Car

Ask a Mechanic Online and Get Answers to Your Car Questions

Ask an Expert,
Get an Answer ASAP!

Car

Will a vacuum leak stall a vehicles engine intermittently at

Customer Question
idle and driving down the...
Will a vacuum leak stall a vehicles engine intermittently at idle and driving down the road?
Submitted: 5 months ago.Category: Car
Show More
Show Less
Ask Your Own Car Question
Customer reply replied 5 months ago
I have a 2003 F150 5.4 that is stalling at idle and driving down the road . Things replaced spark plugs , coil packs, MAF sensor , fuel pump and IAC valve . Trying smoke for vacuum leaks and it has a hole rubbed from belt tensioner on timing chain cover that the smoke is coming out of . I'm just wondering how or if this is normal to have vacuum in timing chain cover? I put smoke in the brake booster hose .
Customer reply replied 5 months ago
I'm going to pull PCV valve out to see if it's not closing completely. Looking for any help I can get trucks not worth taking to dealer and get a huge bill . Thinking about running compression test next
Answered in 16 minutes by:
6/15/2017
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago
Ron
Ron, ASE Certified Technician
Category: Car
Satisfied Customers: 36,320
Experience: ASE Certified Tech
Verified

Hello. My name is ***** ***** I am happy to assist you today. Give me just a moment to review your post, and I'll be right back with the help you need.

Ask Your Own Car Question
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Tom,

The engine gets its vacuum from the PCV system and this is a sealed system and if you have a hole in the timing cover then that needs to be sealed for the PCV system to seal and work as it should. Can you plug this hole off and see if then engine runs better?

Ask Your Own Car Question
Customer reply replied 5 months ago
I can maybe try JB Weld on it if that doesn't hold I would have to get a new or used cover . How can it get down there the smoke that is ? Also can this cause stalling intermittently?
Customer reply replied 5 months ago
If I pull PCV valve will smoke go through it or should it be sealed off?
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Where are you smoking it, the PCV is the vacuum source. It sucks air through the engine.

Ask Your Own Car Question
Customer reply replied 5 months ago
I'm putting smoke in the hose to brake booster
Customer reply replied 5 months ago
Engine off of course just looking for leaks
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Okay that being sucked into the engine as it should be,

Ask Your Own Car Question
Customer reply replied 5 months ago
No codes on it but very dangerous to drive . I have about 3 psi of air that I'm pushing the smoke in with
Customer reply replied 5 months ago
air is pushing it into the system so the PCV should be sealed correct?
Customer reply replied 5 months ago
I'm going to try that now and see the result of it . I will let you know shortly
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Air being sucked out of the engine from the vacuum supply line to the PCV . Try sealing the hole.

Ask Your Own Car Question
Customer reply replied 5 months ago
Any other thoughts on 5.4 triton engine idle is 650 and then drops to 500 intermittently and dies . I will try to seal the hole but smoke should not came out anywhere on the engine correct if it's a sealed system
Customer reply replied 5 months ago
Once the hole is sealed I'm saying
Customer reply replied 5 months ago
I took PCV valve out smoke is coming out of it but still making its way through the engine some how I don't know how but it is
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Yes correct . Usually if you have a vacuum leak you will set lean codes, have you scanned it and are there any fault codes setting?

Ask Your Own Car Question
Customer reply replied 5 months ago
Nothing set or pending codes
Customer reply replied 5 months ago
Long term fuel trims at 18 which is high but give it gas and it gets better like a vacuum leak
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Have you verified the fuel pressure is okay?

Ask Your Own Car Question
Customer reply replied 5 months ago
Fuel pressure is 42 psi at schrader valve test port increases when you pull vacuum line of regulator like it should
Customer reply replied 5 months ago
Fuel pressure regulator
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

A vacuum leak will effect idle but not cause the engine to die while driving.

Ask Your Own Car Question
Customer reply replied 5 months ago
Normally high idle to not low idle right ?
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Yes, usually if you have a leak it will cause the engine to idle high.

Ask Your Own Car Question
Customer reply replied 5 months ago
I've never smoke tested engine before this is first time but it's leaking because I shouldn't see any smoke I will try to plug hole but your not convinced that vacuum leak will fix my problem ? Engine dying
Customer reply replied 5 months ago
Fuel filter has been changed to
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Plug the hole just because it needs to be and then scan the system and see if you have any fault codes setting.

Ask Your Own Car Question
Customer reply replied 5 months ago
Any suggestions on what to check next?
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Are you setting any fault codes?

Ask Your Own Car Question
Customer reply replied 5 months ago
No I have no codes
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Okay let get the hole sealed and see what results we get.

Ask Your Own Car Question
Customer reply replied 5 months ago
Ok I will get back with you in the next few days
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Sure thing. Post back when your ready.

Ask Your Own Car Question
Customer reply replied 5 months ago
Hello Ron ! Just getting back with you I plugged the hole in timing chain cover now I have smoke coming out egr valve that I need to fix not near as much but leaking no the less . I will get that repaired and get back with you . Still dying at idle . I was told to check TPS . I have not checked that but one thing at a time I guess . Never checked TPS before but I have a Haynes manual that will guide me I hope . Would that cause intermittent stalling at idle ?
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Okay thanks for the update. I have enclosed the steps in the link below for testing the TP sensor as well.

https://dl.dropboxusercontent.com/u/104923897/TP%20testing%20Jun%2021.pdf

Ask Your Own Car Question
Customer reply replied 5 months ago
In your opinion would TPS cause stalling at idle?
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

It is possible if the signal out of it is erratic but in most cases this would set a TP code as well.

Ask Your Own Car Question
Customer reply replied 5 months ago
I still have no codes at all but stalls quite frequently
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Well go ahead and check the TP signal and see if by chance its causing the problem.

Ask Your Own Car Question
Customer reply replied 5 months ago
Ok Thank you I will keep you informed in a few days I will get it checked
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Okay, Im here if needed.

Ask Your Own Car Question
Customer reply replied 5 months ago
Thank you
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Your very welcome.

Ask Your Own Car Question
Customer reply replied 5 months ago
Egr valve and TPS I changed no smoke same result it seems to run better at idle but I put it in gear to move it and it died 3 times moving in my yard . I went ahead and replaced TPS because I plan on keeping Truck and for $40 I just changed it
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

And you still not setting any fault codes?

Dose it restart easily?

Ask Your Own Car Question
Customer reply replied 5 months ago
No codes I have snap on solus pro I'm using but I don't know enough about live data to tell where it should be
Customer reply replied 5 months ago
starts back up no problem after dying
Customer reply replied 5 months ago
May take a few minutes to see if there are any pending codes . The other thing I noticed is odometer is not lighting up for some reason it's off and on too
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Well something is sure being overlooked here. Can you keep it running if you give it some gas?

Ask Your Own Car Question
Customer reply replied 5 months ago
I let it run today for 40 minutes idle before I moved it and as soon as I shifted from drive to reverse it died
Customer reply replied 5 months ago
Before it would die just idling
Customer reply replied 5 months ago
No pending codes or any codes found
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Well this could be a problem with the IAC or even a dirty throttle body providing the fuel pressure is okay. Unfortunately with out having any fault codes to go on and not being there to do the testing I am running out of things to try. If you would like, I can open this back up for you and perhaps someone else may have something to add.

Ask Your Own Car Question
Customer reply replied 5 months ago
RPMs are low I think 620 at idle
Engine temp 186 degrees
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Normal temp on a 2003 with the 5.4 should be right at 192 degrees.

Ask Your Own Car Question
Customer reply replied 5 months ago
What about idle do you know?
It may not be warmed up completely yet I shut it off for a little bit
Customer reply replied 5 months ago
Ground problem common? Or ignition switch ?
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Idle speed is controlled by the IAC with the signal from the computer. Have you ever tried cleaning the throttle body and IAC?

Ask Your Own Car Question
Customer reply replied 5 months ago
I replaced IAC and when I changed TPS I bought can of throttle body cleaner and took it off and sprayed it and wiped it off
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Well I am out of idea from here. I can open this back up for you if you want and perhaps someone else has something to add.

Ask Your Own Car Question
Customer reply replied 5 months ago
Ok so they can get into chat?
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Yes if they have something to offer they can respond in this post.

Ask Your Own Car Question
Customer reply replied 5 months ago
Ok Thank you for your advice Sorry to ask so many questions but I want to get it running but I don't want to pay thousands of dollars at a dealership
Auto Mechanic: Ron, ASE Certified Technician replied 5 months ago

Okay opening it back up now for you.

Ask Your Own Car Question
Ask Ron Your Own Question
Ron
Ron
Ron, ASE Certified Technician
Category: Car
Satisfied Customers: 36,320
36,320 Satisfied Customers
Experience: ASE Certified Tech

Ron is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry.

Stephanie PElm City, NC

used your service this weekend with "Trecers" help. thank you ,thank you, thank you. replaced an A/C fan motor. Local Auto Zone had part. $15.00 "tracer" fee and $40.00 for parts, I saved several hundreds of dollers at a shop. i will recommend you and use you in the future.

David L.Richmond, TX

9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much.

PhilMarysville, CA

Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible.

CharlesWalnut Creek, CA

As a single woman, I really appreciate an excellent and affordable opinion.
Thank you Geordie, I will not hesitate to contact justanswer in the future!

SueCharleston, WV

Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, Frank...you do indeed know your stuff.

JimCastleberry, FL

The nearest Volvo dealer is 160 miles away. Best $15 bucks I have spent in a long time!

Paul MCorpus Christi, TX

< Previous | Next >

Meet the Experts:

Chris (aka-Moose)

Chris (aka-Moose)

Technician

1,212 satisfied customers

16 years of experience

Ted G.

Ted G.

ASE Certified Technician

1,708 satisfied customers

20 years auto repair experience, ASE Master Tech, Mechanical Failure consultant, Expert Witness

George H.

George H.

ASE Certified Technician

1,522 satisfied customers

ASE Master Tech 15+ yrs, AAS Automotive Technology, Factory trained Asian specialist

GM Tech (Cam)

GM Tech (Cam)

Auto Service Tech

669 satisfied customers

GM Grand Master Technician 2007. 14 years experience.

Amedee

Amedee

Former ASE Master Tech

2,505 satisfied customers

ASE certified tech advanced level specialist. Wisconsin certified emissions state inspector

Jerry

Jerry

Master Mechanic

2,181 satisfied customers

ASE master, 30+ years. All makes and models. Trouble shooter, shop forman, service manager

Richard

Richard

ASE Certified Technician

1,000 satisfied customers

12 years Ford Lincoln/Mercury Jaguar dealership as a technician and shop foreman reparing all makes

< Previous | Next >

Related Car Questions
Check engine light has been going on and off. 2009 VW
check engine light has been going on and off. 2009 VW convertible. Just put gas in it. Car turns over won't start now. Turns over normally. Plenty of fuel and oil level is good. … read more
David Craig
David Craig
OWNER/MECHANIC
Associates
3,921 satisfied customers
I have a 2013 Dodge Dart GT with a 6-speed manual
Hi, I have a 2013 Dodge Dart GT with a 6-speed manual transmission and the 2.4 liter engine. It came with 18-Inch x 7.5-Inch Hyper Black Aluminum rims and 225-40R18-92h XL--All Season Tires. I like th… read more
Gabriel Grey
Gabriel Grey
Master Service Technician
Associates
170 satisfied customers
Service stability system light comes on periodically. Brakes
Service stability system light comes on periodically. Brakes seem jerky at times and squealing noise when steering wheel is turned to the right … read more
sprinkles08
sprinkles08
Technician
High School or GED
11 satisfied customers
My 85 Ford Bronco headlight switch is bad, i already bought
My 85 Ford Bronco headlight switch is bad, i already bought the replacement and need to know how to R&R the old one. Do I need to take the dash apart? Please send step by step instructions as to the p… read more
Michael Solis
Michael Solis
243 satisfied customers
Service traction control lp comes on. Gmc 1500 2011. 1500
Abs light and service traction control symbol come on sometimes, when this happens it's like rear has no traction, slips? … read more
3pac2222
3pac2222
nissan master auto tech
Associate Degree
2 satisfied customers
Heating and cooling seats not working. What does that have
Heating and cooling seats not working JA: Have you checked the coolant level? Has there been any leaking from the hoses? Customer: What does that have to do with my seats? JA: What is the model/year o… read more
Todd M
Todd M
Owner
ASE Certification
1,283 satisfied customers
P0740 Code and Engine light on. That code I see it in the
that code I see it in the milleage counter when doing the ON/OFF 5 times and also with a scanner … read more
David Craig
David Craig
OWNER/MECHANIC
Associates
3,921 satisfied customers
Not charging new bat new alt looking for posabilities of
Not charging new bat new alt looking for posabilities of what else it could be … read more
Peter Bagley
Peter Bagley
master technition
Vocational, Technical or Trade School
900 satisfied customers
Where is the plug for a Polaris Slingshot diagnostic testing
Where is the plug for a Polaris Slingshot diagnostic testing unit? … read more
Gabriel Grey
Gabriel Grey
Master Service Technician
Associates
170 satisfied customers
We got two OBD II codes. P0700 I did reset it. We will see
P0700 I did reset it. We will see if it comes back, but we are feeling jumpy transmission now and then so I think something is wrong … read more
David Craig
David Craig
OWNER/MECHANIC
Associates
3,921 satisfied customers
While drving it caught on dire underneath the driver side I
While drving it caught on dire underneath the driver side I have MS and i cannot move fast. I don't know if it can be repaired. I don't feel safe in my truck. … read more
Toyota Service
Toyota Service
Toyota Dealership Service & CR Manager
1,344 satisfied customers
I just changed the plugs on 2004 CTS, put the plenum back
I just changed the plugs on 2004 CTS, put the plenum back down, hooked it all up carefully and it starts immediately but quits within about 2 seconds. double checked it all. … read more
David Craig
David Craig
OWNER/MECHANIC
Associates
3,921 satisfied customers
I have a 2006 Toyota Corolla 5 speed. I have had trouble in
I have a 2006 Toyota Corolla 5 speed. I have had trouble in the past of driving the car & it just shuts off. Dealer claimed they fixed it. Now car seems to want to do the same thing but keeps going & … read more
Toyotapro
Toyotapro
Technician
Vocational, Technical or Trade Scho
9,283 satisfied customers
Whenever i turn the steering wheel, i hear a
Second opinion] whenever i turn the steering wheel, i hear a whispering/scratching sound from the power steering. what must be the cause and remedy.… read more
Peter Bagley
Peter Bagley
master technition
Vocational, Technical or Trade School
900 satisfied customers
Alternator needs replacing. Looking for directions. It is a
Alternator needs replacing. Looking for directions … read more
ggrote1
ggrote1
Vocational, Technical or Trade Scho
13 satisfied customers
Not sure, just purchased an 1999 Suzuki Intruder 1400
Not sure, just purchased an 1999 Suzuki Intruder 1400 Motorcycle and was told the choke does not work properly. What might this entail to correct? … read more
TIM MOHR
TIM MOHR
SHOP OWNER
Master's Degree
8,037 satisfied customers
2007 ALTIMA won't start. It's as if I'm not stepping on the
2007 ALTIMA won't start. It's as if I'm not stepping on the brake but I am. … read more
vwtech0405
vwtech0405
VW Technician
Associate Degree
8,868 satisfied customers
Slow drip coming from underneath engine...didn't start until
slow drip coming from underneath engine...didn't start until I had to hit a ditch because of an idiot not paying attention...how do I find/fix leak?… read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x