Newbie needing advice

[Madmac666]

Hi guys, I thought it about time to join the forum as i've had 25 years with Sprinters, mostly 319 V6 as I use them for work and towing the car to Hillclimb events.

Give me a high powered pertol turbo engine and I'll work wonders, but my knowledge of modern diesels is limited and I could do with some help with a problem on my 2011 Sprinter 319 which has the OM642 V6 engine

Mileage is 196k, regularly serviced and it was remapped when new. It had a new DPF a year ago. It needs a new timing chain which is planned to be done soon. The chain rattles loudly on a cold start and it's been concerning me for a while. I have had a cam sensor code showing for 2 years which suggests the cam and crank sensor are out of sync however this hasn't been an issue. The engine pulls very strong and sounds healthy enough.

The problem is: Starts fine, no blue smoke at all. I live at the bottom of a steep hill and after starting it is blowing HUGE clouds of blue smoke until I reach the top then it runs clean for the rest of the day, literally half a mile of smoke then nothing visible. Even at low throttle nursing it up the hill the smoke is obscene. I get regular codes saying the DPF is too choked to regen, and have had this message quickly after the DPF was replaced. I clear the code and it's ok for a few months until it goes into limp mode again with the same code, usually when the tank is below 1/4 weirdly. I suspect the turbo maybe the cause of the smoke and the intake looks clean enough. I haven't split the turbo outlet to DPF yet to see if the hot side seal is gone. I'd have thought that if the seals had gone it would be blowing smoke when warm too. I had noticed the exhaust tone changing as it goes into regen and there has been a little blue smoke during regen attempts. I don't know if it is actually completing the regen process though. I don't have easy access to a Start machine. I only have a DIY scanner that reads and clears codes.

The engine has also suddenly started leaking oil from the sump (I think, still trying to find it), quite a lot of oil at that. I'm thinking it may be easier to pull the engine out to check turbo, EGR valve, sump, do the timing chain and fit a new clutch since it's on the original one.

Can anyone think what would be the likely cause of the blue smoke as described above? I'm not convinced it's broken rings or stem seals and it is concerning me above the other faults. I'm inclined to suspect it's something attached to the engine rather than the engine itself. The symptoms aren't narrowing the issue down to one thing for me, but my knowledge of diesels is limited. I'm hoping someone who knows these engines can help. Thank you in advance

 

[Smiley]

Blue smoke=oil being burned. If it does it only after being left overnight maybe valve stem seals? The oil leak is most likely the oil cooler seals. Replacing the oil cooler is easy enough, getting to it involves a lot of dismantling as it's buried in the bottom of the V of the engine. Just a thought is the blue smoke coming out of the exhaust or is it leaked oil being burned off an exhaust under the engine bay?

 

[Jonesy161]

Agree with smiley on the valve stem seals, especially after 200k they’re probably baked hard by now.

 

[Madmac666]

Smiley, thanks for that suggestion. I hadn't seen any oil marks on the outside of the DPF or exhaust but I guess if it's the oil cooler leaking, that makes sense. I fired it up from cold on Friday and let it idle for 10 minutes then started my journey and there was no oil smoke going up the hill, or any visible blue smoke on startup

I will go and investigate further and report back

 

[Madmac666]

Update on my engine issues:

I replaced the oil cooler seals back in February and the oil leak stopped - good shout on the oil leak Smiley! The job was a pig to do though - both bolts holding the turbo to the mounting block were so rusty I couldn't get anything to remove them, couldn't get in with a drill or a chisel so I did the oil cooler seals without removing the turbo or inlet manifolds. I Must have been a gynecologist in a previous life.... It is possible to get the cooler out without removing the manifolds but getting the bolts out from the cooler took a while using a very short torx bit and a 1/4 flexi

Anyway.... The turbo ate itself a few weeks ago so I had to pull the engine out. The timing chain stretch was pretty bad (cams were 14 degrees out on one bank and 18 degrees out on the other bank). While I was in there I took the heads off and changed the head gaskets and new head bolts etc, removed 4 sheared glow plugs, replaced the valve stem seals and measured the bores. I didn't check the rings but a compression test showed all appeared ok there. I also did some basic port matching of the exhaust manifolds and turbo 'Y' piece which should improve overall performance.

I have it back together and she runs sweet & quiet again. I still have the oil smoke when cold though, despite a new turbo which I suspected was the culprit especially when it failed a few months later, I though that would be the cause of the smoke

I have the P108b/c/d fault codes appearing again which I need to address and the new DPF is showing as being unable to regen so it's booked into Mercedes this week for a sensor re-learn and a forced regen on the DPF. The P108 codes have been present for a while and last time this was cured for 2 years by doing a re-learn of the intake tract sensors using the Star machine. Hopefully that will be a simple fix again... At the moment it is in limp mode. I cleared the faults and they came straight back

One other issue is the clutch hydraulics. I replaced the clutch and slave cylinder while I had the engine out and I couldn't get it to bleed at all. I eventually pressure bled it from the lower bleed nipple and I have a clutch pedal now but the bite point is very low. I can't get it any better than that. Does anyone have any advice to offer here? When I put the pressure bleeder onto the top reservoir it just blew air through which was a real headscratcher for me because the clutch master cylinder gets the fluid from the bottom of the brake reservoir. Interestingly the original clutch plate had only 0.54mm wear and the flywheel/cover had no visible wear at all. I could still see the grinding marks left from manufacture on both steel friction surfaces! I know this is the original clutch because I bought the van new. I was tempted to put it back in but decided at 199k it should be replaced regardless. This is with about 50k of towing the race car up and down the UK to events too.

Still no further forward with the blue smoke issue though. I'm stumped. The bottom end appears healthy and the smoke is only evident within 30 seconds of a cold start. After that it runs clear for the rest of the day.

 

[Tonye]

Just a thought, did you replace the valves with the seals.

 

[Madmac666]

No, the valves were all good so there was no need to replace them. They got a clean and light lap then reinstalled

I'm wondering if the oil smoke is something to do with the crankcase breather valve at the back of the cylinder head. I read somewhere that can cause oil smoke

 

[Tonye]

I was thinking the valve stems themselves might be worn at 200k and passing oil when stood overnight, once warm everything tightens up.
If its not smoking when warm its got to be somthing worn, don't forget diesels run quite hot internally. Hope this helps.

 

[Madmac666]

The valves were okay, no undue wear in the guides or stems so they went back in

 

[Tonye]

Was just a thought, its getting in from somewhere when stood as it runs clean all day. I hope not but it could be a tiny crack in the head. Can you pull the injectors one morning and get a scope in there to check for any oil seepage into a cylinder, a lot of work but at least you will know. Best of luck.

 

[Madmac666]

The machine shop did a dye crack test on the heads when they drilled out the sheared glowplugs and nothing showed up.

All the pipework was cleaned internally on rebuild so it might be worth having a look to see if there is any oil in them now. That might help trace oil travel....

 

[Tonye]

Best of luck with it all pal, I'm out of idea's but keep us posted with your findings

 

[StMarks]

Little bit of a thread hijack (sorry OP Madmac666 ), but the timing chain issue has me thinking...
My little Vito van '07 109 cdi, standard map etc,,, is approaching 275k miles.
Does anyone know if there is a replacement interval for the timing chain on my engine ?

 

[Madmac666]

If the chain isn't rattling on cold start, you're lucky at that mileage! Mercedes dealer told me they expect the chains to last the life of the engine but there's a lot of folk say they had to replace chains from 70k miles upwards.

 

[StMarks]

If the chain isn't rattling on cold start, you're lucky at that mileage! Mercedes dealer told me they expect the chains to last the life of the engine but there's a lot of folk say they had to replace chains from 70k miles upwards.

Fwiw I was told they last the life of the engine, when I was initially concerned and so asked "someone knowledgeable" (don't recall who). But that was at just over 100k miles.
However it strikes me that, being an interference engine, if the chain does fail that will indeed mean it has lasted the entire life .!

 

[Madmac666]

I guess that's true! It may not break but it can reach the point of jumping teeth. The tensioner extends until it doesn't do anything. That's where my chain was - rattle on cold startup and very loose when I pulled it out. My cams were 18 degrees out and fuel consumption averaged 19mpg, down from 23mpg

I think the sprinter service interval is too long at 19k even with 13L of oil in the sump. The soot particles in suspension cant be good for the chain. I'm going to change the oil at 8k from now on.

Replacing the chain isn't a quick job. You can break and join the new chain to the old and wind it through from the right side cam cover then rejoin it but I didn't trust that and had to take the engine out anyway to change the turbo, so I changed the guides too. The old guides weren't that worn to be honest.

See pic of old/new chain comparison

 

[Tonye]

250k, for a chain, come on, its not a scania designed to do 800k. Things rattle and go bang eventually.

 

[Madmac666]

I had the van hooked up to the Star machine today to force the DPF regen and setup the intake sensors. It goes well again and definitely pulls harder than before. The DPF smoked a fair bit during the regeneration process, I occasionally saw a puff of smoke while driving when the DPF was going through a regen so I guess that is normal?

I'm still not convinced the smoke issue is to do with the engine itself. When I cold start it, there is no smoke visible at all which wouldn't suggest stem seals to me. I drive off up the hill, about 50% throttle and the smoke starts maybe 100yds up the hill, becomes a thick cloud, then stops and it runs clean again for the rest of the day, even with a few hours between drives. I took a video in the mirror this morning which I'll post on Youtube. I'll drop the link here once I have it:

 

[Tonye]

Either over full of oil or a VERY steep hill im thinking now, and maybe worn rings. That breather at the rear might also be blocked solid causing back pressure or could be sucking oil in. All guesses now pal.

 

[Madmac666]

It is quite a steep hill to be fair! Oil level is at the top mark (13L). I read the other day that the breather has a valve inside which can fail and push oil past the rings. That is going to be my next check

Looking at my video, it's difficult to tell if the smoke is more white than blue. It's maybe not oil smoke. As I said at the start, I'm no diesel engine expert. Could it be white smoke due to an injector fault?