MikeFl4
Active Member
Hello everyone,
Taking a break from my recent exploration in the V8 world, today we are back to the hard slog that is slowly chipping away at my diesel P38 in order to make it “as good as possible”
I have been having an engine issue that’s just a bit strange, but I think it all stems from a timing issue (unless one of you guys has another idea!)
The engine runs good, starts instantly after a single cycle of the glow plugs and runs nice and smooth (if you don’t touch it, more on this later)
It really seems to be an injection timing issue just based on that modulation read out. Unfortunately, from what I have read, it seems in order to set the modulation correctly I need the engine to come up to proper temperature! (Note: I have swapped the thermostat and although this finally brought my temperature up from below C all the time – It only gets to about 1/3 the way there)
Since my car has 230K miles, would it really be worth getting all of the proper timing equipment in order to set the timing correctly? I have read its possible to adjust the timing "by ear", this type of adjustment is more common on high mileage engines which are too worn to be adjusted using factory measurements.
The actual problem:
Inconsistent idle and a lumpy/bumpy return to idle while being driven… Let me explain in this video:
**Stuff to mention below to narrow down the problem**
Jobs that have been done:
Full service of every single oil and filter in the vehicle
Refurbished injectors x 6
Intake manifold gaskets (1999 model so rubber type)
Cleaned/flushed intake manifold
New glow plugs
New leak off pipes
Cleaned / swapped MAF (for testing purposes)
Cleaned / swapped MAP sensor (for testing purposes)
Pipes free from crap going from manifold to MAP sensor
EGR bypassed – one of those straight through pipes
Intercooler swapped (original one was leaking oil so I assume had a hole in it)
Note: Ac system has been removed from the car.
No CEL but often gives a code of “ignition timing deviation”
Things ive tested:
Turbo wastegate – I was able to move the rod so I assume its not stuck
All hose clamps are tight and pipes seem to be good with no obvious splits
Engine power is O-K, I’ve never driven a “good” M51 so I don’t really know what to base it off of
Removed cam cover and cleaned the oil sponge thing (engine seems to have high-ish top end pressure – no pressure from crankcase testing through dip stick – only what I would consider as slightly excess pressure coming from the cam breather hose
Things to note / im not happy with:
I have swapped the thermostat and although this finally brought my temperature up from below C all the time – It only gets to about 1/3 the way there. I have another thermostat that im going to swap in when I get a chance as having the engine running at the correct temperature is always a good thing.
Engine still seems what I would consider as excessively smoky when accelerating – very very much so at full throttle, it will cloud out the whole road behind you!
Taking a break from my recent exploration in the V8 world, today we are back to the hard slog that is slowly chipping away at my diesel P38 in order to make it “as good as possible”
I have been having an engine issue that’s just a bit strange, but I think it all stems from a timing issue (unless one of you guys has another idea!)
The engine runs good, starts instantly after a single cycle of the glow plugs and runs nice and smooth (if you don’t touch it, more on this later)
It really seems to be an injection timing issue just based on that modulation read out. Unfortunately, from what I have read, it seems in order to set the modulation correctly I need the engine to come up to proper temperature! (Note: I have swapped the thermostat and although this finally brought my temperature up from below C all the time – It only gets to about 1/3 the way there)
Since my car has 230K miles, would it really be worth getting all of the proper timing equipment in order to set the timing correctly? I have read its possible to adjust the timing "by ear", this type of adjustment is more common on high mileage engines which are too worn to be adjusted using factory measurements.
The actual problem:
Inconsistent idle and a lumpy/bumpy return to idle while being driven… Let me explain in this video:
**Stuff to mention below to narrow down the problem**
Jobs that have been done:
Full service of every single oil and filter in the vehicle
Refurbished injectors x 6
Intake manifold gaskets (1999 model so rubber type)
Cleaned/flushed intake manifold
New glow plugs
New leak off pipes
Cleaned / swapped MAF (for testing purposes)
Cleaned / swapped MAP sensor (for testing purposes)
Pipes free from crap going from manifold to MAP sensor
EGR bypassed – one of those straight through pipes
Intercooler swapped (original one was leaking oil so I assume had a hole in it)
Note: Ac system has been removed from the car.
No CEL but often gives a code of “ignition timing deviation”
Things ive tested:
Turbo wastegate – I was able to move the rod so I assume its not stuck
All hose clamps are tight and pipes seem to be good with no obvious splits
Engine power is O-K, I’ve never driven a “good” M51 so I don’t really know what to base it off of
Removed cam cover and cleaned the oil sponge thing (engine seems to have high-ish top end pressure – no pressure from crankcase testing through dip stick – only what I would consider as slightly excess pressure coming from the cam breather hose
Things to note / im not happy with:
I have swapped the thermostat and although this finally brought my temperature up from below C all the time – It only gets to about 1/3 the way there. I have another thermostat that im going to swap in when I get a chance as having the engine running at the correct temperature is always a good thing.
Engine still seems what I would consider as excessively smoky when accelerating – very very much so at full throttle, it will cloud out the whole road behind you!
..
