Diesel engine health

[saboor73]

@saboor73

I attached oil catch can back in April then emptied it in july. 1300km. I think it was around 300mL oil that I removed.

Now it's just 400km, I have not emptied it but catch can is leaking and I expect some oil collected inside. Can confirm after emptying it only.

What does high oil in pcv indicates about the engine?

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Yes only way is to open and drain it

High oil in pcv indicates retard pump or tigher valve clearance or both

[ali_ak]

Yes only way is to open and drain it

High oil in pcv indicates retard pump or tigher valve clearance or both

Well one of my valve broke last month that resulted in head job. I think valve clearances are correct.

Then I timed the pump slightly on advance side. Though I feel my pump disturbs it's timing pretty quick.

Can it be some other calibration issue of the pump?

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[Mirza967]

@saboor73

I attached oil catch can back in April then emptied it in july. 1300km. I think it was around 300mL oil that I removed.

Now it's just 400km, I have not emptied it but catch can is leaking and I expect some oil collected inside. Can confirm after emptying it only.

What does high oil in pcv indicates about the engine?

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it means increased blowby.....which can be due to tight valve clearance ,wrong pump adjustment or worn rings.

[ali_ak]

it means increased blowby.....which can be due to tight valve clearance ,wrong pump adjustment or worn rings.

Do blow by gases also enter pcv?

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[Dongskie]

What does high oil in pcv indicates about the engine?

one possibility is a worn/loose valve seal, as per experience.

[ali_ak]

one possibility is a worn/loose valve seal, as per experience.

Head job was done last month. So probably that's not true

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[Xulfiqar]

Well one of my valve broke last month that resulted in head job. I think valve clearances are correct.

Then I timed the pump slightly on advance side. Though I feel my pump disturbs it's timing pretty quick.

Can it be some other calibration issue of the pump?

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The pump injection timing is critical to make sure the engine loads up each cylinder perfectly - it will then not burn its lubricating oil as the piston rings would be correctly loaded up during the powerstroke.

Head job was done last month. So probably that's not true

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It is possible in Pakistan. I have seen mechanics hammer the valve seal into place and then ram the valve in the head. Both actions can destroy the seal. The correct way is to use some very nice quality warm engine oil to lube the seals and slip them over the valve stems with the aid of a drinking straw. This action prevents the seal lip from tearing from the valve collet rings. The warm oil softens the seals too.

The final push onto the valve guide is done with a deep socket or tube - the seal literally clicks/pops into place if you do it correctly.

[ali_ak]

The pump injection timing is critical to make sure the engine loads up each cylinder perfectly - it will then burn its lubricating oil as the piston rings would be correctly loaded up during the powerstroke.

It is possible in Pakistan. I have seen mechanics hammer the valve seal into place and then ram the valve in the head. Both actions can destroy the seal. The correct way is to use some very nice quality warm engine oil to lube the seals and slip them over the valve stems with the aid of a drinking straw. This action prevents the seal lip from tearing from the valve collet rings. The warm oil softens the seals too.

The final push onto the valve guide is done with a deep socket or tube - the seal literally clicks/pops into place if you do it correctly.

Ab kya kr saktay hain, most of these guys resist technical input.

Is their a way to verify if valve seal is leaking?

Today I emptied the catch can, it was around 100mL oil.

I think it must be timing/pump related issue. Or may be tappets if he measured incorrectly

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[Xulfiqar]

Ab kya kr saktay hain, most of these guys resist technical input.

Is their a way to verify if valve seal is leaking?

Today I emptied the catch can, it was around 100mL oil.

I think it must be timing/pump related issue. Or may be tappets if he measured incorrectly

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if your engine has bad valve seals you can check by removing the manifolds and looking into the ports, if the exhaust is not dry the seals are leaking, The intake is almost always wet from the blowby but you should not be seeing oil pooled in the valve pockets.

Most probably your engine is not timed correct - please remember that the injector pressure also affects timing, lower pressure makes the timing advanced as the break pressure is reached earlier. So please make sure everything is done to the dot by the book.

[ali_ak]

if your engine has bad valve seals you can check by removing the manifolds and looking into the ports, if the exhaust is not dry the seals are leaking, The intake is almost always wet from the blowby but you should not be seeing oil pooled in the valve pockets.

Most probably your engine is not timed correct - please remember that the injector pressure also affects timing, lower pressure makes the timing advanced as the break pressure is reached earlier. So please make sure everything is done to the dot by the book.

I adjust nozzle pressure by the book. But i have to check that again after the headjob.

Even today i was saying somehthing to mechanic and his comment was "Engine agay weak ha pump powerful kr k bera ghark..." something.
I was enquiring him about a nearby by lab, as i wanted to check internal pump pressure.

But what is this concept of Not renewing the pump, or keeping nozzle break pressure low in case of weak engine??

How will that approach damage/benefit a genuinely weak engine?

[Xulfiqar]

I adjust nozzle pressure by the book. But i have to check that again after the headjob.

Even today i was saying somehthing to mechanic and his comment was "Engine agay weak ha pump powerful kr k bera ghark..." something.
I was enquiring him about a nearby by lab, as i wanted to check internal pump pressure.

But what is this concept of Not renewing the pump, or keeping nozzle break pressure low in case of weak engine??

How will that approach damage/benefit a genuinely weak engine?

At this moment I would see what the mechanic is smoking for leisure. I suspect a loaded red n white ciggie.

[ali_ak]

At this moment I would see what the mechanic is smoking for leisure. I suspect a loaded red n white ciggie.

Yeah but when all of them smoking one can genuinely suspect that something is wrong with me[emoji14]

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[ali_ak]

At this moment I would see what the mechanic is smoking for leisure. I suspect a loaded red n white ciggie.

I have seen his approach at too many places. Though I believe even a weak working engine will have very less affect on the nozzle timing.

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[ali_ak]

@xulfiqar @saboor73 @dongskie

Today i had my compression tested, after around 2 years.

Compression seems to be OK, but if i take into account Gauge was rested at 0.5MPa instead of 0, then compression is bit low.

Comression Test Settings:
Gauge had a range of 0-7Mpa, with resolution of 0.2MPa.

Same gauge was used 2 years ago and 3 cylinders were above 2.8MPa, 1 cylinder was slightly above 3Mpa.

This time i made video and tabulated the results.

I have tabulated pressure every revolution, as well as the final stable pressure value.

I never used oil to measure increased pressure, but in my first pressure test on cylinder 1, technician forgot to remove Injection Pump solenoid connector, and pressure value touched 4Mpa, then i removed the connector, gave few revs to engine before taking a reading. I hope subsequent reading were not affected by this diesel spray.

Compression Limits:
Min 2.452 MPa, Max 2.942 Mpa,, max difference among cylinders, .49 MPa

Car Data:
Car is 4wd.
it was giving average of 10-11 km/L in city, mileage dropped to 7.5 to 8.5km in last few months.
then one of valve broke, resulted in head work.
No noticeable change in mileage before and after the head job.

2 days ago diesel lab guy reduced fuel feed of the pump, still 7.5km/L mileage.
Now i intend to callibrate pump on his machine and check internal pressure etc.

What is you guys opinion on the compression result??
One thing i can say, cylinder 1&2 readings have fallen to 2.4ish from 2.8ish, cylinder 3&4 seems to be same as before.

thanks and regard...

Final Pressure
(6/7th revolutions in first 2 cylinder, 7/8th revolution in other 2, where reading donot increase any further)

Cyl1: 2.45 MPa
Cyl2: 2.5 MPa
Cyl3: 2.9 MPa
Cyl4: 3.05 MPa

[Dongskie]

@ali_ak good job and effort on the compression test.

you mentioned it broke a valve and did head works, were all the valves replaced?

My assumptions are:
1. If ALL valves were replaced and re-seated, then it may be a bad rings already. **
2. If only the broken valves were replaced and reseated, possibly the untouched valves may already be leaking pressure.
3. Shim may be too thick hence too small clearance, could lead to leak when engine warms up to temp.

[ali_ak]

@ali_ak good job and effort on the compression test.

you mentioned it broke a valve and did head works, were all the valves replaced?

My assumptions are:
1. If ALL valves were replaced and re-seated, then it may be a bad rings already. **
2. If only the broken valves were replaced and reseated, possibly the untouched valves may already be leaking pressure.
3. Shim may be too thick hence too small clearance, could lead to leak when engine warms up to temp.

All valves were replaced, as well as seals.

Shims were used as it is, instead they grinded the valves (i don't know its seat or stem) to adjust the tappet.

But i think compression test is not that bad.

[ali_ak]

the pages you are showing do not have your model in it, its all corolla, camry, corona etc. The area where it says to apply pressure is a turbo diesel engine, the pressure is applied in the aneroid device. The closest you have would be the corolla.

In toyota literature the pump advance function is called the timer device. The timer device rotates the camplate in the pump advancing it, when the engine runs - the system advances under hydraulic pressure - thats why its important to have the pump internal operating pressure correct - because if the pump pressure is low, it cannot build enough pressure to advance the camplate at 2000 rpm.

@xulfiqar

Can u please also comment on my above mentioned compression test.

2ndly, these are my deductions for choosing right specs from these pages.
My car is CE95, 2.0D, 2C engine.

Presetting Full Load injection volume is categorized as follow:

a CE70
b CE80, CM(STD)
ruled out both of them, as they are 1C-L engines, CM is ruled out for reasons given at the end.

c CV
ruled out, as engine list indicates all turbos like 1C-TL, 1C-TLC, 2C-T, 2C-TL, 2C-TLC, &3CT series which is out of scope of my manual.

d CT (w/o HAC), CR
Most Probably THIS, as both these series are in 1C-L and 2C-L engine category, my chassis CE95 is also in 2C-L engine category in wikipedia.

e CT (w HAC)
Ruled out; HAC, i understand, is Hill-Start Assist Control

f CM: Opt High Altitude
Ruled out; this category has both 1C and 2C engines with/wihout turbo, but they are liteace/town ace vehicles, not sedans like CT.

Inspect Injection Volume (at various RPMs) categorize cars as following:

CE70
CE80, CM(STD)
CV
CT (w/o HAC)
CT (w HAC)
CR
CM: Opt High Altitude

In contrast to previous list, CR & CT(w/o HAC) are separate. I think CT(w/o HAC) is closest to my car although it has turbo variants, else CR category is 2C engine mostly but its a liteace, not sedan.

Should i go ahead with using CT(w/o HAC) specs??

Other tables have less categories and its easier to choose specs their.

Now i have noticed, in 2nd table where my closest CT(w/o HAC) & CR are separate, data is exactly the same.

Only difference is Adjusting Lever Angle
for CT its 13-23 degrees, for CR its 3-13 degrees.
what is meant by this?

[Xulfiqar]

HAC means "high altitude compensation" - its the opposite of a turbo aneroid device, it reduces fuel as the gets to lower air density area (mountains)

The adjusting lever means the "accelerator lever" on the pump - CT means a corona with a C diesel engine, CR means a liteace/townace/masterace etc with C diesel engine. Their engines are bolted a bit different in the vehicle and hence have a slightly modified levers on the pump, thats why the slightly different external adjustment - the townace pumps have a longer lever.

your compression numbers are excellent for cyl 4 but at wear limit for cyl 1, the engine will be a bit shaky with this condition and when you mention you have blowby its indicating that those cylinders are the weak ones. This happens when this engine is ran out of tune/time for a long time. The rings clog and wear out. The out of time can also be from a badly set injector too as it changes injection timing too.

I would have the pump adjusted correctly along with the nozzles, then time the pump correct. Keep on driving till the engine gives you problems later on, then rebuild it (it will be ages from now even in this condition)

[ali_ak]

HAC means "high altitude compensation" - its the opposite of a turbo aneroid device, it reduces fuel as the gets to lower air density area (mountains)

The adjusting lever means the "accelerator lever" on the pump - CT means a corona with a C diesel engine, CR means a liteace/townace/masterace etc with C diesel engine. Their engines are bolted a bit different in the vehicle and hence have a slightly modified levers on the pump, thats why the slightly different external adjustment - the townace pumps have a longer lever.

your compression numbers are excellent for cyl 4 but at wear limit for cyl 1, the engine will be a bit shaky with this condition and when you mention you have blowby its indicating that those cylinders are the weak ones. This happens when this engine is ran out of tune/time for a long time. The rings clog and wear out. The out of time can also be from a badly set injector too as it changes injection timing too.

I would have the pump adjusted correctly along with the nozzles, then time the pump correct. Keep on driving till the engine gives you problems later on, then rebuild it (it will be ages from now even in this condition)

Thanks for the reply. Well blow by was already too much when cylinder 1 has well above borderline, but yes i have noticed it increased even more.

And yes there was a pic of lever on the manual, and when i matched them to mine, CT w/o HAC is the most compatible thing to my CE95 chassis. I intend to use those specs for tuning my car.

I have been told that toyota ravi motors has in house diesel lab, i may visit them to see the way they work. Their manual might have specs for me as well.

Only thing i fear is, that their MASTER of Diesel cars would not entertain my way of doing things and do as he always do, with a much higher bill. I have met a new lab guy, he is also typical person but was more then willing to do things as i ask him to do.

One thing i don't understand, how do we count 200 strokes needed to measure fuel injection volume??
They have rpm meter, i haven't noticed a stroke counter.

[ali_ak]

@xulfiqar

I cannot find timer advance measuring device any where on internet.

Only 1 shop from india is selling on ebay, he names it timer travel gauge.

2ndly, can u tell me what How much CSD extends its plunger on hot engine.

I had earlier taken pics on Cold and Hot engine, and i think CSD extends around 3-4 mm on hot engine (may be more).