Lift the engine rocker cover without specific reason?

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jonjo

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Given:

  • A lightly used Volvo 2020, 11 years old with 700 hours.
  • It starts after months of inactivity within 2 seconds on the starter motor.
  • Stable idle tickover.
  • Max revs the same as 10 years ago and the same for hull speed.
  • I had the fuel tank sucked dry 2 years ago as a preventative cleaning measure.
  • During its life the engine has only had light services e.g. oil and filters.

I am now waiting for a Volvo certificated engineer, known to be a stickler for best practice, to visit and perform a long overdue service. My concern is that he will want to fiddle with valve cleanaces and hence break the factory seal on the rocker cover gasket. In my semi technical mind as soon as that rocker cover gasket seal is broken I will have a middled aged engine that will weep oil into the bilges for ever more.

Are my concerns rational?
 
I did the same on my 2020 a couple of years ago, renewed the rocker cover gasket and there have been no leaks, at all.
I have to ask, why are you bothering spending money on a Volvo engineer to service the thing, given your description of it? If the rockers aren't unduly noisy, they don't need adjusting, and assuming you do routine stuff like checking the hoses and hose clamps as well as changing oil and filters, drive belt, impeller etc, I don't know what else an engineer would do.
 
Cantata said:
I did the same on my 2020 a couple of years ago, renewed the rocker cover gasket and there have been no leaks, at all.
I have to ask, why are you bothering spending money on a Volvo engineer to service the thing, given your description of it? If the rockers aren't unduly noisy, they don't need adjusting, and assuming you do routine stuff like checking the hoses and hose clamps as well as changing oil and filters, drive belt, impeller etc, I don't know what else an engineer would do.
Click to expand...

+1
 
jonjo5 said:
Given:

  • A lightly used Volvo 2020, 11 years old with 700 hours.
  • It starts after months of inactivity within 2 seconds on the starter motor.
  • Stable idle tickover.
  • Max revs the same as 10 years ago and the same for hull speed.
  • I had the fuel tank sucked dry 2 years ago as a preventative cleaning measure.
  • During its life the engine has only had light services e.g. oil and filters.

I am now waiting for a Volvo certificated engineer, known to be a stickler for best practice, to visit and perform a long overdue service. My concern is that he will want to fiddle with valve cleanaces and hence break the factory seal on the rocker cover gasket. In my semi technical mind as soon as that rocker cover gasket seal is broken I will have a middled aged engine that will weep oil into the bilges for ever more.

Are my concerns rational?
Click to expand...

Surely checking the valve clearances is one of the items on the routine service schedule, If there is an unbroken seal after 11 years / 700 hours surely it indicates that the engine has never in its life been serviced fully, something you appear to admit any way


Thre should be no worries about oil leakage. Id expect a certificated fitter to use a new gasket! Although personally on my own engine if the gasket is not damaged I would ( and have regularly) reuse(d) them

I would not see it as an inevitable source of an oil leak .... If it did then I'd call the ******* back to fix it !
 
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It is not really a Volvo engine. It is an Ishibaura that was marinized by VP.
It is identical to the Perkins M20.
An excellent engine. The only weakness of this series is the freshwater circulating pump.They tend to dry out the pump seal when left un-used for long periods. Not saying this will happen,but keep a check on it. Replacement pumps are available from many places for < $ 140 US.
Technically,it is time to check valve clearances. You may or may not need a new gasket,but after 10yrs,rubber can dry out. I suggest a new gasket. I also suggest you check every piece of rubber for signs of dry cracking.

Cheers/ Len
 
Volvo Penta advise checking the valve clearances every 400hrs or at least every other year, so technically it ought to be done. There's no reason it should leak oil afterwards. The upside is it might be a bit quieter/smoother.

If it's only ever had oil and filter changes, as you say, then you should certainly get the coolant changed and the vacuum valve cleaned.
 
Most non-racing engines will run fine with larger than spec clearances other than the clacking noise which is the engine telling you it's time to reset them. If the noise is the same as it always was then the engine is fine.

True story - a German biker on a low revving Motor Guzzi (basically like a diesel!) asked me if I understood engines when we were camped next to them on our bikes in Istanbul. I asked him to start it up and the noise from one of the heads was deafening. I had some tools so removed the rocker cover. Both the tappets were loose with a clearance of about a 1/4 inch (25O thou) rather than say 20 thou. He had driven for the last 500 miles with this racket and said that the bike seemed OK!

I didn't have a feeler gauge so just had to guess 20 thou. The guy was delighted with the bike and paid for the beers that night!

Richard
 
RichardS said:
Most non-racing engines will run fine with larger than spec clearances other than the clacking noise which is the engine telling you it's time to reset them. If the noise is the same as it always was then the engine is fine.
Richard
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can you hear the sound of an over wide valve clearance on diesel engine like the MD2020 above the overall noise of the engine.

They are only 0.2mm anyway ... I'd guess they would have to be quite a long way out before they made much sound .
 
RichardS said:
True story - a German biker on a low revving Motor Guzzi (basically like a diesel!) asked me if I understood engines when we were camped next to them on our bikes in Istanbul. I asked him to start it up and the noise from one of the heads was deafening. I had some tools so removed the rocker cover. Both the tappets were loose with a clearance of about a 1/4 inch (25O thou) rather than say 20 thou. He had driven for the last 500 miles with this racket and said that the bike seemed OK!
Click to expand...

My ex wife had a Ural 650 flat twin, which was the quickest bike ever to do the tappets on, plugs out, timing mark plug out, one bolt to take rocker cover off, turn engine over to timing mark, check which cylinder was at TDC, adjust till push rod would just spin in the fingers... I could spin it out to 10 minutes if I was being really lazy
 
Rightly or wrongly, my 11000 hour engine has not been touched (apart from routine renewals, alternator, impellors etc) I asked the engineer if I should service the injectors. He said does it start and run OK? No smoke? If so leave it.
 
I've never had weeping gasket problems on any engine, and wishing to avoid this is a ridiculous reason not to do the manufacturers recommend servicing checks & adjustments.
 
Rocker clearances can also close up if the valve wears faster than the valve gear.
Over-wide clearances can increase stress to the valve as it closes, sometimes related to the head of the valve coming off.
Not aware of either of these things happening on diesels though!

I would have the cover off.
 
Thanks everyone, a clear but not overwhelming opinion that a proper service is due.

My take from reading replies is that the fresh water coolant needs a change, I should be alert to drying out of the freshwater pump rubber seal due to inactive periods and some vacuum valve needs attention.

Think I will opt for the full works this time and then return to my minimal intervention mechanical philosophy for the next 1000 hours as this works for others here.
 
lw395 said:
Rocker clearances can also close up if the valve wears faster than the valve gear.
Over-wide clearances can increase stress to the valve as it closes, sometimes related to the head of the valve coming off.
Not aware of either of these things happening on diesels though!

I would have the cover off.
Click to expand...

Closed up clearances are also not noisy thus giving the illusion that all is well....
 
macd said:
Not a motorcyclist of a certain age, then? ;)
But a big plus one with the second phrase.
Click to expand...

Was a motorcyclist until 10years ago, but not an owner of anything of dodgy British build quality. Although the 3 Ducatis were not exactly faultless either. (the Jap sports bike were reliable)
 
jonjo5 said:
Thanks everyone, a clear but not overwhelming opinion that a proper service is due.

My take from reading replies is that the fresh water coolant needs a change, I should be alert to drying out of the freshwater pump rubber seal due to inactive periods and some vacuum valve needs attention.

Think I will opt for the full works this time and then return to my minimal intervention mechanical philosophy for the next 1000 hours as this works for others here.
Click to expand...

Yes the coolant should be changed IIRC every 2 years, Its not a long life OAT type just a conventional type ( Volvo green). Remember is the inhibitors in the antifreeze that protects the cooling system from corrosion.


The anti siphon valve should be checked regularly. If it fails to open when the engine is stopped you run the risk of flooding the engine with salt water if you dont shut the inlet sea-cock or it lets by slightly. Every year is recommended IIRC.

The trouble with the minimal intervention / "if it aint broke, dont fix it" philosophy is that things that ought to be done tend to be put off, forgotten or ignored.

It would be a good idea to draw up some sort of service schedule that reflects both the low use and the requirements to check/adjust/renew on a regular basis. Some things you should keep on an annual "to do" list while others can be reduced to the recommended running hours interval.
 
Stork_III said:
Chap who does mine says "if it ain't broke..." so ignores the VP schedule.
Click to expand...

That rather begs the question of why you're employing him to "do" yours. Does he change the oil only when he can see fissures in it?

"If it ain't broke..." is a truly moronic approach to routine maintenance. In fact if it were universal there would be no such thing as routine maintenance, just problem-fixing after the fact. I doubt that's where the OP wants to go.
 
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