Perkins 4108 sludge

[pappaecho]

I have just returned froma quick trip to adjust the tappets on a Perkins 4108. It starts and runs perfectly, but was rattling due to mis adjusted tappets.
On inspection of the rocker box and the valve gear, there is a major build up of sludge which behaves exactly like thick grease. We reckon we have removed about 300 ml of thick grease.
The engine is original, over 25 years old, has never been removed, and whilst it has had oil changes etc, my friend has never touched the tappets, because he did not know how to do it.

The question to the forum is how this grease build up took place. For example his engine is direct cooled and the temperature gauge never goes above 50 degree C. Could it be the low temperature running which caused the grease build up?
The engine oil is removed by a brass side arm pump on the side of the engine. It removes all the sump oil. We used a Pela extractor via the dipstick and this again has brought up a lot of semi solid material.

The second question for the forum is:-

a) Do we use flushing oil to remove the build up in the sump
b) Do nothing on the assumption " dont fix what aint broke"
c) Something else - like say take the engine out and rebuild it?

 

[rich]

[ QUOTE ]
The question to the forum is how this grease build up took place. For example his engine is direct cooled and the temperature gauge never goes above 50 degree C. Could it be the low temperature running which caused the grease build up?

[/ QUOTE ]

I would say the engine needs to be run hotter, to get rid of the condensation build up, what oil is being used?

 

[Marsupial]

Many years ago I was a workshop controller for a Ford dealer. The 4108 was used in Transit vans. owners who "extended" oil change periods beyond the reccomended 3000 miles were rewarded by thick sludge like bitumen accumulating in the sump. I ve seen sumps so solid that the stuff had to chipped out.

This is a "feature" of the 4108 the only answer is to change the oil regulary and use a good quality mutigrade oil.

In a boat thats around every 50 hours.

60mph for 3000 miles = 50 hours

The good news is that if you catch it in time no harm seems to come to the engine.

 

[pappaecho]

Oil is apparently Comma or Duckhams to API SJ grades suitable for older engines.
Presumably the waxes in the oil come out and stick to the sides of the sump and the rocker box housing, and again the cool running of the engine may encourage it.
By the sounds of it then, leave as is, and change the oil every 50 hrs.
I also have a 4108 which does not show the same degree of wax build up, but then again it gets regular oil changes, every year and I am unlikely to do more than 30-40 hrs per year

 

[Guest]

Our does anything from 100 to 200 hours between service. The oil is always the best quality Shell or similar. It is 32 years old and never had any sludge anywhere. Filters are always good.

Check the thermostat. The engine must get up to temperature. Die hard sailing that uses the engine for 5 minutes for each marina/mooring is a killer to engines.

A transit van never does 60mph. It is the original white van! The old ice cream vans also had 4.108 and the garages are a good source of information on looking after them and getting non-marine priced parts.

Check the exhaust is not a problem for water ingress into the cylinders. A little bit each time will make the oil go a bit odd. Along with all the other damage.

 

[Marsupial]

Yes right, oils have come a long way since the 1970's. But that engine the 4108 was prone to sludge, many examples would be brought for service and nothing would come out of the sump when the plug was removed. And by the way 1971 4108 van version tranny was good for 80mph, unloaded on a motorway, the round the town version usually had a different diff and the V4 petrol engine, some had a 1600 straight 4 but they were slow, put a luton body on it and it would struggle against the wind. Saddly I spent 7 years of my life living with these things - I think i know what's what. anyway the 4108 engine is very sound it just needs proper attention, lots of oil changes with good quality oil. Temperature can be an issue and running cold would enhance its sludge producing abilities.

 

[pappaecho]

I am at a bit of a loss here with regard to engine temperature.
My 4108, fitted in an Evasion 32, has the original Perkins instrument cluster complete with oil pressure, temperature, revs etc. My direct cooled engine never, never moves the temperature gauge above 50 degrees, unless I switch off the incoming water supply, when it goes quite happily up to about 85 degrees, and I chicken out, not wanting to blow the hoses.
My friends 4108 is similar, though it does usually register about 60 degrees Centigrade.
My thermostat does not apparently restrict the water flow, where obviously it should. On the other hand I have not got the sludge/wax problem! Maybe I will lash out on a new thermostat and see what happens temperature wise on my friends engine first!

 

[rich]

Duckhams, used to make sludge build up in the old BMCs in the 60s,
I use Shell Rimula in my twin 4108,s they were clean as a whistle,
when i rebuilt them 2 years ago