Nissan

Nissan Repair Questions? Ask a Mechanic for Answers ASAP

Ask an Expert,
Get an Answer ASAP!

Nissan

HJave A 3.0 V6 pathfinder 1987 Auto Trans. Runs okay When

Customer Question
hi HJave A 3.0 V6...
hi HJave A 3.0 V6 pathfinder 1987 Auto Trans. Runs okay When @3500rpm It Down shifts to lower gear And goes to 4000rpm?Bad on Gas Milage.what to do?
JA: Are you fixing your Pathfinder yourself? What have you tried so far?
Customer: Had a lot of work done on it new sensors Injectors runs fine except down shift to lower gear?
JA: Which particular sensor are you asking about? And have any trouble codes been triggered?
Customer: replaced all @trottle body The issue is the trans 3speed auto downshifting to lower gear @55miles an hour?
JA: Anything else you want the mechanic to know before I connect you?
Customer: no
Submitted: 1 year ago.Category: Nissan
Show More
Show Less
Ask Your Own Nissan Question
Answered in 45 minutes by:
10/8/2016
Nissan Mechanic: Matt, Engineer replied 1 year ago
Matt
Matt, Engineer
Category: Nissan
Satisfied Customers: 22,472
Experience: BEng hons Mech engineering, worked in auto industry for 22 years on engine, transmission and suspension design
Verified

Hello

This could be an airleak after the airflow meter, any air dragged in here isn't 'seen' by the ECU and so not compensated for and can lean the engine out and can also allow the engine to rev up when not desired causing rough running.

as the MAF output is the load input into the ECU then any issues with it can effect the transmission control

As its a mechanical fault it tends not to turn on the fault light and you can sometimes hear a 'hissing' noise with the engine running.

Check the hose clips for tightness and inspect the trunking for any cracks or splits and also all the vacuum system, the small bore pipes and fittings for cracks and missing parts.

The best way to locate a leak is to have the engine running and warm and then spray lighter gas /propane or brake cleaner around each joint in turn. If the engine rev's up you've found your leak.

Now you might think that spraying lighter gas around a hot engine isn’t wise, however the flash /ignition point of gas is about 400°C so you need a naked flame or spark to set it off and I’ve used this method for many years without incident.

Work your way through each possible joint one at a time and you should find it. I use a slightly flattened piece of brake pipe and some rubber hose from the can of lighter gas to provide a spraying 'wand' and allow a direct blast of gas into each area, especially those difficult to reach with large implements.

It’s also worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a poorly pump will all result in insufficient fuel being delivered to the engine

Might also be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can do a quick fault find if you unplug the meter and run the engine without it.

if the engine condition is the same then chances are the meter or the connection to it is faulty

It’s also worth cleaning the MAF sensor wires, as they can get coated with dirt over time which then offsets the reading

Use some contact cleaner or brake cleaner to spray onto the wires to remove the dirt – on no account touch the wires with anything as they are very fragile

Ask Your Own Nissan Question
Customer reply replied 1 year ago
Thanks
Nissan Mechanic: Matt, Engineer replied 1 year ago

Glad to help

Bear in mind that the site takes a deposit from you at the beginning and this is held by the site until you rate my answer at which point the cash is split between the site and the expert. I am only paid for my work on this question if you rate my answer, using the star system at the top of the screen. Please do not forget! Thank you

Ask Your Own Nissan Question
Ask Matt Your Own Question
Matt
Matt
Matt, Engineer
Category: Nissan
Satisfied Customers: 22,472
22,472 Satisfied Customers
Experience: BEng hons Mech engineering, worked in auto industry for 22 years on engine, transmission and suspension design

Matt 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 was in trouble with an electrical issue with my brand new Nissan. I frantically went online trying to find help and luckily I found your site. I reached a NISSAN tech named RIP. He was absolutely tremendous and helped me work through the issue. What a pro!

cjazLexington, KY

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

< Previous | Next >

Meet the Experts:

Chris(aka-Moose)

Chris(aka-Moose)

Nissan Technician

664 satisfied customers

16 years of experience

Tim Mohr

Tim Mohr

ASE MASTER TECH

584 satisfied customers

30 YRS EXPERIENCE, FOREIGN AND DOMESTIC, GAS AND DEISEL

Marty

Marty

ASE Certified Technician

152 satisfied customers

ASE & Bosch master tech. 30 years experience.

Mike V.

Mike V.

Nissan Technician

9,332 satisfied customers

Nissan factory trained and Certified Subaru Technician.

Ron

Ron

ASE Certified Technician

555 satisfied customers

34 years of automotive Repair

Anthony

Anthony

ASE Certified Technician

332 satisfied customers

ASE Master Automobile Technician with over 18 years exp. in this field.

Richard

Richard

ASE Certified Technician

92 satisfied customers

Nissan Tech ASE certified technician

< Previous | Next >

Related Nissan Questions
I have a 2006 Pathfinder that the front passenger door will
I have a 2006 Pathfinder that the front passenger door will not open from the inside or outside handles, it is stuck closed. I've tried unlocking it manually, with the key fob, and int. switch; but no… read more
FixUrNissan
FixUrNissan
Shop Forman / Lead Tech / Parent
Vocational, Technical or Trade Scho
1 satisfied customers
2008 Pathfinder ... Cranks, won't always start. Good
2008 Pathfinder ... Cranks, won't always start. Good battery, newer starter, new ignition switch, replaced IPDM board, new relay ... Kind of sputters when does start, then runs great. … read more
Jake
Jake
Vocational, Technical or Trade Scho
292 satisfied customers
2005 nissan pathfinder will not start on cold days (below
2005 nissan pathfinder will not start on cold days (below 20F) … read more
David Craig
David Craig
OWNER/MECHANIC
Associates
4,420 satisfied customers
2015 pathfinder radiator cooling fan not running.... Relay
2015 pathfinder radiator cooling fan not running.... … read more
Todd M
Todd M
Owner
ASE Certification
1,487 satisfied customers
04 Pathfinder daytime running lights...left side very dim.
04 Pathfinder daytime running lights...left side very dim … read more
Marty
Marty
ASE Certified Technician
Associate Degree
152 satisfied customers
My daughters 2001 Pathfinder has a new battery and will not
My daughters 2001 Pathfinder has a new battery and will not start - I am thinking a Starter Relay, but cannot find a replacement part number. … read more
Jake
Jake
Vocational, Technical or Trade Scho
292 satisfied customers
The lift gate will not open. 2016 pathfinder. Tried nothing.
tried nothing. hope it is an easy fix that i am overlooking it won't open manually or with the switch … read more
heavy_chevy_396
heavy_chevy_396
Vocational, Technical or Trade Scho
2,518 satisfied customers
My Nissan Pathfinder was working perfectly fine and then all
My Nissan Pathfinder was working perfectly fine and then all of a sudden the ABS light went on, along with the hazard light, 4WD light and also my speedometer stopped moving. All at once … read more
Stephen, MBA
Stephen, MBA
Master's Degree
166 satisfied customers
I have a 2008 Nissan pathfinder with a intermitted problem
I have a 2008 Nissan pathfinder with a intermitted problem vehicle at time doesn't turn I have to wait like 15 min and then the vehicle turn on. I replaced the starter and immobilizer and had the anti… read more
Jake
Jake
Vocational, Technical or Trade Scho
292 satisfied customers
2002 Nissan Pathfinder - the shifter will not lock in
2002 Nissan Pathfinder - the shifter will not lock in Park... the shifter can be moved into reverse without depressing the shift lock button on the shifter column handle. … read more
3pac2222
3pac2222
nissan master auto tech
Associate Degree
2 satisfied customers
2007 Nissan Pathfinder. Had transmission and radiator and
2007 Nissan Pathfinder. Had transmission and radiator and hoses replaced less than 10K miles ago due to the Nissan issue with coolant leaking into the transmission. Now my coolant is yellow paste agai… read more
3pac2222
3pac2222
nissan master auto tech
Associate Degree
2 satisfied customers
2006 Nissan Pathfinder. Engine Cranks, but sometimes wont
2006 Nissan Pathfinder. Engine Cranks, but sometimes wont start. When sitting in the vehicle, I use the key fob to lock the doors (doors lock and horn beeps). I try starting again, and the engine fire… read more
David Craig
David Craig
OWNER/MECHANIC
Associates
4,420 satisfied customers
2008 Nissan Pathfinder, radio and navigation screen stay on
2008 Nissan Pathfinder, radio and navigation screen stay on after the car is turned off and key is removed. How do I trouble shoot this? … read more
Chris(aka-Moose)
Chris(aka-Moose)
Nissan Technician
Vocational, Technical or Trade School
664 satisfied customers
I have a 97 pathfinder the brake line broke I repaired the
I have a 97 pathfinder the brake line broke I repaired the line and replaced the master cylinder but I can't get the brakes to bleed… read more
FixUrNissan
FixUrNissan
Shop Forman / Lead Tech / Parent
Vocational, Technical or Trade Scho
1 satisfied customers
My fiancé's 2006 Nissan pathfinder started squeeling and
my fiancé's 2006 Nissan pathfinder started squeeling and limping while it was driven. The mechanic said it was the left front wheel bearing, hub bering, ball joint upper and bottom and outer ty rob en… read more
roy
roy
Associate Degree
3 satisfied customers
96 Nissan Pathfinder. Airbag Light on dash is blinking.
39;96 Nissan Pathfinder. Airbag Light on dash is blinking. Cannot find anything in manuals of what to check or how to reset. … read more
FixUrNissan
FixUrNissan
Shop Forman / Lead Tech / Parent
Vocational, Technical or Trade Scho
1 satisfied customers
2006 Nissan Pathfinder ABS code C1101 and C1103 ABS,Brake
2006 Nissan Pathfinder ABS code C1101 and C1103 ABS,Brake light, VDC and slip light on No spedo Did contunity test on the ,rear ABS power and signal wires, as well as grounds all the wires checked out… read more
Gunvir Singh
Gunvir Singh
1,817 satisfied customers
When I hit a bump in my 2010 pathfinder 4wd - the brake
When I hit a bump in my 2010 pathfinder 4wd - the brake pedal shakes ? … read more
FixUrNissan
FixUrNissan
Shop Forman / Lead Tech / Parent
Vocational, Technical or Trade Scho
1 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