2003 TD4 Coolant going down, oil going up...?!?!?!

davidsmith1307 said:

If unplugging the MAF makes no difference then I suggest you DO need a new one as your fuelling will be all over the shop. Not cheap though.

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I have posted on another MAF thread about this as its bamboozling me; if the MAF is on its way out, then surely the car would have displayed rough running symptoms that other people tend to be getting namely poor idle, excessively smokey, sluggish below 1800rpm ish. What's odd is I don't seem to be getting any of that, car runs just fine. Yet I unplug the MAF, and nothing happens!

I'm sure when you unplug your MAF your car then runs on a pre-programed standard setting, so really you should find a difference as your MAF alters the settings as needed while driving

What confuses me though, is why should the effect be so noticeable when the ECU reverts to stock values if it cannot sense MAF input? Surely the stock parameters the ECU is programmed to revert to in that instance wouldn't make the car run so terribly, as its there as a failsafe?

I think i need to do it again and take it for a longer drive on a road i know well to see if there really is a difference

I don't think the car runs terribly on the default settings - what would happen if the MAF dies at 70mph?!
Car will be better if the MAF dies (revert to default map) than if it just gives crappy values.

In that case, an unplug test might be hard to use an conclusive proof that the MAF is faulty.

Thinking logically about it, the car is not displaying any of the main symptoms or issues that people have with faulty MAFs so it might be a moot point. The only thing that made me think it could be the MAF is when I disconnected it last night, and seemingly very little changed.

Plus, the reason for this thread was mainly the seemingly overfilling upon start-up and the slight misfire at 2k rpm, both of which I don't think the MAF could or should be to blame for?

So, I think for now I'll leave tinkering with it until such a time that the usual duff-MAF symptoms DO rear their heads

I think I'd be changing the glow plugs and putting a good injector cleaner through it before doing anything else.

I think you are right re: glow plugs, for the money and time to replace it can't hurt and at least would be something ticked off the list.

It's already had a fair whack of injector cleaner through it last three months, and I am trying to use higher quality fuel when possible, too, rather than Asda jungle juice

Is there a great variance in the glow plugs that appear incredibly cheap online? eBay in particular, set of four for about £12?!?!?! Rather not...

Paddock spares have loads but doesn't say which engine they're for, and have tried searching for a part number, does anyone have one so I can make sure I'm buying some decent parts?

Rimmers have a decent page to pick from:
http://www.rimmerbros.co.uk/Item--i-GRID009805

great thanks David

A quick test for the MAF if you have a scan tool is to watch the MAF while giving the engine a snap of the throttle to 100%. You should see the airflow rise rapidly with the snapping of the throttle then a rapid return to normal.

wlshyd said:

Is there a great variance in the glow plugs that appear incredibly cheap online? eBay in particular, set of four for about £12?!?!?! Rather not...

Paddock spares have loads but doesn't say which engine they're for, and have tried searching for a part number, does anyone have one so I can make sure I'm buying some decent parts?

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I suggest getting Beru glow plugs. Deffo not the Britpart crap!

Evening all just wanted to say that I've been trying to figure out the stutter/smoking at 2000 rpm on my td4 for a couple of years. I've got a long list of parts/fixes behind me that have not solved it and I thought as I'd got xmas out the way I would take the plunge and get the injectors tested as I'm knocking on 150,000 miles. Well what a fun job that turned into, 2 seized solid so had to resort to making a puller and lots of swearing. All 4 tested and all 4 well out of Spec, I knew it was gonna cost me but I was looking forward to getting the problem finally sorted so I had bosch refurb em all in exchange for a shed load of money! Well put em back in today and guess Wat. Starts nice and smooth all the way up to 2000 rpm and then the coughing and spluttering returned! So the moral of the story is give up whilst your ahead as if it runs it's good enough.

+1, gave up and got rid in the end.