Hello!

My car's currently running happily, although I'll admit to being a bit unhappy about the level of blowby.

However, an opportunity's come up that I'm not sure whether I should take up or not. A friend of mine's going through an auto tech program at a local community college, and he's wanting a project engine for the final quarter of his class. Basically, the only thing I'd need to pay for is parts; all machining and labor woul dbe done by him as part of his class. Given that, other than the blowby, my engien seems to be in decent shape (runs well, doesn't seem to burn much oil although I do have oil leaks, etc), I'm guessing that the only parts I'd need are gaskets.

So, I'm torn between "if it ain't broke, don't fix it" and "I may not have another opportunity like this, so take it while I've got it to ensure trouble-free service over the next 500K miles".

What do you all think?

Any thoughts would be appreciated...thanks in advance!

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2001 VW Jetta TDI, 5 speed, daily driver
1991 Ford F-350, work in progress
1984 Ford F-250 4x4, 6.9l turbo diesel, 5 speed manual
Previous oilburners: 1980 IH Scout, 1984 E-350, 1985 M-B 300D, 1979 M-B 300SD, 1983 M-B 300D
Spark-free since 1999

Once upon a time in University I had a hole in my right lower molar filled by a junior dentistry student on campus for FREE. Twenty six hours later, I could not open my mouth due to an infection! She was very cute though

I wouldn't take apart an engine just to replace the gaskets. Anytime the crank is out you might as well go in for new bearings ($130) and a new oil pump ($350) and a new lower chain, etc. Blow-by is typically a problem with poor sealing rings. You might get away with honing the cylinders and new rings ($150) or you might need to go with oversize pistons ($900, or a running 83 SD). Those are some pretty expensive 'mights' even if the labor is free. Makes an Adsit or Mertic Motors long block seem pretty cheap.

You might be bucks ahead having the turbo rebuilt... and generating even more blow-by.

Sixto
95 S420
87 300SDL
83 300SD ... $950, see cars forum

If I had the $$, I'd go that route...not to replace my 300D, but to complement it (Robin needs a car, eh? ).

BTW, regarding blowby/rings, I haven't taken the time to re-check my compression yet, but as of the day I bought the car, all 5 cylinders had happy compression...IIRC, 4 of them were at 400 and the 5th was at 375. The blow-by hasn't changed since then...

I do'nt know if his school's set up to rebuild turbos; I'l ask him next chance I get...

I think these engines just have more blowby than we're normally used to on a gasolene engine. That's one of the reasons the oil turns so black so quickly.

I have a small Yanmar diesel tractor and the oil is still pretty clean at the change interval.

Your car is in good shape - don't play with it.

By the time it actually needs work, you will have added several other diesels to your fleet - - - - so you'll have a spare - - -

Ken300D

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1982 300D at 351K miles
1984 300SD at 217K miles
1987 300D at 370K miles

Personally, I think I'd jump on it if I could afford to be without the car. We always claim these cars are so easy to DIY, here's a chance for some with access to proper tools and instruction to do the work. I'm assuming:
1. That your friend is half way competent. I assume that's the case, or you wouldn't even consider this move.
2. That there will be one or more experienced instructors present who have experience with diesels. The beauty of the OM617 is that the basic design goes back to the 50's, so there's plenty of opportunity for people to be familiar with it.
3. That you have or can get the shop manuals to give your friend. Pretty much every job you would need to do is on the CD, with it as a guide, and with experienced instruction, available you could get a new engine that you can baby for 500,000 miles. Of course the chassis will fall apart before then, but hey, that's another story . . .

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Tjohn

82 300 SD
77 450 SL (gone)

". That your friend is half way competent. I assume that's the case, or you wouldn't even consider this move.
2. That there will be one or more experienced instructors present who have experience with diesels"

Those are not things one can assume.... and even if the first is correct other people may be working on it... or have access to it.... etc....

Warden.... I investigated a similar situation at the Austin Community College.... and I don't want to have to elaborate on the reasons this is a bad idea.... for fear of painting other programs with too broad a brush... but you stopped by here on the way home with that car.... and you know that you are a ' worrier' when it comes to stuff like this.... so I am suggesting that you NOT do THIS.... your car is not broken.... don't mess with it... unless you do it with this guy in your garage, with you supervising and consulting both the manuals and the board at each step...

I agree with Greg for the reasons he indicated plus:

Diesels will keep running with blow by as long as you can carry enough oil with you to get where you're going. They typically don't burn valves, foul spark plugs or suffer any of the fates that a tired gasoline engine does. For this reason, as long as it has enough compression to start, keep driving your money out of it.

Secondly, this would be a BAD engine for this being a good step economically. Even assuming that all the work would be done competently, unlike most engines, the biggest expense in rebuilding one is not labor, but parts cost.

Maintain it, drive it and enjoy it. When it gets too tired to start then see to it. If you properly maintain it, I think you will find that overhaul time to be in your DISTANT future.

Good luck,

Why not buy a car that is not running or running well, and have you buddy pull the engine on it?

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1980 300TD-T (82 Turbo and Trans) 159,000 Miles "Jackie-O"
1983 300SD 272,000 Miles "Aristotle"
1987 Jeep Wagoneer Limited - keeps the MB's off the ice and out of the snow
1994 BMW 530it

I would not do it Warden unless you have up to around $2k that you want to spend. The reason you will want at least that is because once you start tearing it down you will say to yourself - well since I am in here I may as well replace ________ and the parts costs will gobble up some hard earned cash fast. I have an engine in my garage right now that is torn down waiting for pistons and liners. Once I saw the price of new pistons I found another complete engine for $750 which was as good as the guy advertised. I will eventually get the parts together and get around to putting the engine back together but it is low on the priority list right now.

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Jim

One word, eBay, find an old running or non-running engine there, have him rebuild it. Then you've got a spare...... assuming you've got the money to spend to get all the needed parts. If i were you I wouldn't touch your car if it's running ok, rebuilt engines just don't seem to be as good as one put together at the factory.

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1985 300D Turbo ~225k
2000 F350 (Powerstroke) 4X4, SWB, CC, SRW, 6spd ~148k
1999 International 4900, DT466e (250hp/660 ft/lbs), Allison MD3060 ~73k

Well, that's about the most loudly resounding "NO" I've ever heard from this group.

Thank you all for your input...actually, for his project, I wish I could find a blown-but-rebuildable 6BT Cummins at a decent price; I could let him play with that and then put that engine in my truck...but I'll leave my car alone and hope that there aren't any underlying problems that I don't know about.

Good luck finding a blown 6BT cummins!!

Nothing short of a direct hit by a 16 inch gun seems to be able to destroy a 6BT.

Tim

I'm sure there are some dead 6bt's out there but I doubt they would be worth the effort to rebuild after they get that far along. You can get a good used running one for under $4,000.... but that's a lot of dough.

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1985 300D Turbo ~225k
2000 F350 (Powerstroke) 4X4, SWB, CC, SRW, 6spd ~148k
1999 International 4900, DT466e (250hp/660 ft/lbs), Allison MD3060 ~73k

Back a few years ago my parents were looking for property to build on, one the property we ended up buying there is this huge pole barn and in the corner a generator. Since we didn't have power yet and it was setting there we made it part of the deal (this is the reason why you don't leave stuff out in the open when up for sale). He agreed, he told us how he got it for free anyway after taking a class to rebuild it. I think they start with a new machine and redo it or something like that. Well it has never stopped dripping oil, the head bolts are loose, and last time I checked the oil in the sun I seen metal flakes in it! Sure it may be free, but I don't know if that is the best way to get it done.

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Jeff M.
Mercedes W123 DIY pages are now located here.
1983 / 1984 300D Sold
2000 CLK430 Cabriolet ~58k Sold
2005 Avalanche 4x4 ~66k