Burning water - comments on combustion chamber?
Discussion
Would anyone care to comment on the photos below? This is a Honda B18C6 engine which I rebuilt 3500 miles ago but continues to burn water.
I believe that there is coolant getting into all of the cylinders due to the red colouring on the exhaust valves, but this does seem odd. The head was torqued down correctly and in sequence. The only thing I did differently this time was to use a little wellseal on either side of the (OE MLS type) gasket on the advice of my machine shop. This appears to have baked on and left the black residue you can see.
Symptoms are water loss, slight miss when cold, runs fine hot. No noticeable smoke when running, but if you get it hot, turn off and restart a few minutes later it blows out a big plume of white smoke before settling down as before. There are no visible cracks in either bores or head, though I haven't had it pressure tested.
I believe that there is coolant getting into all of the cylinders due to the red colouring on the exhaust valves, but this does seem odd. The head was torqued down correctly and in sequence. The only thing I did differently this time was to use a little wellseal on either side of the (OE MLS type) gasket on the advice of my machine shop. This appears to have baked on and left the black residue you can see.
Symptoms are water loss, slight miss when cold, runs fine hot. No noticeable smoke when running, but if you get it hot, turn off and restart a few minutes later it blows out a big plume of white smoke before settling down as before. There are no visible cracks in either bores or head, though I haven't had it pressure tested.
Steve_D said:
Does the inlet manifold have water passages?
Perhaps you are introducing the water into the inlet air stream.
Steve
Yes, it does - good point. However, it would only "feed" number 4 pot, and I think that all of them are getting a bit of a bath looking at the redness in the combustion chambers - would you agree?Perhaps you are introducing the water into the inlet air stream.
Steve
Also, regarding the system pressurising - I think it must have been. I did notice once when the car was hot that the level in the expansion tank was well over the max.
Boosted LS1 said:
You may be losing water but I wouldn't associate redness of the exhaust valves with water in the cylinders. I can't see any evidence of steam cleaning going on in there. Is there any way for water to get into an exhaust port, a crack maybe?
I'll get the head pressure tested tomorrow which should confirm. I'd agree that there's no sign to show a specific failure on any of the cylinders, though I've never had exhaust valves that red before. I half wondered whether the wellseal had caused problems and was allowing a little water in across all the bores?Given the symptoms, should I be able to exclude problems at the bottom of the liners - my reasoning was that it had to be leaking into the combustion chamber under pressure rather than under the pistons otherwise it wouldn't steam on re-start.
stevieturbo said:
You might want to look at what fuel additives you are using as opposed to water.
Water in the combustion chamber cleans things, not colours them.
No fuel additives, usually just Esso super unleaded.Water in the combustion chamber cleans things, not colours them.
I'm definitely using water, which is expelled as water vapour, therefore I guess it's getting into the combustion chamber at some point. I agree that it hardly looks steam cleaned, though I'm struggling to think of other hypothesis.
itiejim said:
I have no reason to believe that it isn't pressurising correctly - when hot the level in the expansion tank is higher then when cold. What are you thinking???...
Any car with HG/coolant issues will interfere with the normal operation of the cooling system.It will either pressurise too much, or simply blow the water right out. It may maintain pressure long after the car has cooled down again too.
It can introduce air into the cooling system so it no longer functions correctly due to air locks, heater may be erratic, gauge may not work as normal etc
Either way, it will not be normal.
Did you conduct any tests before stripping the engine again ? Sniffer test ?
OK, firstly, this was a very minor loss - max to min on the header tank in about 200 miles. Normally I would have let this develop, however, I'm booked on a track day next Monday so wanted to make sure it was all sorted.
The amount of white smoke on a hot start, plus the coolant loss and seemingly excessive increase in header tank coolant pressure when hot convinced me that there was a minor seep in the gasket (or cracked head / liner) so I stripped it without a sniffer test.
In terms of other symptoms - a slight miss when cold, plus the engine seemed to get to operating temperature very quickly. Water temperature was stable and never overheated.
I've just checked the bores and can't see any cracks, the head is in the machine shop today being pressure tested and checked. I keep coming back to this "oranging" in the chambers though. It's even present in the top of (all of) the bores and the colour is identical to the coolant.
The amount of white smoke on a hot start, plus the coolant loss and seemingly excessive increase in header tank coolant pressure when hot convinced me that there was a minor seep in the gasket (or cracked head / liner) so I stripped it without a sniffer test.
In terms of other symptoms - a slight miss when cold, plus the engine seemed to get to operating temperature very quickly. Water temperature was stable and never overheated.
I've just checked the bores and can't see any cracks, the head is in the machine shop today being pressure tested and checked. I keep coming back to this "oranging" in the chambers though. It's even present in the top of (all of) the bores and the colour is identical to the coolant.
Edited by itiejim on Tuesday 10th May 17:06
I think the colour is misleading.
I dont see how anything in the coolant which is mostly water could cause discolouration.
But you should really have done some proper diagnostic checks before stripping the engine. As you arent really sure what you are looking for now.
Out of interest...why is the coolant orange ?
I dont see how anything in the coolant which is mostly water could cause discolouration.
But you should really have done some proper diagnostic checks before stripping the engine. As you arent really sure what you are looking for now.
Out of interest...why is the coolant orange ?
itiejim said:
No fuel additives, usually just Esso super unleaded.
I'm definitely using water, which is expelled as water vapour, therefore I guess it's getting into the combustion chamber at some point. I agree that it hardly looks steam cleaned, though I'm struggling to think of other hypothesis.
You do know you get water from burning petrol as well as co2I'm definitely using water, which is expelled as water vapour, therefore I guess it's getting into the combustion chamber at some point. I agree that it hardly looks steam cleaned, though I'm struggling to think of other hypothesis.
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