Busaboy

New to this forum and hope someone can point me in the correct direction. I have a 2001 grand Cherokee with the 4.0. Recently got it back from my ex after she smoked the motor. Completely rebuilt it and got it street able again when it decided to start spraying oil out back side of motor. 99.9% sure it's the rear main seal. But bigger problem is why is there coolant leaking from between transmission and those plates between motor and tranny? Drained oil and it is not milky or have any coolant in it so I am ruling out bad head. Any suggestions so I know which way to attack this. Thank you all in advance.

andrewmp6

Only places it can leak coolant back there is the heater hoses or from a freeze out plug in the head/block.

Bugout4x4

And it is pretty easy to distort a Freeze plug while tapping it in, even for experienced builders, it happens. This is why I always put a little yellow weather-stripping adhesive on the plug and the seat before tapping it in

Busaboy

with that being said. The machine shop put them all in. Where are the located at exactly and what all will I have to remove to replace them and how can u tell which one is leaking?

Bugout4x4

The first question would be how bad is it leaking? I ask this because if it is the one in the back of the block, the trans and bellhousing have to come out to change it. I have successfully stopped mild leaks on these permanently by using just a little Solderseal stop leak (not the whole tube) rather than pull the Trans.

Busaboy

its not leaking a whole lot. And really hard to tell actually how bad it is. Just put motor back in and drove almost 1,000 miles before the new rear main seal decided to take a crap. While laying under jeep I could see where it was dripping coolant with the oil. Was worried at first it was a head issue but it is dry. And ruled out heater core since it is leaking from Inbetween trans and those plates between motor and trans. Trying to get it running back to perfect but chasing my tail at the moment lol.

SteveMongr

Of the three Welch Plugs on rear of block, the middle one I know contains coolant.
To replace mine I dropped the transmission and transfer case using a transmission jack. Did not have to remove it from under vehicle, just rolled it rearwards a couple feet.
As often suggested I used brass plugs. The fit of the installation tool in plug is critical to a good seal.
http://go.jeep-xj.info/HowtoWelshPlugs2.htm

Bugout4x4

Yep it is the one in the back of the block then. If it is not leaking bad then the Silver dry Solderseal should work. There is a trick to it though, You want to use only about a half of a tube at first. You will want to put it in with the engine completely cold and then take a decent length drive in it, 30-40 miles at least.


You will want to drain out enough coolant to get the level below the bottom of the filler neck then put the sealer in and then replace the coolant making sure you get all the air out of it. The sealant has to end up down in the system and not be stuck in the filler neck.


Then take your drive. Please let me know if it works for you.

Bugout4x4

Yep...The one on the bottom right in your photo is the Camshaft plug and should not be touched.


Unless...? I wonder if the cam plug could be the source of the oil he is also leaking from this location? There is oil pressure behind the cam plug and if it was not installed correctly it would also leak.

SteveMongr

Will solderseal clog the small passages in radiator? I know that regular radiator repair stuff will.

Bugout4x4

I have had very good luck for years with the Solderseal not clogging up stuff Steve. I will not use any of the other sealers at all because of this issue. But like everything, I try to use it in moderation to prevent chances of this happening.


I always do it in two separate application attempts a half tube at a time. If it doesn't stop after one whole tube has been used then it is not going to work and needs better attention. But usually a half tube works great on small leaks and is not enough to clog things up


The one thing you absolutely want to stay away from for sure is Sodium Silicate sealer!

Busaboy

You mentioned the cam plug which opens a new can of worms as in trying to exactly pin point the leak. Is it that is it the upper rear main seal starting to think as much as I want to continue doing all my own work that maybe it is time to bow out and drop it off at the shop and let them deal with it all.

Bugout4x4

At this point Steve might be right about just pulling the Trans back, making sure and fixing it right. If you pull the trans and bell housing the Cam Plug can also be changed at the same time as the Freeze plug if it is also leaking. But you could first try the main seal because it is fairly cheap to do and the Solderseal to see if these work before deciding the trans actually needs to come out. This is what I would personally try myself before pulling the trans.


Taking it to a shop could be substantially more down time for your vehicle? Man, it sucks that no one takes pride in doing things right anymore. Now it is costing you time, funds and labor If it was my shop I would have made it right with you, the last thing I would want from my shop is an engine leaking from these particular locations after it was installed because of the amount of work required to now fix it.


Plain old shoddy workmanship and this should not have happened. Actions like this cost everyone in the industry credibility every time it happens. There is indeed collateral damage to those of us that try to do things right.

SteveMongr

Have not tried the following, just recall reading it somewhere.
Remove inspection plates from bell housing. Using a good light and a dental mirror, the lower two welch/freeze plugs can be inspected.

Bugout4x4

I wasn't sure about this either, I wonder if these can also be seen with the dental mirror through the starter hole? You have a great suggestion here and it would be well worth his time to try it!