Foreign object in cooling system

[LShute]

About 3 weeks ago I had my cooling system flushed at Cummins Cumberland in Knoxville. They used the Restore product. The temp gauge normally shows about 1/3 max, but when I left the shop, it went just past 2/3 then dropped below 1/3, bobbled around some then settled in at about its normal reading. I drove 2 hours home with nothing unusual. The next time in the truck, the temp gauge went up to 2/3 again and showed no sign of topping out so I came back home and called the shop. I noticed I had heat in the cabin so we concluded the water pump was ok, and the radiator must have gotten clogged from the crap washed out during flusing. So I installed a new OEM radiator, and drove it only to find the same condition; overheating with no sign of topping out at 2/3 gauge. So this time I did what I should have done the first time; felt the top radiator hose. It was cold, but the head was warm just past the thermostat. So I figured this meant a bad thermostat. When I pulled the thermostat housing, I noticed what looked like a grommet of some kind setting about where it appears in this picture . I'd changed thermostats a couple of times before and didn't remember seeing this thing then, but figured it must normally reside in the little pocket behind where it appears in the picture. The grommet was pretty well degraded, I could push right through it with my thumbnail, and a small piece was missing along the outside. So I called parts at Cummins Cumberland, and said I needed what seemed to be a grommet. The parts guy was looking at an exploded view and picked right up on the term grommet so I thought all was ok. When the part came today, it was the normal gasket, about 2. 5" in diameter that goes in in back of the thermostat in the housing. So, on the phone again, this time nothing that would be described as a grommet was seen by the parts guy so I asked to be bounced over to service. The service guy didn't know what I was talking about so I emailed him this picture. He figures it is something that shouldn't be in the cooling system; just got left in or dropped in during assembly.



So I wonder if anyone knows what this thing is. The fact that it's degraded, while the thermostat gasket is still in good shape after 13 years indicates to me the grommet was not intended for the cooling system environment. Here's another picture of it. It's about 3/4" in diameter (OD), with a hole about 1/4" or less in the center. It's about 3/16" thick and has 4 little tabs or ears 90 degrees apart around the oustide.



If anyone recognizes this thing, I'd sure appreciate knowing what it is.



Thanks.



Larry

 

[RGT]

it looks a bit like the sealing gasket for a garden hose, possibly used in flushing system? or maybe the sealing gasket for one of those T's that you splice into a heater hose to perfom flush?

 

[JLEONARD]

It looks like a garden hose washer to me as well.

How about sending the pic to Cummins and ask them??? Yae right!

At least you found it!

 

[bmoeller]

Originally posted by RGT

it looks a bit like the sealing gasket for a garden hose, possibly used in flushing system? or maybe the sealing gasket for one of those T's that you splice into a heater hose to perfom flush?

Thats what I think it is too.

 

[LShute]

Thanks for the ideas. I called the night service guy at Cummins Cumberland and asked if they use any hoses etc. when doing a flush. He said no; they just dump it in the top of the radiator and this thing didn't come through a radiator. Of course this doesn't rule out the hose grommet idea. I had the prior flush done at a Dodge dealer and don't know what they did. It doesn't look like a hose grommet to me mainly because the center hole is only about 3/16" and it has the 4 tabs. I'd think the tabs might be some kind of alignment device although there isn't much alignment to do in a perfectly round object.

 

[BushWakr - RIP]

I don't know... ... . I'm leaning toward a grommet or gasket for the 'valve' used when doing reverse flushes too... ...

But how would it get from inside the valve (assuming that is were it is from) thru any hose and into the thermostat housing...



Too wierd... . but you never know with some dealers, often the guy who does the rad flushing is a generalist or the detail guy...



bob.

 

[Joseph Donnelly]

I don't think it is a garden hose washer. It looks like a flow restrictor; such things are found in some heater hose nipples. I don't know of them being used in the Cummins, but I am not familiar with the heater lines and fittings on first gens.

 

[Deezul1]

I agree with Joe, the hole in the center is too small to be a hose washer. Is the problem solved? It sounds kinda like air is trapped in the system causing poor circulation.

 

[RGT]

I thought the hole in the middle might be a little small for a standard garden hose,( but I have seen some pretty small diameter garden hoses) that's why I thought maybe the sealing gasket for one of those splice in T's with cap. I have noted tabs on hose/cap sealing washer's to keep them in the threaded collar when the connection is broken, or cap removed. I like the idea of some sort of flow restrictor for a heater hose though... ...

 

[RBergman]

does it fit in the 2nd smaller hole closest to the cylnder head ?



i have never had one of these out but have changed some

with a rubber cushion/stop?



just a idea

 

[LShute]

Originally posted by RBergman

does it fit in the 2nd smaller hole closest to the cylnder head ?



i have never had one of these out but have changed some

with a rubber cushion/stop?



just a idea

If you're refering to the little 'pocket' just inside the head, this was my first thought too. But surely a parts exploded view would show it there or somewhere on the drawing. Anyway, the one I have is shot so I'd have to find a new one which I can't do unless it's identified.



I went to a Dodge dealer today, looked at the parts view and talked to a tech. Nobody had any idea what this thing is. I also went to an auto parts store to look at their flush kits. Nothing like this anywhere. So the common guess is this thing doesn't belong in the cooling system. The Dodge tech did say it doesn't take much at all to stop the thermostat from opening. Given where I found this thing, I'm hoping that was what was happening. So I'm going to put things back together without this item, and see how it goes.



Thanks to everybody who commented.



Larry

 

[DPKetchum]

Any possablity it has anything to do with block heater fitting?

 

[LShute]

Originally posted by DPKetchum

Any possablity it has anything to do with block heater fitting?

I'll go past the Dodge dealer and see if the parts guy will let me look at that drawing. Thanks.