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Diesel refuses to diesel

It has a combustion chamber! Just very small, and completely tucked up inside the head.

Actually, the compression ratio is high enough that even a modest amount of oil could be causing the PSi readings to go up. even if it didn't really improve the ring sealing (much).

I'm no diesel mechanic, though, I have no idea how far 180 psi is from what it needs to be.

Is it possible you just have dead glow plugs? That would be a more likely sudden no-start vs. a rapid loss of compression across all cylinders. Do a risitance test across each one, make sure they're getting 12V+ when the key is initially turned on.
 
JohnMc said:
It has a combustion chamber! Just very small, and completely tucked up inside the head.

Actually, the compression ratio is high enough that even a modest amount of oil could be causing the PSi readings to go up. even if it didn't really improve the ring sealing (much).

I'm no diesel mechanic, though, I have no idea how far 180 psi is from what it needs to be.

Is it possible you just have dead glow plugs? That would be a more likely sudden no-start vs. a rapid loss of compression across all cylinders. Do a risitance test across each one, make sure they're getting 12V+ when the key is initially turned on.
Click to expand...

My rabbit (same motor less 2 cylinders) had ~450psi compression after a hone and rering. IIRC, 375psi is minimum spec.
 
JohnMc said:
That's waaaay low. Strange that it would go from running to that low so quickly, though.

Did it suddenly get cold there?
Click to expand...

Sudden drop in temp, or snapped ring,
Maybe the compression was already low and finally just gave up the ghost.
Check your valves.

Or just redblock swap because it just plops right in there
 
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John V said:
I wouldn't..
Ever hear of the little fact that diesels with those Ricardo design heads don't have a combustion chamber ? Can you say "hydraulic-ing"

The tiniest bit of fluid of any sort and its STOP!..
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My om617 started making hydraulicing noises around las vegas,slapslapslap really loud but i still had 400 more miles to go to salt lake. I refueled it still running, put in a few quarts of motor oil in the fuel tank, and drove the rest of the way. Smoked real bad but got there.
As soon as I parked it I knew it was dead, and the 20* temp wasn't helping. I managed to get it started one more time but had to rent a car to go home. Came back the following week to tow it home and swapped in the om601.

But we already know a Mercedes OM diesel was ions ahead of a VAG piece of crap D24.
 
240240 said:
Sudden drop in temp, or snapped ring,
Maybe the compression was already low and finally just gave up the ghost.
Check your valves.

Or just redblock swap because it just plops right in there
Click to expand...

Do a VW Quantum/Audi 4000 5 cylinder turbo engine swap.
 
Redblock swap is boring and I already have a redblock car. I'm thinking along the lines of either a Merc diesel or an LS. Maybe a D24t if I can find one.
 
I'm just punning along.

LS swap is easier now than it's ever been. And not even terribly expensive if you stay away from the small number of 5.7/6.0 aluminum versions that come with a higher HP cam already installed from the factory.
 
I'd like a V8 but at the same time I'd like to keep it diesel, I'm still learning about them and I want to make one go fast.
 
It's a 4 cylinder, but the VW TDi has lots of aftermarket support, and some of them make some serious amounts of grunt.
 
Does this look right? Lined up TDC mark in the bell housing hole. Intake was oily as hell.

8CAWXJnh.jpg
 
Cwazywazy said:
This car only has about 152k on the clock, I'm really hoping it's not the compression..
Click to expand...

Not likely the compression would have drastically dropped in multiple cylinders from one day to the next, but a glow plug can, and these engines are notoriously hard to start with one (or more) failed GPs. Test them individually-- just verifying they are receiving +12VDC isn't telling you enough, although if the GP relay is malmunctioning that is obviously a problem.

My money's on either GP issues OR air intrusion into the fuel supply. You did say that 3 injector lines were not spitting? Troubleshooting step: Install a section of clear fuel line at the injector pump out (return) line and watch for air bubbles.

Cwazywazy said:
Is this little nub on the pump belt a timing mark?
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Not the belt, but the cog? It should line up with the corresponding indentation line on the IP when at TDC. Are you suspecting the timing jumped?
 
Cwazywazy said:
Does this look right? Lined up TDC mark in the bell housing hole. Intake was oily as hell.

8CAWXJnh.jpg
Click to expand...
Maybe, but ONLY if the timing belt has NEVER been changed (65k mi. requirement). The "0" mark on the flywheel against the pointer in the sight hole is a much more reliable indicator.

Oily intake normal-- your car has EGR, no?

Is that a radiator hose going up over the top of the engine?
 
tintintin said:
Maybe, but ONLY if the timing belt has NEVER been changed (65k mi. requirement). The "0" mark on the flywheel against the pointer in the sight hole is a much more reliable indicator.

Oily intake normal-- your car has EGR, no?

Is that a radiator hose going up over the top of the engine?
Click to expand...

Sight hole, that's what I used. No EGR. Put the hose up there out of the way.
 
tintintin said:
Not likely the compression would have drastically dropped in multiple cylinders from one day to the next, but a glow plug can, and these engines are notoriously hard to start with one (or more) failed GPs. Test them individually-- just verifying they are receiving +12VDC isn't telling you enough, although if the GP relay is malmunctioning that is obviously a problem.

My money's on either GP issues OR air intrusion into the fuel supply. You did say that 3 injector lines were not spitting? Troubleshooting step: Install a section of clear fuel line at the injector pump out (return) line and watch for air bubbles.

Not the belt, but the cog? It should line up with the corresponding indentation line on the IP when at TDC. Are you suspecting the timing jumped?
Click to expand...

I replaced the first 5 GPs awhile ago, not like that would cause low compression anyway. I've started this engine in ~50 degree weather without glow plugs. According to the service history the head was rebuilt and belts replaced about 20-25k ago. (2006.)
 
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