Every BMW that we service always needs coolant, even though they don't leak and its not mixing. They all use it, maybe thats where its showing up.
RLI BioSynXtra 15w-40 Low Ash, 7024mi, 1996 BMW M3
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A head gasket is an afternoon job FYI. However, I would recommend sending it off to a good local machineshop thats done BMW stuff before to have it decked & pressure tested.
Maybe I wasn't clear.
I'm trying to figure out how likely it is that the head gasket is leaking in the first place. Thus, I ask: is there any way for coolant to get into this engine's combustion chambers other than through a leak in the head gasket?
I'm trying to figure out how likely it is that the head gasket is leaking in the first place. Thus, I ask: is there any way for coolant to get into this engine's combustion chambers other than through a leak in the head gasket?
Cracked block could be an entry point, bu doubtful. I also think there is a heater line that runs to the throttle body to warm it up quicker.
I know of an entirely different engine that leaked coolant into the throttle body, as mentioned above. That makes it way into the combustion chambers.
But that is a lot of sodium in your oil, yet glycol test said zero and potassium is low, so I have some doubt that the sodium is not from the oil.
But that is a lot of sodium in your oil, yet glycol test said zero and potassium is low, so I have some doubt that the sodium is not from the oil.
MolaKule
Staff member
Quote:
So, here's something potentially troubling: after checking with RLI, it seems sodium is NOT an additive in this oil after all.
What did the VOA of this oil show?
So, here's something potentially troubling: after checking with RLI, it seems sodium is NOT an additive in this oil after all.
What did the VOA of this oil show?
MolaKule
Staff member
recommendation: Either have the oil sample restested or do a VOA to make sure the sodium is NOT an additive component.
Some coolant manufacturers do use Sodium 2-mercaptobenzothiazole as an corrosion inhibitor.
But some detergents in engine oils may show some high sodium as well:
https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2764914#Post2764914
Some coolant manufacturers do use Sodium 2-mercaptobenzothiazole as an corrosion inhibitor.
But some detergents in engine oils may show some high sodium as well:
https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2764914#Post2764914
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Originally Posted By: MolaKule
recommendation: Either have the oil sample restested or do a VOA to make sure the sodium is NOT an additive component.
Some coolant manufacturers do use Sodium 2-mercaptobenzothiazole as an corrosion inhibitor.
But some detergents in engine oils may show some high sodium as well:
https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2764914#Post2764914
Thanks so much, Mola.
I do have a couple of Blackstone kits kicking around. Maybe I'll fire one off with virgin oil.
recommendation: Either have the oil sample restested or do a VOA to make sure the sodium is NOT an additive component.
Some coolant manufacturers do use Sodium 2-mercaptobenzothiazole as an corrosion inhibitor.
But some detergents in engine oils may show some high sodium as well:
https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2764914#Post2764914
Thanks so much, Mola.
I do have a couple of Blackstone kits kicking around. Maybe I'll fire one off with virgin oil.
Originally Posted By: Seventh
Pretty common to see S52 motors with very slow HG leaks. One of the classic symptoms is sputtering and misfires upon initial start up after sitting overnight or more, clears up after revving the engine a bit. Yours do that?
Not as far as I can tell. It's a bit jerky on throttle transitions, but it's like that at all temps. I figured there's probably something electrical to blame for that.
There's no white smoke or sweet smell from the exhaust, either.
Pretty common to see S52 motors with very slow HG leaks. One of the classic symptoms is sputtering and misfires upon initial start up after sitting overnight or more, clears up after revving the engine a bit. Yours do that?
Not as far as I can tell. It's a bit jerky on throttle transitions, but it's like that at all temps. I figured there's probably something electrical to blame for that.
There's no white smoke or sweet smell from the exhaust, either.
Originally Posted By: d00df00d
Originally Posted By: Seventh
Pretty common to see S52 motors with very slow HG leaks. One of the classic symptoms is sputtering and misfires upon initial start up after sitting overnight or more, clears up after revving the engine a bit. Yours do that?
Not as far as I can tell. It's a bit jerky on throttle transitions, but it's like that at all temps. I figured there's probably something electrical to blame for that.
There's no white smoke or sweet smell from the exhaust, either.
Good. Your complaint about WOT behavior makes me think ignition though. There are only two acceptable spark plugs for this app, what do you run? Easy enough to check the resistance of the coils and plug boots too, but that alone isn't going to tell you everything. New Bosch coils ain't cheap but are easy to swap, got a buddy with a similar car? Have you checked the torque on the plugs? I went to change my (S52) 332ti's plugs and found three loose! Car ran great but even better now!
Edit: On the other topic, it would also be worthwhile to pay a competent shop with a smoke machine to do a leak test on the intake/crank case, and know definitively whether or not you have a leak.
Originally Posted By: Seventh
Pretty common to see S52 motors with very slow HG leaks. One of the classic symptoms is sputtering and misfires upon initial start up after sitting overnight or more, clears up after revving the engine a bit. Yours do that?
Not as far as I can tell. It's a bit jerky on throttle transitions, but it's like that at all temps. I figured there's probably something electrical to blame for that.
There's no white smoke or sweet smell from the exhaust, either.
Good. Your complaint about WOT behavior makes me think ignition though. There are only two acceptable spark plugs for this app, what do you run? Easy enough to check the resistance of the coils and plug boots too, but that alone isn't going to tell you everything. New Bosch coils ain't cheap but are easy to swap, got a buddy with a similar car? Have you checked the torque on the plugs? I went to change my (S52) 332ti's plugs and found three loose! Car ran great but even better now!
Edit: On the other topic, it would also be worthwhile to pay a competent shop with a smoke machine to do a leak test on the intake/crank case, and know definitively whether or not you have a leak.
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Originally Posted By: Seventh
There are only two acceptable spark plugs for this app, what do you run?
These:
http://www.boschautoparts.com/VehiclePar...p;part_num=7405
...and they're probably overdue for replacement. No idea why I hadn't thought of that until now. Thanks!
On another note, a mechanic friend of mine is going to hook me up with a compression check, cooling system pressure test, and coolant hydrocarbon test.
I also had the opportunity today to inspect the throttle body and intake manifold inlet for coolant. I thought I saw a very light fluid film in the manifold, but couldn't tell if it was coolant.
There are only two acceptable spark plugs for this app, what do you run?
These:
http://www.boschautoparts.com/VehiclePar...p;part_num=7405
...and they're probably overdue for replacement. No idea why I hadn't thought of that until now. Thanks!
On another note, a mechanic friend of mine is going to hook me up with a compression check, cooling system pressure test, and coolant hydrocarbon test.
I also had the opportunity today to inspect the throttle body and intake manifold inlet for coolant. I thought I saw a very light fluid film in the manifold, but couldn't tell if it was coolant.
Can't tell for sure because the part number isn't legible in the pic, but that looks like the correct FGR8KQC plug. BKR6EQUP is also ok.
The thin fluid in the intake is likely just a bit of oil. Never once have I seen a throttle preheat leak get inside the engine of a modern BMW. It's just not possible unless the throttle housing cracks or is internally corroding away.
The coolant line goes into the housing, flips a 180 and comes out. It doesn't pass through any gaskets or anything. The whole passageway is cast into the throttle housing and is fully contained within.
Coolant hydrocarbon test is good. If you're gonna do a compression test, easy enough to do a leak down test as well. Do that with the coolant cap removed and the cooling system pressure tester attached but NOT pressurized. Watch for the needle on the pressure gauge to come up from zero during testing - BAD.
You can also do your coolant pressure test with all the plugs removed. Let it marinate like that for as long as possible and when you're done use a really long q-tip or clean paper towel on a coat hangar rod and use it like a dipstick in each cylinder, see if you come up with blue (or whatever color coolant you use). - BAD
But honestly without any significant symptom besides some mysterious UOA numbers, I don't think you have a HG problem. I think you have an intake or crank case ventilation leak. Possibly an ignition problem based on the minor symptoms you do have. That's my internet diagnosis
The thin fluid in the intake is likely just a bit of oil. Never once have I seen a throttle preheat leak get inside the engine of a modern BMW. It's just not possible unless the throttle housing cracks or is internally corroding away.
The coolant line goes into the housing, flips a 180 and comes out. It doesn't pass through any gaskets or anything. The whole passageway is cast into the throttle housing and is fully contained within.
Coolant hydrocarbon test is good. If you're gonna do a compression test, easy enough to do a leak down test as well. Do that with the coolant cap removed and the cooling system pressure tester attached but NOT pressurized. Watch for the needle on the pressure gauge to come up from zero during testing - BAD.
You can also do your coolant pressure test with all the plugs removed. Let it marinate like that for as long as possible and when you're done use a really long q-tip or clean paper towel on a coat hangar rod and use it like a dipstick in each cylinder, see if you come up with blue (or whatever color coolant you use). - BAD
But honestly without any significant symptom besides some mysterious UOA numbers, I don't think you have a HG problem. I think you have an intake or crank case ventilation leak. Possibly an ignition problem based on the minor symptoms you do have. That's my internet diagnosis
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