SportShifters



Go Back   SEAT Cupra.net - SEAT Forum » Diagnostics, Tuning and Modification » Engine Discussion » TDi - SEAT Diesel specific topics

TDi - SEAT Diesel specific topics exclusively for SEAT diesel specific topics only.

Reply
 
Thread Tools Rate Thread Display Modes
Old 12-03-2017, 21:14   #1
Muttley
Catch that diesel!
 
Muttley's Avatar
 
Join Date: Mar 2006
Location: North Kent
Posts: 4,946
Muttley has far too many pointsMuttley has far too many pointsMuttley has far too many points
Altea TDI 140: spluttering, black smoke, disconnecting MAF fixes it. Turbo?

Been away from the forum for a long time. Redundancy, job searching and etc proved to take a lot of time and sap confidence, leaving me not in a good place. Now I have a problem and hope someone here can help.



Altea TDI 140 Sport, BKD engine, 130K miles. Good service history, no previous engine problems.

On the way home from the last of several recent visits to the North East from Kent, sorting out my newly-deceased father's estate, house and belongings (another story, maybe later) the car lost power, stuttering and putting out black smoke. Was able to get home (carried on for 100 miles or so) but all is not well.

Removing connection to MAF cures stuttering and black smoke. Without MAF connected, engine is down on power, struggles to reach 4000 rpm when under way, but is otherwise polite, does not choke following motorists.

Put it in to local independent VAG specialist. They say the MAF signals are good, but turbo actuator not holding vacuum. Diagnosis is 'turbo problem', but they (quite reasonably) don't rebuild turbos and the VAG fix for this car is 'replace turbo'. Not able to afford > £1K at this point.

Tried replacing turbo actuator (not a simple task) setting rod length to match the one we took out. Somewhat better response but still stutters and puts out black smoke. Removing MAF connection still has the same effect, stops the black smoke and reduces power output.

My hope is that someone here recognises the symptoms and ca either cofirm it is a turbo failure of some kind or can identify what else might be at issue. It's confounding me.

Will also post in Altea section, to try to catch all possible answers. Forgive me for double-posting this once?

Last edited by Muttley; 14-03-2017 at 01:48.
Muttley is offline   Reply With Quote
Old 13-03-2017, 20:23   #2
cheshire cat
Full Member
 
cheshire cat's Avatar
 
Join Date: Dec 2002
Location: cheshire
Posts: 1,758
cheshire cat has 10 points
I think I'd be looking at the egr /intake for leakage /clagging up
__________________
Nic
cheshire cat is offline   Reply With Quote
Old 14-03-2017, 01:47   #3
Muttley
Catch that diesel!
 
Muttley's Avatar
 
Join Date: Mar 2006
Location: North Kent
Posts: 4,946
Muttley has far too many pointsMuttley has far too many pointsMuttley has far too many points
Hiya Chesh. No audible boost pipe leakage. I cleaned the EGR, but that was a couple of years ago. It's just so odd that disconnecting the MAF cures the problem, and I was hoping someone else may have had the same symptoms. I've changed the thread title to make that a bit clearer.

Last edited by Muttley; 14-03-2017 at 01:48.
Muttley is offline   Reply With Quote
Old 15-03-2017, 14:33   #4
Muttley
Catch that diesel!
 
Muttley's Avatar
 
Join Date: Mar 2006
Location: North Kent
Posts: 4,946
Muttley has far too many pointsMuttley has far too many pointsMuttley has far too many points
Update: A second investigation by a local garage/service center/whathaveyou has found a hole in the intercooler. This would fit the symptoms pretty well - when the turbo goes you usually know all about it. So, fingers crossed that that is all it is. Will soon know. No idea how my usual mechanics-of-choice missed this.
Muttley is offline   Reply With Quote
Old 15-03-2017, 14:35   #5
Dan FR
Meth addict. Stage 2+ Yo!
 
Dan FR's Avatar
 
Join Date: Nov 2013
Location: Caerdydd
Posts: 1,825
Dan FR has 60 points
It'll be the intercooler - loosing all of your metered air that the ECU has accounted & fuelled for. Stay away from first mechanic in future
__________________

VCDS, MPPS, VAG Commander, Tacho & Revo SPS - South Wales. Logging, Coding, Immo/SKC, Autowindows, Diagnostics etc. 1.9 TDI PD - Mapping, Launch Control,Rev limiters etc.
Dan FR is offline   Reply With Quote
Old 15-03-2017, 18:06   #6
cheshire cat
Full Member
 
cheshire cat's Avatar
 
Join Date: Dec 2002
Location: cheshire
Posts: 1,758
cheshire cat has 10 points
great :-) old DUMB pressure /boost guages are worth their weight in gold
__________________
Nic
cheshire cat is offline   Reply With Quote
Old 20-03-2017, 16:29   #7
Muttley
Catch that diesel!
 
Muttley's Avatar
 
Join Date: Mar 2006
Location: North Kent
Posts: 4,946
Muttley has far too many pointsMuttley has far too many pointsMuttley has far too many points
Intercooler replaced and new seals all round. No smoke, no stuttering, boost is back to what I expect. Have hit limp mode a couple of times. I suspect the turbo and maybe the cat are a bit sooty, I will try to get the turbo nice and hot and see if it improves things.
Muttley is offline   Reply With Quote
Old 20-03-2017, 19:53   #8
cheshire cat
Full Member
 
cheshire cat's Avatar
 
Join Date: Dec 2002
Location: cheshire
Posts: 1,758
cheshire cat has 10 points
great stuff now for an Italian tune up :-)
__________________
Nic
cheshire cat is offline   Reply With Quote
Old 03-04-2017, 19:36   #9
Muttley
Catch that diesel!
 
Muttley's Avatar
 
Join Date: Mar 2006
Location: North Kent
Posts: 4,946
Muttley has far too many pointsMuttley has far too many pointsMuttley has far too many points
Some further remedial work needed, so I took it back to the guys who diagnosed and replaced the intercooler: it turns out that when we replaced the actuator, we set the rod length by counting threads, and did not notice that the rods themselves were of different lengths... Embarrassing error, and it accounts for the overboost in no uncertain terms.

Rod reset to correct length (by comparing it with the original, which we still had), and a little tuning done to match boost demand to boost delivered.

My goodness, what a difference. Not only am I now a good citizen, leaving no black sooty trails, the power delivery is better than it was before the work, and the fuel economy is notably better too, on short runs something like 5mpg better. Not done a long run yet, but it all looks very good.

So, probably two faults, the leaky actuator (which may be due to age, or the strain of dealing with the holed intercooler, or both) and the intercooler itself. What seems to have happened there is that one of the square-section tubes has failed along one edge, which is where they are weakest of course. I suppose that they flex a little when containing boost.

So all is well again. Except now I have to investigate why the mirrors have stopped working. I suspect the switch, but it's not a simple matter to get the console off so I can have a look at it. And its not just a simple set of contacts, no, there's resistors in there too. Never a dull moment.
Muttley is offline   Reply With Quote
Old 03-04-2017, 21:11   #10
cheshire cat
Full Member
 
cheshire cat's Avatar
 
Join Date: Dec 2002
Location: cheshire
Posts: 1,758
cheshire cat has 10 points
moral of the tale "Never throw anything away" never know when it "comes in" :-)
__________________
Nic
cheshire cat is offline   Reply With Quote
Reply

Bookmarks

« Previous Thread | Next Thread »

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 

(View-All Members who have read this thread : 15
Altea, boxer1968, buckshot, cheshire cat, Dan FR, Fishy, Greegiecee, imikk3, lew893, Muttley, paradyne, propane94, Speed-FReek, SwinDan, vagman2001
Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 23:17.




Website © 2014 SEATCupra.net

Disclaimer: SEATCupra.net is not an official SEAT site and is not affiliated to SEAT in any way. Visit the Official SEAT Website.

SEATCupra.net are not directly responsible for information which maybe posted in this forum.
All content is viewed and used at your own risk. We do not warrant the accuracy or reliability of any of the information.
The views expressed herein are those of the individual contributors and not necessarily those of SEATCupra.net or SEAT
All trademarks and copyrights remain property of their respective owners.