Hi all
My Pug Expert has had a few diesel problems which have mostly been sorted thanks to advice from several very helpful members of this forum.
It's running much better now since a local diesel specialist found way too many copper seals under the injectors (he found 11 seals in the end) and gave it all a good clean up and bypassed the EGR valve, but I'm still getting black smoke especially under heavy (ish) acceleration and it's worse when the turbo kicks in.
The mechanic thought that the turbo felt a little weak, and also that the pressure out of the exhaust wasn't that great, so he suggested that the catalyst / particulate filter could be blocked, therefore causing too much back pressure to the turbo. I guess this would mean that the turbo's not spinning up quite as well as it should, and therefore it's not giving much boost which in turn means that it's not getting enough air to mix with the fuel that the ECU thinks it needs - end result is over-fueling and black smoke.
I have disconnected the exhaust where the cat connects to the centre silencer and the cat seems to be clear. The engine runs a little better and the turbo seems to come in a bit quicker, but it's not a massive difference and I am still getting plenty of black smoke coming out the cat.
Even with the exhaust silencers disconnected the intercooler pipes don't bulge when the turbo's spinning. I can squash the pipes with my hand and I only feel a small increase in pressure as the turbo kicks in.
Is it likely that one or both silencers is blocked since I seem to get less black smoke when the silencers are attached? Is it worth removing the innards from the cat (to reduce back pressure) or is this likely to make the smoke even worse?
I'd be very grateful for any advice on where to go next!
Thanks,
Mike
Edited by Dynamic Dave on 31/10/2008 at 23:35
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Mike
Eleven[!] injector seats? Were they on special offer?
Silencers rarely block, but cats do. This causes excess EGR - what did this "bypass" entail - it's more usual to blank it off. [Although the ECU can sometimes detect the low flow.]
I've decatted several HDis with blocked soot filters; the non-monitored ones are not missed.
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Hi Screwloose, good to hear from you again!
I was surprised by the number of seals too, but I can confirm that they were nothing to do with me - all there before I got the van. I guess the previous guy didn't know how to take out the old ones before shoving new ones in.
I don't know what the mechanic did to bypass/blank off the EGR but I could have a look if you can let me know what to look for.
May I also ask what you've done in the past to decat these exhausts? I had been hoping to break the insides out of the cat so that it still looks original from the outside, but the cat has a 90 deg bend leading into it from the turbo and a bit of a kink on the way out to the rest of the exhaust too, so I don't know what I can use to knock the insides out with. I had wondered about using a long drill bit (a 400mm SDS drill seems like a good idea) but I'm not sure if even this will go in through the bend in the pipe coming out of the cat. I know that the cat is not required for an MOT, but I'd still like to keep the exhaust looking as standard as possible rather than removing the cat and replacing it with a flexi or cutting the pipes and having to put clamps round them afterwards.
Regards,
Mike
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Mike
The easiest way is to slice the weld at one end of the cat, knock the brick to pieces and then re-weld. No real problem - if you can mig-weld stainless...
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