Water in oil?

[mstockton]

Hi all, been awhile since I been on here, but I need some 6.2 advice.

When I rebuilt my 6.2, it was a redneck rebuild. Necessary due to time and monetary restrictions. No machine work, checked bores for oversize, check crank journals, polished it up and put new bearings, rings, all new injection components, timing chain and gaskets. Of course I also installed new water pump. PO had not taken care of engine at all, and headgasket had blown at some unknown time. While deck surface was not perfect, I couldn't afford to get it decked.

Have not had any symptoms of blown head gasket, BUT, I am getting a slight amount of water in crankcase. Not enough to milkshake the oil, or be present when draining the oil, but enough to evaporate and condense under oil filler cap and in oil filler tube (kind of a petroleum jelly). I pressure tested to the cooling system with a snap on unit. No pressure increase or drop. I am swapping in a 4 speed into the blazer right now and have the engine out, and need to reseal a few things. I am wondering which bolts are the ones on the waterpump that are supposed to be sealed (i've always heard regular pipe dope recommended). I was informed certain bolts run through water jacket and crankcase.

The crummy manual I had when rebuilding didn't tell me which ones to seal, I am wondering if I sealed the wrong ones and am getting a very slow leak into the crankcase, its enough to drain my recovery tank every 4.5 months or so. While I've got it apart I was hoping to take a shot at fixing this. I am going to get a 6.5 to start rebuilding (the correct and proper way) as soon as I get some other things squared away. Also because of the poor coolant quality the backing plate on the water pump was rusted and pitted. I'm wondering if its not the bolts, if I've got a pinhole leak. I could also have a slow headgasket leak, but I'm not seeing any signs of a leak into the combustion chambers, and my CAT coolant still looks fresh as the day I poured it in. The old headgasket blew between rear coolant passage and #7 cylinder.


I think I'm going to pipe dope all the bolts, but if someone could clarify which ones need to be sealed that would be terrific! Any other input would be appreciated as well.


-Martin

EDIT: I forgot to mention I also had a leak at my Tstat housing, not sure how bad it was, because I believe fan simply blew it over engine and it evaporated, so that could account for some of my coolant loss as well. Mainly I'm concerned with keeping the coolant out of my oil..

[Robyn]

The water pump bolts are generally not an issue with these so if you like a little dope, use it.

The one issue that popped into my head was, during your REDNECK overhaul did you replace the head bolts and if you did not did you use a good sealer on the threads.
The head bolts on the 6.2/6.5 family are use once and toss. These are torque to yield bolts and come with sealer on the threads when you get the new set.

If you are not seeing a pressure drop in the cooling system then whatever the cause, its very small. Are you seeing coolant loss over time?

The white goop may be condensation and not coolant leakage.

How much of the white goop are you seeing in the oil filler?
Be sure the CDR (Crankase vent valve) is working correctly and is hooked up to the intake properly.
Let us know any more particulars you can think of.

Robyn

[mstockton]

I did use new headbolts, but I do not believe i put pipe dope on them, I just used my cat graphite anti-seize. How many of the head bolts go into the coolant passages? The CDR might not be working correctly, I thought of that last night after I logged off. Is there any way to test it? I was talking to an ex-auto mechanic at work and he says it could be condensation. The coolant loss is over time, but filler neck gets (vertical part) gets fairly packed with the jelly that forms. But with the cdr pipe right under the cap, I don't know if that might be the cause... thanks for the reply Robyn. (and just as a side note: I would never cut any corners on our customers engines, every CAT engine or piece of equipment gets done 100% right and triple checked when I'm at work ;) ; I just couldn't justify the time loss or cost at the time for what was my beater truck)

Thanks again,

Martin

[john8662]

I just used my cat graphite anti-seize.

No Antiseeze on head bolts, this will cancel out the dry sealant on the bolts.



How many of the head bolts go into the coolant passages?

ALL of them, they're all wet (a poor design IMHO).

J

[Robyn]

YESSSSSSSSSS all the bolts go into water. GM did this with the Mark IV engines too (396-502)
Not my absolute feel warm and fuzzy design but as long as the threads are coated with a suitable sealer it fine.

If the bolts dont have the red silicone sealer on them they can be dipped in red hightack gasket sealer and this will work fine.

What you need to do at this point before you go on a "Witch Hunt" is to get the rig running and stir the oil good then take a sample and have your cat shop run a test on it to see if there is any Ethelene Glycol in in.
If no glycol turns up then its just condensate and due to temp changes.
If you find glycol then you are going to have to go searching for the leak.

A little bit seaping by a bolt could be enough to cause the goop, but it will also show in the oil too.
If you are not seeing any loss of coolant then its a ???????????

A head bolt seep could possibly be sealed with a product like Bars Leaks.
If its a tiny little crack in a head it wont do it.
Same goes for leaking gaskets ect.

Keep us posted though and see what the oil test shows up .

Robyn

[mstockton]

Well I've got the truck torn down right now, so i started tearing into the engine to find the leak. I had to pull the pan anyways to replace the rear main seal (I goofed the rope seal the first time, learned my lesson, went to neoprene :D ) I saw the oil and water emulsion (goop, jelly), and I could see my ELC in it (strawberry red, hard to miss), running in a bead on the inside of the timing cover from the bottom of the pan up to the oil filler. Not sure how this plays into it however, I think thats just the path the water was taking from the pan (in the oil, ouch!) to the oil filler neck where it was collecting. Now, I could see droplets of my coolant on the timing chain and behind the baffle that goes behind the injection pump drive gear. Because it was back there I am leaning towards a leaky seal between the timing cover and block, in particular around the inlets to the water jacket. I could find no problem with the water pump gaskets, etc. I realize this may not be concrete, because Im sure that timing chain slings so much around under that cover that I'm never going to be able to tell for sure. I had one of those military 6.2 rebuild manuals and it told me to only use RTV between the timing cover and block, but now with this, I'm starting to question that. There are some machined grooves in the timing cover around the block inlets that would seem to serve a purpose (weeping coolant away to the outside rather than have it enter the crankcase perhaps??) so I am thinking I am going to use a gasket. If someone has some knowledge with sealing this thing, I'd appreciate it. I'm already cringing at what all my bearings look like after 10,000 miles like this. I was changing the oil ever 3000, but still, this may have been a very bad thing. I had a noticeable amount of oil in the pan, some of that may have been forced in when I pressure washed it before I removed the pan, but I doubt it.

Oh on another note, my brand new (from partsamerica though!) oil pump is already chewing itself up! The gears a scuffing pretty well and the driven gear is thrusting itself into the cover, enough so you could slice your finger up pretty well when you run your finger over it. I guess I might try to find out the price of a new gm pump, but god I don't wanna know. I tore down my old pump (GM new at 250,000 miles ago) and it looked alright, but the gears are pretty bruised, and i don't know how long I would trust it.


-Martin

[Robyn]

The leak could very well be the steel plate that is between the water pump and the timing housing. (These can and do corrode through)
Use a gasket between the block and the steel cover plate as well as between the plate and the pump and be sure the little drip grooves around the water feeds on the front of the block (waterpump ports) are free of goop.
The factory used a shelac on the plate to block surface. (Bad plan)

Good luck

Robyn

[DmaxMaverick]

The reason there is a weep channel in the first place has nothing to do with the pump, plate, cover or block. It's the bolt! If you don't use an anaerobic sealer on the bolt threads (or a just plain lucky), it will leak and weep out the channel. If you block the channel with RTV, the coolant (that leaked past the threads) may go the other way and end up inside the timing cover. The best sealing job I've come up with is a gasket at the block (with RTV on the forward side), and RTV elsewhere. Be sure to use anaerobic sealer on the bolt threads. RTV usually doesn't cure properly there, and doesn't mix well with coolant until it is cured. Loc-tite Anaerobic is a good product, and goes on like thread locker. It's also good for head bolts that don't come with the dry sealer (don't know if you can get those anymore).

Unless you find an obvious blown RTV seal or gasket, your leak is likely the threads.