MY 6.2 has been leaking oil out of the rear main seal, or bearing. I rarely have to add oil to it, but it seems to make it's own oil somehow. Anyway...i'm sure this topic has been brought up, but is it worth it to rebuild a 6.2? I've looked on the net, and everything is around $5-$6K for a rebuilt engine. Guess i'm not sure if to drop a 6.5 or change it over to a 350 gasser. It's a farm truck, and I love the diesel, but I only bought it for $2k with a new interior in it. Any thoughts are appreciated.

Where are you, Might be cheaper to buy a good running one and I can help you with that.

Making its own oil, whats probably really happening is diesel is leaking into the crankcase and diluting the oil.

The source is probably the injection pump, but it could be the supply pump. If it were the injectors, you would have a serious fuel knock and white smoke.

As far as the leaky main, its a very common problem with the old 6.2 engines, but I wouldn't say it warrants rebuilding the engine either. You might be able to replace it if you drop the tranny, but I don't think it would be worth the effort. My advice is just to maintain the oil level near the add mark, usually thats about the level where the rear main won't leak anymore.

I'm around Wichita, KS. I only bought the thing for two grand, so doesn't make sense to spend 3-5 grand for an engine.

I agree, but rebuilding the engine won't fix your dilution problem anyway. but if you don't fix it, then your going to wipe out your bearings and then you won't have much choice.

Do you have any fuel in the valley that could be coming from the weep hole in the injection pump?

If not, then the supply pump is probably the source of your dilution problems.

Oh well...i'm not too concerned with this truck. I've got my two grand out of it with the use. If it goes it goes and then to the salvage yard. It's already in the paper for sale.

You are jumping the gun on rebuilding your 6.2 engine. You just need to replace the rope seal in the rear main with a Fel-Pro 2 piece neoprene seal to take care of an engine oil leak. You don't need to remove the trans., just the oil pan. If you don't have the skill to replace the seal then find out how much a 6.2 mechanic would charge.

If it is a diesel fuel leak that you have then you need to locate the source of the leak. Any leak from a hose, injector lines, or the pump in the engine valley (underneath the intake manifold) must be located and fixed. No fuel leak can flow into the oil pan so there is no dilution of your engine oil. There is a drain hole at the rear of the valley that drains any fuel leak to the rear top area of the engine and in front of the flex plate or flywheel ,depending on your type of transmission. Any fuel leak or rear main oil seal leak will then drain out at the bottom of the bell housing. Any water that might get into the valley will follow the same path.

I rarely have to add oil to it, it seems to make it's own oil somehow.
He's not talking about what oil/fuel may be leaking on the ground, if he's 'making' oil he's got a dilution problem.

The only reason I told him to check for fuel leaking out the weep hole is because the way the pilot tube is made, the fuel has to fill the cavity between the seals on the driveshaft and go out a port at the top of the pilot tube, a leak would indicate that fuel is leaking past the seal, and his oil seal is probably brittle and allowing the most of the fuel to pass into the crankcase.

They can leak either way, for some reason GM's tend to dilute the crankcase and Ford pumps tend more to dilute the fuel in the pump with oil.

While on subject i bought 6.2 from usa and on saturday i busted it open..man, what a scene. Pistons, connecting rods,bearings,chain, rings and so on. Now it is good to go to o/h the block and heads. Now i curiose are those ''engine kits'' from ebay worth the money or is it just a piece of crap kit?

thx

The price on a reman 6.2 in NW Oregon is $2195. The two shops I have bought from are reputable. They specialize in diesels. Cummins, Intl., GM, etc. They have good warrantys as well. I'm sure prices vary around the country, but it seems I'm seeing prices much higher than this. The 6.5's run $2395 - $2595 depending on year. It seems somebody is "gouging" again!

Some web page if possible would be nice.

thx

.majti

Fred , If it's OK can you mention the names of those shops. I have seen at least two suppliers up there and shipping to So Cal isn't bad. Also if you were going for a 6.2 n/a replacement would you use the 599 567 combo, and what mods would you allow a supplier to perform? Thanks

I would definetely like to use the 599 block if you can find one. My first choice is:
R & G Machining & Engine Parts, 123 N. Molalla Ave., Molalla, OR 97038 They have an 800 number but I don't have it with me. Their listed number is (503)829-6038 Talk to them about mods, they do a lot of these. If you can't get in touch, pm me and I'll get more info. Fred

Sounds good I have a good friend from Portland, love it up there, so late summer I'll have go see those guys. Wondering what you thought the minimum mods to a seasoned blocks would be (e.g. bottom end griddle, single plane intake etc) just the minium for the maxium return for durability Thanks

Re: the "manufacturing oil" he may be describing the oil level remaining OK but still fluid leaks as you describe - by the flywheel. An old injector pump has the tendency to oblong the holes where the shaft (exact name?) goes through from the throttle linkage. It will leak out that hole - only a re-build will stop that leak.

From there the fuel runs back along the top of the engine, down the back of the engine, and appears under the bell-housing area.

Dennis

I would carefully review the info on this site and decide what and how you want to approach the rebuild. I have little experience with many of the mods I've read about. I wouldn't comment on what I haven't tried and proven myself. I usually build mostly stock engines with upgraded bolts/studs, properly preped block/heads and balancing. I stay away from heavy power mods. I try to use it as GM designed it and improve it where they needed help.

I have used the DSG girdle once and liked it. It's (the engine) still running strong. I used ARP head studs as well. Of course, anything you can do to improve airflow will help. The open, non-EGR intake is a good start. Bigger exhaust (than stock) helps as well. An I.P. setup is also a plus. I take mine to a pump shop here in Portland and they set it to the "maximum side" of factory specs. This is good for the type of driving I do, not meant to be a big power booster. The balancing is just to help make it smooth and longer lasting. If problems are found, this will correct them before they fail. My machine shop has found some rod/piston combinations that were so heavy, they couldn't match them with the rest and had to replace them before balancing was "within specs".

Hope this helps, Fred

Thanks Fred, I too agree I would not want to push my "light duty" GM engine over the limit. I just want to gain the maximum HP out of the N/A motor. I have installed an GV OD because I do alot of freeway driving. I have built gassers foreign and domestic and had them B&B. I was wondering if the 4911 pump was an overkill for an N/A 6.2L? Would that pump be set at the "lower limit " of the spec in a N/A application? Is 2.5" exhaust system enough? I know it depends on the amout of air in and there's mods listed on this site, but it has to max out at some level slightly greater than stock. That's an interesting comment regarding rod/piston weight, are you saying stock GM R&P's were that far out of a reasonable tolerance from factory spec? What manufacturer of R&P did you use? Thanks

My balancer tech says, "Those things are not out of specs by grams, they're out by pounds!" I supplied enough cores to be able to match stock GM rod and pistons and get a good balance. I had several engines that I had torn down for parts due to cracked main webs. Stock, used rod and pistons were not in short supply.

I hope he was just kidding about the "pounds" comment. I think the 4911 pump would be slight overkill for a 6.2NA. It would definetely need to be recalibrated for the smaller engine. TGD could probably comment on this better than I. The exhaust should suffice as well. Just my opinion, somebody here may have other thoughts. Like you said, it's a matter of airflow.

How Much For The Truck??

Hey Fred, Just wondering what IP you run, ID number? Mine is a hardened pump
(interior pieces), the military wanted it that way. What where the numbers that the injection shop turned yours up to? And if you couldn't get a seasoned 599 block would you get a new one and which one? Greg