OK,

So I'll be replacing the rear main seal, oil pump, timing chain, and waterpump starting Wed. I just discovered a fresh Coolant leak that is collecting at the bottom of the oil pan. Any ideas what it is? I'm hoping it's just a leak around the T-stat or possibly bypass tube as these will be replaced, but I will know more later as I rip into it. I just hope I don't have a crack in the water jacket anywhere.

One more question, is the bottom pic the coolant drain plug in the engine block?





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Hey aim it might be a freeze plug thats leaking which wouldn't be so bad but it does get a little tight trying to replace those. And that does look like the drain plug.

 

Just guessing here, but here are two possibilities as to the cause of your leak.

1) Intake manifold gasket leak allowing antifreeze to go out the back (This is what happened to me but in a mauch larger version).
2) heater hose/heater core issue as those lines run at the back of the engine. Hoses, clamps, core itself.

Without running a cooling system pressure test this is the best options I can give you, but I kinda lean toward the intake manifold.
Good luck.

 

I just had mine replaced freeze plug by the engine mount was a pita but possible. took it a shop had them do it was driving me nuts trying to find it, buddy works at shop cant afford days off. Also waterpump might be spilling thru weepign hole.

 

Well crap,

Actually, with all the stuff I've got on the plate this Wed, It's not that much more a job to pull the intake off. I'll just stop by A-Zone and pick up some new gaskets, then If I don't need them, return 'em. Any recommendations? Is Fel-Pro a good brand for Intake Gaskets?

I kind of doubt it's the core, I don't ever smell a thing in the cab and it's driver's side only. It's running from the front of the engine back as far as I can tell. But I can check to see if it's running down the heater return line.

 

Fel-pro gaskets are very good for this. BTW, if your gonna pull the intake, replace your plenum gasket too. Only adds about 30 minutes to the job and saves you a big headache later.

I would try pressure testing your coolant system first since you think the fluid is coming from the front area of the engine. The pressure test will allow you to accurately diagnose where the leak is at. It might just be that PITA short hose from the water pump to the intake manifold.

 

I actually replaced the plenum gasket in October w/ the Hughes kit. It's possible I didn't get everything positioned properly. Just bought a Felpro set from Oreilly's. How would I go about pressure testing it?

 

I have exact same problem on 99 Dakota 5.2L. Leak coming from drivers side. Water pump and gasket, timiing cover gaskets have been replaced. Also it is not leaking around thermo. IS it intake or freeze plugs?

 

Thats not coolant, its Predator blood, u just ran over one of em invisible preditors

 

I noticed when I was looking for mine that when I took photos to post up here, the flash really made the coolant pop out. You might crawl under there and snap a few to see it you can find the source.

Here's some ideas:

If it's coming from the driver's side, check the thermostat and housing, the bypass tube that runs from the intake to the water pump. (pretty hard to see from the engine side, if you remove the AC and Alt hold down brackets you might get a better view.) The heater return hose that goes to the black metal tube that sticks out of the water pump. Then hterer the heater outlet line that goes into the heater core that's connected to a fitting that is screwed in to the top of the intake manifold next to the thermostat. It's also possible that a bolt in the timing cover was put in the wrong spot. Most bolts for the TC are long but one or two were shorter and the top two bolts are supposed to go all the way into the water jacket. A short one wouldn't have sealed properly. You could also have a leaky intake manifold gasket and would need to pull the intake and replace them. I had this problem and a set of felpro gaskets fixed it and I haven't seen a drop of coolant in 2 months.

The worst case senerio is that you've cracked a cyinder head so badly that you're leaking coolant through that crack. You can pull a head and possibly have it magnafluxed at a machine shop. If you're leaking coolant into the cylinders you'll have smoke from the tailpipe and a nasty sweet smell from the exhaust, just don't stick your nose right up there and start sniffing.[:'(]
If you're having somebody do the work for you, don't even mention this as a possibility or they'll probably jump at the chance to "fix" this problem as it'll basically allow them to check every other possiblity I just mentioned and then charge you for a much bigger job.