Rover 75 diesel strong exhaust smell
 

Hello,

We still have a problem with my dads car.. since about early last year.. and it seems to be getting worse. We have checked all the items mentioned in a previous thread where I asked (PCV, flexi pipe, EGR valve etc).. and have had several people look at it including a diesel injector specialist, but no one can pinpoint the cause. My dad is now thinking of replacing the car, which is a shame as this is the only real issue.. but the engine now stinks and it is becoming intolerable.

It just had it’s MOT .. and passed on the emissions.. the reading for “smoke” being 1.05 (limit is 1.5). My ZT (with the same engine) was 0.76. So I’m not sure if this value is particularly high?

I’m now not certain if the smell is actually coming from the engine or from the tailpipe.. it’s hard to tell as the smoke drifts around.. however the exhaust gas from the tailpipe does smell stronger than on my ZT.
Also there is some black smoke when accelerating (not a huge amount though) and the MPG has dropped (to about 37) – although recently he has only done fairly short journeys in it.

It also takes a lot longer to warm up than my ZT.. but does get up to halfway on the gauge eventually.. we fitted the inline stat mod a few years ago on both cars.

Based on the above could it be that the engine is running too rich? And if so how to check that and diagnose the cause? I have TOAF and it said the "correction factor" on one of the injectors was 4%.

The car now has 120k on it so we were thinking if keeping it for longer then it may be worthwhile to get the injectors reconditioned even if that doesn’t fix this particular issue .. it certainly made my ZT start and run better (the injector specialist said that may fix the smoke issue but he couldn’t be sure).

But we don’t want to spend that much on it if the problem still remains and can’t be fixed.

So anything else we can check before injectors? Note the MAF was already changed.

Any other help or suggestions would be much appreciated.. many thanks

Richard

what is the smell?

macafee2

I’m now not certain if the smell is actually coming from the engine or from the tailpipe.. it’s hard to tell as the smoke drifts around.. however the exhaust gas from the tailpipe does smell stronger than on my ZT.


The exhaust I think macafee

It does smell like exhaust gases, but is very strong.. gets right to the back of your throat.. much worse than what you normally smell from a diesel car ..

could be a blocked or worn cat

I would think a Blocked CAT would show up in poor performance,Worn out CAT:shrug:

Has it had a good "Italian tuneup"? I'd pop the fuel filter off and fill it full of forte or redex. Re-fit it, run the engine for 30 seconds then leave it overnight. This will allow neat injector cleaner to sit inside the injector bodies and nozzle tips and hopefully remove any varnishing and blockages. Then take it out for a drive, get it good and warm and let it sit at 4500rpm in 3rd for half a mile.

It'll be a different beast after that. If not, time to identify if one of the injectors is out of spec. T4 or TOAF will tell you which one it is.

Ok, we'll give that a go.. thanks :-)

Hi Richard.
Have you removed the engine cover and looked at all the injectors for any pooling around one of them, also do a leak back test, purchase ne of these below.
https://www.ebay.co.uk/itm/6-Cylinde...MK9q:rk:9:pf:0

When was the last time it had a full service, manifold off and cleaned, EGR cleaned or by passed clean MAP sensor, air filter, PCV filter, new oil & filter, etc.

What colour is the smoke, grey/blue does it go away after the engine is fully hot up to temp.

Just a few questions you could ask your self then check and report back to the thread.

PS you do not have a synergy fitted do you ?

Hi. Thanks for all that. We have checked most of those points. There is some black smoke when accelerating. The EGR has been bypassed. It doesn't have a Synergy. The manifold has never been cleaned as far as i know. I fitted a MAF sensor a while back and the air filter was changed recently (the car is always fully serviced on time), the PCV was changed too, a few years ago, for the type that is never meant to need cleaning.. hopefully that is the case! ..
thankyou.