Insight Coolant Flow Diagram

[jeff652]

Hahah Cool! Neat pics. Glad to be a part of this in a very small way!

Very informative! Those parts in the pics are off of a 2004 for documentations sake

[highwater]

Thanks Jeff, I edited that year (2004) into the first post.

Have had some questions presented about the actual function of that oil/coolant interface, that Honda calls a warmer.

I see it acting as a temperature equalizer between the oil and coolant.
I labeled it warmer/cooler in the diagram, although Honda calls it only a warmer in their descriptions.

I question; once the entire mass of the ICE assembly, gets up to maximum operating temperature, this piece of hardware does nothing?
Randall

[jeff652]

When I saw it, I immediately thought about how similar it looks to the oil cooler on some of the VTEC Integras. It's basically identical:


When I was racing, my oil temps would regularly get up over 280+ degrees. Running the oil through a water-to-water (oil to coolant) intercooler significantly reduces oil temperatures.

Edit: Just read your post that Honda has labeled this as a warmer on the Insight. Strange. Probably to warm the oil faster and keep it hot when the engine is doing start/stops around town

[highwater]

As the G1 Insight ages, we will begin to experience difficulty getting factory Honda parts. I read a post, found during searching for information on the coolant path, where the person had received notification from Honda that the part in question, was not in any of Honda’s US warehouses. This was one of the hardline coolant tubes that mounts to the water outlet cover, with an o-ring seal. I believe this hardline had corroded quite badly, and there was concern over re-installing it.

So, let’s look at options and scenarios that might present themselves, in regards to the cooling system parts and ways of dealing with those parts shortages, possible hardware damage, and some fixes to these problems.

Once again, we will encounter that oil warmer thing. Obviously, Honda decided this part could be eliminated, so we know we can do without it. Easy to work around when you don’t actually need it.

Simplest problem to fix would be if the outer housing of the warmer, became ruptured due to puncture from road hazard, or was eaten through by corrosion. The coolant flows inside the outer jacket in this item, and the oil flows in and out through the center portion, on its way to and from the oil filter. Provided there has been no breach between the oil and coolant passages of the oil warmer, we can just bypass it, even if caught away from home. Simply take either of the small hoses coming out the bottom of the water pump housing going to the warmer, and connect this hose, using a clamp, back to the other fitting on the water pump. Doesn’t matter if it has a kink in it, there will be no flow through this hose, nor is any needed. Check coolant level. Get back on road.

Once the warmer is no longer functioning as an integral part of the coolant system, we can physically remove it, if we wish. This will need to be done during an oil change, or the engine oil will need to be drained. We will also need the shorter oil filter mounting bolt from the 2004 and later model G1’s. Honda calls it “bolt, oil filter base”, PN 15560-PHM-000. After the oil filter is removed, take the longer original bolt out, remove the warmer and the thick aluminum spacer behind the warmer. Using the new shorter bolt, mount the aluminum spacer back to the block. The aluminum spacer has a key, on the bottom edge pointing toward the engine, that indexes against a boss on the engine block, which keeps the spacer from turning clockwise when the bolt is tightened. If notice is taken on disassembly, we can easily see how to put it back. Now we are back to something that feels familiar. Complete the oil change.

If we want our fix to look pretty, we can replace the possibly kinked hose running from one fitting on the pump housing to the other fitting, with a couple of those nifty little rubber caps, like up on the fill port. Same size plumbing. We would have needed to order 2 of them, known as; Cap, sealing PN 91657-SD5-000, when we ordered the short mounting bolt.

On my latest Honda parts order, I got the “not in any US warehouse” reply on the longer oil filter base mounting bolt for use with the oil warmer, on the 2000-2003 model years. Can’t say about the shorter bolt, haven’t tried ordering one of those yet. Wasn’t in need of the longer bolt, just wanted to take some measurements.

Randall

[retepsnikrep]

A really excellent series of posts and ideas. Thanks

[highwater]

Originally Posted by highwater

As the G1 Insight ages, we will begin to experience difficulty getting factory Honda parts. I read a post, found during searching for information on the coolant path, where the person had received notification from Honda that the part in question, was not in any of Honda’s US warehouses. This was one of the hardline coolant tubes that mounts to the water outlet cover, with an o-ring seal. I believe this hardline had corroded quite badly, and there was concern over re-installing it.

So, let’s look at options and scenarios that might present themselves, in regards to the cooling system parts and ways of dealing with those parts shortages, possible hardware damage, and some fixes to these problems.

I had gathering up some notes on the cooling system stuff, and need to get them posted before "wrote it down, but forgot where i put it", takes place.

About the connecting coolant hose from the hard line, view #8 on the coolant flow diagram; Honda PN #19503-PHM-000 HEATER PIPE, over to the water pump. Its the larger of the coolant hoses (not radiator hose) that is connected to the water pump.
The factory replacement for this hose is PN #19509-PHM-000. They were still available from Honda, last time I ordered, so I have one here in front of me to play with (plus a used one, thanks Jeff). The neck on the water pump measures (point 889/point 890) inches, which is 22.5mm. So this gives us the inside diameter of hose needed for a replacement. Didn't have much luck finding that size metric coolant hose.
However; I think we could push .875 inch, 7/8ID hose over those 2 pieces of hardware at either end of that hose. Still I find 7/8inch to be a rare animal.
Gates lists 3 PN's in their catalog for 7/8 molded coolant hose:
PN 19802 7/8 x 5.125
PN 21222 7/8 x 5.8125
PN 21746 7/8 x 6.3125

The factory hose 19509-PHM-000 measures 12cm along the bend, just short of 5 inches. Looks like any of the Gates hoses would work, even the shortest one needing to be trimmed slightly. The molded bend in some of them might be troublesome. Since I have the factory hose in hand, I will go to NAPA and see what the guys there can get for me of the Gates numbers. Can compare with the factory hose. I'll report back on this.

Now, about that hard line the member had trouble getting from Honda, the same we will talk about here PN 19503-PHM-000. I searched most all of the Honda models and years for something from the factory that might work. Other than the Insight that is, because the Insight parts are the ones disappearing off the radar. If we could find a late year model, perhaps we would have the needed replacement available for a longer time frame. The only thing I found close was Honda PN #19510-R40-A50 HEATER PIPE. Accord 2010 2dr EX; on the Water Hose L4 page. It is view #4 in the top corner. Looks like there has been an update, because view #13 is not listed (using Majestic parts page).
You will have to flop ends over to make it look like(fit) the one on the Insight diagram. It has the little fitting welded to it, that might be used for the smaller hose going down to the IAC. As long as we can cut it off past the little fitting, if it is too long. The reason I think this might work, is the o-ring size. The o-ring size on the Accord part is 19.3 x 3.8. The o-ring size on the Insight is 19.6 x 3.8. Point 3mm is not much. That's 12 thousandths (point 012) for we inch guys. Another reason this might work is the size of the smaller IAC hose fitting on both hard lines in question. On both the Accord part, and the Insight part, the hose clamp is the same PN #95002-41250-04 (D12.5). I couldn't find the actual size of the hose listed, but if the OD is the same, perhaps the ID is the same.

This hard line fix is not known for sure at this time. Just observation on my part. Next time I order factory parts, I will probably order the Accord part and see if it can be made to work. For 18 bucksUS inquiring minds want to know.

Another "get back on the road fix", might be to run bulk hose from the heater return on the firewall around to the water pump, bypassing the outlet cover/hard line all together. That would take the fill port out of the system, so that would need to be addressed, and the IAC would have to be taken out of the loop. But I haven't found any bulk 22.5mm hose.

More later.

Randall

[highwater]

fixed all pic links to gallery with 4009dash
Randall