75ZT Community

My 04 CDTi ZT 70k miles (passed mot only 3 days ago) had it's orings done on the intercooler at the same time as mot and also a new centre section of the exhaust, the bit with the cat in it and the flexi pipe.

It now smokes an awful lot, looks like a fire in a tyre depot from the back of the car, it was always a bit smokey with the ron tu3b and mafam with pierburg maf but now it lays black trails, unless I turn the mafam down and then I get greyer trails but still plenty of smoke. It has had a Recent service and I can hear the turbo spooling but power seems a bit off and throttle response is not what I expect almost woofly.

I have turned off the tu3b and smoke is gone for all intents and purposes, so I have tried the bottom setting on the tu3b and a little smoke re-appears, adjusting the mafam is not doing much unless i turn it right down to 9 o'clock.


Any ideas? I must stress this is a company car and I have spent enough of my own time on it this year and I have also spent quite a bit of company money, about £600 in the last 2 months. Actually thinking about it that is more than the new lease car was going to cost I hope I am not going to regret keeping it.

Could be a leak in the intercooler & or pipework or another thing to try is replacing the PCV (Positive Crankcase Ventilation Valve) valve on top of the engine............certainly mine was very smokey til I changed that

DeuxGazoles wrote:Could be a leak in the intercooler & or pipework or another thing to try is replacing the PCV valve on top of the engine............certainly mine was very smokey til I changed that

Did the pcv about 25k ago.

I had a leak before on the intercooler rings now I haven't but I have got smoke.

In fact the rings were done and the pipework sorted only 40 miles ago, can it blow something else off?

Grossebaby wrote:In fact the rings were done and the pipework sorted only 40 miles ago, can it blow something else off?

I wonder if it's just blowing the oil through from the bottom of the intercooler

Is it performing ok??

No it's a bit off, took it up the motorway for 10 miles and back again at speeds I won't type here but it smoked all the way up and for the way back I switched out my tu3b and got comprehesively outdragged by a VW T4 (Testbook version 4.Computer Diagnostic System) transporter!

I would double check that the intercooler hose is still connected to the EGR (Exhaust Gas Recirculation Valve)...........I forgot to tighten the jubilee clip on mine during my recent diagnostic experiments & it popped the hose off & it was like being in an old pit village on a damp day it was that smokey & quite gutless

the pipe is on at egr, i would have noticed while changing the settings.

Hmmmmm! only other thing springing to mind is your turbo's not very well

OR the injectors are ill.

Grossebaby wrote:OR the injectors are ill.

always a possibility though it seem that these type of injectors suffer more from leakback than anything else & mine wasn't really smokey as a result it was just very difficult to start & cut out now & again.

The reason behind my turbo/pipework leak thinking is that if you have a load of fuel going into the engine but no turbo pressure to feed the air in then that causes heavy smoking & poor performance

I'm sending it in then.

Just a thought, if not the Intercooler pipe coming out again, it could be the MAF (Mass Air Flow Sensor) gone US which can cause smoke through it being over fuelled.

If there is any oil in the intercooler after replacing the oil seals it can take quite a while to clear, running it round town at lower revs won't do it and the car will smoke badly with the tuning section turned on the smoke will be worse.
A long run with higher revs and engine hot may clear it.

Russ

Having just removed the maf plug and turned the box back up to 7. I can report that it must be maf related as the wooflyness has gone even though she is still a little smokey, It is a pierburg so I may try with the mafam turned down very low but the woofly throttle response and lack of power at higher revs is telling.

What is current thinking on MAFS? Which to go for and where?


I have reconnected maf and set mafam to bottom setting and it seems not too bad but a bit smokey, I think I will try for another longer run before spending but I do think i may be maf hindered on this one.

Maybe I should put my old bosch back in to try?

Been playing and I am now totally confused, the car smokes but it is very variable and does not seem to be related to just one thing. There do not appear to be any air escapes from an engine running at 3500rpm but stationary. The turbo is defo spooling but I find it can feel very flat performance wise, in fact I am full throttle everywhere just to go at normal speeds.

Disconnect maf it stops smoking, then it starts, reconnect maf it doesn't smoke then a little later it does. turn Tu3b down stops smoking then starts again, turn it off no smoke then a little later smoke.

I have cleaned the egr which wasn't very bad tbh, it seams stiff but then I think it is supposed to be.

Got myself new pcv filter to fit but I am not sure that is the problem.

Come to think, progressive use of the throttle, i.e. don't go for full mashings and she isn't too bad, but ask for performance and all you get is smoke.

I have now done the pcv and am about to take for a run BUT, and I am very annoyed about this, I note the garage have replaced my BMC airfilter with a paper one. Could be the cause all along and I am going to tell em.

Now tested with old bosch maf with and without mafam, still smoking.

I find the turbo is very noisy, lots of whoosh much like the subaru imprezza we used to have, not at all like an mg zt, I think we may have a pipe problem.

I think the mystery is solved but not sorted. When I was testing I found that you can feel a draught coming from the intercooler through the rad, not sure where so either the outlet is not sealed properly or the intercooler is holed!
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