redmuck

well when that one guy was told about they always leak a little. they either leak or they dont, if its leaking you hav to find the problem. thats the lazypersons excuse. i've got oil leaking everywhere and i dont say, oh they always leak, thats normal. its somthing i hav to fix.

Mike1998XJ

Any suggestions on what the cause might be?
Mike

Dr ZEE

Mike! That's a good question..heh heh
Here's what I think based on what I "gathered" so far.
One thing is pretty clear to me is that the coolant gets through between the lever and the o-ring.
Now, as it leaks only for a short period of time , right after the start when the valve unit is cold and after some period of time of engine being off (so no coolant movement for , let's say, 8 hours of so...) , I think there maybe two factors here - space between o-ring and the lever and the sealant "condition".
I am attaching here couple of close-up photos here. There are photos as what it was "originally" like. As you see there's actually some kind of lube or lube/sealant stuff in there, it was some sort of jello stuff. Maybe it ment to provive lubrication, maybe seal, maybe both ... I'm just guessing here. But the most of it was applied around the washer, and then I see very little down to the o-ring, but there was some of it there too.
So, what I think is happening here, as the parts get gold and a bit dried ...the space between the o-ring and the lever opens up a little. So the first "hit" of the coolant at the start gets through and leaks for a while. Then as the sealant being pushed by coolant and as the parts gets warmer and so do expand - the space gets tighter and the sealant clugs better the tighter space...and so the leak stops.
Does this make sense??? I think in theory it kind of does make sense, but I really only wish that the reality was following the brain's fantasy ...
here are these close ups of how it was originally there:

Dr ZEE

so again, my idea was to apply some pressure on the o-ring and add some more and stikier sealant.
I've edited the diagram, so it shows before/after "situation" , maybe this illustrates a bit better what I was trying to achive.
Well, tommorow morning will be the first dry/cold start. I shall see. But then again, I guess, it all worthy only if it works long run, so only time will show how it works if it works at all.
here's diagram:

84supersport

Personally I think its a bad design issue. I know on mine we replaced and flushed and burped and refilled with new coolant everytime the system was serviced. We were trying to compete with the common XJ higher than normal coolant temp on summer so we were in there alot trying different t-stats and drilling bypass holes in the t-stats.

Mike1998XJ

Dr Zee:
I see what your getting at, yet can't help but ponder the original design intent of the valve. Assuming the new part did not have a defect (always possible it does) it had to have been designed to function without the washer spacer your adding.
I can see you are very detail oriented... We aren't missing something simple like flash at the parting line of the rubber washer causing the leak are we?
Just out of curiosity what manufacturer built the valve? To rule out the possibility of a bad "new" valve why not take it back 1 more time and get another one?
How about contacting the manufacturer of the valve, giving them the nomenclature off the valve and see if they had a suspect batch go through. You never know what you might find until you dig...

Mike

Dr ZEE

Mike,
I've got it from Advanced Auto Parts
Part Number 74777
the "title" is "Factory Air Heater Valve"
who makes it(them) - I have no clue. Honestly I kind of don't care to find out at this point.
Yeah, I'd love to chat with The ACTUAL designer/engineer of this valve, but chating with a sales person - nop , I'm not in the mood for that one right now...heh heh
The reason I've got into this was mostly because I've seen many posts and found some other on different b-boards, people saying that they have these valves leaking, and even after trying "different" parts from autozone and from NAPA..., well, maybe they are not so different really.
So the whole "idea" here maybe to find the way to "improve" that valve's seal.
I thought of few ideas how it could be designed a bit differently, but that would be just more "fantasy talk"...

From what I see - it does not look to me that there is any "deffect" there per say. Now, well, maybe it was "designed" to function as designed, but it does NOT function. If it did, then there would be nothing to talk about ...heh heh
Maybe all it needs just very slightly thiker(so sitting tighter) o-ring... ,
If I was designing this thing, I'd think, I'd add groove to the lever, so the ring would snug into it, and so there would be no "straight forward" channel for the coolant to pass through, and also this would provide better "cave" for the sealant compaund.
well, blah blah ...heh
**********

this morning everything was cool ... btw , will see how it goes ...

Dr ZEE

Also, I failed to mention, I think that maybe there's no need for the "second washer" (but I don't have that "experiment" on hands, as I did both - sealant and the washer).
But maybe just adding extra thiker/stickier sealant, that will fill the channel down beyond the o-ring, will be just enough to stop that 'minor' leak. As I understand, the coolant can leak through very small spase, but under the same pressure the thiker/sticky sealant will not , and so the coolant will "push" through and be stopped by sealant. But then again, the question is - how long such sealant will maintain its properties under the conditions in place?
The good thing is, that if it works for some period of time, so then you don't have to keep getting new valves if it leaks, but instead just open it up, re-seal it - and it's like new again ...

redmuck

i hav no idea. i just flushed mine yesterday and today and i hope i dont hav any problems.

calijeep

is that installed correctly? i just removed my old one and installed a new one and i think i put mine in opposite of how you show. am i wrong? that arrow is up or down? hmm

Dr ZEE

Uh! That's a good question.
Actually I was thinking myself about that arrow... I did connect everything the same way as it was before and decided to not try "experiment" different way. But maybe it's was not "correctly" connected by PO/or a mechanic. I was searching the web and could not find any exact valve with exact "correct" connection/installation diagram anywhere.
Then when I had that valve unistalled and was looking into it trying to figure out how it works, I was running water through it and was opening/closing the valve by pressing the actuator...so I "figured" that it works either direction the same way, well, that's accordingly to my "in the bath sink" investigation ..heh heh
As you see on the diagram I've made-up and posted above, the valve is routing the flow, and as long as when the valve is OPEN the coolant flows from pump through valve into heater's intake and then from heater's out through valve to thermostat "body" on the engine, then it should work. But I MAY BE WRONG , so don't take my word on it.
If anybody knows for sure, please speak up ... or maybe there's somewhere on the web a detailed instruction on how to exactly install/connect this specific type of valve that I just could not find.
The valve I bought from Advanced Auto did not have any installation instruction paper, ..hmmmm, maybe it was missing (???)
**********

btw, so far - everything is dry and I had no leak since, there were couple really cold nights here, started cold - no leak so far, so that last "fixture" seems to work at least for now
If the leak will come back - I'll post an update.

calijeep

yeah. i'm not sure either. i just looked for the arrow on the old part and put it in exactly the same as before...which is inverted from your diagram. so far i have no leaks and heater is hot and temp has stayed at 210 (although it crept up tp 220 a few times which is unusual for Stella). i'll keep looking for this post.

calijeep

you did it correctly. the arrow indicates flow from t-stat housing. i did it wrong..but with a four port valve it works the same either way save for some efficiency loss at heater. i'll swap it this weekend when i replace hoses.

Dr ZEE

oh, but then my "diagram" is wrong. I thought that the direction is from pump to t-stat?
So which way is the coolant flows ..arghhhhhhhhh. If my diagram is wrong, then I better edit it and re-post. I'd hate to spread wrong info around. Could somebody confirm for sure, pleeeeeeeeeeese
i'll try to search...
************
.........
.........
UPDATE!!!!:
I've edited the diagram. Also I still am not 100% sure about this. Oh, well.

Dr ZEE

hmmmm, searching does not help much .
here's one: http://media-2.web.britannica.com/eb...4-809BD332.jpg

here's another: http://www.autorepairintheknow.com/w...ing-system.jpg

go figure...
I thought there should be some general "rule"...I guess not, then
which way waters flow in XJ-"river" , does anybody know for sure????