I had buried this problem in an obscure thread about cylinder head parts. I think it deserves its own treatment.
I am fixing a car that overheated and ultimately warped the cylinder head beyond Honda's limits for resurfacing. The car had a host of possible causes: broken water pump belt, failed rad cap seal, poor thermostat response and even a bad AC clutch. But I might have found out the source failure. It looks like the water outlet header was leaking at one or both rubber O rings at the pipes at the front. The overheating would have been caused by loss of coolant leading to other failures.
Those pipes were very stuck and after removing the chalky corrosion at the point of the O ring seal it was obvious that aluminum material was missing. I replaced that header with one from a donor engine but there was potentially a worse problem.
As you can see in the picture the plate covering the three high voltage connections below the header was almost completely eaten and had tapered down to the thinness of paper. In the picture the small break was caused by my fingernail but I could easily have broken off a large chunk. It was still sealing but would have corroded through very soon.
Who knows what would have happened if coolant had leaked into that electrical pocket. I guess the moral of the story is to eyeball that area every now and then. Does anyone know if coolant on those HV connections would be catastrophic?
Does anyone know if you can use plumber's grease or silicone on those coolant connection points? The O rings are a worry but actually, depending on how you count, there are 7-9 actual water to air points on that header. New, that aluminum header is $132 from Majestic. Maybe it would be possible to expand the steel pipe a bit to tighten the fit. This is a potential problem for our Gen1 Insights. Anyone want to comment?
Rick Hall
Caledon, Ontario, Canada
I am fixing a car that overheated and ultimately warped the cylinder head beyond Honda's limits for resurfacing. The car had a host of possible causes: broken water pump belt, failed rad cap seal, poor thermostat response and even a bad AC clutch. But I might have found out the source failure. It looks like the water outlet header was leaking at one or both rubber O rings at the pipes at the front. The overheating would have been caused by loss of coolant leading to other failures.
Those pipes were very stuck and after removing the chalky corrosion at the point of the O ring seal it was obvious that aluminum material was missing. I replaced that header with one from a donor engine but there was potentially a worse problem.
As you can see in the picture the plate covering the three high voltage connections below the header was almost completely eaten and had tapered down to the thinness of paper. In the picture the small break was caused by my fingernail but I could easily have broken off a large chunk. It was still sealing but would have corroded through very soon.
Who knows what would have happened if coolant had leaked into that electrical pocket. I guess the moral of the story is to eyeball that area every now and then. Does anyone know if coolant on those HV connections would be catastrophic?
Does anyone know if you can use plumber's grease or silicone on those coolant connection points? The O rings are a worry but actually, depending on how you count, there are 7-9 actual water to air points on that header. New, that aluminum header is $132 from Majestic. Maybe it would be possible to expand the steel pipe a bit to tighten the fit. This is a potential problem for our Gen1 Insights. Anyone want to comment?
Rick Hall
Caledon, Ontario, Canada