280 V6 total engine failure @ 77k

[big x]

At some point in the future I'm going to try a V6,I've had 4's,IL 6's,V8's and a motorcycle V4 I which all feel very different.
I'm wondering if anyone here has had a problem like this or is it a one off ? I was under the impression these engines had proved very sound since introduced some 7 years ago.I tend to buy cars around the 100k mark when they are nice a cheap and have never had an engine fail me but I'm slightly concerned whether I would spot a problem if these engines continue to run smoothly while grinding the bearings down ?
http://forums.mercedesclub.org.uk/showthread.php?t=17087

adam

 

[stats007]

I've never heard of this - I'm also surprised he didn't write to Milton Keynes or anyone suggest that he should, I know I would have.

 

[996jimbo]

I guess any engine will run fairly smoothly whilst grinding down the crank until the bearings fail completely. The one mentioned was (supposedly) damaged by petrol diluting the oil and the issue therefore was how enough petrol had got in to the oil.

Hands up anyone that has ever had an engine knackered by petrol getting in to the oil over a couple of thousand miles?

 

[Kwack]

This was a known problem with early Kawasaki GPz900s. The fuel tap was opened by a vac feed from the inlet side of the carbs. This operated a diaphragm which acted on a small piston in the fuel tap. Rust from the inside of the tank prevented the piston from seating fully in the closed position & the fuel continued to run into the carbs ( the needle valves in the carbs suffering the same problem).

In a worst case one cylinder would fill with fuel & when started the relevant piston would try to compress the fuel & bend a conrod... can't see how it would happen in a modern fuel injected vehicle.. but I'm sure someone can dream up an explanation

 

[big x]

If excess petrol was getting into a bore wouldn't the lamda warning light come on as the mixture would be to rich ?

adam

 

[Dieselman]

Not necessarily.
These engiens have a known problem with bore glazing. If the bores glaze and thus lose comression there will be excess petrol entering the oil. All petrol engines pass petrol into the as a result of incomplete combustion during the warm up phase, but if there is a loss of compression this can be severely exacerbated.

if the oil wasn't getting hot enough to boil off the petrol or the amount was excessive then the oil will be diluted causing accellerated wear.

The mixture strength wouldn't alter just the power output for a given throttle setting.

 

[Dave Bailey]

Not necessarily.
These engiens have a known problem with bore glazing. If the bores glaze and thus lose comression there will be excess petrol entering the oil. All petrol engines pass petrol into the as a result of incomplete combustion during the warm up phase, but if there is a loss of compression this can be severely exacerbated.

if the oil wasn't getting hot enough to boil off the petrol or the amount was excessive then the oil will be diluted causing accellerated wear.

The mixture strength wouldn't alter just the power output for a given throttle setting.

Dieselman - What causes the bore glazing & how can it be avoided?

Cheers,

Dave (Now a very worried 280 owner)