N/A D24 loses power nearing max revs, brown black grey smoke

[ngoma]

Originally Posted by 245d6

I have a (new) d24t radiator. Didnt fit with current hoses but will switch them with other engine. Also my mechanical fan has no cowl or air box, would that matter? And thermostat its a 87 degrees one, is that okay.

What radiator is in there now? Maybe that's what is causing the overheat problem-- wrong radiator (too small) in addition to being clogged with rust flakes?

Fan shroud most helpful at lower road speeds as it improves the fan's efficiency.

Originally Posted by 245d6

Still strange, i measured temperatures again today, 3/4 of the gauge was 100 degrees, not that hot right?

How did you measure? Normal operating temp. more like 90*C.

[245d6]

2nd hand d24 240 radiator. I flushed it multiple times. Also bought another d24 radiator (nos) but hose connections are on different sides. Will get new hose to run the new new radiator in the future.

Measured with laser on top radiator hose / head.

Yesterday I changed the oil, no water, no debris(bearings), did smell very bad (burnt).

Listened to the whole engine with screwdriver to my ear, can't really find anything unusual, except some injectors are louder than others. Even put car on lift to listen to the oil pan, no strange bearing knocks there.

Rerouted crankcase breather into a can, now know where all the oil is going. Quite some oil in the can after 40km drive.

Today further investigation into the ticking noise and another coolant flush. Did notice temperature was better yesterday, gauge in the middle all the way to 120km/h

Also, noticed left rear brake drags a bit (wheel was warm), extra resistance, engine needs to work harder? Or maybe it got hot because of constant overfueling through crankcase breather?

[ngoma]

Originally Posted by 245d6

2nd hand d24 240 radiator. I flushed it multiple times.

If the passageways are clogged it can be difficult to impossible to clear it by simple flushing. Radiator shops remove the end tanks and use metal rods to physically "rod" out the small passageways.

Why not test the radiator with your laser thermometer? Take readings from different locations on the radiator. Should be near uniform gradiated temp. difference as you work from the inlet to the outlet. Distinct cold spots indicate clogs.

Originally Posted by 245d6

Also bought another d24 radiator (nos) but hose connections are on different sides.

Guessing one of them may be for a different model (7xx?).

Originally Posted by 245d6

Also, noticed left rear brake drags a bit (wheel was warm), extra resistance, engine needs to work harder?

Obviously, but unless it was really locked probably not causing engine overheating by itself. The brake would be smoking and red-hot.

Originally Posted by 245d6

Or maybe it got hot because of constant overfueling through crankcase breather?

Not likely.

[245d6]

I have the original 240 d24 radiator in there now, the other one I have is for later model 240 / 740 turbo? Last week I flushed the old one several times, lots of shit came out and afterwards the car ran less ''hot'', needle stays in the middle / bit above the middle now.

The engine I picked up came with different (longer) radiator hoses, which match up with the other NOS radiator I have. Engine is d24 but from 1991. I suspect they changed radiator & hoses somewhere inbetween.

So did some more diagnosing last week, replaced the suspected injector with one from the other engine, ticking noise went away, car still started fine and drove okay except for a bit of blue smoke when cold. Still drank A LOT of oil (i filled up more than a liter in 400 kilometers). Made a catch can inbetween the ventilation of the engine to the inlet, half of all oil that it consumes now goes into the can.

But a new problem: engine started fine until yesterday, now it won't start at all anymore (not even on brake cleaner). When trying to start, smoke comes from exhaust, oil filler cap and OUT OF THE INTAKE? Fuel gets to the injectors, so that shouldn't be a problem. Checked glow plugs and they are also functioning. When using brake cleaner to start it, it should always start if it even only has a tiny bit of compression?

I suspect the engine has 0 compression, rings are done?, maybe some valves are screwed? No idea how long they drove it around without adjusting, they were all too tight (some I couldn't even get my 0.04 feeler gauges between). Looking at it's history, sitting for 20 years with water rather than coolant, no valve adjustments, crazy oil consumption I don't have much hopes for this engine other than rebuilding it in the future.

Next week i'm gonna swap in the other d24, just ordered new belts, waterpump & motor mounts to replace those while i'm there anyway. History of this one sounds a bit more promosing, hope it runs better so I can start taking apart the old one and see what it needs. Curious to find out what is broken, as it just stopped running all of sudden.

[v8volvo]

Based on the oil usage it does sound like the engine is getting tired.

BUT even so, an engine cannot go from starting easily to not starting at all due to low compression with such little warning. Compression loss is a gradual process and you would see the engine get progressively harder to start. It wouldn't go to zero literally overnight like you are describing, on an engine that ran OK the day before, even if it did show signs of wear.

What this sounds to me like is a TIMING issue. That is almost the only way sudden loss of starting ability can occur. You already took the good steps of confirming fuel delivery to the injectors and functional glow plugs. Assuming it has fuel and glow, then what you are almost certainly dealing with is a slipped timing belt or spun crankshaft timing gear (very common if correct torque spec is not achieved on the front crankshaft bolt).

Sounds like you already have a better/stronger engine to swap in so might not be worth the effort with this one anyway, except as a possible rebuildable core for the future as you say. But if you do want to investigate it further, best course of action is probably to check camshaft timing and injection pump timing (in that order) with engine set to TDC. Greenbook gives good procedures for this or you may already know how.

[245d6]

Yes thought about timing too, maybe due to starting on brake clean pretty violently? Ran fine though last time I drove it, nothing different than before.

I redid the whole timing, build my own tools to achieve 450 nm on the crank bolt. Curious to see once I get the engine out, i think im going to loosen the crank bolt while its still in the car, rather than on a stand. Didn't replace the key though, but I read that it won't do much anyway.

[ngoma]

Using starting fluid on an IDI engine with glowplugs is not a good idea. As soon as the starting fluid hits the hot GPs you get mis-timed violent explosions. Has been known to break GPs, piston rings, pistons, and bend rods and valves.

If you must use it, at least deactivate the GPs first.

Better explanation here:
https://www.dieselhub.com/tech/start...l-engines.html

[245d6]

Lesson learned the hard way then I guess.. now I know what not to do with the other engine.

Edit: is it possible to remove engine without removing the gearbox? I have everything disconnected, but would rather not mess with the gearbox if possible. Is it as simple as undoing the bellhousing bolts, pulling engine forward? Or is it easiest to remove the full unit?

[245d6]

Alright, engine is out together with the gearbox. Spare engine did not come with flywheel, is there any way to determine the position of the flywheel onto the crankshaft? Without the gearbox on there are no marks to line it up. As simple as putting cyl. 1 on tdc and then approximately mounting the flywheel? Couldn't go too bad i think as there are only 8 bolts / positions.

[ngoma]

Originally Posted by 245d6

...is there any way to determine the position of the flywheel onto the crankshaft?... Couldn't go too bad i think as there are only 8 bolts / positions.

Look closer and you should be able to see the holes are not spaced evenly. The flywheel can only be fitted one way.

Bolts get threadlocker, 55 ft-lbs (75 Nm).