Sump oil contaminated with diesel.

[grahama]

I’m hoping someone here can help with my engine problem, diesel is getting into the sump oil at quite a rate, dip stick goes up by about 1ltr in about 1.5 hours of running at 2000ish rpm.

I’ve had the oil lab analysed and it’s definitely diesel, over 10% in new oil after 1 and a half hours of running. (Water levels fine and correct colour etc.)

Exhaust smoke:- thick grey from first start, although when the boat was re-launched 8 weeks ago the thick grey smoke only appeared when the engine was hot – now, a few hours running time later it makes no difference – it’s not black but heavy grey that lingers and stinks. No obvious blue smoke.

History:- Engine, new Ford FSD (4 cyclinder direct injection 2.5 ltrs, read transit pre 2000) marinized by Lancing with PRM box, engine hours 150 total over about 6 years. Last 2 years on the hard, engine cranked over every month to get oil around to prevent corrosion and ran once every 6 weeks for a few minutes until the water cooled exhaust got too hot. Engine was fine prior to re-launch.

The most obvious cause I would have thought was the crank driven diaphragm pump, have now changed this twice with new ones, one from ebay which I didn’t know the history of so last week I bought another new one from the main Ford dealer – no improvement.

I’ve just returned from having the injectors tested, apparently they’ve never seen such a good spray pattern from a Stanadyne injector! – I was hoping one or all would be been dribbling fuel and it finding it’s way past the rings into the sump.

Engine fires first turn of the key, absolutely no cranking needed whether hot or cold.

Injector pump is belt driven, so no route from the pump into the engine as some installations.

Injectors are mounted ontop of the engine, not under a rocker cover .

The only other change I’ve made is the engine was previously run using Shell semi-synthetic oil and now I have changed to Gulf Multi G – a ‘CD’ only rated oil due to all the advice on this forum regarding bore glazing etc – I can’t believe that the type of oil has anything to do with this problem though.

Any idea’s chaps?. I’m at a total loss,

 

[penfold]

The only remaining component is the injector pump; time to have it off and give it a health check. Other than that I'm as stumped as you are. How prompt is the starting? How did the smokiness arise; did it appear suddenly or was it gradual? Do you have a compression tester?

 

[grahama]

.

The only remaining component is the injector pump; time to have it off and give it a health check. Other than that I'm as stumped as you are. How prompt is the starting? How did the smokiness arise; did it appear suddenly or was it gradual? Do you have a compression tester?

Starts first turn of the key. The smokiness appeared quickly, virtually after first launching this season.

I've not got a diesel compression tester, been trying to find someone that hires one any ideas?

 

[tinkicker0]

You need to get the compressions checked.

 

[higler]

By the sound of it your making a lot of diesel into the sump, the only thing that I can think of is the seal in the lift pump. If thats split or leaking is there some way it can get in??

 

[grahama]

.

By the sound of it your making a lot of diesel into the sump, the only thing that I can think of is the seal in the lift pump. If thats split or leaking is there some way it can get in??

Yes that was my first thought, but I'm now on my second new lift pump change with no change to the problem

 

[aztec]

just a thought...

are you sure that the pump timing is right?

I've had belt driven engines with the injector pump timed 180 degrees out. they still run ok, but obviously not as well as they should. timing the pump on the crankshaft without a corresponding check on the cam timing can lead to this.

It's possible that although it's injecting ok, the fuel is not atomised into the chamber on compression, but on the exhaust stroke. only burning on the next compression.

as i said, just a thought.

 

[Marsupial]

I would go with Aztec, the grey smoke you are seeing is unburnt diesel, so there is a lot of it about in the combustion chamber, some is burnt, some goes out through the exhaust port (as smoke) the rest finds its way to the sump down the sides of the pistons. Grey or sometimes white (ish) smoke usually indicates injector timing problems - and yes white can also be steam in a marine installation.

 

[Bodach na mara]

It's not one of these common rail engines with the injectors timed electrically is it? I read that there was a problem could develop where the high pressure line leaked within the rocker box.

I should add that I know nothing about this specific engine and it probably shows.

 

[grahama]

.

Thanks for the input but no it's not a common rail engine, it's the last of the mechanical injector type engines made by ford so no electronic control of injectors etc

It's not one of these common rail engines with the injectors timed electrically is it? I read that there was a problem could develop where the high pressure line leaked within the rocker box.

I should add that I know nothing about this specific engine and it probably shows.

 

[willie4646]

Get your injectors checked out, sounds as if one is injecting raw diesel instead of spraying.
Willie

 

[grahama]

.

Get your injectors checked out, sounds as if one is injecting raw diesel instead of spraying.
Willie

Thanks, I thought that too but as mentioned in the initial post they have been checked and are working very well,

 

[vyv_cox]

Many years ago I bought a Triumph TR5 that had an almost identical problem. Petrol, of course, but with the Tecalmit mechanical injector pump that is not a million miles different from a diesel one. It pumped petrol into the sump at an astonishing rate, did 11 mpg and smoked horrendously. I obtained the workshop manual and my local garage owner was a Triumph specialist, so I had the full professional info. I did everything possible, checked fuel delivery pressure, (105 psi), all the adjustments, but nothing made any difference. Ultimately there was only one thing left - the overall fuel supply control inside the pump. All the manuals said 'on no account touch this screw, factory set!' So I adjusted it and found instant improvement. Presumably a previous owner had played about with it. I changed the big-end and thrust bearings because the dilution had thinned the oil so much and ultimately the car was super reliable and did nearly 30 mpg.Is there a similar adjustment on your pump?

Incidentally I can see absolutely no reason to suppose that compression has anything to do with it. Turn the engine over manually with a spanner on the pulley nut or with a drive belt. If it goes easily there may be a compression problem but if you struggle to turn it over, and all cylinders are the same, there isn't much wrong.

 

[grahama]

.

Many years ago I bought a Triumph TR5 that had an almost identical problem. Petrol, of course, but with the Tecalmit mechanical injector pump that is not a million miles different from a diesel one. It pumped petrol into the sump at an astonishing rate, did 11 mpg and smoked horrendously. I obtained the workshop manual and my local garage owner was a Triumph specialist, so I had the full professional info. I did everything possible, checked fuel delivery pressure, (105 psi), all the adjustments, but nothing made any difference. Ultimately there was only one thing left - the overall fuel supply control inside the pump. All the manuals said 'on no account touch this screw, factory set!' So I adjusted it and found instant improvement. Presumably a previous owner had played about with it. I changed the big-end and thrust bearings because the dilution had thinned the oil so much and ultimately the car was super reliable and did nearly 30 mpg.Is there a similar adjustment on your pump?

Incidentally I can see absolutely no reason to suppose that compression has anything to do with it. Turn the engine over manually with a spanner on the pulley nut or with a drive belt. If it goes easily there may be a compression problem but if you struggle to turn it over, and all cylinders are the same, there isn't much wrong.

Firstly thanks for the input - I'll rotate the engine tomorrow to check the compression on each cylinder.
It's a bosch fuel injector pump, I'm not too sure about the adjustments on this as I don't have a pump manual.
Are you suggesting that the pump could be over pressurizing the injectors and thus too much fuel is being forced into the cylinders resulting in liquid deisel passing into the sump via the rings? This pump is cam belt driven.

 

[Marsupial]

NO the suggestion is that the right amount of diesel is being injected but not all of it is being burnt. What is not burnt is expelled as greyish smoke AND some is finding its way into the sump passed the piston rings. Its not a compression problem, or an injector problem. Have you had a cam belt change recently? I which case thats when the injection timing was changed.

 

[vyv_cox]

Firstly thanks for the input - I'll rotate the engine tomorrow to check the compression on each cylinder.
It's a bosch fuel injector pump, I'm not too sure about the adjustments on this as I don't have a pump manual.
Are you suggesting that the pump could be over pressurizing the injectors and thus too much fuel is being forced into the cylinders resulting in liquid deisel passing into the sump via the rings? This pump is cam belt driven.

Marsupial may very well be correct. I'm not certain what the adjustment screw in the Tecalmit unit did but changing the injection timing seems a strong possibility. With a belt driven injector pump I would be looking at the timing first. I assume there is a mark/hole/peg on the shaft to mark the TDC point, which must be aligned with the engine TDC.

 

[grahama]

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NO the suggestion is that the right amount of diesel is being injected but not all of it is being burnt. What is not burnt is expelled as greyish smoke AND some is finding its way into the sump passed the piston rings. Its not a compression problem, or an injector problem. Have you had a cam belt change recently? I which case thats when the injection timing was changed.

No the cam belt hasn't been changed or adjusted in any way - it's a job I was scheduling for this winter

 

[vyv_cox]

No the cam belt hasn't been changed or adjusted in any way - it's a job I was scheduling for this winter

But has it jumped a tooth?

 

[grahama]

.

But has it jumped a tooth?

That I don't know.

I'll have to read the manual to check the alignment procedures - sounds like it's worth checking doesn't it.

 

[trying]

Check the pump timing...

these engines have a hole through which a pin can be inserted which engages with a lug on the flywheel (whether that is still there in its marinised state i could not say) putting the engine at TDC. With the crank in that position both the camshaft pulley and injection pump pulley have locking pin holes (about 8 o'clock and 11 o'clock respectively) which allow locking pins to be inserted through and into the block behind. Correctly timed both those pulleys will be able to be locked in the correct position with the crankshaft in the #1 TDC position.