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So, this looks like a really lame engineering choice, running the big coolant pipe right between the turbo/ cat and the engine block.
Comparing the Honda motor:
To the Mazda 2.5 motor. Mazda puts all the hot parts in back, well separated from other stuff, that makes service access a whole lot harder, but the coolant won't get cooked.
I am just trying to get my head around the design. Any comments? Do these engines need to be idled for a minute after a spirited drive to cool them?
John Davies
Spokane WA
2022 RDX SH-AWD A-Spec Advantage on order
Last edited by John E Davies; Nov 7, 2021 at 10:38 AM.
Probably for packaging reason. The Mazda engine also has a pipe going from water pump to the other side, and also under the hot turbo. Is it worse than Honda then? I would not say so, I rather believe the engineers have taken all factors into account, and made the most reasonable choice based on the constraints they needed to work with.
As long as an engine does not knock and overheat easily, I would not think too hard about the details, even though marketing materials may say otherwise.
The top pic is an ACURA motor, with hard stainless steel pipe. I posted a HONDA pic below that to show the location of the turbo. Yes it does indeed appear to have a rubber hose there, holy cow!. That is even worse. I wonder how often that will fail from heat? Here is the ad I took that top image from:
I think you should immediately cancel your RDX order if you can site any issues on any 4 cylinder HONDA engine with a coolant pipe or any other pipe on the front for the engine.
Also….The pipe is not stainless and has never been stainless for the last 40 years or more years ………if the type of metal or rubber has you concerned.
I don't want to be offending, but if OP needs to be this worried about the coolant pipe design, then perhaps you should look elsewhere. I am sure there are engineering tradeoffs everywhere you can find that is not the best in theory, but works just fine in reality.
The coolant circulates all the time, and you know the coolant passes through the exhaust port surrounding, so the extra passage on the outside really does not matter as much as you think. The coolant does its job, and Honda tends to over-spec the radiator so really I would think this is non-issue.
