TD4 smoke @~2000rpm (low speed)

Hi all. New poster but lurker for a while. Need advice to nail something.

My 'Landy' ('04 Freelander Sport TD4) does an odd thing intermittently. And it's almost repeatable.

Usually, if I'm trundling, I'll notice grey (not black/white) smoke wisping from the exhaust. If I continue to hold the engine steady, which is usually ~2000rpm , 3rd gear, 30mph, the smoke gets worse until it's chuffing out.

Now if I rag the revs, it goes. Give it a blast where I can open it up, it runs clean, for the remainder of the trip, even when I come back to 30 zones and forced to trundle.

Last week it did it in 2nd gear, at 2k rpm. It was after first night's rain after several days of sun. I wonder if the moisture is a contributory factor? Also it's never done it in 4th or higher so air flow related also.

Yesterday I thought I had perfect conditions but could get it to repeat.

IT'S NOT . . .
- MAF sensor. That was what other faults on here said, so went for that first. No change.
- Injectors. Got them tested for re-tipping. 3 were condemmed, with 4th on last legs. Fresh set in and running sweet. Still smokes.
- EGR. Tested that. Was manky but found to be operating properly. To completely rule it out it's now been blanked off. Still smokes.
- Turbo pipes. All checked.
- Fuel. Always gets posh. Has had a few doses of injector cleaner (prior to changing them). Gained loads of economy back but still smokes.
- Service. Just had one. Always gets a 6 & 12 pro service.

After all that, the car runs amazing. Like new dare I say. Smoother, more powerful, more miles. The smoky issue is now a niggle but it's a damn annoyance.

Any thoughts from the floor please?

You have just described exactly the annoying problem I have with my 53plate TD4 :confused2:

How gundged up was the inlet manifold? I heard someone had same problem and the cure was cleaning the thick black gunge from the valve stems courtesy of the EGR bollards. Also check the MAP sensor is not gunged up. It bolts into the lower left corner (above alternator) of the manifold. It is a pressure sensor and should be a hollow pipe.

Now if I rag the revs, it goes. Give it a blast where I can open it up, it runs clean, for the remainder of the trip, even when I come back to 30 zones and forced to trundle.

Last week it did it in 2nd gear, at 2k rpm. It was after first night's rain after several days of sun. I wonder if the moisture is a contributory factor? Also it's never done it in 4th or higher so air flow related also.

Click to expand...

rain/moisture can effect the td4's injector harness .. particularly the fuel rail sensor
i.e. it's plug/socket wiring .. it only goes from a few mv. to a max of 5v ..
a bit of moisture / pin corrosion / dirt can cause all sorts of intermittent fueling wierdness .. .. grey smoke suggests it's on the edge of overfuelling ..

clean the plug / socket pins and smear some 'contralube' on them ..

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also the air-intake temp. sensor .. check that as it effects the fueling
if it tells the ecu that the air is cold .. the ecu will add more fuel ..
and the opposite .. hotter air 'read' will reduce the fuel ammount injected ..
so an out of spec a.i. sensor .. or moisture on the connector .. could cause it
to give the ecu the wrong air-intake temp. reading ..

the coolant temp. sensor will also effect injection quantity ..
i.e if the ecu 'thinks' the engine is cold/cool it will add more fuel

although note that Some of those sensors .. if faulty .. will cause the ecu to use a default reading ..
i think with the a.i. sensor .. it uses a default of -5c .. causing overfueling / smoke ..
that info be in the m47r pdf link .. via the link at end of this post ..
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was the crankcase vent filter changed at service ??
as it's sometimes overlooked

and has the turbo vent filter been changed ?
check it's condition ..
( although that probably wouldn't cause the same symptoms you described .. intermittently
( it usually cause a loss of top end power ..
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has the ecu been re-mapped .. or a tuning box added ?

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for more info see the td4 links here :
links to freelander1 info