Smoking from the exhaust
 

In need of a bit of advice guys. I've got an issue with my 2005 2.0 CDTI. Not had it that long and since buying it it tends to smoke a little too much for my liking. Not all the time, just randomly really. Sometimes it's when I'm travelling at 30 mph and sometimes when I'm travelling at 50 mph. I've spoken to the guy I bought it off and he insists that its not the head gasket.
I've checked the usual symptoms (oil looks fine, no loss of coolant, heaters work fine) so I'm at a loss. Is it the head gasket or something else? I have noticed that the temp gauge doesn't go above 1/4 for some reason.
I've used a rad sealant and a catalytic cleaner so far but nothing has changed.
Can anyone offer their ideas and thoughts please.
Thanks guys

It almost definitely isn't the head gasket. A clogged EGR valve maybe? Hows the power? is it struggling? Have you changed the oil recently? A common low running temperature is the thermostat, usually cured by fitting the R5 stat in the top hose (do a search):}

Check inter cooler o rings for the smoke problem

The power seems to be ok, not noticed anything untoward as far as that's concerned. As for the oil, it was changed in November by the previous owner.

As yours is a diesel, it will definitely not be headgasket failure as the engines are pretty solid. I think I've only heard of 1 HGF in the two years or so I've been on here.

Things to check for the smoke will be:
1. Intercooler O-rings at the bottom of the intercooler hose as mentioned above. Also check that your intercooler hose isn't split.
2. Blocked EGR Value, this can cause it to stick as a lot of black gunk gets stuck in there. I think a blocked EGR can damage your turbo. Can replace for a EGR bypass.
3. MAF sensor, might be worth unplugging the MAF to see if it makes a difference.
4. PCV Valve/ Crankcase Breather filter - may be worth changing this as it is a serviceable item which is often missed. A blocked filter may cause excess smoke I'm not sure but one clear symptom is if oil is being pushed out the dipstick slot.

Those would be my main pointers. All can be searched on this forum, plenty of info on them here.

Also, in regards to your engine temp not getting past 1/4 mark, this will be due to a stuck thermostat which is a common issue. Thermostat gets stuck in open position. This can be fixed with the inline thermostat mod which is also documented on this forum in detail :)

Lastly, make sure you have checked your plenums on your cdti to make sure they are clear, as the ECU is located in the plenum on the passenger side and can get flooded if the plenums are blocked. Quite an expensive fix if that happens.
Rick :)

Thanks for all that advice Rick, plenty there to keep me going for a while. Appreciate your help

your welcome :}

When you say "smokes" what is the colour black/blue/grey-White ?

Each colour could help to identify the issue

Regards mick

By the time the air gets to the EGR it has passed the turbo so wont damage that, the most likely cause of smoke is a blocked PCV filter.

Overfuelling causes Black smoke, so The MAF may be faulty, unplug it as a test.

I had both "O" rings blown into the base of the pipe on my car, but it didn't smoke or lose much power... :shrug:

Give your car a good blast in 3rd gear doing 70 mph to clear out all/any build up of gunge... It's called a Mexican tune up.. :D :D :D
...

Lots of little jobs to do to get a CDTi running as it was designed to do.

1. EGR clean out and maybe disable/bypass.

2. CDTI worn thermostat's open too early, replace with OEM or put an extra one in the top hose.

3. Clear out the plenum and make sure it stays clear, or it may wreck your week.

4. PCV filter choked up, could wreck your turbo.

5. All of the above could cause smoke, but usually the MAF will have failed too. Unplugging it might help prove it, but best if it has failed to replace it. Don't be fooled by the many fakes, copies and etc.. read up (see below) and buy one from the MAF-shop in Berlin, the only known source of the genuine item.

6 Do the viton o ring replacement at the intercooler.

7. The Intercooler to EGR pipe is known to become soft and porous and even split - worth replacing.