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Coolant leak '99 Plymouth grand voyager

17K views 6 replies 6 participants last post by  gemnet 
#1 ·
Sorry if this has been asked and answered here, but I couldn't for the life of me find it....maybe cause I don't know exactly what I'm looking at.

Anyway, I have a '99 Plymouth grand voyager SE 3.3 with a coolant leak. I replaced the radiator, water pump, and upper and lower hoses last week and the car is still leaking like a sieve. If I pressurize the radiator, the leak seems to be coming from a hose that leads underneath the thermostat housing/water box down into a pipe that (I think) is attached to the timing chain cover. I replaced that hose but the leak still continues. Could there be a small pinhole in that pipe causing the leak? What exactly is that pipe? Do I have to replace the whole timing case?

Any help would be greatly appreciated. I have no problem doing the work myself, I just don't know what part I actually have to get. Thanks in advance.
 
#2 ·
Look at where it is leaking from carefully. That hose does connect to an outlet on the back of the timing cover, behind the water pump. It's possible that either the hose, or the clamps at either end are leaking. It's also possible that the t-stat housing gasket is leaking. It is also possible that the leak may be coming from the timing cover gasket. In that area, there is a coolant passage from the engine into the timing cover. It is sealed by an o-ring that sometimes gives out, causing the coolant to leak. Once the o-ring gives out, the coolant may leak past the gasket and out the back of the timing cover. Does the leak look like it is coming from the top of the timing cover? If it is coming from below, there is another inlet directly behind the water pump that leads to the metal heater return tube. These have a tendency to rust out over time and spring a leak.
 
#3 ·
That hose is the bypass hose. It keeps the water circulation in the block when the thermostat is closed and keeps warm water to the thermostat to help it open on time.
The fitting on the top side of the hose that goes into the intake manifold is rather thick and would take a long time to rust out. The lower fitting (pipe) is thinner and tends to rust out faster. It is pressed into the timing cover so you would have to remove the cover to do anything with it.
Also the intake manifold gasket is very close to the bypass hose so check to see if it is leaking and spraying out onto the hose.
If the timing cover seal fails it will look like this.
View attachment 5618
 
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#4 ·
Thanks for the prompt suggestions!

I've dried up all the wet areas and pressurized the radiator. The leak is definitely coming from the area where the bypass hose goes into the fitting behind the water pump where the timing case is. I'm going to pull everything off tomorrow and replace the hose and the gaskets and see if that works. If not I guess I'll be junkyard scavenging for a timing case cover.

I'll try and update as I go. Thanks again!
 
#5 ·
Did you look closely with a flashlight to see exactly where the leak is coming from? I have heard of the pipe coming from the back of the water pump loosening up and leaking (and sometimes falling out), but it seems more common for the timing cover O-ring/gasket to fail. Looks like if either one is leaking you will have to replace the timing cover anyway (or fix it). New timing covers are cost prohibitive, and difficult to get. I believe one member reattached that pipe with JB Weld and traded/sold the van.

I had to replace the timing cover gasket/O-ring on our van once, and it is leaking again 20,000 miles later. I used the Fel-pro gasket kit, and that may have been the problem. Next time I am using the OEM gasket and O-ring as it is a different material. Also, you have to drain the oil and remove the oil pan to remove the timing cover, because the oil pump is in the timing cover and the pick-up tube connects to it. It's kind of a big job that takes a whole weekend to do.
 
#7 ·
While I agree with Road Ripper, I feel I want to give you my version. I had a mysterious leak and no one was able to understand from where it was leaking. Not a huge leak but enough to empty the reservoir every month. The leak was so stupid, really stupid and was happening ONLY after I was driving a lot during the day... well, one night me and my friend were checking for a Chrysler MIL 31 (there's a thread here on that) and we noticed that a small hose, on top of the radiator, near the cap was leaking! Not just a drop or two... was a small stream... what was missing? A Clamp! Put the Clamp, now it's a month, going to be two that the reservoir is not emptying anymore! Yey...

Morale, some times it can be big but some other times... it can be a really small thing that make the difference... For the OP sake and wallet I hope it's a small one.
 
#6 ·
1999 Voyager 3.3 mystery coolant leak

My problem is similar to the mysterious coolant leak. I drive a 1999 Voyager with the 3.3 engine. I noticed there was a coolant leak that I initially thought was from the lower radiator hose, but once the engine cooled down and I jacked up the passenger side of the car the dripping became obvious. There is a bypass hose that goes between the thermostat housing and the back side of the water pump assembly. It was coming from the lower end of the bypass hose. I thought maybe the hose had sprung a leak so I began loosening it. When the top end was removed from the thermostat housing I jiggled the hose to get a better look at the other end, and much to my surprise the entire hose just slipped out of the block end, complete with the corroded nipple attached to it! When I cut the hose and peeled the nipple out of it, it looked like this...

Rock Artifact


A tube of rusted lace. This had to be where the leak was comig from, right?

The nearby parts store told me I would have to have it welded back in... I was crushed.

Then came the unholy odyssey of trying to find out what the name of that little doodad was so I could find one. There didn't seem to be any diagrams that showed it as a separate part. Eventually I found a dealership who knew what it was and gave me the part number (it’s an AC nipple, part #04621652AC) but didn't stock it. Long story short, another dealer did have it for the completely reasonable price of $12.95! It looks like this...

Cylinder Auto part Electronic device Metal


A stark difference!

Now came the time to install it. There is precious little room to work here so I had to be inventive. I solved the problem with an aluminum drinking straw from 7-11. I put the straw into the hole (it won't go too far inside, so don't worry) and slipped the nipple over the straw. Jiggling the straw helped to help seat it. Then I slipped a heavy washer onto the straw that had a hole a little bigger than the straw. It came to rest on the top of the nipple (you see where I'm going). Then a slightly larger pipe was fed over the straw and came to rest on top of the washer. Making sure the orientation of the nipple was just right, I began tapping into the hole. Tap tap, check progress. Repeat process until the nipple is seated almost to the graduated ring on the barrel. Fits like a glove! Remove the tools and replace the hose (5/8" heater hose). Honestly, the hardest part of the process was setting the lower spring clamp in place, but keep at it... it will eventually work out. I had to do that part from underneath the car.

Please let me know if this helped you at all at agentthirt33n@aol.com.

Happy motorin'
 
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