280GE Oil drinking and smoke
New member here. Bought an 87 280GE a few months back and shes been solid since. Started noticing oil light going on rather more often than it should and an increased smoke from the exhaust. I put it down to the cold weather but she has since failed her mot for drinking the oil.
Garage is suggesting Valve Stem seals. What would be your initial gut feeling, don't think i've blown the head as temperatures stay good.
failure on emissions
is the oil travelling down the valve stems ?
Get a compression test done that will tell you the overall health of the head but at the age of your car a rebuild doesn't seem an out of the ordinary sort of issue; my ge300 had a head rebuild at 150,000 miles and that's the next generation engine compared to your 280. Do you know the mileage, its often difficult to tell with w460's as the odometer only goes up to 99,999.
and if you rebuild the engine you have the option go for the non-G spec: 185 hp (136 kW) at 5800rpm and 240 Nm at 4500rpm.
Oil smoke from exhaust upon start up only indicates valve stem oil seals.
Constant oil smoke at idle or during driving indicates piston rings and, or oil control rings which amounts tothe same thing as these equally wear out during each stroke of piston travel.
The M110 engine; i.e. your 280GE is designed to consume some oil and it is quite normal to be replenishing something like up to 1.5 Lts per 1500 miles. Therefore frequent oil check and replenishing of oil is paramount.
Accessing the engine for wear; I suggest an independent oil pressure gauge to take oil pressure readings on a normal operating temperature engine; oil replenished as it should be. The minimum permissible is 0.7 bar at idle speed. This pressure should immediately rise to 3 bar or just below above idle speed. Having this sort of oil pressure reading could improve by using a thicker viscosity of oil, instead of the 15W/40, use 20W/50. You can get different rated oil relief valves to increase oil pressure but in my view this could be a short term resolve as there is wear in the engine to give you low oil pressure in the first instance.
Have a compression test done which will give general indication to condition of compression indicating wear at the piston rings and valve condition. Pedantically, compression test should be done having firstly checked and adjusted valve clearances to get best results - preferably checked on a cold engine.
The idle test for piston ring wear is a leakage test, this can test out ring wear and indicate leakage via valve seats hence condition.
Check for oil leaks; commonly if the head gasket leaks it will be at the rear left corner of No: 6 cylinder looking into the engine from the front of vehicle. Further oil leaks is the rocker cover gasket - oil leaks out from the side of the cylinder head and oil can be seen from under the exhaust manifold.
Should you determine the engine is worn; in my opinion fit a re-manufactured engine rather than a reconditioned engine. These are more expensive than the reconditioned engine but the workmanship you get in return is as good as a new engine from the factory with new components and not accessed for re use. The cost difference is relatively small for the new components fitted to a re-manufactured engine. Company Vege used to do M110 engine, Ivor Searl is another reputed name.
If you are going for the second hand route then note M110 engine from saloon models will fit into the G-Wagen with some changes made to oil pump pick up and sum pan. These engine are of higher compression than G-Wagen engines as these are detuned to cope with off roading and the engine torque map is slightly different. If you are not very serious about off roading you should not have any problems with this solution.
If your engine does come up with low oil reading, I would NOT recommend using engine oil flushes to clean the internals of your engine. These products are fine but on a good engine.
Keep us informed.
oil passing through the stem seals won't harm your engine in any way might even help it along, I'd be worth doing a compression test b4 you decide on gasket replacement, if the pressure is down do the whole head overhaul at that point
I think it is possible to replace the valve stem seal without lifting the head which is by by passing air into each cylinder keeping the valves in situ. CARE is needed to do the work in this fashion but in this way it may not be possible to properly check the valve stem wear.
Depending on your current mileage determines how to best tackle this job.
I don't have much broadband time currently to run through the whole procedure but I shall try to draft this off line an post an answer for you if possible a little latter.
If you are burning oil and the car is smoking; I would suggest fitting a hotter range of spark plug to help burn off the excess oil. Don't go too hot otherwise you will have cold starting issues. One heat range hotter should be fine.
You say " The thermostat has so far never gone above middle level"
Mine is a different engine (300) so running temperatures may well be different and someone who knows will hopefully come on and confirm, but mine used to run with temp gauge "in the middle" until I was told it should be nearly at the 3/4 mark. I changed the thermostat to the correct one and engine been running much better ever since.
Pistonhead or Arnie will know the answer.
On the W460 the normal temperature reads circa 90 degrees centigrade.
This translates to the needle sitting on the top of the digit 'eight' of eighty shown on the temperature gauge.
More common failure on the 280GE engine is the viscous fan failing. To test, in hot weather this when it cuts in makes a howling noise and with bonnet lifted, standing by the offside wing one can feel the hair blow on your head when the engine is revved up a little. The fan never locks up unless made to but when the engine is switched off the fan when turned by hand becomes stiffer to turn.
As people have said previous this would be my checks
Check compression on each cylinder to make sure they are all good. I would be looking for half way between max and min readings to be happy. People take readings so many different ways heres my way
Cold engine and foot half way on throttle and crank until max is achieved. (hopefully 6 engine revolutions)
Then check hot the same way and measure readings. If all is good and even with good numbers bores and pistons are fine
Next check all breather pipes are clean from crankcase and cylinder head to air intake are clean and not blocked
Do the valve seals as a matter of cause anyway if people know how to do them in situ without saying remove cylinder head
Any gaskets will not help at all. They either leak or they are ok. With exception to any that are oil fed and could pass oil into intake side of engine causing smoke
This is not a possibility on this engine unless something major has failed and i am sure you would have other major leaks of oil running out of engine on floor before this could happen
Main things are bores, pistons and compression and clean breather hoses etc. valve seals but this normally shows worst after standing from hot shut down for 30 minutes then re start and a big cloud of white smoke for a while
rebuilding the head can cost a lot of money so its worth trying the quick fixes but don't expect them to be anything other than a short term solution
Slightly off topic but is it usual for the fan belt to squeal only on intial start up and rev. I figure the belt is going, but surprised the squeal disappears after about 3 seconds.
Some properly tighten belts can sometime squeal initially. If having made sure you have the CORRECT belt fitted (in terms of length and width and the vee profile) then the only alternative you have is remove the shine off the all the pulleys that is alternator, crankshaft and idlers. Or spray anti squeal spray on the belt. Alternative is rub some chalk on either side of the belt profile.