Pugly

[gmanpaint]

Leak never stops, hot or cold. Find a puddle under it every morning. Had it running for 30 mins today as I watched the leak run to the ground. I need to clean the engine so I can get a better look of the leak origin.

 

[Naasau]

Sounds just like the issue I had on the beast for over a year that I just 'resolved'.
For me the leak started when I swapped the water pump. Never over torque those damned little bolts... Anyway, I ended up identifying the leak as the back end of the passage from the pump into the block through the timing chain. This is a bad thing. I hate to admit it, but I bought some of that 'stop leak' radiator goup that we should never use, then added it to a fresh radiator fluid blend and drove for an hour on the highway to see a friend of mine.

The stuff actually did the trick! I have no leak and no overheating issues. I know it is just a bandaid, but it has been holding for 2 months, so far.

 

[Rick]

Well if that's the case, it will need a new block.

The corrosion is probably on the intake manifold and the gasket.

 

[Rick]

Found this:

I crawled under my Explorer (for the 15th or 20th time) and found one drop of green antifreeze on the bottom side of the front protrusion of the head. Further investigation (OK, a great deal of time under the Explorer with it running and off) found that the coolant apparently was leaking down the front side of the engine, dripping off the oil pan stud on to the transmission cooling lines, running down the cooling lines to the bracket behind the engine mount, and dripping to the ground from there.

I spent $80 at Autozone for the valve cover gaskets, RTV, intake manifold gaskets, and a cheap torque wrench.

 

[gmanpaint]

Wait...

Ok, the leak I found is lower than the valve covers. It is where the head meets the block. I understand the the head meets the intake as well, and I can't tell exactly where the leak is coming from yet until I clean all the gunk off it to see better. Not like it is spewing, its dripping. That intersection where the intake, timing cover, head & block all meet up is suspect. Let me get some cleaning done to it, run it, watch for the leak, and take some pics of it. I will post them up, and maybe you guys can enlarge them to get a close look at it.

I am going to try a band aid fix for the heck of it, because right now is not a great time for me financially to be swapping engines out, or having too much down time.

Seriously appreciate all the advice & thoughts you guys! Thank you!

 

[Dono]

If I were a betting man, Id say lower intake manifold gasket. This was the start of me learning about the 4.0 ohv.

Mine started to blow out from the rear and showed the same symptoms, except coolant was coming from the rear leaking down to the trans.
It didn't take long for mine to blow wide open and coolant just poured out the back. I had to have it towed home to see what's going on as I couldn't keep enough coolant in the motor.
Once I pulled the lower intake off, I could clearly see the lower intake manifold had blown out. I understand this is a common issue on these motors.

Its a good thing the motor is running great and not fowling spark plugs. The coolant isn't making it to the cylinders. That's great news. Hows the oil look? The coolant could be starting to leak in to the valley below the lower intake, mixing with the oil.

After saying all this, make sure its not a coolant hose before you tear the top off your motor. Im betting that if its not a hose, you will need to start taking pugley apart from the top. Make sure you have lower intake gaskets, upper intake gaskets, and valve cover gaskets on hand. Hopefully that's all it is. Easy job, just go slow and be clean about it.

 

[gmanpaint]

Dono..

I checked the new(ish) hoses today. There all fine. I removed them and cleaned the inside of them, then cleaned the outsides of the necks, and put them back on with new clamps.

Oil looks good and clean still. I did an oil change recently, no signs of contamination.

Front plug boot is getting some coolant on it, but that's about it. The coolant flow is mainly following the head at the block to the rear and drops off at the trans bell housing to the ground. Now the starter is getting wet tho.

So a tear down and new gaskets seems to be the general consensus here. Guess me & my repair manual is going to become buddys again. Been a long time since I have had to tear down the top end. Stuffed a lot of new things in my head since than. LOL

 

[Dono]

At the front of the motor, how does the area around the water pump look?
Check it again please. I havn't really ever heard of anyone with the 4.0 ohv have a water pump start leaking, but you could be the first.

I sure hope you see the lower intake gasket's bad when that lower intake comes off.
If not, that head's coming off. I guess its not so bad though, as your almost there anyway.

I have a full set of new head bolts if you need them. Id be happy to send them to you for cost of shipping. Id have to check shipping cost to your location and make sure its actually a deal first though.

 

[gmanpaint]

Thanks for the advise & help Dono.

I have the engine soaking in cleaner and will be looking again for the leak origin shortly.

The front area around the pump is fine too. I replaced it a year ago, and it seems to be sealed up & working. The timing chain cover is wet on the edges where it meets the block on the right side, but that could be from a leak above.

Funny thing is there was a wet spot on the drive this morning (as usual). After returning from work, nothing has leaked like it has been. ???? How typical is that? Never shows the issue when you want to find it. :scratch:

 

[gmanpaint]

Does any of the waterpump bolts go thru the timing chain cover into the block?

The farthest up the engine I can see the leak flow is up to the bottom bolt for the AC compressor mount. It's somewhere behind that. Looking from the top of the engine down, I can't see any leak trails.

Looking at the side of the engine thru the wheel well. You can see the path of the leak fairly easy.

Its a mess because of a power steering leak at one time.

 

[ahodges]

That has all the ear marks of a lower intake leak. It could be head gasket but due to the way the top of the 4.0 is put together I would say it is an intake leak from the corner by the head.

 

[Dono]

Well, just from how common the lower intake gaskets are to be needing replacement, i vote lower intake gaskets also.
I'm not completely sure how much coolant is leaking, but it looks like more than would come from a head unless the gasket had blown right out, and that's extremely unlikely.

It will be an easy weekend job. A couple hours here, a couple there, and your done.

 

[gmanpaint]

Ok than.
The skies have opened up, a cold front had pushed thru, and the rains have passed. I'm going to give it the old college try, and get that lower intake off.
Any tips on going about this is welcome! Lol

Thanks for the help guys!

 

[Dono]

There's a pdf on doing this floating around. It's very detailed.
Also, don't fight the alternator, pull it off. Much easier, so it's worth the few bolts to take it off.

Take the bolts off the airconditioning pump so you can move it around, it frees up more space.

The egr can be fun, I remove the dipstick tube, and 2 bolts on the egr. Careful with that gasket as I've dropped it in to never never land a few times.

Once the link is reinstalled, let it sit overnight and re-torque it. This part is important and you will be amazed how loose the bolts are as the gasket compressed overnight.

You need that pdf though. Google 4.0 lower intake, I think. Have a look for it, if you can't find it ill get on a real computer and email it to you.

It's really not a difficult job.

 

[gmanpaint]

Welp, the intake gasket kit is $90, and the head gasket kit is $116 at O'reilly's auto parts, so I'm getting the head gasket kit as it has more in it in case I need it.

Replacing the T-stat and neck gasket, the EGR ring gasket if needed, valve cover gaskets, and of course both intake gaskets. I am hoping it is an intake & not a head gasket right now.

So from what I read, gray RTV is the stuff to use on the gaskets. Distilled water not tap water for a mix. EGR is going to be a a bane to my existence, and my back is going to be killing me from this. (Lifted 8" over stock, and the engine is lowered from the body lift.)

Altogether this should cost me my weekend, and around $200. I need to replace my fan removal tool as I lost it, new coolant, rtv, gasket kit, t-stat, distilled water, & what ever the heck else I can think of. lol Thank goodness I already own a Haynes manual.

Wish me luck guys!

 

[Dono]

Yup, your pretty much dead on. No question about the sore back. Cleaning before replacing the lower intake isn't fun. Then the rtv, and trying to drop that lower intake directly where its supposed to be so the rtv stays in the right area isn't fun either. Sounds like you need a step stool, and you will be sitting on the engine bay for a lot of your work.

You don't need to pull the fan off though, so don't rush out for that fan removal tool

Good luck! (You won't need it though).

 

[gmanpaint]

Got a real late start on this. Only have the upper intake off so far.
Hardest thing so far have been those plastic ribbed clips that hold the wiring to the mounts. PITA! Found that going thru the wheel well for the lower nut holding the coil pack bracket on makes it a cinch.

Was pleasantly surprised at how clean it was underneath. Lets hope it continues that way once the lower is off, and only a mess where the leak is. All the routine maintenance is paying off.

Got a little bit of daylight left. Will do what I can, and will have to continue in the morning.

 

[gmanpaint]

Does the A/C bracket HAVE to be unbolted and moved to the side to remove the Lower intake? Anyone????

Never mind. Its off and its a frigging mess. I spoke too soon. The ports are very dirty. I'm not sure why this thing ran so good now to be honest.

Good news is the lower intake gasket was bad at the far right corner port. Cracked from corrosion. You guys guessed right.

 

[gmanpaint]

Couldn't stand the crud so I spent the rest of the day cleaning.

Took the wire wheel to the stat neck and painted it. Used it to clean the valve covers real good and will get a coat of paint on them as well, just for rust prevention.

Entire Upper intake was surprisingly clean. Gasket came off clean as can be. Lower Intake, well thats another story. I cleaned out the ports as best I could with wire brush rods, and blew compressed air to clean it out. The underside is all translucent brown, not much I can do with it. The top where the valve covers go was all full of crud like they were leaking, cleaned that all up.

Stuffed rags in the head ports when I cleaned for new gaskets and blew compressed air as well. It's as good as it's going to get.

I will get some pics of this later when I'm finished. IF I ever finish!! Going to be another day getting it all back together if I can remember how the engine harness goes back on...LOL

 

[Dono]

sounds like your almost there.
The cleaning is the hardest part.

The lower intake manifold is ugly, I think thats fairly normal. You could try a spraying it with oven cleaner and throwing it in a bag for an hour. Dont leave it in the bag overnight or the chemical will pit the manifold (ask me how I know).

Great to hear you could see where the gasket blew out. Im impressed how quick you got going on this.