I would like to do compression/leak-down testing on my 617 (for sale in my sig), but as it is not in the car, I do not have a cooling system in place for it. Is it okay to run the engine up without coolant to heat it up, or would this result in uneven heating/other nasty stuff? Is there a way I can block off areas where the coolant leaves the engine for the heater/radiator so that I can run it with coolant/the water pump without setting up a rad as well? Or should I set up a rad... that seems like too much time.

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"Senior Luna, your sense of humor is still loco... but we love it, anyway." -rickymay ____ "Your sense of humor is still loco... " -MBeige ____ "Señor Luna, your sense of humor is quite järjetön" -Delibes

1982 300SD -- 211k, Texas car, tranny issues ____ 1979 240D 4-speed 234k -- turbo and tuned IP, third world taxi hot rod

2 Samuel 12:13: "David said to Nathan, “I have sinned against the Lord.” And Nathan said to David, “The Lord also has put away your sin; you shall not die."

I've run a 617 on the floor dry for several minutes with no harm done.

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'83 300D, 126K miles.

They make little to no heat idling, under 5-7 mins should not cause any issues.

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

I would think that heat wouldn't be the problem. On the other hand, lubrication of the water pump might be an issue.

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Sam

84 300SD 350K+ miles ( Blue Belle )

Can always run it without belts....I don't think the water pump will care either way....

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

Water pump belt not in place. Problem solved.

__________________
"Senior Luna, your sense of humor is still loco... but we love it, anyway." -rickymay ____ "Your sense of humor is still loco... " -MBeige ____ "Señor Luna, your sense of humor is quite järjetön" -Delibes

1982 300SD -- 211k, Texas car, tranny issues ____ 1979 240D 4-speed 234k -- turbo and tuned IP, third world taxi hot rod

2 Samuel 12:13: "David said to Nathan, “I have sinned against the Lord.” And Nathan said to David, “The Lord also has put away your sin; you shall not die."

...so how long should I run the engine before I shut it off and pull compression numbers? 10 minutes? I want to make sure they are accurate or close to accurate.

__________________
"Senior Luna, your sense of humor is still loco... but we love it, anyway." -rickymay ____ "Your sense of humor is still loco... " -MBeige ____ "Señor Luna, your sense of humor is quite järjetön" -Delibes

1982 300SD -- 211k, Texas car, tranny issues ____ 1979 240D 4-speed 234k -- turbo and tuned IP, third world taxi hot rod

2 Samuel 12:13: "David said to Nathan, “I have sinned against the Lord.” And Nathan said to David, “The Lord also has put away your sin; you shall not die."

I would do a cold compression test and if the numbers are good leave it at that.

I don't like to run an engine without flowing coolant through the head, especially aluminum head engines. If you must run the engine, take the belt off so the water pump is not run dry.

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

X2; Since I am a person who never gets away with things like others do I would never run an Engine without Coolant as described by the OP.

I have done it on Gassers but just to see if the Engine would start. As soon as it started I shut it down.

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84 300D, 82 Volvo 244Gl Diesel

Not a problem. We'd run a V8 engine in auto shop on a stand all the time. Really gets your juices flowing....

The problem (for me anyway) is there is no easy way to verify that the head was not compromised. Sure, it would still start and run afterwards. But how would you know if the head was not stressed more than if it had coolant flow? It is well known small cracks develops between in/ ex valves and the head can still be good. How would you know if that crack was not widened from running it w/o coolant? How do you determine how long and how hot is safe to run w/o coolant?

I would let it run for a few seconds w/o coolant and shut it off. Maybe I am being over cautious.

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

I would not be afraid of running a 617 for four or five minutes wo coolant. Its all iron. But for a compression test I'd probably test with it cold and see where I was first.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Setting up the rad is easy, two hoses, take the fan off, prop up the rad up so the hoses don't rub the belts.

Diesels have a lot of air running through the combustion chambers so they do tend to run cool without a load. ( This is also why idling a diesel unloaded is a very bad idea as the fuel does not burn very well leading to wet stacking. ) For a valid hot compression test, everything must be evenly warmed up. This is difficult to do without coolant as the cylinders run much cooler than the head. By the time the cylinders are warm enough, the head will likely to be overheated.

I'd either hook up a rad or just do a cold compression test if you know the motor runs and has good hot oil pressure.