Oil in Exhaust

This forum is about the Fordson Dexta, Super Dexta and Petrol Dexta.
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AndyRo
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Oil in Exhaust

Post by AndyRo »

Folks,

I have noticed an ever increasing amount of oil at the base of my exhaust, so much so it leaves a small puddle of black oil when i remove it and set it on the ground. Also, I've had the odd splat of oil coming out of the exhaust whilst my super is running, landing on the seat, along with being very smokey in general.

I do use her for some log splitting, but I often take her for a good road run before doing so in order to clean her out. However despite this the oil in the exhaust remains. Wondering if this could be an underlying issue?

Your thoughts and advice would be appreciated.

Billy26F5
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Re: Oil in Exhaust

Post by Billy26F5 »

To clear the engine you need to do ploughing, running on the road only will cause smoke, so do some hard ploughing before and after your log splitting run. It sounds like the valve stems might not be sealing very well, it could also be bore wear, but that will probably show other symptoms such as hard starting and less power.
Sandy
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AndyRo
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Re: Oil in Exhaust

Post by AndyRo »

Hi Sandy.....never ploughed before and haven't got any land to do it so will have to see if the neighbours want their fields wrecked :shock:

Definitely no issues starting. Will have go check the valve stems as you have mentioned. Can you offer advice around doing this as I'm a complete novice and have only ever done routine repairs and filter changes. Thanks, Andy

Billy26F5
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Re: Oil in Exhaust

Post by Billy26F5 »

Try ploughing first, if it's the same or worse after ploughing the head will be coming off to check the valves.
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SvendH
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Re: Oil in Exhaust

Post by SvendH »

Why not borrow or buy a big old trailer and tow it on your roadruns,should help clear the cobwebs.
Svend

AndyRo
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Re: Oil in Exhaust

Post by AndyRo »

Hi Svend....funny enough I have got a big trailer but its blocked in by all the logs I need to split :lol: As soon as I get it out and treated for woodworm I'll take it on the odd road run. Thanks, Andy

Billy26F5
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Re: Oil in Exhaust

Post by Billy26F5 »

That's nothing like heavy enough, the engine needs stable hard work to clear itself, that's why ploughing is needed.
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shepp
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Re: Oil in Exhaust

Post by shepp »

Engines that have done a lot of running on light work can suffer from oil glaze on the bores, so that the rings do not seal properly, allowing oil past the rings and out through the exhaust. It's a bit unusual for tractors with 2 oil rings though like the Dexta and Major, the 1000 series tractors could suffer from it. Dextas with double valve springs did not have valve stem oil seals as there was no room for a cup type seal, same as on the MF 35 3 cylinder tractors, so leakage down the valve stem would be due to worn valve stems and/or guides.

If it is an issue of oil glaze, then as Sandy says some serious hard work is called for, at least ploughing and preferably some hard PTO work on a Rotavator or similar. You could also try using a "running in " oil for a while as well as hard work, these claim to allow friction between the rings and bores to allow them to " bed in " together, Morris Lubricants do one. They are not used much these days but in the 1950's and 1960's when cars and tractors and trucks were sent out new they were filled with a running in oil, the first service at 50 hours included draining the running in oil and refilling with a normal spec oil.

If your tractor is generally smokey are you sure you do not have a defective injector that is "hydraulicking" a bit so that unburnt diesel is mixing with black carbon in the exhaust and being blown out?? The Perkins "aeroflow" combustion systems on these engines is so good that they can still fire on a cylinder even though not all the fuel is burnt, unburnt fuel will then end up going out of the exhaust or down the bores into the sump. I once bought an MF 35X that was running and starting reasonably well, but the sump was overfull and the oil was thin and diluted. An injector service revealed 2 defective injectors that were jetting rather than spraying, so that there was some unburnt diesel that found it's way past the rings into the sump but there were no real symptoms from the starting and running!
1946 E27N, 1952 Major Diesel, 1959 Power Major, 1962 Dexta, 1962 Super Dexta, 1963 Super Dexta NP, 1964 Super Major NP, 1965 Super Dexta 3000, 1966 Major 4000, 1967 3000 PF, 1994 5640,plus Basildon built NH.

AndyRo
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Re: Oil in Exhaust

Post by AndyRo »

Thanks Shepp, will certainly work my way through the issues you have raised and try to establish where this is coming from.

There is definitely no symptoms from the starting or running which she is able to do the best.

Will she likely always do this with only being used for light work or is it just from the engine being newly refurbished and the bedding in period not having been established?

shepp
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Re: Oil in Exhaust

Post by shepp »

When you say that the engine was refurbished what exactly was done? If new liners were fitted (with or without new pistons) then the surfaces will be clean and free from oil glaze. Depending on the liner fitted they might have needed to be honed out after pressing in to the correct bore size by a specialist with the right boring and honing equipment. If this was not done there could be an issue there with out of round bores. Were new valves and guides fitted?

If just new rings were fitted did you use a glaze buster on the bores to remove the oil glaze and top ridge? If not it is going to take some considerable time for the rings to bed in, the amount of wear on the old liners will also affect the issue. Try running in oil and some hard PTO work.
1946 E27N, 1952 Major Diesel, 1959 Power Major, 1962 Dexta, 1962 Super Dexta, 1963 Super Dexta NP, 1964 Super Major NP, 1965 Super Dexta 3000, 1966 Major 4000, 1967 3000 PF, 1994 5640,plus Basildon built NH.

AndyRo
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Re: Oil in Exhaust

Post by AndyRo »

Thanks again shepp. All I know is she was running a lot more smokey than what she os now and was very hard to start prior to the restoration.

A local tractor mechanic took her away and rebuilt the engine for me, took off the head and refurbished it all. I'm afraid that's all i know as I'm a complete novice I'm afraid when it comes to that kind of work. I will check in with him what exactly was done in comparison to what you have said.

Should be able to try the oil myself though and get some PTO work done in the near future. Will update you all on my progress and if there's anything any improvement.

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