300 TDI blue/grey smoke on start up and overrun

[Freeby]

Lots of blue/grey smoke  smelling of diesel on start up, after 3 miles or so much less smoke but just a little on overrun. I consulted all the forums for info but nothing stopped the smoke, ie no oil in water or water in oil, Injectors all OK Eventually I decided to remove the head, found one bent push rod on cyl 1 inlet so these have been changed as well as the tappet, check head for cracks, none to be seen, ground in and checked all the vales reassemble the engine. OMG it still smokes and had started missing but not all the time. I decided to check the timing I found the belt had jumped a tooth now it is running fine again. I have never seen this problem on any forum before.

[western]

Replace the valve stem seals if you haven't done them, could be a stuck piston ring. 

[Peaklander]

2 hours ago, Freeby said:

I decided to check the timing I found the belt had jumped a tooth now it is running fine again. I have never seen this problem on any forum before.

He’s found the problem @western and is letting us know.

@Freeby, I haven’t had this problem but it has been mentioned on here I’m sure.

I have 5% battery left. If I can get a search result before it dies I will share.

[Snagger]

I think he’s saying all is now well and it transpired to be the timing slipping a tooth.

I’d make sure the belt and tensioner were replaced with a new Dayco (OEM) or LR Gen Parts kit and would inspect all the sprockets very closely to see if any of them need replacement.  That skipped tooth might be the reason for the bent push rod, not just the unburnt fuel, and if it happens again could destroy the engine.

[Peaklander]

 

[steve b]

Cam belt failure on 200 and 300 Tdi will not destroy the engine . at worst rocker arms break and push rods bend. 

Freeby's description of the symptoms are exactly what you get with retarded timing . The pushrod bent when the timing belt jumped and the valve hit the piston.

good work through @Freeby. 

Now pic's are required  of your RRC 

Steve

[Snagger]

1 hour ago, steve b said:

Cam belt failure on 200 and 300 Tdi will not destroy the engine . at worst rocker arms break and push rods bend. 

Freeby's description of the symptoms are exactly what you get with retarded timing . The pushrod bent when the timing belt jumped and the valve hit the piston.

good work through @Freeby. 

Now pic's are required  of your RRC 

Steve

Shouldn’t destroy it, and yes, the rods and rockers should be sacrificial, but it is best not to test the theory or tempt fate - break the head off a valve or knock a chunk out of a piston and the results will be a lot of scrap.

[steve b]

absolutely , but sometimes belts let go so it is good there is a high probability damage will be limited to external top end, sadly not the case with just about all newer diesel engines across all types of vehicle

Steve

[Little mule]

I have a truck that just came into the shop and it had a lot of white smoke and blue . 
they broke the end of the crankshaft where the key ways sit .

they took a chunk out of the crank where the balancer goes on and they also broke the timing gear on the crank and took a chunk out of that gear as well .

the timing belt was out by one tooth and a half no that’s not true lol the cam belt sprocket was moving that tooth and a half . 
the pistons did hit the valves . 
so it turned out to be a complete rebuild because the head gasket was leaking as well . When I took the crank out they crank had 120 thought of play in side to side movement on the damper and the timing gear . 
luckly I had a crank already done to install into another 200. 
the pulley bolt came loose and the damper had the triple cast pulls on the engine and it just destroyed the crank.

I personally rebuilt this engine 14 years ago and when I took out the mains and rods the bearings were just like I had installed them .

they previous owner used to off road the truck HARD and did not put in the vent plug on the bottom of the timing belt.

there was mud half way up the inside of the outer timing cover .

luckly we are waiting for a set of rings because there was no wear in the cylinders or pistons . We took the glass off the liners and they are ready for new rings .

you mentioned you over ran the engine going down hill . That’s a huge mistake because the little valve caps will bounce off the end valve and now you have an instant miss and the push rods will pounce past the rocker shaft and will bend .

good thing you caught it time and did the work to correct the problem .

If your engine has these valve caps on the end lol the valves you MUST creep a close eye on when you last adjusted the valves and adjust them properly . if you over run the engine down a hill there is a very good chance one or more will pop off the valve and could cause damage .I have found a set of these valve caps at summit racing and are far better quality than the ones from the UK.
many a time I have seem this problem and most people take them off and you can get away with it for a while but the end of the rocker arm will ware out because the little valve caps provide a wider surface for the rocker arm to press on when opening the valves.

the engine Im fixing now is just owner abuse and neglect. The truck was driven as fast as it would go for almost 1200 Kim’s . 
the crank bolt can loose and made the end of the crank shaft look like a egg from the pulley and damper bouncing up and down ..
here is a link to a video of when I did the engine swap one a series three 109 LHD . 
 

 

 

Tony 

 

 

 

[Nonimouse]

I snapped a lobe on the crank shaft of a 200tdi - britpart replacment. It still ran. Got me home from That London to Devon. STill ran ok. A friend did the same on the same route