I'm stumped

[strada-caster]

looking for causes of high fuel consumption, high oil consumption and lack of power. any suggestion will be helpful. thanks for reading all this.

fuel consumption was 10.5l/100km a year ago, its currently 13l/100km
oil consumption is about 700ml for 3500km, happened just this last oil change, never had oil consumption like this before
-blue smoke on start-up only then goes away
lack of power.
-I adjusted the valves and this corrected it except still feels like a little is missing.


Current thoughts:
-valve seals


Things that have been done:
-timing belt, idlers, water pump, t-stat, timing checked afterwards
-IP shaft seal
-valve lash
before
1E .007
1I .007
2E .007
2I .002
3E .000
3I .007
4E .000
4I .002
all set back to .010 warm
-fuel/air filter new in april
-new fuel lines (rubber only)
-comp test done warm - 8 cranks
cyl 1 440psi
2 400psi (2 more cranks put it at 440 psi)
3 400psi (2 more cranks put it at 440 psi)
cyl 4 440psi
compression test done prior to valve lash reset.

-new injector nozzles, reset professionally.


I have noticed the following:
-oil on glowplugs (inside)
-halfmoon gasket leaks accounting for some of the oil loss
-oil spits out the dipstick tube while engine is on

[Blackberry]

looking for causes of high fuel consumption, high oil consumption and lack of power.
...oil consumption is about 700ml for 3500km,
lack of power.
-I adjusted the valves and this corrected it except still feels like a little is missing.
Current thoughts:
-valve seals
I have noticed the following:
-oil on glowplugs (inside)
-halfmoon gasket leaks accounting for some of the oil loss
-oil spits out the dipstick tube while engine is on

I've had a leak in that small hose that goes from the ?(intake manifold?) to the injection pump (actually was where I'd put in a T to my boost guage) and that caused it to have reduced power and, I think, use a little more fuel (not sure why the latter). Maybe when you did some work (when valve cover off) that hose didn't get completely reconnected? Oil blowing out the dipstick suggests too much crankcase pressure (could also contribute to the half-moon leak). Not sure how that could happen if you don't have blow-by (diesel ppl: do those compression-test numbers suggest that?) and your breather vent/hose (coming out of the valve cover) isn't plugged (did you install a catch-can system that's now plugged/full?). I think the 700ml in 3500kms could be entirely attributable to your dipstick & half-moon leaks.

[yojimbo]

I dont know what compression figures should but they look good, except for 2 right? I would check how much oil is going through the breather set up, if tits spitting oil into the cylinders it would account for 2 cylinders coming up to pressure after being cranked a while, and it might be being forced out by blow by on those 2.

[yojimbo]

I've had a leak in that small hose that goes from the ?(intake manifold?) to the injection pump (actually was where I'd put in a T to my boost guage) and that caused it to have reduced power and, I think, use a little more fuel (not sure why the latter).

This would just reduce fueling and hence power, since diesels don't have a 'mixture' as such i dont see why it would increase consumption unless your driving style was somehow modified because of it. Diesel engines dont care how much fuel they have per air, they just burn whats available, unless they can't because of overfueling, poor timing, or poor spray from the injectors so the oil isnt in the right place at the right time in the right state of atomisation.

[strada-caster]

Thanks for the input. I'm gonna get a leak down test. see what comes up there.

[TardisDeli]

On my L300 I had a mystery oil leak, Butch at CVI found it was where the dipstick attached to the engine block, apparently there is a small o ring there that dies with age. You should replace the air filter frequently, it is a major cause of rough starting and severe rough idling, I know it seems too simple a fix, but just do it, the difference is amazing. Cheers, Christine.

[jessef]

your compression is good and your valves settings as well

when did you notice the drop in fuel economy?

Every fall/winter I notice a 10% or so decrease in fuel economy due to the winter blend diesel that the gas co's use.

This may be your issue.

As mentioned before, the rear halfmoon seal enjoys leaking all over the backside of the engine and you'll always get some oil through the tube. An oil catch can will help with that.

One thing to note is that your fuel economy will actually improve if you put in 1/2 liter of 2stroke oil for each full tank of diesel, especially in the winter.

[thedjjack]

Leak down test for sure??? If you have oil coming up to the top of the dipstick tube and running over it sounds like you might have a problem with the crankcase pressure??

Maybe blocked crankcase emissions?

[strada-caster]

I've got a crappy homemade oil catch can that is not sealed completely, I'm going to put on a new one I got.

Crankcase pressure is still there, although it seems lower than it was in the past(difference may be from valve adjustment). is there a PCV? valve inside the valve cover before it exits or just the hole to the hose to the air intake? if there is a valve, maybe its a little plugged?

I've noticed the bad fuel economy throughout the year, although starting 3 months ago my driving is now 30% dirt road (a very nice dirt road, consider it a chipsealed road, it's that nice, but i do drive down it in 4th at 3000rpm). 60% highway(5th @ 3000rpm), 10% city.
I haven't kept good enough records to follow everythign through, i'm working off a bad memory.

I don't have oil LEAKING out of the dipstick, it stays sealed if I don't touch it. It only sprays when I take it out when the engine is running. It makes sense there would be some pressure down there (oil pressure....) maybe this is not a symptom at all, although there are many opinions on the net saying otherwise (for different vehicles).

[thedjjack]

I've got a crappy homemade oil catch can that is not sealed completely, I'm going to put on a new one I got.

Crankcase pressure is still there, although it seems lower than it was in the past(difference may be from valve adjustment). is there a PCV? valve inside the valve cover before it exits or just the hole to the hose to the air intake? if there is a valve, maybe its a little plugged?

I've noticed the bad fuel economy throughout the year, although starting 3 months ago my driving is now 30% dirt road (a very nice dirt road, consider it a chipsealed road, it's that nice, but i do drive down it in 4th at 3000rpm). 60% highway(5th @ 3000rpm), 10% city.
I haven't kept good enough records to follow everythign through, i'm working off a bad memory.

I don't have oil LEAKING out of the dipstick, it stays sealed if I don't touch it. It only sprays when I take it out when the engine is running. It makes sense there would be some pressure down there (oil pressure....) maybe this is not a symptom at all, although there are many opinions on the net saying otherwise (for different vehicles).

I asked about the dip stick because I blew the head gasket in my VW 1.6 NA diesel and it started to empty the crank case oil out the dipstick tube

How many KM on the motor? I not sure about the crankcase emissions system (have not had to work on it yet).... I think the leak down test will give some more ideas plus invest the crankcase emissions system...

You are on the right track, how is the turbo running it could explain power problems and what ever tells the pump to turn up when the turbo is boosting (I had a problem with a vacuum line on my Mercedes TD powered Jeep, turbo would boost and the pump would not turn up...Stumped me for a while....

[strada-caster]

140,000 km's
truck goes into the shop tonight for a little help, let you know how things turn out.

[strada-caster]

well I got my valve seals done, seems like they had a minor effect on the oil burning but it didn't fix it.

I guess i'm at the turbo leaking internally or the rings.
what is the best way to test these two theories?
thanks

[FalcoColumbarius]

...I don't have oil LEAKING out of the dipstick, it stays sealed if I don't touch it. It only sprays when I take it out when the engine is running. It makes sense there would be some pressure down there (oil pressure....) maybe this is not a symptom at all, although there are many opinions on the net saying otherwise (for different vehicles).

Ha, I've done that. Makes me wonder what the dip stick is: The thing in my hand or the thing holding it.

I took the EGR out. When I did this I had welded onto the mounting platform a quarter inch piece of aluminium, as the mild steel blanking plate had a galvanic reaction with the aluminium elbow. I remember "pulling" the bolts out to find springs wrapped around them ~ those springs were the threading from the female receptacles. I also had made a 3/16" steel blanking plate for the exhaust manifold end and I initially did this with no gasket. To my surprise that little leak caused a loss in power so I made a gasket out of brass shim which solved that issue.

Another item to consider is the interior condition of your intake manifold. If you get build up on the inside piping it effectively narrows the channelling of the air flow to the chambers. That means less airflow, even by a little bit ~ and that can rob you of power (and fuel efficiency). One other point, the nuts holding the exhaust manifold plate can loosen over time and might need tweaking.

I'm not even sure whether you have blanked or removed your EGR but these have been my observations, as a painter.

Oh, and one more thing ~ I have a suspicion that the diesel coming out of the pumps has recently (past year) changed from LSD to ULSD, which is a change from 500 parts per million to 15 parts per million sulphur content, and that suspicion makes me think the fuel efficiency has diminished.

Just my thoughts.

Falco.

[strada-caster]

no EGR on the strada, so thats gone.

I've never checked the exhaust bolts though...

loss of power was pretty much from the valves being out of whack, adjustment fixed that.
My main concern is the oil burning, where is it comming from? why is it happening? how detrimental is it to my engine?....
I just want a truck to rely on when i'm in the bush sledding for a day, i'd like to be certain my truck will start in -30 temps.

[Profister]

Strada-caster:
The best way to check 'the rings' theory is to measure the gas flow coming from the vent hose The pressure test is useless when it comes to the issue like this; there is enough liquid in the pistons to seal the gaps. Ideally you need a rotameter and the numbers to compare the readinds with. I am not sure about your engine but the numbers for a 4M40 are as follows; anything under 20 L/min is excellent, 20-40 L/min is fair and readings above 50 L/min will tell you that the piston rings are not working properly. One of rotameter examples is a household gas flow meter. There are some tecniques you can use without a rotameter; the picture below is showing the idea. Collect the vent gas into a plastic bag for 1 minute and push it into the measuring tank. On the second picture you can see how to use a household gas flow metering device. There might be some other ways of doing it in your home garage but don't rely on a pressure test.