codes?  

 

[BodybyFisher]

From the 05 manual

Rough, Unstable, or Incorrect Idle and Stalling

Inspection/Test	Action
DEFINITION: Engine runs unevenly at idle. If severe, the engine or vehicle may shake. Engine idle speed may vary in RPM. Either condition may be severe enough to stall the engine.
Preliminary	Refer to Important Preliminary Checks Before Starting in Symptoms - Engine Controls . Search for bulletins.
Sensor/System	Test the positive crankcase ventilation valve (PCV) system for proper operation. Refer to Crankcase Ventilation System Inspection/Diagnosis Test the throttle body, and throttle position (TP) sensor for proper operation and damage. Inspect the knock system (KS) for excessive spark retard. Test the exhaust gas recirculation (EGR) system for proper operation. Refer to Exhaust Gas Recirculation (EGR) System Description Inspect the idle air control (IAC) valve and valve housing for deposits and/or damage. Refer to Idle Air Control (IAC) System Diagnosis Inspect for dirty or damaged air cleaner element. Inspect for collapsed or damage intake air ducting.
Fuel System	Test the fuel pressure. Refer to Fuel System Diagnosis . Test the fuel injectors and related wiring. Refer to the following: Fuel Injector Balance Test with Tech 2 or Fuel Injector Balance Test with Special Tool Fuel Injector Coil Test Inspect the minimum idle speed. Test for contaminated fuel. Refer to Alcohol/Contaminants-in-Fuel Diagnosis . Inspect the following that may cause the engine to run rich: Notice Refer to Heated Oxygen and Oxygen Sensor Notice in Cautions and Notices. Any water intrusion in the heated oxygen sensor (HO2S) connector Engine oil contaminated by fuel An evaporative emission (EVAP) canister purge condition Incorrect fuel pressure--Refer to Fuel System Diagnosis A leaking fuel pressure regulator Any rich fuel injectors--Refer to Fuel Injector Balance Test with Tech 2 and Fuel Injector Balance Test with Special Tool Inaccurate mass air flow (MAF) sensor Blockage on the inlet screen of the MAF sensor Vacuum hoses for splits, kinks and proper connections The air intake duct for being collapsed or restricted The air filter for being dirty or restricted--Refer to Air Cleaner Element Replacement Inspect the following that may cause the engine to run lean: Notice Refer to Heated Oxygen and Oxygen Sensor Notice in Cautions and Notices. Any water intrusion into the HO2S connector An exhaust leak between the HO2S and the engine--Refer to Exhaust Leakage in Engine Exhaust. Any vacuum leaks Incorrect fuel pressure--Refer to Fuel System Diagnosis . Any lean fuel injectors--Refer to Fuel Injector Balance Test with Tech 2 and Fuel Injector Balance Test with Special Tool . An inaccurate MAF sensor Fuel contamination--Refer to Alcohol/Contaminants-in-Fuel Diagnosis . Vacuum hoses for splits, kinks and proper connections
Ignition System	Inspect the ignition control (IC) circuits for proper connections at each ignition module assembly. Test for proper ignition voltage output using the J 26792 spark tester. Inspect the ignition coils for cracks, or damage. Inspect for a missing or damaged ignition module assembly grounding spring. Inspect for misaligned, or damaged spark plug boots. Inspect the spark plugs. Refer to Spark Plug Inspection .
Engine Mechanical	Inspect for the following: Engine compression--Refer to Engine Compression Test in Engine Mechanical. Sticking or leaking valves Worn camshaft lobes Valve timing Worn rocker arms--Refer to Valve Rocker Arms Cleaning and Inspection in Engine Mechanical. Broken or weak valve springs--Refer to Valve Spring Inspection and Measurement in Engine Mechanical. Excessive oil in the combustion chamber-leaking valve seals Inspect for incorrect basic engine parts. Inspect the following: Camshafts Cylinder heads Pistons, etc.
Additional	Inspect the exhaust system for possible restrictions. Refer to Restricted Exhaust in Engine Exhaust.

[KHE]

12 hours ago, Love-Hatemycaddy said:

Thanks and I have no problem with turning wrenches and have much better then average tools for a guy thats not a mechanic at trade but I am a big DIY guy and to me a huge part of doing things yourself is that good tools make a HUGE difference and I figured that when I was looking at it lastnight b/c I seen know way to get to it from the throttle Body Assembly side at all so Ill be jumping...

 

Now all that said I have a NEW BIGGER problem that is all my fault for messing with as I was pulling off all my vacumm lines and replacing anything with signs of cracking and wear and I got this "WONDERFUL IDEA" sarcasm greatly intended to remove my I guess what is the fuel pressure regulator atop my fuel rail and car is running like complete Garbage since I put it back on. Sigh I know I know (I feel stupid enough already) but any clues on how to I guess to gett his go back on correctly and what do I do to get my cars fuel pressure working right again. Didnt even know I messed it up till I drove after I posted lastnight as car cranks fine but runs as if not getting proper fuel pressure at all. Jerking and jumping when I try accelerating with my iand DRINKING gas like 454 BIG Block with a Huge Holy Double Pumper carb trying to power a  Monster truck down a drag strip (for those that dont get that it pretty much like drive with a huge hole in your gas tank, 

It has been a long time since I replaced a fuel pressure regulator but I recall a small o-ring on the bottom of the fuel pressure regulator that can get lost when removing it - usually, it results in a fuel leak.  There is also a larger ring that seals it to the fuel rail housing. 

[BodybyFisher]

Thanks Kevin,  that is what I recall, and I recall we have had a few members including myself the first time have trouble with it.  

There is a screen in there also.

I looked for a blow up illustration but didnt find one.

Its possible with removing the throttle body carbon was dislodged in the IAC port.

[BodybyFisher]

Love-Hate, here is a thread I posted on the crossover, throttle body back in 2007.   Go down this page and you will see the IAC port caked with carbon.  Make sure the IAC pindle and port are clean.   A restricted port will slow the idle.

If you had a vacuum leak the idle would be fast.    Again check for codes and disconnect the battery to erase any air/fuel trim compensation that may be present because of the lean codes you had

 

[Love-Hatemycaddy]

IM finishing it up today and I decided to just change out the entire fuel rail off my parts car. Parts car ran perfect (other then Blown head gasket) So I figured to do this to be Sure its(Fuel Regulator) Ok. I Replaced the Rubber intake part between Intake and Throttle Body Assembly(thanks again for pointing this out) to fix the original problem. I also decided to spray a couple coats of  rubber coating over the OUTSIDE of the rubber Intake part to try and help protect it. Diidnt want to coat inside in case coating starts to flake in the future to prevent rubber flakes from being sucked into my Intake. I had to repair damaged wires to one of my knock sensors which explains why I kept getting a knock sensor code, so I hope another problem taking care of. Replaced all my Intake seals tho many said it wasnt necessary I just didnt really like the way my old seals looked. Also replaced the seal to the Throttle body that came in kit. Replaced Power steering pump as well b/c my old one was leaking and wow is that stupid easy I must Admit. Easiest PS pump I've ever changed in my life, lol. Taking break to take a bit of Football and will rap it up shortly. I took pics to post later after Im done...

Thanks again guys and i will let you guys know the outcome soon, Fingers crossed  

[BodybyFisher]

[FullStrength]

It's easiest to remove the power steering pump to get to the elbow boot going into the intake manifold rather than removing the fuel injection rails, manifold itself and everything else in the way. Although the throttle body rubber boot connected to the manifold may need to be replaced to. They tend to crack or split at the bottom and will cause another leak. This requires taking off the manifold.