Blue smoke after top end rebuild?

[KLP 92]

I'm having a problem with the SEC. I had the top end rebuilt on the car a couple of hundred miles ago. The rebuild was done as i wanted the high lift cams fitted so it seemed to make since at the time.

Anyway before the engine was stripped the car never smoked or consumed oil. After the rebuild i noticed slight puffs of blue smoke when revving the car in neutral. As i was unhappy i took the car back to George Fraser who inspected the valve seals and said they looked fine. Plugs 6&7 showed slight oil deposits, but only slight. After that the blue smoke has worsened. When the car is on its resting temperature its gently puffing out blue smoke!!

Now having spoken with George he reckons it may be the bottom end? Is this right, as the car didn't smoke before the rebuild and has worsend since the valve seals were inspected? One of their mechanics reckons the car needs 500-1000 miles for the carbon to build up and it will stop smoking by itself? The car has only done 100-200 miles since the rebuild.

I will get the bottom end done if its required, as i've done so much to the car a little more won't hurt

The car has done a genuine 100k with full MBSH. MAybe something related but the resting temperature has gone up to 90-100'C and uo to 105'C in slow moving traffic. It used to sit on 85'C. I have had the water pump, viscous fan and radiator changed as well.

 

[Glenn Smith]

sounds like a problem with the top end rebuild, how much work was done, ie valves, valve guides could be a poorly fitted head gasket which could explain the temperature increase as the coolant flow is disturbed by combustion gases.

 

[jaymanek]

yep, I know you probably have a good relationship with GF, but thats a load of rubbish, there is a problem with the top end..

I wouldnt take that, insist they sort it out...

Last time one of his monkeys changed my diff oil, ended up costing me £250 for another diff (which i ended up fitting myself).. he denied it was his fault that the diff was bone dry 100 miles after his service...

 

[david_h]

Definitely something not sitting right in the head. Either valve guides or valves are letting oil and causing it to be combusted.

I won't even ask how much you paid for a top end rebuild, but the whole point is to stop any excess oil consumption.

Out of interest did you pay for a new/replacement head or recondition the existing one?

 

[grober]

If your engines putting out blue smoke then oil is finding its way into combustion chambers to get burnt. CAN YOU SMELL THE BURNING OIL AT THE EXHAUST.This could be 1. worn valve guides or seals. unlikely if they have been renewed. 2.Some sort of crankcase breather/emission recirculator problem where pressure in the crankcase is forcing oil vapour into the inlet system somehow.OR 3.a dodgy cyinder head gasket which seems the most likely candidate. 4. worn piston rings also unlikely.A bottom end problem would not cause excessive smoke unless it was causing 2. indirectly. I assume cylinders 6 and 7 are on the same bank of the v8. I would have another look at all the plugs again to see if the situation has got worse. Have GF tried the car on an engine analyser since fouled plugs should show up on the ignition firing line. My money is on on the cylinder head gasket/s you just got done. BOTTOM END PROBLEMS SEEM HIGHLY UNLIKELY

 

[C43AMG]

jgevers up in Scotland seems to know whats what, i would PM him. See what he says.He signs off as Job. Good luck i hope it's not to bad.

 

[KLP 92]

If your engines putting out blue smoke then oil is finding its way into combustion chambers to get burnt. CAN YOU SMELL THE BURNING OIL AT THE EXHAUST.This could be 1. worn valve guides or seals. unlikely if they have been renewed. 2.Some sort of crankcase breather/emission recirculator problem where pressure in the crankcase is forcing oil vapour into the inlet system somehow.OR 3.a dodgy cyinder head gasket which seems the most likely candidate. 4. worn piston rings also unlikely.A bottom end problem would not cause excessive smoke unless it was causing 2. indirectly. I assume cylinders 6 and 7 are on the same bank of the v8. I would have another look at all the plugs again to see if the situation has got worse. Have GF tried the car on an engine analyser since fouled plugs should show up on the ignition firing line. My money is on on the cylinder head gasket/s you just got done. BOTTOM END PROBLEMS SEEM HIGHLY UNLIKELY

Would the cylinder head gasket cause the oil to make its way to the plugs?

6-7 are on the same bank, passenger side. The temperature crept up to 110'C today so am getting concerned. Done a few hundred miles today, smokes the same!

Smell the burning oil?? Its enough to make you go dizzy! The siutuations definately got worse. Initially after the rebuild the car smoked on revving but once idling it was ok. Its now puffing on idle! Its definately blue smoke and smells of burning oil.

 

[jaymanek]

really sounds like the head gasket hasnt gone on properly...assume the head was skimmed when off?

 

[KLP 92]

really sounds like the head gasket hasnt gone on properly...assume the head was skimmed when off?

Head was skimmed, polished and then reassembled. The valves/guides/springs were meant to be changed.

I'm just really frustrated as after 5 months i finally get the car back with a prob which is more serious than what it went in for!

And the diff still whines......

 

[jaymanek]

mate, i say kick up a bit of fuss at GF's, im sure you've spent a LOT of money there and its pretty definite that its a problem with the top end...

 

[Ian B Walker]

Take it back mate and accept nothing but perfection. Your cars always scream class and detail so why should you put up with shoddy workmanship. I too believe that the problem is top end oriented. Having spent £X (thousands) on this car you should have it right.

 

[Sp!ke]

Agree with everybody else. Suspect top end for sure. Should do a cylinder leakage test (not compression test) and find out exactly what the cause is.

Before you do however, just check the crank case breather isnt blocked or restricted, you never know.

 

[grober]

2nd opinion

I think Jaymanek,Ian and Spike are right. If you feel GF are not cooperating get a good reputable 2nd opinion professional mechanic, car inspection engineer AA inspector etc, who will back you up when you go back to ask to get the work rectified. Stay calm but stick to your guns if its down to them.

 

[nickmann]

When you say it smoked on revving, did you mean as the pedal went down and revs went up, or pedal up and revs down?

Smoke on the throttle is likely to be a rings/bore problem
Smoke on the overrun is likely to be a valve seals/guides problem.

Constant smoking also likely to be rings/bore problem. Valve seals/guides generally only allow oil into the combustion chamber during vacuum - ie throttle shut.

Either way, take it back and park it on his foot until he agrees to sort it.

 

[KLP 92]

When you say it smoked on revving, did you mean as the pedal went down and revs went up, or pedal up and revs down?

Smoke on the throttle is likely to be a rings/bore problem
Smoke on the overrun is likely to be a valve seals/guides problem.

Constant smoking also likely to be rings/bore problem. Valve seals/guides generally only allow oil into the combustion chamber during vacuum - ie throttle shut.

Either way, take it back and park it on his foot until he agrees to sort it.

Well it smokes on idle, on revving and when you back off as well!

I've spoken to George and he is adamant its my bottom end. He recommends finding a second hand engine with a good bottom end. MY main concern is why would the bottom start smoking at 100k and when it didn't smoke before the rebuild?

If it is the bottom end i will have it rebuilt rather than buy a second hand engine.

 

[Will]

If the bottom end really is shot, why wasn't this mentioned before the extensive overhauling of the other engine parts (heads/cams/etc etc) - seems strange that it was fine before and now has become damaged?

I'd be looking for a rapid dose of decent customer service, especially considering the amount of money you must have spent here - not really a good advertisement IMO

Good luck getting it sorted as I know how much time, money and effort you've put in

Will

 

[grober]

The block maybe trashed!

I dont want to be the bearer of bad tidings KLP92 but if it is the bottom end . i.e. the cylinder bores/piston rings then thats VERY bad news. If my memory serves correctly ( others may correct me here) your car has an aluminium block with siliconised bores- no liners. If these are damaged/ badly scored I dont think they can be rebored. I think the block is trashed. This is probably why GF is telling you to source a 2nd hand one. Normally this Alusil coating is very wear resistant 5 times harder than cast iron but doesnt take well to overheating! Good news is that if you do get a good second hand one the bore wear should be negligible. They can sleeved with liners or sometimes honed with specialist tools and materials but not many engine shops could do this and probably prohibitively expensive. Mercedes sometimes use a endoscope thro the spark plug holes to examine the bores rather than remove the cylinder heads. Crewe engines http://www.creweengines.co.uk/ maybe able to advise you better than me on a potential rebuild but its not looking good if thats the problem. Sorry I really hoping I'm wrong here but if this is the case you really need to have an impartial 3rd party expert to witness your negotiations. :

 

[C43AMG]

Yes I agree with Graeme you need to get an impartial 3rd party expert, you must be SERIOUSLY PI**ED off after all the hard work time and money you have spent on this project, i feel for you.

Best Regards,

 

[Vlad]

It would have to be very bad luck to have a bottom end go on a M117 engine....these things are built like brick S**t houses and at 100,000 miles the thing is only just run in.

The thing I can't understand is that your engine was fine before you took it in.....have they done a compression test on your engine?

Next....as this engine does indeed have nicasil liners you can not rebore them, however you can have metal liners pressed in or new nicasil liners put in, but that is a much harder job.

The easiest best would be to get a good second hand block....there are loads of these around in breakers yard going cheap, as there is not much demand for them as they never wear out....ironic in your case.....the most demand they have for parts on a M117 engine are the heads which get stripped off and the blocks are just left lying around.

I managed to get a free block for my engine rebuild (cracked block on original)......ask George if he has any kicking about in that large store of his.

Good luck.

 

[Flash]

Tell G/F that I and posisbly other members shall think twice before taking any vehicle to him in the near future if he fails to satisfactorily resolve this issue for you...

I personally doubt that it is the bottom end of the engine that has gone especially as it was fine before G/f pi$$ed about with it.