Discovery TDI smoke and power loss
Keith
London, UK. The Disco is not used a lot these days but is NOT used for
short stop/start around town journeys; it's mainly for longer trips. It
has only 78K miles on the clock, has been serviced regularly from new
and has done about 2000 miles since the last service in April.
The other day, the day after a trip to Norfolk from London, I noticed
some black smoke when pressing the throttle fairly hard at slow speed.
Power also seemed a little down when accelerating at higher speed. The
smoke seemed to get more frequent as the day went on but otherwise the
car seemed OK.
Next day I set off back to London, about 130 miles away. I kept the revs
low at 2200-2500, and speed lowish at 40-50 mph in 4th. Everything
seemed OK at first but after maybe 30 miles power was seriously reduced
and there was black smoke when only slight extra throttle was applied.
After a while I had to increase the revs to 3000 plus and drop down to
3rd or 2nd when going up even a slight hill. If I dropped the revs the
engine laboured.
This went on for maybe another 40 miles with speed between 25 and 45
mph. If I gave the engine any extra throttle I got black smoke.
Performance seemed to get better when I got to continuous dual
carriageway and did not heve to keep slowing for roundabouts and
junctions and I was able to use 4th gear at 2800-3000 rpm. By the time I
hit the M11 motorway I was up to 60 mph and down the M11 I could even
use 5th and go over 75 mph. After I left the M11 the car seemed more
normal but still seemed down on power with a little black smoke when the
throttle was pressed hard. I got the few miles home from the motorway
without difficulty.
Before I take the Disco in to my local independent LandRover garage has
anyone any ideas what might be the cause of this?
Jeff
Had a very similar problem due to an air leak into the fuel line.
Jeff
"Keith" <notin...@live.co.uk> wrote in message
news:h6bs36$2o3b$1...@adenine.netfront.net...
Keith
> Had a very similar problem due to an air leak into the fuel line.
>
> Jeff
>
>
> "Keith" <notin...@live.co.uk> wrote in message
> news:h6bs36$2o3b$1...@adenine.netfront.net...
How did you spot the leak?
Jeff
Spotted fuel dripping from the sedimenter drain plug.
What was happening was at low revs air was being sucked in and because there
was not a high fuel flow the air/fuel mix was quite high, but at high revs
there was a greater fuel flow so proportionally not so much air. That is why
things seemed better at high revs.
Jeff
Keith
But my symptoms seem a bit different to yours. I wondered if it was air
starvation of some sort as black smoke usually means too little air or
too much fuel.
Keith
EMB
>
> Before I take the Disco in to my local independent LandRover garage has
> anyone any ideas what might be the cause of this?
A collapsed air filter, a split or collapsing intercooler hose (with one
collapsing internally the most likely), or possibly a blocked intercooler.
Paul - xxx
That's what I'd check first, the intercooler hoses, they're known to
collapse after de-lamination inside (mine did it).
I'd also check the injector leak-off pipes, they perish and split
letting air in, easy replacement .. but they normally only produce hard
to start engines and lumpy all over running.
--
Paul - xxx
'96/'97 Landrover Discovery 300 Tdi
Dyna Tech Cro-Mo comp
Keith
>
> A collapsed air filter, a split or collapsing intercooler hose (with one
> collapsing internally the most likely), or possibly a blocked intercooler.
I'll check the hoses for splits today. Thanks.
--
Keith
1997 Landrover Discovery 300 Tdi
2003 Triumph Trophy BBBB
2002 BMW C1
EMB
> EMB wrote:
>>
>> A collapsed air filter, a split or collapsing intercooler hose (with
>> one collapsing internally the most likely), or possibly a blocked
>> intercooler.
>
>
> I'll check the hoses for splits today. Thanks.
>
Kev Ellis
I had a similar problem with my 1995 300tdi Disco, though not quite as
bad as your sounds.
My problem was with the EGR valve. I fixed this by fitting a blanking
plate (much cheaper than a new EGR valve, and I'm not sure of the merits
of putting exhaust gas back through the engine anyway). After blanking
off the EGR power was restored and no more smoke.
Just search you favourite online auction site. The plates only cost a
few quid and might just fix your problem. I think main dealers also sell
them.
Kev.
Dave Baxter
says...
> Hi Keith,
>
> I had a similar problem with my 1995 300tdi Disco, though not quite as
> bad as your sounds.
> My problem was with the EGR valve. I fixed this by fitting a blanking
> plate (much cheaper than a new EGR valve, and I'm not sure of the merits
> of putting exhaust gas back through the engine anyway).
At low engine loads/speeds, it reduces the Oxygen content in the inlet
air, so reducing NOX emissions.
Them that cause SMOG in the unlikly event we get enough LA type
sunshine...
Regards.
Dave B.
GbH
"Dave Baxter" <g8...@nospam.uko2.co.uk> wrote in message
news:MPG.24fc7c121...@freenews.netfront.net...
Does tend to make one wonder at the point of using an intercooler if
you're going to shove red hot exhaust into your cooled air?
--
Wisdom and experience come with age, they say, but I wish I could
remember the darn question
Dave Baxter
Geoff_Ha...@IEE.ORGasm says...
>
> Does tend to make one wonder at the point of using an intercooler if
> you're going to shove red hot exhaust into your cooled air?
The Intercooler is only realy of any benefit, when the engine is working
hard, like when the Turbo is doing it's full job, and the compressed
"Boost" air will be hot. Cooling it makes it more dense, and therefore
more O2 to burn more fuel with = more power. At least, that's the idea
and we all know that...
At light loads such as idle and overun (such as deceleration, going down
a hill with your foot off the throttle) the turbo will be doing next to
nothing, also the exhaust gasses will be very very much cooler too, so
the EGR, as earlier, recirculates some waste gasses into the inlet to
reduce the O2 content of the air therefore reducing Oxides of Nitrogen
production, at a time when the Turbo and Intercooler will not be doing
much if anything.
It's an anti polution control, as even on overun, the engine is still
producing polutants purely due to the temperatures created by the
compression part of the cycle, even though no "fuel" is being used.
If you look at such an equipped vehicle, the EGR gas feed to the inlet
is directly into (or very close to) the inlet manifold, after the
intercooler. It should not be recirculating anything when you are
working the engine hard. It's also often "blown backwards" into the
airstream to promote good mixing.
Removing or disabling the EGR will not bring about any remarkable
performance increase, if it was working correctly. But on later
vehicles where the ECU can sense the actual valve position, it can
sometimes (ECU software dependent) cause a warning light to show.
Regards.
Dave B.
Dave Liquorice
> Removing or disabling the EGR will not bring about any remarkable
> performance increase, if it was working correctly.
Not a "remarkable preformance increase" on a TD5 with EGR valve and
EGR throttle but enough to be noticeable and give you a couple of
more MPG.
On my TD5 I've settled on EGR valve connected but EGR throttle
disconnected. With the throttle connected it really is rather
sluggish until you get the revs well above 1500 and you don't feel
the turbo start to kick in either.
> But on later vehicles where the ECU can sense the actual valve position,
> it can sometimes (ECU software dependent) cause a warning light to show.
Not on a TD5. There is no positional feedback from either the vacuum
solenoids or the valve/throttle themselves.
In general terms and on other marques maybe...
--
Cheers
Dave.
Dave Baxter
allsortsn...@howhill.com says...
A local farmer friend who had a TD5 90, said he had no noticable
difference with it connected or not (he had to try to save fuel) as he
regularly pulls a livestock trailer about, and being a "gentleman of the
earth", if its economy (such as it is) was badly affected, it'd be back
at the dealer all too quick.. Mind you, he's not exactly a quick or
enthusiastic driver.
He's since sold the 90 at 3 years old with gearbox problems, and now
uses an old Toyota pickup (more rust than body!) to pull the livestock
box. He does say it has some "interesting" handling features when the
trailer is heavy, but it uses much less fuel than the 90 did, and is
more comfortable he said at the time. (Similar model as the TG lads
tried to destroy.) I have no idea if it has an EGR, or if it has, if
he's tried to fiddle...
I had an intermittently sticky EGR on a works car a while back, that did
adversly affect the economy (and smoke generation!) but the performance
(such as it was) was not that badly affected, at least at legal road
speeds.
That was a Passat with the 1.9 4 pot common rail lump. It developed an
intermittent "Engine Warning" light at about a year old, sometimes it
would come on at idle, sometimes when driving, sometimes not for a few
days. I figured out eventualy, that 250 smokey miles a tank was not
good when that light comes on, when it could do nearly 500 a tank if the
light never lit. Still took the dealer three attempts to find it, and
another week to get the replacment part. I should have learnt after the
saga with the alarm system, not to take it to them...
Since then, all the works cars have been Japanese. Supurb reliablility
it has to be said. (OK, so they are made in the UK, but are not of UK
design.)
My LR hybrid has an early X Disco 200TDi, so no such potential failure
thankfully. The only "High Tech" item on that, is probably the
alternator voltage regulator.
In truth, there are many things that can cause a Turbo Diesel to loose
power and/or smoke. Methodical diagnosis is needed, rather than jumping
to conclusions as I'm sure you agree. Some common symptoms (excessive
smoke being one) can be caused by all sorts of bad (often expensive)
things, or something as simple and easy to fix as a clogged filter.
Yes, EGR's can stick open. But with the 100's of 1000's of TD cars and
vans about, there seem to be relatively few EGR failures, compared to
the number of knackered turbos, blown head gaskets, melted pistons and
snapped timing belts, that keep a mate and his pal's employed full time.
Cheers.
Dave B.
Keith
> Hi Keith,
>
> I had a similar problem with my 1995 300tdi Disco, though not quite as
> bad as your sounds.
> My problem was with the EGR valve. I fixed this by fitting a blanking
> plate (much cheaper than a new EGR valve, and I'm not sure of the merits
> of putting exhaust gas back through the engine anyway). After blanking
> off the EGR power was restored and no more smoke.
> Just search you favourite online auction site. The plates only cost a
> few quid and might just fix your problem. I think main dealers also sell
> them.
>
> Kev.
>
My mechanic took the hoses off and there were no splits, delaminations
or blockages. Checked the EGR valve and it was OK. The air filter looked
a bit dirty so it was replaced. Everything was put back together and the
problem seems to have gone. The whole process took an hour of his time.
So either the problem has been fixed by the old method of take it apart
and put it back together or it was the air filter (which did not seem
paticularly bad).
Austin Shackles
<no-spam...@home.com> enlightened us thusly:
>Hi Keith,
>
>I had a similar problem with my 1995 300tdi Disco, though not quite as
>bad as your sounds.
>My problem was with the EGR valve. I fixed this by fitting a blanking
>plate (much cheaper than a new EGR valve, and I'm not sure of the merits
>of putting exhaust gas back through the engine anyway). After blanking
>off the EGR power was restored and no more smoke.
>Just search you favourite online auction site. The plates only cost a
>few quid and might just fix your problem. I think main dealers also sell
>them.
You can use a 2p piece in the pipe joint to blank the EGR...
--
Austin Shackles. www.ddol-las.net my opinions are just that
Travel The Galaxy! Meet Fascinating Life Forms...
------------------------------------------------\
>> http://www.schlockmercenary.com/ << \ ...and Kill them.
a webcartoon by Howard Tayler; I like it, maybe you will too!
Keith
I spoke too soon. The bugger has got the same symptoms again. So not the
hoses, not the air filter. EGR valve intermittently dicky?
Dave Baxter
says...
Have you got a boost gauge, or old vacuum gauge you can temporaraly fit?
Plumb it into the inlet manifold. If you get "Vaccuum" There is a
blockage, end of story. The only time I've 'Ever' seen any Vaccuum on
the idiot gauge I've got on my 200TDi (there was a spare hole in the
dash) was when I forgot to take a rag out of the air filter when putting
it back. Trying to start it, it would catch instantly, the gauge went
full -ve (1 bar vaccuum!) and with lots of smoke, it stopped...
The rag was sucked right down into the turbo! It all came out OK, no
damage to anything (not even the rag!) other than to my pride...
That was after replacing the timing belt. All sorts of horible things
were being thought about, but a sleep and beer (or was it beer and
sleep?) and logical thinking figured it out.
Regards.
Dave B.
Keith
> Plumb it into the inlet manifold. If you get "Vaccuum" There is a
> blockage, end of story. The only time I've 'Ever' seen any Vaccuum on
> the idiot gauge I've got on my 200TDi (there was a spare hole in the
> dash) was when I forgot to take a rag out of the air filter when putting
> it back. Trying to start it, it would catch instantly, the gauge went
> full -ve (1 bar vaccuum!) and with lots of smoke, it stopped...
>
> The rag was sucked right down into the turbo! It all came out OK, no
> damage to anything (not even the rag!) other than to my pride...
>
> That was after replacing the timing belt. All sorts of horible things
> were being thought about, but a sleep and beer (or was it beer and
> sleep?) and logical thinking figured it out.
>
> Regards.
>
> Dave B.
No blockage. Maybe it's an intermittently stuck EGR valve. We've fitted
a blanking plate to stop the EGR. It was OK afterwards, but it was last
time too, so I'll see what happens now.
Do you know if the lack of EGR valve affects the MOT particle emission test?
Austin Shackles
enlightened us thusly:
yes and no.
yes I know, no it doesn't.
Keith Wilknson
> On or around Thu, 10 Sep 2009 20:50:31 +0100, Keith <notin...@live.co.uk>
> enlightened us thusly:
>
>>
>
> yes and no.
>
> yes I know, no it doesn't.
Many thanks. I'll leave the blanking plate in place then.