W124 E36 AMG curious oil related problem
Discussion
Here's an interesting one.
For the last couple of weeks the yellow oil light has been coming on intermittently.
There's plenty of oil and the oil pressure gauge shows a solid 3 bar
Talked to my indy and it was agreed that the sensor is probably u/s
They've now fitted the correct new sensor but the oil light is still coming on and off.
On investigation, the water expansion tank has about a litre of dark brown / black engine oil in it!
This is completely mystifying, as the golden yellow oil on the dipstick is at the correct level and has not gone down at all.
There is no mayonnaise on the oil filler cap and it runs really well. No blue smoke.
It's almost like someone has deliberately put used oil in the expansion tank!
The garage are also at a loss as to the cause.
They'll remove the expansion tank, clean it and flush the cooling system and I will drive it about for while and see how it goes.
Anyone have any ideas please?
For the last couple of weeks the yellow oil light has been coming on intermittently.
There's plenty of oil and the oil pressure gauge shows a solid 3 bar
Talked to my indy and it was agreed that the sensor is probably u/s
They've now fitted the correct new sensor but the oil light is still coming on and off.
On investigation, the water expansion tank has about a litre of dark brown / black engine oil in it!
This is completely mystifying, as the golden yellow oil on the dipstick is at the correct level and has not gone down at all.
There is no mayonnaise on the oil filler cap and it runs really well. No blue smoke.
It's almost like someone has deliberately put used oil in the expansion tank!
The garage are also at a loss as to the cause.
They'll remove the expansion tank, clean it and flush the cooling system and I will drive it about for while and see how it goes.
Anyone have any ideas please?
That's really weird and no wonder you're concerned.
I'd be thinking it's an accidental mistake by a mechanic or as you alluded to, sabotage.
I think that's a very rare car/engine so would someone be jealous or trying to buy it off you at a discount with a dodgy engine?
I'd read on PH of car buyers who put oil in the coolant to claim engine damage so they could buy the car cheaper.
I'd be thinking when did this start and what happened around that time. Had it been for sale, on show or servicing that would cause it to be out of your sight?
I could go on being Hetty Wainthrop but I think you get the point.
I hope it's nothing suspect.
I'd be thinking it's an accidental mistake by a mechanic or as you alluded to, sabotage.
I think that's a very rare car/engine so would someone be jealous or trying to buy it off you at a discount with a dodgy engine?
I'd read on PH of car buyers who put oil in the coolant to claim engine damage so they could buy the car cheaper.
I'd be thinking when did this start and what happened around that time. Had it been for sale, on show or servicing that would cause it to be out of your sight?
I could go on being Hetty Wainthrop but I think you get the point.
I hope it's nothing suspect.
Start with the basics, have the garage put an oil pressure test gauge on where the pressure switch goes. Every competent garage would be able to do this.
It may be that your pressure switch is correctly picking up low oil pressure and the oil pressure gauge in the car is giving false readings. Oil in the coolant mayonnaise or not isn't a good sign either.
Is this car new to you?
It may be that your pressure switch is correctly picking up low oil pressure and the oil pressure gauge in the car is giving false readings. Oil in the coolant mayonnaise or not isn't a good sign either.
Is this car new to you?
Given what you described I am hoping that I am wrong but the 36 engine is noted for having a somewhat fragile head gasket. Furthermore iirc there is some confusion as to replacement part numbers, something like the part number in EPC is for a standard 3.2 car not the AMG one or some such.
Good luck with getting it sorted, the car is well worthy of the best attention.
The M104 engine cylinder head gasket occasionally leak-out oil, but total failure is quite rare.
My C36 is on its original gasket (I think the AMG ones may have been reinforced), my 29 year old 300-24 SL is also on its original gasket, but has a tiny seep above the alternator, which is quite usual.
The M104 engine cylinder head gasket occasionally leak-out oil, but total failure is quite rare.
My C36 is on its original gasket (I think the AMG ones may have been reinforced), my 29 year old 300-24 SL is also on its original gasket, but has a tiny seep above the alternator, which is quite usual.
I don’t know if the E36 has a separate engine oil cooler, but on the E320 on which it’s based the oil cooler in the radiator is for the ATF. If it does have an engine oil cooler, it’s likely to be forward of a front wheel, within one of the arches, protected with a splash shield.
Doesn’t explain the light though.....!
Doesn’t explain the light though.....!
Well, it seems my indy have thrown in the towel.
They've cleaned and flushed the expansion tank and refilled the coolant system.
Dipstick still reading spot on.
I've asked them to check ATF level is OK and I will collect it on Friday morning and take it to MB for the once over
Interestingly, I posted my tale on a dedicated Mercedes forum and another 3.6 AMG owner has exactly the same problem
https://forums.mbclub.co.uk/threads/w124-e36-amg-o...
They've cleaned and flushed the expansion tank and refilled the coolant system.
Dipstick still reading spot on.
I've asked them to check ATF level is OK and I will collect it on Friday morning and take it to MB for the once over
Interestingly, I posted my tale on a dedicated Mercedes forum and another 3.6 AMG owner has exactly the same problem
https://forums.mbclub.co.uk/threads/w124-e36-amg-o...
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