Badger5Sky Insurance
Results 1 to 11 of 11
  1. #1
    filipharvey's Avatar
    Amusing Tagline

    Status
    Offline
    Join Date
    Aug 2006
    Location
    Fakenham, Norfolk
    Posts
    518

    SEAT Altea Hot Starting Issues

    I have here a SEAT Altea that has been to many different places to try and sort this problem, including both SEAT and VW main dealers and specialists. It even spent 3 weeks and an engineering college!

    It will start first time every time when cold. But after it has been run and left for a while, on the first turn of the key the engine turns but fails to fire.

    The original codes stored in the ECU showed P0171 [Fuel Trim Too Lean] (present and intermittent) along with P2626 [O2 Sensor Pumping Current Trim]. Both of these point to a faulty lambda or MAF reading, however these were shown to be functioning correctly under test. They have also not shown up again during the 5 days I have had the car.
    The coolant temperature sensor was then replaced as a matter of course, due to this being a regular failure of VAG models and widely attributed to the symptoms of this vehicle.

    Since that time, the vehicle has been tested on several cold to hot runs, both static and mobile.
    The starting issue arose again on a few occasions. On each of these occasions the coolant temperature was indicated to the ECU at 66°c. This seemed about right, but it just seems strange that it was the same temperature reported each time.

    During further testing, the vehicle was found to have a misfire on 2 cylinders, although this was not a fault reported to the ECU. This was shown on cylinder 1 and more predominantly on cylinder two.

    Full sensor, switch and relay diagnostics have been carried out, and appear to be working.
    The EVAP control valve has been removed, checked for leaks and retested.


    On one particular scan, the CAN network reported a break in communication to the engine ECU that hadn't shown up before. It was also noted that this fault had been reset 22 times previously.
    This fault may however not be related to the starting issues, and has not shown up when testing the car during fault conditions.

    Any ideas? Anyone?
    Last edited by filipharvey; 12th May 2012 at 18:14.
    Audi A6 1.8T Avant



    Alfa 156 3.0 V6 Veloce


  2. # ADS
    ADS
    Join Date
    Always
    Location
    Global
    Posts
    Many
     
  3. #2
    Viking's Avatar
    1st Gear

    Status
    Offline
    Join Date
    Mar 2010
    Posts
    217
    Have you changed the battery?

  4. #3
    filipharvey's Avatar
    Amusing Tagline

    Status
    Offline
    Join Date
    Aug 2006
    Location
    Fakenham, Norfolk
    Posts
    518
    I'm not sure when the battery was last changed. I shall enquire!
    The crank seems to be strong though, and will turn over at a decent speed for as long as I dare to try when it won't start.
    Audi A6 1.8T Avant



    Alfa 156 3.0 V6 Veloce


  5. #4
    Neutral

    Status
    Offline
    Join Date
    Mar 2012
    Posts
    67
    If you disconnect the temp sensor will it start straight away?? That's a sure sign the starter's on its way out!

  6. #5
    Neutral

    Status
    Offline
    Join Date
    Dec 2011
    Location
    Basingstoke
    Posts
    84
    This, and the starter motor.

    When the engine is hot, it has to turn over faster than a certain speed before the ECU will inject fuel.

  7. #6
    Viking's Avatar
    1st Gear

    Status
    Offline
    Join Date
    Mar 2010
    Posts
    217
    I'm not sure if I'm being helpful here or not, as my Altea had the same problem but was a 2.0ltr TDI while I think from your post yours is a petrol? It's not an Altea specific problem.

    On mine the engine needs a minimum crank speed for the ecu to enable fuel injection. From memory the speed is 280rpm. If the battery is getting old then it doesn't hold charge as well, and when in use it drops charge slightly and can't deliver the correct engine speed. Given time to recover it can then spin the engine over fast enough for the ecu to see the correct rpm, and this isn't an engine temperature issue, more like time for the battery to recover.

    If the battery change doesn't solve it, and the engine speed is still below 280rpm when hot then the starter is probably faulty and should be replaced.

    Engine crank speed can be measured in VCDS somewhere (again, my memory fails me) and this will tell you if you're looking in the right direction.

  8. #7
    filipharvey's Avatar
    Amusing Tagline

    Status
    Offline
    Join Date
    Aug 2006
    Location
    Fakenham, Norfolk
    Posts
    518
    Quote Originally Posted by J0N35Y View Post
    If you disconnect the temp sensor will it start straight away?? That's a sure sign the starter's on its way out!
    That is not really something I can easily test, as it is only with the first turn of the key that it happens.
    That pointed me to immobiliser issues, but everything checks out as it should there, so I'm at a loss.

    I should point out that this isn't my car and that it has been doing this for over two years, so degrading sensors and battery don't really make any sense.
    The battery whilst obvious, doesn't seem plausible, as it will start when hot (around 70+) and also cold. Not only that, but when this happens, it is literally: turn the key off, turn it on again and it fires. If the battery wasn't strong enough on the first attempt, then it is electrically impossible for it to have more power to enable a faster crank speed on the second turn of the key, surely? - And why 66°c?

    The battery showed just under 14v whilst running, although I haven't tested it without running.
    Audi A6 1.8T Avant



    Alfa 156 3.0 V6 Veloce


  9. #8
    Neutral

    Status
    Offline
    Join Date
    Mar 2012
    Posts
    67
    Trust me, try it!!

  10. #9
    filipharvey's Avatar
    Amusing Tagline

    Status
    Offline
    Join Date
    Aug 2006
    Location
    Fakenham, Norfolk
    Posts
    518
    I can't believe that a starter motor that was on it's way out over two years ago would still work today.
    I've tested the crank speed whilst it won't start and it is around 320rpm, so I think we can discount the starter motor anyway.
    Audi A6 1.8T Avant



    Alfa 156 3.0 V6 Veloce


  11. #10
    Viking's Avatar
    1st Gear

    Status
    Offline
    Join Date
    Mar 2010
    Posts
    217
    Can you tell us exactly what engine this is please, and age of the car (in case I missed it).

  12. #11
    filipharvey's Avatar
    Amusing Tagline

    Status
    Offline
    Join Date
    Aug 2006
    Location
    Fakenham, Norfolk
    Posts
    518
    Sorry, it is a 2004 Seat Altea 1.6 (BGU) - 54,000 miles.
    Audi A6 1.8T Avant



    Alfa 156 3.0 V6 Veloce


 

 

Similar Threads

  1. Forum/advice for Seat Altea
    By pi quattro in forum General Chat
    Replies: 3
    Last Post: 8th August 2011, 23:43
  2. Starting issues 2.8 v6
    By Foxmeister in forum A4/S4 forum(B5 Chassis)
    Replies: 4
    Last Post: 18th December 2010, 11:45
  3. A3 starting issues
    By JustCharlie in forum A3/S3 Forum (8L Chassis)
    Replies: 1
    Last Post: 24th April 2009, 10:36
  4. Will Seat Altea Coilovers fit my 8P?
    By Red Head in forum A3/S3/Sportback (8P Chassis)
    Replies: 5
    Last Post: 28th January 2008, 21:03
  5. Will Seat Altea coilovers fit my 8P A3?
    By Red Head in forum Handling
    Replies: 0
    Last Post: 24th January 2008, 20:53

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Single Sign On provided by vBSSO

Garage Plus, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.

Content Relevant URLs by vBSEO