A bigger problem than we think, low sulphur diesel.

Submitted: Thursday, Mar 11, 2004 at 10:41
ThreadID: 11164 Views:3909 Replies:7 FollowUps:9
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Have just been talking to my local fuel supplier about the new regs (out since the 01/01/04 by the Comm Gov) lowered the sulphur content in diesel again.He said this time we have no come back to the oil companies as it is a gov reg. He heard that Mobil is closing down in Australia because it is going to cost them $300 million to change they equipment to satisfy new regs.
A friends Delica's pump started to leak and he was told there is up to a months waiting time to have it fixed and a cost of $450 in Rockhampton. It is believed it can happen to any diesel pump. I was told that all we can do is canvas our local federal minister. What I wonder is how long will the new seals last, after replacement.
What has anyone else heard about this and is it a major problem?
Regards Bruce.
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Reply By: Topcat (WA) - Thursday, Mar 11, 2004 at 10:54

Thursday, Mar 11, 2004 at 10:54
If this is the case, perhaps one way around it is to add additives to your fuel e.g. Redline Diesel Fuel Additives which have the properties of lubricating fuel injection systems.
AnswerID: 49911

Follow Up By: Member - Bruce and Anne - Thursday, Mar 11, 2004 at 11:00

Thursday, Mar 11, 2004 at 11:00
Good point topcat, did ask the fuel supplier but there does not seem to be a product that will save it , so will have to find out more about this one your talking about, lets hope it works.
REgards Bruce.
FollowupID: 311715

Reply By: Member - Captain (WA) - Thursday, Mar 11, 2004 at 12:10

Thursday, Mar 11, 2004 at 12:10
Australia previously had about the highest available sulphur content in diesel worldwide. Many engines used in Europe cannot be used in Australia because of our "dirty" diesel. The new regs bring us into line worldwide and will enable more high performance diesels to be used in Australia.

The main reason petrol refiners do not want to change is the cost of upgrading their refinery to meet the new fuel regs. Australia is amongst the last place to regulate for low sulphur and its just a case of the multinationals not wanting to spend their profits giving us cleaner air (less sulphur pollution)

Advantages of low sulphur diesel, apart from cleaner exhaust emmissions, include reduced corrosion on pistons/rings/bore, reduced contamination of oil and improved storage life of diesel. Note that sulphur is not a lubricant.

The corrosion improvement occurs as previously the sulphur reacted with the water (combustion by-product) and produced sulhuric acid. This acid aggressively attacks metals as well as contaminating the oil.

The seal problem is supposedly related to "Buna-N" rubber material seals and is potentially a problem for rotary injection pumps. In-line injection pumps are not affected as they do not have rubber seals in contact with the fuel.

Apparently the sulphur in diesel causes the seals to swell and switching to low sulphur causes the seal to shrink, cracking it. Buna-N seals that have always used low sulphur fuel apparently are not affected.

Western Australia has had low sulphur diesel since 1/1/2000, when it dropped from 1300ppm to 500ppm. While its a significant (~60%) drop, sulphur is NOT totally removed from the fuel.

I believe most manufacturers no longer use Buna-N rubber seals, but will stand corrected if they still do. If there is a problem, I believe it is likely to only affect older rotary diesel pumps with the Buna-N type seals. But whether a 60% drop is enough to cause a problem is very debatable. Remember, operational wear will cause the seal to deteriorate over time anyway.

What one may "lose" by using low sulphur fuel on a rotary pump will, long term, probably be more than saved by the reduced corrision effects of the lower sulphur.


AnswerID: 49918

Follow Up By: Member - Bob - Thursday, Mar 11, 2004 at 12:23

Thursday, Mar 11, 2004 at 12:23
excellent post - thanks.
PS Your tyres all look a bit flat
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Follow Up By: Willem - Thursday, Mar 11, 2004 at 15:24

Thursday, Mar 11, 2004 at 15:24

Which common diesel 4x4 vehicles have rotary pumps and which have in-line injection pumps. I am about to buy an older diesel 4by.

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Follow Up By: Member - Captain (WA) - Thursday, Mar 11, 2004 at 15:46

Thursday, Mar 11, 2004 at 15:46

I am not familiair with exactly what pumps are in what 4x4's, but I think that most older 4X4's have the inline pumps. Rotary pumps are a relatively new design (by automotive standards) and I am pretty certain that the 1HZ motor is a rotary pump (had the thing for 10 years, now not 100% sure!!!). But I am certain that the older toyota diesels had the inline pumps.

Pretty easy to tell when looking at the pump itself, the inline ones have all the fuel lines in a row while the rotary ones are like a circle on the back of the pump.

The rotary ones use the diesel fuel itself to lubricate the pump while the inline ones use the engine's oil to lubricate the pump internals. Hence the inline ones do not contact the diesel.

According to the BP website, it seems that post-1995 diesels should not have any problems. I suspect that the Buna-N problem started to surface in California, which has had low sulphur fuels for many years, and manufactures changed the seal type (note-not confirmed, just an educated assumption here).

Any vehicle pre-1995 with a rotary pump "may" have a potential problem. But at that age, wear would certainly be a factor. Just make sure Buna-N seals are not used in any rebuild.

I am not convinced a 60% reduction in sulphur would have that much effect on a seal, but stranger things have happened. Either way, I would not place too much emphasis on it. All diesels in WA have now been running on low sulphur diesel for over 3 years and its the first time its been raised as an issue.

But, just to confuse the issue, I had to replace the seals in the diesel pump in my 1990 1HZ 80 series about a year ago after it started to leak. Hmmm... was it the low sulfur fuel, or the fact it had done 300,000kms !!!


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Follow Up By: Willem - Thursday, Mar 11, 2004 at 16:21

Thursday, Mar 11, 2004 at 16:21
Thanks for the info, Mark. Much appreciated.

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Follow Up By: Savvas - Thursday, Mar 11, 2004 at 16:27

Thursday, Mar 11, 2004 at 16:27
Mark ... Excellent post. Informative and factual.
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Follow Up By: Phil G - Thursday, Mar 11, 2004 at 18:07

Thursday, Mar 11, 2004 at 18:07

Re pumps, the 4 litre 2H pre'90 toyotas have an in-line pump. The post '90 1Hz's have a rotary pump. Don't be deterred by rotary pumps - replace the seals if they leak, and they are fixed.

FollowupID: 311766

Follow Up By: Member - Eskimo - Thursday, Mar 11, 2004 at 18:46

Thursday, Mar 11, 2004 at 18:46
mmmmm buna N

Trying to think of which material we substituted it with for use with the new refrigerants and oil in the airconditioning arena......

A good rubber (not the other kind) supplier will be up with this and should know...

its on the tip of my tongue scratch scratch knock knock////
FollowupID: 311782

Reply By: Member - Bruce and Anne - Thursday, Mar 11, 2004 at 13:17

Thursday, Mar 11, 2004 at 13:17
Mark thank you for the feed back, good reading wiil keep my fingers crossed and hopemine does not start leaking.
Regards Bruce.
AnswerID: 49922

Follow Up By: Member - The ghost - Thursday, Mar 11, 2004 at 16:46

Thursday, Mar 11, 2004 at 16:46
Thanks for the great informative reply Mark obviously a man who knows whats going on, I will go ahead and order the new diesel "truck" as planned and sleep easy.
FollowupID: 311750

Reply By: Member -Bob & Lex (Sydney) - Thursday, Mar 11, 2004 at 16:52

Thursday, Mar 11, 2004 at 16:52
I thought I would have heaps of trouble with the trucks with low sulfer fuel but so far no problems with the pumps as i was told their would be (knock on wood ) I heard Shell was also going to shut down production in OZ but I dont think it is true as they are currently doing heaps of upgrades at Rosehill, must have changed their minds as mobil is closing ,less compertition
AnswerID: 49939

Reply By: ianmc - Thursday, Mar 11, 2004 at 17:00

Thursday, Mar 11, 2004 at 17:00
Oh No Willem, not the G60! Will it be set in concrete in some park for us all to ponder????
Seriously, my 1991 Triton diesel has a rotary pump & must have had a few litres
of low sulphur thru it. No leaks or other problems yet & it seems to be going harder than ever at 220,000kms.
Doesnt seem to have made the exhaust any cleaner as it still blows muck at take off or full throttle.
I recently adjusted the notched wheel in the pump by a few clicks & it seems a bit cleaner. Has probably been incorrectly set since new. Will report later if kms/litre are any betterthan before. It is easy to do in the rotary pump & yet to see what effect it has but the truck is very lively at 1500 - 3500 rpm.
AnswerID: 49940

Reply By: Member - John- Friday, Mar 12, 2004 at 07:44

Friday, Mar 12, 2004 at 07:44

Excellent post - great information and clears up a lot of questions.

As an aside, the last time I looked at a fuel pump on a 1HZ they were an inline
not rotary.

AnswerID: 50043

Reply By: Member - John- Friday, Mar 12, 2004 at 07:49

Friday, Mar 12, 2004 at 07:49
Sorry people,

Re my last post - the fuel pump on a 1HZ is a rotary, must be blind as well
as stupid.....
AnswerID: 50044

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