603.971 syndrome

[jef d]

I think I got 603-971 syndrome ! It uses approx 1 qt per 500 miles, 1 tea spoon of oil at turbo boot! intake is very wet ! No oil comes from breather pipe, looks like some is coming out of #1 exhaust manifold ! as well as the front half of block is wet, runs real well no smoke, but a small amount after its been shut down fo ahour or so ,than clears up! What next?
#1 a rebuilt 603.971
#2 a rebuilt 3.0 lit with some perf mods.
#3 606 into this puppy ?
Who am I kidding ? I want #3 but I cant brake the bank ! thanks J

[jef d]

What

[rrgrassi]

Sounds like a head gasket from posts I have read. Do a forum search also.

[sixto]

If you're doing the work yourself, change the head gasket and check oil consumption. If you can live with it, good for you. If not, you have the practice you need to drop a 3.0 603 block in place

You have to be in a real hurry to need more than a 3.0 603. It didn't take me long to get used to lazy starts with the 3.0. And when going fast matters, I'd rather have the free reving 3.0 over the asthamtic-beyond-4000-rpm 3.5.

As you say, it's about money. A 606 is about $4000. A 3.0 603 long block can go for as little as $500 if you have time to look (a new head gasket will buy some time). On the other hand it's about the same amount of work. What would you rather end up with for the effort?

If that's a 140 in your avatar, good luck with the topmost couple of transmission-to-block bolts. They're a b!tch and a half with the starter cable conduit and the overhanging firewall. Still less work than pulling the tranny.

Sixto
87 300D

[babymog]

This is a copy of my PM reply, always good to see if my logic holds up to the scrutiny of this group:

I bought a '91 350SDL that was parked in a driveway, garage burned, scorched the nose on the SDL, good maintenance and I wanted the engine. Paid too much, ...

Pulled the drivetrain, a #22 head for my 3.0. Great plan. Then thought about just transplanting the 3.5L into my '87 300D, make a 350D, bigger engine and all, sounded fun.

But then I looked into it. The 3.0L was 143hp, guys say the trap-ox removal was good for around 5hp or more, so lets say 148hp. The 350SDL 603.971 engine only has 134hp!!! And at lower RPM! I don't want LESS power! So I decided that the 603.971 was the result of emission regulations forcing the engine to be less efficient, to run at lower RPM, and increasing the engine size (displacement) to compensate and recover part of that lost horsepower. It does reputedly have a better launch due to the lower RPM grunt of the torque curve.

The best IMO is to put a .961 engine in your car, with the .96x injection pump, the .971 turbo (55 trim), and the .971 head (complete with injectors). I'm not sure whether the cam in the .971 engine is detuned for emissions also or equal to the .96x cam. If the .971 IP is tuned for 134hp it is likely that it will limit the .96x engine, simple diesel IP logic there.

This would give you the robust 603.96x 3.0L block and rods, with the updated/stronger 603.971 head, and all of the horsepower of the 603.960 (143-148) for a more powerful engine, likely more fuel efficient, and your .971 exhaust doesn't have the catalytic converter that the .96x was used to breathing through so maybe even a touch more hp.

To your other question: It might be a head gasket, or other problem, cart before the horse at this point.

Sixto or GXSR will probably be able to tell you what parts from the .971 engine (such as oil filter and engine mounts) would need to go on the .960 engine if you found a .960 (300D) instead of a .961 (300SD/L).

Good luck.

[mirage1]

if you are going to get a rebuild get from MB.
I was quoted around 9k installed