Topic: Coolant Leak

[Saggy]

Gentlemen, (and ladies if you're out there!)

I have coolant dripping out the back side of my engine and I can't...for the life of me...figure out where it is coming from.

It looks like it is running along the channel in the top of the oil pan on the passenger side and dripping down the front transmission plate (when it gets to the back of the pan).  With that said, there is a not insignificant amount dripping directly underneath the clutch plate.

I have added dye and pressurized the system.  That helped identify a small leak out of the lower heater core hose which I fixed along with a couple of other drips from system hoses.  I don't think any of those would have actually leaked under normal conditions.  I had it pressurized to 16psi...the max cap load...so I think that forced the hoses to leak.

I have also concluded (I think!) that it is not coming from the top side.  Freeze plugs look good.  What I can see of the head gasket looks good.

What am I missing?!  I have been around everything I can think of with UV light and mirror with the system under pressure.  I can't find anything!

Thanks in advance for your help.  This forum is awesome.  I have learned so much from you guys.

I forgot to add...rig is a '95 4 banger.

[sharpxmen]

is there a freeze plug on the cyl head in that area?

[Saggy]

Thanks for the response.

There is a freeze plug on the back of the head.  It is dry.  The other three plugs are dry too.

[neale_rs]

How about the overflow bottle, could it be dripping onto there?  That is a part of the system that would not get pressurized in the test.

[Saggy]

I went around the bottle with the UV light and didn't see any leaks.  Thanks for the idea though.

By the way, I converted to an electric fan so I have my fan shroud removed.  I have pretty good visibility to the entire front side and both passenger and driver side of the engine.  I can't see any coolant dripping down the block.  The ONLY place I see it is when it drips down the front side of the tranny and just behind the oil pan.  And I can only see it there when laying underneath and looking up.

[sharpxmen]

Thanks for the response.

There is a freeze plug on the back of the head.  It is dry.  The other three plugs are dry too.

is that UV die you used? if yes you should be able to wipe/wash the area and see the leak afterwards (if it's a crack on the block or head).

there is also a drain plug somewhere on the block, can't remember where it is exacly, i have a core in the garage i can have a look at.

do you have some pictures of where you see the coolant? would help to come up with ideas of what this can be.

-- you already posted answers to the above

so based on your last post, is it possible that the coolant is carried over the oil pan? i'm thinking of a drip from the front rather in that case. And another thing, are you sure it's coolant since you can't find any leaks with the UV light?

[Saggy]

Hmm...forum won't let me  post pics.  Is there a minimum post threshold before pics can be posted?

The leak is coming from the left (passenger) side in the pic I took on the south-east side of the starter (on the wall where the starter is bolted to).  It could definitely be coming from the front (although I can't see it) and running along the top of the pan.  I just can't think of where else to look.  Can I email you the pic?  Wish I could post it.  Forum says 'the upload folder is full'.

The dye is UV.  I should clarify...the UV light makes this liquid glow and the pressure gauge on the radiator pressure tester dropped from 15psi to 10psi overnight...and kicked a bunch of this liquid on the ground.  I am certain it is coolant.

Can you describe where the drain on the block is?  I didn't know that existed!

[sharpxmen]

Hmm...forum won't let me  post pics.  Is there a minimum post threshold before pics can be posted?

The leak is coming from the left (passenger) side in the pic I took on the south-east side of the starter (on the wall where the starter is bolted to).  It could definitely be coming from the front (although I can't see it) and running along the top of the pan.  I just can't think of where else to look.  Can I email you the pic?  Wish I could post it.  Forum says 'the upload folder is full'.

The dye is UV.  I should clarify...the UV light makes this liquid glow and the pressure gauge on the radiator pressure tester dropped from 15psi to 10psi overnight...and kicked a bunch of this liquid on the ground.  I'm am certain it is coolant.

Can you describe where the drain on the block is?  I didn't know that existed!

i'll look when i get home and let you know where the drain is (later today) - i'll check the FSM to see if i find a reference for it as well

The pictures posting is done thru a hosting site like photobucket.com or imageshack. Then you use the tags for forums generated on these sites and just copy/paste those links in your post, that way they appear as being uploaded and are shown in your post.

[Saggy]

Ahh. 



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[Saggy]

Let me know if a different angle would help.

In the pic above, the only coolant drip I can see actively leaking under pressure comes from a crease on the top of the oil pan at the bottom-left (in this picture) side...right next to and above the starter.  So I can watch it drip from here but I can't locate the leak anywhere from the head gasket up...even with the lights out searching around with a UV light.

[Saggy]

So...I found the following in the FSM.  I took a look at that plug on the block and it looks dry.  Is this the plug you were referring to?



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[neale_rs]

Sounds like you need to drop the oil pan to see exactly from where it is leaking.

[Saggy]

That's what I'm afraid of.  Thanks for the input guys.  I think I'm going to hang around here for a couple more days to see if anyone can come up with some more ideas.  If not...then I guess it's off with the pan.

[Saggy]

So...I had an idea.  I raised the back end up as high as I could and repressurized to see if I could cause it to drip from somewhere else.  Will post what I find.

Alright...this picture sucks, but I think it will get the idea across.  With the back end raised it is more obviously coming from right in the middle of where the transmission couples to the engine.  Also, when I raised the rear a bunch of fluid spilled out like it was pooled up there.



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[sharpxmen]

ok, the drain plug is on the driver's side of the block towards the rear.

what i see in the picture is probably coming from under the bellhousing (just by looking at the pic), i'm not 100% on it though but you might be able to see if there is any coolant behind the flywheel thru the crankshaft position sensor. You could also take the inspection cover off and see if the coolant is dripping on the inside of it but again it won't be proof of where it comes from. I am trying to find a pic of the block without the flywheel to look at - just found one in the FSM, i think there is a freeze plug behind the bellhousing - might be coming from there

EDIT: Look at 95xj_9.pdf (Engines chapter) page 9-50 (page 50 of the document) Fig 11 - there is a cam plug, an oil galley plug and by the looks of it a freeze plug.